Temporal coherence in an unbalanced SU(1,1) interferometer.

In classical coherence theory, coherence time is typically related to the bandwidth of the optical field. Narrowing the bandwidth by optical filtering will result in the lengthening of the coherence time. In the case of a delayed pulse photon interference, this will lead to pulse overlap and recovery of interference, which is otherwise absent due to time delay. However, this is changed for entangled optical fields. In this Letter, we investigate how the temporal coherence of the fields in a pulse-pumped SU(1,1) interferometer changes with the bandwidth of optical filtering. We find that the effect of optical filtering is not similar to the classical coherence theory in the presence of quantum entanglement. A full quantum theory is presented and can explain the phenomena well.

Pregnancy loss in major fetal congenital heart disease: incidence, risk factors and timing.

OBJECTIVE: Fetuses with congenital heart disease (CHD) are at increased risk of pregnancy loss compared with the general population. We aimed to assess the incidence, timing and risk factors of pregnancy loss in cases with major fetal CHD, overall and according to cardiac diagnosis. METHODS: This was a retrospective, population-level cohort study of fetuses and infants diagnosed with major CHD between 1997 and 2018 identified by the Utah Birth Defect Network (UBDN), excluding cases with termination of pregnancy and minor cardiovascular diagnoses (e.g. isolated aortic/pulmonary pathology and isolated septal defects). The incidence and timing of pregnancy loss were recorded, overall and according to CHD diagnosis, with further stratification based on presence of isolated CHD vs additional fetal diagnosis (genetic diagnosis and/or extracardiac malformation). Adjusted risk of pregnancy loss was calculated and risk factors were assessed using multivariable models for the overall cohort and prenatal diagnosis subgroup. RESULTS: Of 9351 UBDN cases with a cardiovascular code, 3251 cases with major CHD were identified, resulting in a study cohort of 3120 following exclusion of cases with pregnancy termination (n = 131). There were 2956 (94.7%) live births and 164 (5.3%) cases of pregnancy loss, which occurred at a median gestational age of 27.3 weeks. Of study cases, 1848 (59.2%) had isolated CHD and 1272 (40.8%) had an additional fetal diagnosis, including 736 (57.9%) with a genetic diagnosis and 536 (42.1%) with an extracardiac malformation. The observed incidence of pregnancy loss was highest in the presence of mitral stenosis (< 13.5%), hypoplastic left heart syndrome (HLHS) (10.7%), double-outlet right ventricle with normally related great vessels or not otherwise specified (10.5%) and Ebstein's anomaly (9.9%). The adjusted risk of pregnancy loss was 5.3% (95% CI, 3.7-7.6%) in the overall CHD population and 1.4% (95% CI, 0.9-2.3%) in cases with isolated CHD (adjusted risk ratio, 9.0 (95% CI, 6.0-13.0) and 2.0 (95% CI, 1.0-6.0), respectively, based on the general population risk of 0.6%). On multivariable analysis, variables associated with pregnancy loss in the overall CHD population included female fetal sex (adjusted odds ratio (aOR), 1.6 (95% CI, 1.1-2.3)), Hispanic ethnicity (aOR, 1.6 (95% CI, 1.0-2.5)), hydrops (aOR, 6.7 (95% CI, 4.3-10.5)) and additional fetal diagnosis (aOR, 6.3 (95% CI, 4.1-10)). On multivariable analysis of the prenatal diagnosis subgroup, years of maternal education (aOR, 1.2 (95% CI, 1.0-1.4)), presence of an additional fetal diagnosis (aOR, 2.7 (95% CI, 1.4-5.6)), atrioventricular valve regurgitation ≥ moderate (aOR, 3.6 (95% CI, 1.3-8.8)) and ventricular dysfunction (aOR, 3.8 (95% CI, 1.2-11.1)) were associated with pregnancy loss. Diagnostic groups associated with pregnancy loss were HLHS and variants (aOR, 3.0 (95% CI, 1.7-5.3)), other single ventricles (aOR, 2.4 (95% CI, 1.1-4.9)) and other (aOR, 0.1 (95% CI, 0-0.97)). Time-to-pregnancy-loss analysis demonstrated a steeper survival curve for cases with an additional fetal diagnosis, indicating a higher rate of pregnancy loss compared to cases with isolated CHD (P < 0.0001). CONCLUSIONS: The risk of pregnancy loss is higher in cases with major fetal CHD compared with the general population and varies according to CHD type and presence of additional fetal diagnoses. Improved understanding of the incidence, risk factors and timing of pregnancy loss in CHD cases should inform patient counseling, antenatal surveillance and delivery planning. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Propagation of temporal mode multiplexed optical fields in fibers: influence of dispersion.

Exploiting two interfering fields which are initially in the same temporal mode but with the spectra altered by propagating through different fibers, we characterize how the spectral profiles of temporal modes change with the fiber induced dispersion by measuring the fourth-order interference when the order number and bandwidth of temporal modes are varied. The experiment is done by launching a pulsed field in different temporal modes into an unbalanced Mach-Zehnder interferometer, in which the fiber lengths in two arms are different. The results show that the mode mismatch of two interfering fields, reflected by the visibility and pattern of interference, is not only dependent upon the amount of unbalanced dispersion but also related to the order number of temporal mode. In particular, the two interfering fields may become orthogonal under a modest amount of unbalanced dispersion when the mode number of the fields is k ≥ 2. Moreover, we discuss how to recover the spectrally distorted temporal mode by measuring and compensating the transmission induced dispersion. Our investigation paves the way for further investigating the distribution of temporally multiplexed quantum states in fiber network.

SU(2)-in-SU(1,1) Nested Interferometer for High Sensitivity, Loss-Tolerant Quantum Metrology.

We present experimental and theoretical results on a new interferometer topology that nests a SU(2) interferometer, e.g., a Mach-Zehnder or Michelson interferometer, inside a SU(1,1) interferometer, i.e., a Mach-Zehnder interferometer with parametric amplifiers in place of beam splitters. This SU(2)-in-SU(1,1) nested interferometer (SISNI) simultaneously achieves a high signal-to-noise ratio (SNR), sensitivity beyond the standard quantum limit (SQL) and tolerance to photon losses external to the interferometer, e.g., in detectors. We implement a SISNI using parametric amplification by four-wave mixing (FWM) in Rb vapor and a laser-fed Mach-Zehnder SU(2) interferometer. We observe path-length sensitivity with SNR 2.2 dB beyond the SQL at power levels (and thus SNR) 2 orders of magnitude beyond those of previous loss-tolerant interferometers. We find experimentally the optimal FWM gains and find agreement with a minimal quantum noise model for the FWM process. The results suggest ways to boost the in-practice sensitivity of high-power interferometers, e.g., gravitational wave interferometers, and may enable high-sensitivity, quantum-enhanced interferometry at wavelengths for which efficient detectors are not available.

[Detection of the spontaneous blinking pattern of dry eye patients using the machine learning method].

Objective: To establish a method to record the spontaneous blink pattern with a machine learning model, and to clarify the spontaneous blink pattern in patients with dry eye. Methods: It was a cross-setional study.We selected 357 dry eye patients (102 males and 255 females), aged (46.2±13.3) years, who visited corneal specialist clinics of Beijing Tongren Eye Center in 2019, as the dry eye group. The control group enrolled 152 normal controls, including 32 males and 120 females, aged (48.1±13.9) years. All participants completed the Ocular Surface Disease Index questionnaire, blink video capture, lipid layer thickness measurement, tear break-up time measurement, corneal fluorescein staining, and Schirmer Ⅱ test. Based on the assembled model built using UNet image segmentation algorithm and ResNet image classification algorithm, single frames of the blink video were analyzed, and then the palpebral opening height of each frame was obtained in order to establish a spontaneous blink wave. Finally, the characteristics of spontaneous blinks in dry eye patients were analyzed based on different types of complete blinks (types A, B and C) and partial blinks (types Ⅰ, Ⅱ and Ⅲ). Independent sample t test and Wilcoxon rank-sum test were used to judge if there was significant difference between the dry eye group and the normal group. Results: The accuracy of the segmentation model and the classification model was 96.3% and 96.0%, respectively, and the consistency with the manual analysis was 97.9%. In dry eye patients, the number of blinks was 30 (18, 42)/min, which was higher than that in normal controls [20 (9, 46)/min] (U=18 132.50, P=0.002). The number of complete blinks in dry eye cases was significantly lower than that in normal controls [6 (3, 24)/min vs. 12 (3,33)/min; U=12 361.00, P=0.016], and the number of partial blinks was significantly higher than that in normal controls [15 (6, 27)/min vs. 3 (0, 10)/min; U=22 839.00, P<0.001]. In complete blinks, the proportion of type A blinks in dry eye patients was significantly higher than that in normal controls [53.7% (2 796/5 177) vs. 39.3% (633/1 698); χ²=101.83, P<0.001]; in partial blinks, the proportion of type Ⅱ blinks in dry eye patients was significantly higher than that in normal controls [36.0%(2 334/6 477) vs. 29.6%(126/426); χ²=6.99, P=0.007]. The average interblink interval of dry eye patients was 1.2 s, which was not significantly different from that of normal controls (1.1 s; U=15 230.00, P=0.093). The eyelid closed phase of dry eye patients was 0.8 s, which was significantly shorter than that of normal controls (1.3 s; U=16 291.50, P=0.006). There were no significant differences in eyelid closing phase, early opening phase and late opening phase between the two groups (all P>0.05). Conclusions: In dry eye patients, the number of partial blinks increased, the number of complete blinks decreased, and the duration of eyelid closed phase shortened significantly. The main blink patterns of dry eye patients included type Ⅱ partial blinks with a reduced closure amplitude and type A complete blinks with a shortened closure time.

Direct Temporal Mode Measurement for the Characterization of Temporally Multiplexed High Dimensional Quantum Entanglement in Continuous Variables.

Field-orthogonal temporal mode analysis of optical fields has recently been developed for a new framework of quantum information science. However, so far, the exact profiles of the temporal modes are not known, which makes it difficult to achieve mode selection and demultiplexing. Here, we report a novel method that measures directly the exact form of the temporal modes. This, in turn, enables us to make mode-orthogonal homodyne detection with mode-matched local oscillators. We apply the method to a pulse-pumped, specially engineered fiber parametric amplifier and demonstrate temporally multiplexed multidimensional quantum entanglement of continuous variables in telecom wavelength. The temporal mode characterization technique can be generalized to other pulse-excited systems to find their eigenmodes for multiplexing in the temporal domain.

[Effects of sleep quality and mood of patients with Parkinson's disease on their caregivers].

Objectve: To evaluate the relationship of Parkinson's disease(PD) patients' sleep quality and depression with burden, quality of life, and depression of their caregivers. Methods: A total of 120 PD patients (68 males and 52 females) and their caregivers (48 males and 72 females) from Changshu Hospital Affiliated to Nanjing University of Chinese Medicine between January 2017 and June 2019 were recruited. Patients' sleep quality, depression and quality of life was evaluated. Burden, quality of life, quality of sleep, and depression of caregivers were assessed by the Caregivers Burden Questionnaire (CBI), Health Survey Brief (SF-36), Pittsburgh Sleep Quality Index (PQS1) and Hamilton Depression Scale (HAMD), meanwhile, the correlation between relevant factors was analyzed. Results: The CBI of caregivers was positively correlated with the unified Parkinson's disease rating scale (UPDRS)-Ⅲ scores of PD patients (r=0.436, P<0.05). The CBI, SF-36GH, SF-36MH, HAMD and PSQI scores of caregivers were positively correlated with Parkinson's disease sleep scale (PDSS) scores of PD patients (r=0.546, 0.762, 0.528, 0.562 and 0.522, respectively, all P<0.01). The caregiver's CBI score was positively correlated with PD patients' Epworth sleepiness score (ESS) score (r=0.442, P<0.05), and caregiver's CBI, SF-36GH, SF-36MH, HAMD, PSQI scores were positively correlated with PD patients' HAMD scores (r=0.765, 0.813, 0.635, 0.884 and 0.601, respectively, all P<0.01). The caregiver's CBI score was positively correlated with the PDQ-39 score of PD patients (r=0.834, 0.452, 0.463, 0.421 and 0.387, respectively, all P<0.05). Multiple regression analysis indicated that the caregiver's CBI score was significantly correlated with the patient's PDQ-39, PDSS and HAMD scores (r=0.512, 0.645 and 0.635, respectively, all P<0.01), and the caregiver's SF-36GH score was significantly correlated with the patient's PDQ-39, PDSS and HAMD scores (r=0.452, 0.682 and 0.506, respectively, all P<0.01). The caregiver's SF-36MH score was significantly correlated with the patient's PDQ-39, PDSS and HAMD scores (r=0.426, 0.608 and 0.598, respectively, all P<0.01). There was significant correlations between the caregiver's HAMD score and the patient's PDSS and HAMD scores (r=0.568 and 0.496, both P<0.01), and the PSQI score of the caregiver was significantly correlated with the PDSS and HAMD scores of the patient (r=0.532 and 0.461, both P<0.01). Conclusions: This current study underscores the presence of a significant relationship of patient's sleep quality with caregiver's burden, quality of life, depression and sleep quality. Specifically, sleep quality and depression of the patients are independent predictors for burden, quality of life and sleep quality of the caregivers.

[XBP1 modulates hypoxia/reoxygenation injury in mouse renal tubular epithelial cells through TXNIP-NLRP3 signaling pathway].

Objective: To investigate the role and regulation mechanism of X box binding protein 1 (XBP1) for hypoxia/reoxygenation(H/R) injury in mouse renal tubular epithelial cells (TCMK-1) through thioredoxin interacting protein (TXNIP)-nucleotide-binding domain (NOD)-like receptor protein (TXNIP-NLRP3) signaling pathway. Methods: The cells were divided into 4 groups: si-NC group transfected with negative control siRNA (si-NC), si-XBP1 group transfected with siRNA targeting XBP1 (si-XBP1), si-NC+H/R group transfected with si-NC and exposed to H/R, and si-XBP1+H/R group transfected with si-XBP1 and exposed to H/R. The Annexin Ⅴ/PI double-staining method was used to detect cell apoptosis; The mitochondrial membrane potential (MMP) was determined by using JC-1 dye; The mitochondrial reactive oxygen species (mROS) was assessed by using MitoSOX™ dye. The interference efficiency of XBP1 was tested by Western blotting and quantitative real-time polymerase chain reaction. The expression levels of TXNIP, NLRP3 and IL-1ß protein were detected by Western blotting. The colocalization of mitochondria and TXNIP was detected by double-labeling immunofluorescent staining. The intergroup difference was compared by using an independent samples t-test. Results: Compared with the si-NC group, more mROS, apoptosis and lower MMP were observed in si-NC+H/R group. Compared with the si-NC+H/R group, less apoptosis (12.08±0.51 vs 19.01±1.80, P<0.05), mROS (34.63±0.64 vs 48.17±1.84, P<0.01) and higher MMP (1.03±0.11 vs 0.45±0.08, P<0.05) were observed in si-XBP1+H/R group. Down-regulation of XBP1U (protein: 1.31±0.18 vs 0.23±0.02, P<0.01; mRNA: 1.12±0.07 vs 0.38±0.01, P<0.001) and XBP1S (protein: 1.13±0.17 vs 0.28±0.07, P<0.01; mRNA: 8.39±0.63 vs 2.45±0.22, P<0.001) inhibited expression of TXNIP (0.15±0.02 vs 0.04±0.01, P<0.01), NLRP3 (1.13±0.12 vs 0.51±0.12, P<0.05) and IL-1ß (1.02±0.04 vs 0.19±0.06, P<0.001) during H/R. Meanwhile, TXNIP exhibited significantly much less colocalization with mitochondria in the si-XBP1+H/R group. Conclusion: Supression of XBP1 expression can effectively alleviate H/R-induced TCMK-1 cells injury, whose mechanism may be inhibition of TXNIP-induced NLRP3 inflammasome activation.

[Current consensus and controversy in neoadjuvant therapy for pancreatic cancer].

Pancreatic cancer is malignant and has a poor prognosis.At present, the treatment mode has changed from "Surgery First" to systemic therapy under multi-disciplinary team, but surgical resection is still the only way to cure pancreatic cancer. In systemic treatment of pancreatic cancer, the effect of postoperative adjuvant therapy is significant, and preoperative neoadjuvant therapy has gradually attracted widespread attention. Neoadjuvant therapy can improve the rate of R0 resection in patients with pancreatic cancer.There is a consensus on neoadjuvant therapy for patients who with borderline resectable and locally advanced, but for the patients who with resectable remains controversial.

Phenotypic association of 15q11.2 CNVs of the region of breakpoints 1-2 (BP1-BP2) in a large cohort of samples referred for genetic diagnosis.

In view of conflicting reports on the pathogenicity of 15q11.2 CNVs of the breakpoints 1-2 (BP1-BP2) region and lack of association with a specific phenotype, we collected phenotypic data on 51,462 patients referred for genetic testing at two centers (Magee-Womens Hospital of UPMC and Baylor Genetics Laboratories, Baylor College of Medicine). Using array CGH, 262 patients with deletions and 215 with duplications were identified and tested for their association with four phenotypes (developmental delay, dysmorphic features, autism group of disorders, and epilepsy/seizures). Only association of deletions with dysmorphic features was observed (P = 0.013) with low penetrance (3.8%). Our results, viewed in the context of other reports suggesting the lack of a clear phenotypic outcome, underscore the need for detailed phenotypic studies to better understand the pathogenicity of 15q11.2 (BP1-BP2) CNVs.

Pulsed entanglement measured by parametric amplifier assisted homodyne detection.

Balanced homodyne detection relies on a beam splitter to superpose the weak signal input and strong local oscillator. However, recent investigation shows that a high gain phase sensitive amplifier (PSA) can be viewed as homodyne detector, in which the strong pump of PSA serves as the local oscillator [1]. Here, we analyze a new method of measuring the continuous variable entanglement by assisting a balanced homodyne detector with the PSA and implement it experimentally. Before measuring quadrature amplitude with the balanced homodyne detectors, two entangled fields generated from a pulse pumped fiber optical parametric amplifier are simultaneously coupled into the PSA. We find that the normalized noise for both the difference and sum of the quadrature amplitudes of the two entangled fields fall below the shot noise limit by about 4.6 dB, which is the record degree of entanglement measured in optical fiber systems. The experimental results illustrate that the advantages of the new measurement method include but not limit to tolerance to detection loss and characterizing entanglement with only one homodyne detector. The influence of mode-mismatching due to multi-mode property of entanglement on the measured noise reduction can also be greatly mitigated, indicating the new method is advantageous over the traditional measurement in multi-mode case.

Versatile and precise quantum state engineering by using nonlinear interferometers.

The availability of photon states with well-defined temporal modes is crucial for photonic quantum technologies. Ever since the inception of generating photonic quantum states through pulse pumped spontaneous parametric processes, many exquisite efforts have been put on improving the modal purity of the photon states to achieve single-mode operation. However, because the nonlinear interaction and linear dispersion are often mixed in parametric processes, limited successes have been achieved so far only at some specific wavelengths with sophisticated design. In this paper, we resort to a different approach by exploiting an active filtering mechanism originated from interference fringe of nonlinear interferometer. The nonlinear interferometer is realized in a sequential array of nonlinear medium, with a gap in between made of a linear dispersive medium, in which the precise modal control is realized without influencing the phase matching of the parametric process. As a proof-of-principle demonstration of the capability, we present a photon pairs source using a two-stage nonlinear interferometer formed by two identical nonlinear fibers with a standard single mode fiber in between. The results show that spectrally correlated two-photon state via four wave mixing in a single piece nonlinear fiber is modified into factorable state and heralded single-photons with high modal purity and high heralding efficiency are achievable. This novel quantum interferometric method, which can improve the quality of the photon states in almost all the aspects such as modal purity, heralding efficiency, and flexibility in wavelength selection, is proved to be effective and easy to realize.

Non-Hermitian Magnon-Photon Interference in an Atomic Ensemble.

The interference of photons in a lossy beam splitter (BS) exhibits anticoalescence, which is surprising for bosons. Such a non-Hermitian system involving open quantum dynamics is of particular interest for quantum information processing and metrology. The Hermiticity of photonic devices is generally fixed according to the material, but is controllable at the interface of photons and atomic systems. Here, we demonstrate a tunable non-Hermitian BS for the interference between traveling photonic and localized magnonic modes. The crossover from a Hermitian to a non-Hermitian magnon-photon BS is achieved by controlling the coherent and incoherent interaction mediated by the excited levels of atoms, which is reconfigurable via the detuning of a control laser. A correlated interference pattern between the photons and magnons is demonstrated by such a non-Hermitian BS. Our system has the potential to operate with photons and magnons at the single-quanta level, and it provides a versatile quantum interface for studying the non-Hermitian quantum physics and parity-time symmetry.

[Clinical analysis of carotid artery stenting with severe stenosis and extracranial distortion under proximal protection technique].

Objective: To investigate the feasibility, efficacy and safety of endovascular reconstruction of the carotid artery with severe stenosis and extracranial distortion under proximal protection. Methods: A retrospective analysis of 21 patients with severe carotid stenosis and extracranial distortion who were admitted to the Second Affiliated Hospital of Soochow University between January 2011 and August 2017, of which 16 patients were symptomatic stenosis with acute ischemic stroke. All the patients were treated with carotid artery stenting under (CAS) proximal protection technique, and assessed with the National Institutes of Health Stroke Scale (NIHSS) before the treatment and hospital discharge. The clinical outcome and vascular morphology were followed-up regularly after the treatment. Results: Twenty-one patients were successfully completed the CAS procedure under the proximal protection technique, the average blocking time was 241.0 (232.5-261.0) seconds. Nine patients received 1block attempt, 6 patients received 2 block attempts, and the other 6 patients received 3 block attempts. Three patients experienced transient ischemic attack (TIA) during the procedure, the maximum duration of TIA was 10 minutes. In 16 patients with symptomatic stenosis, there were no significant differences in NIHSS score before CAS procedure and hospital discharge (P>0.05). The residual stenosis rate of the carotid artery after stenting was(13±6)%, compared with preoperative (87±16)%, which appeared a significant difference (t=19.948, P<0.05). All the patients had no adverse events such as myocardial infarction, recurrent ischemic stroke and death in the follow-up period. Restenosis was assessed in 6 patients by DSA or CTA and no restenosis was found. Conclusion: Endovascular reconstruction of the carotid artery with severe stenosis and extracranial distortion under proximal protection technique has been proven as a safe and effective therapy.

[Analysis of prognostic factors and therapeutic patterns of recurrent stage â b-â ¡a cervical squamous carcinoma treated with radical hysterectomy].

Objective: To analyze the prognosis and appropriate treatment modalities of the patients with recurrence of early stage (Ⅰb-Ⅱa) cervical squamous cancer primarily treated with radical hysterectomy. Methods: This retrospective study included patients with International Federation of Gynecology and Obstetrics (FIGO) stage Ⅰb and Ⅱa recurrent cervical squamous cancer who underwent radical hysterectomy primarily from January 2007 to July 2015. Kaplan-Meier method and Cox regression analysis were performed to analyze related prognostic factors of overall survival and progression-free survival, which included age, postoperative therapy, the site of recurrence, therapy-free interval (TFI) and treatment modality. The patients who were treated with palliative chemotherapy after recurrence were selected as a subgroup. The responses of palliative chemotherapy were evaluated and analyzed among different factors, included TFI, the site of recurrence and chemotherapy regime. Results: Of the 2 071 patients, 116 relapsed Ⅰb-Ⅱa cervical squamous cancer were included in the study with the average age of (45.6±7.2) years old. 3-year progression-free survival rate and 3-year overall survival rate after recurrence were 30.2% and 42.2%, respectively. Univariate analysis implied that postoperative radiotherapy, recurrence site, TFI and treatment modality were associated with progression-free survival (P<0.05), while postoperative radiotherapy, TFI and treatment modality with overall survival (P<0.05). Multivariate analysis showed that TFI and treatment modality were independent prognostic factors for progression-free survival (P<0.05), while postoperative radiotherapy at initial treatment, TFI and treatment modality were independent prognostic variables for overall survival (P<0.05). In the analysis of treatment modality, 3-year progression-free survival rate and 3-year overall survival rate of 47 patients who were treated with definitive local therapy were significantly higher than that of 69 patients who were treated with palliative chemotherapy (P<0.01). In the subgroup analysis of palliative chemotherapy, 15 patients achieved complete response (21.7%) and 16 displayed partial response (23.2%). The overall response rate (ORR) was 44.9%. TFI (P<0.01) and chemotherapy regime (P<0.05) were significant factors associated with ORR. The ORR of TFI ≥12 months was significantly higher than that of TFI <12 months. Besides, the ORR of paclitaxel plus platinum chemotherapy was prominently higher than that of other regimens, while there was no significant difference between the ORR of paclitaxel plus cisplatin and other platinum (P=0.408). Conclusions: For recurrent stageⅠb-Ⅱa cervical squamous carcinoma treated with radical hysterectomy, use of definitive local therapy for suitable patients is advised to achieve better prognosis. In terms of palliative chemotherapy, longer TFI may mean better ORR and the combination of paclitaxel plus platinum is preferred.

Loss-tolerant quantum dense metrology with SU(1,1) interferometer.

Heisenberg uncertainty relation in quantum mechanics sets the limit on the measurement precision of non-commuting observables in one system, which prevents us from measuring them accurately at the same time. However, quantum entanglement between two systems allows us to infer through Einstein-Podolsky-Rosen correlations two conjugate observables with precision better than what is allowed by Heisenberg uncertainty relation. With the help of the newly developed SU(1,) interferometer, we implement a scheme to jointly measure information encoded in multiple non-commuting observables of an optical field with a signal-to-noise ratio improvement of about 20% over the classical limit on all measured quantities simultaneously. This scheme can be generalized to the joint measurement of information in arbitrary number of non-commuting observables.

Absolute sensitivity of phase measurement in an SU(1,1) type interferometer.

Absolute sensitivity is measured for the phase measurement in an SU(1,1) type interferometer, and the results are compared to that of a Mach-Zehnder interferometer operated under the condition of the same intra-interferometer intensity. The interferometer is phase locked to a point with the largest quantum noise cancellation, and a simulated phase modulation is added in one arm of the SU(1,1) interferometer. Both the signal and noise level are estimated at the same frequency range, and we obtained 3 dB improvement in sensitivity for the SU(1,1) interferometer over the Mach-Zehnder interferometer. Our results demonstrate a direct phase estimation and may pave the way for practical applications of a nonlinear interferometer.

[Comparison of knowledge and behavior toward hearing protection among workers in different workplaces and its influence factors].

Objective: To compare the knowledge and behavior toward hearing protection among workers in different workplaces and investigate its influence factors. Methods: 2 manufacturing companies with obvious noise hazard in workplace were selected into the study. Health management level was distinguished through field investigation and verification. Questionnaire focus on basic knowledge of hearing health, acceptance level of noise hazard, comfort of wearing hearing protectors and atmosphere in workplace was designed and was used to investigate the knowledge and behavior toward hearing protection. Results: Hearing protectors that meet the level of protection are distributed throughout the workplaces. Although company A has a lower noise hazards level, the health management system was poorly executed. The proportion of workers persisting in wearing hearing protectors throughout the work shift in company A was lower than B (P<0.01) . Workers in company A intended to underestimate the noise level (P<0.01) and the health effect of hearing loss (P<0.01) . All the workers were worry about suffering from hearing loss (P>0.05) , but those in company B had more positive attitude toward the protection of hearing protector (P<0.01) and relied on the protector (P<0.01) . The awareness of protection, in turn, help workers adapt attitude and get used to wearing hearing protectors consciously in workplace (P<0.01) . Conclusion: Health management performance play a key role in help workers form good knowledge and behavior. To protect workplace health, employers need to creative a healthy supportive environment for workers.

Quantum non-demolition measurement of photon number with atom-light interferometers.

When atoms are illuminated by an off-resonant field, the AC Stark effect will lead to phase shifts in atomic states. The phase shifts are proportional to the photon number of the off-resonant illuminating field. By measuring the atomic phase with newly developed atom-light hybrid interferometers, we can achieve quantum non-demolition measurement of the photon number of the optical field. In this paper, we analyze theoretically the performance of this QND measurement scheme by using the QND measurement criteria established by Holland et al [Phys. Rev. A 42, 2995 (1990)]. We find the quality of the QND measurement depends on the phase resolution of the atom-light hybrid interferometers. We apply this QND measurement scheme to a twin-photon state from parametric amplifier to verify the photon correlation in the twin beams. Furthermore, a sequential QND measurement procedure is analyzed for verifying the projection property of quantum measurement and for the quantum information tapping. Finally, we discuss the possibility for single-photon-number-resolving detection via QND measurement.

Generation of frequency degenerate twin beams in Rb85 vapor.

We demonstrate a new phase-matching geometry for four-wave mixing processes in hot Rb85 vapor, in which all four fields propagate in different directions but two of them are degenerate in frequency. When used as a parametric amplifier with an injected seed, two types of quantum mechanically correlated twin-beam states, either frequency degenerate or nondegenerate, can be generated. The quantum noise reduction in the intensity difference is almost 7 dB for the nondegenerate type and nearly 5 dB for the degenerate type. The spatial nondegeneracy of the four waves allows a variety of configurations of parametric processes, leading to flexible control for both phase insensitive and sensitive parametric amplification. The spatially nondegenerate but frequency degenerate four-wave mixing process will find wide applications in quantum metrology, quantum communication, and quantum information of continuous variables.