A Label-Free Optical Biosensor Based on an Array of Microring Resonators for the Detection of Human Serum Albumin.

We introduced a label-free sensing system based on an array of microring resonators (MRRs) which was successfully employed for human serum albumin (HSA) detection. The sensing-ring surface was functionalized to immobilize anti-HSA, facilitating HSA binding. Our refractive index sensing system demonstrates high sensitivity at 168 nm/RIU and a low limit of detection (LOD) of 63.54 ng/mL, closely comparable to current HSA detection methods. These findings confirm the potential of MRRs as biocompatible sensors for HSA detection. This system holds great promise as an innovative platform for the detection of HSA, carrying significant importance in medical diagnostics.

Single-mode interband cascade laser based on V-coupled cavity with 210†nm wavelength tuning range near 3†µm.

Interband cascade lasers (ICLs) are efficient and compact mid-infrared (3-5 µm) light sources with many applications. By enhancing the coupling coefficient and using a type-I ICL wafer, single-mode ICLs were demonstrated based on V-coupled cavity with significantly extended tuning range and with a side mode suppression ratio (SMSR) exceeding 35 dB in continuous wave operation near 3 µm. A V-coupled cavity ICL exhibited a wavelength tuning up to 67 nm at a fixed temperature, and the total tuning range exceeds 210 nm when the heat sink temperature is adjusted from 80 to 180 K. The realization of single-mode in such a wide temperature range with a tuning range exceeding 210 nm verified the advantage of V-coupled cavity ICLs for effective detection of multiple gas species. This is very different from the conventional distributed feedback (DFB) laser where the single-mode operation is restricted to a narrow temperature range, in which the match between the gain peak and the DFB grating period determined wavelength is required. Another V-coupled cavity ICL is tuned over 120 nm from 2997.56 nm to 3117.50 nm with the heat-sink temperature varied from 210 K to 240 K, over 100 K higher than the previously reported maximum operating temperature for V-coupled cavity ICLs.

4*10 Gbps WDM communication system based on a tunable V-cavity semiconductor laser.

This paper is about the V-cavity tunable semiconductor laser with a 1550 nm band used as a transmitter to build a wavelength division multiplexing (WDM) optical fiber communication link. In the experiment, a 20 km optical fiber communication link with a reasonable eye diagram and low bit error rate (BER) transmitted by 40 Gbps can be established. The experimental results show that a single laser can achieve a wavelength tuning range of 25 nm, reach 32 channels at a 100 GHz frequency interval, and the average side mode suppression ratio (SMSR) is above 39 dB. The advantages and application potential of V-cavity tunable semiconductor laser (VCL) for wavelength routing in optical communication networking are verified by experiments.

Molecular subtypes predict the preferential site of distant metastasis in advanced breast cancer: a nationwide retrospective study.

Objective: This study aimed to explore possible associations between molecular subtypes and site of distant metastasis in advanced breast cancer (ABC). Methods: 3577 ABC patients were selected from 21 hospitals of seven geographic regions in China from 2012-2014. A questionnaire was designed to collect medical information regarding demographic characteristics, risk factors, molecular subtype, recurrence/metastasis information, and disease-free survival (DFS). The cancers were classified into Luminal A, Luminal B, HER2-enriched and Triple Negative subtypes. Chi-square test and multivariate Cox proportional hazard models were performed to explore the associations between molecular subtypes and distant metastasis sites. Results: A total of 2393 cases with molecular subtypes information were finally examined. Patients with Luminal A (51.1%) and Luminal B (44.7%) were most prone to bone metastasis, whereas liver metastasis was more frequently observed in HER2-enriched ABC patients (29.1%).The cumulative recurrence and metastasis rates of ABC patients at 36 months of DFS were the most significant within molecular types, of which Triple Negative was the highest (82.7%), while that of Luminal A was the lowest (58.4%). In the adjusted Cox regression analysis, Luminal B, HER2-enriched and Triple Negative subtypes increased the risk of visceral metastasis by 23%, 46% and 87% respectively. In addition, Triple Negative patients had a higher probability of brain metastasis (HR 3.07, 95% CI: 1.04-9.07). Conclusion: Molecular subtypes can predict the preferential sites of distant metastasis, emphasizing that these associations were of great help in choices for surveillance, developing appropriate screening and cancer management strategies for follow-up and personalized therapy in ABC patients.

Optical-electronic hybrid Fourier convolutional neural network based on super-pixel complex-valued modulation.

An optical-electronic hybrid convolutional neural network (CNN) system is proposed and investigated for its parallel processing capability and system design robustness. It is regarded as a practical way to implement real-time optical computing. In this paper, we propose a complex-valued modulation method based on an amplitude-only liquid-crystal-on-silicon spatial light modulator and a fixed four-level diffractive optical element. A comparison of computational results of convolutions between different modulation methods in the Fourier plane shows the feasibility of the proposed complex-valued modulation method. A hybrid CNN model with one convolutional layer of multiple channels is proposed and trained electrically for different classification tasks. Our simulation results show that this model has a classification accuracy of 97.55% for MNIST, 88.81% for Fashion MNIST, and 56.16% for Cifar10, which outperforms models using only amplitude or phase modulation and is comparable to the ideal complex-valued modulation method.

Temperature-insensitive optical sensors based on two cascaded identical microring resonators.

We demonstrate a novel, to the best of our knowledge, temperature-insensitive optical sensor based on two cascaded identical microring resonators (CIMRR) in this Letter. The structural parameters of the reference ring and sensing ring are designed to be identical. The upper cladding in the sensing windows of the two rings is removed. With different microfluidic channels, the reference ring and sensing ring are exposed to the reference solution and reagent sample, respectively. For wavelength interrogation experiments in the transmission spectrum contrast ratio and low-cost intensity interrogation experiments, the sensitivities of refractive index (RI) sensing are 3402.4 dB/RIU and 1087.3 dB/RIU, respectively, while the temperature sensitivities are as low as 0.023 dB/K and 0.0124 dB/K, respectively.

Age at initial diagnosis and prognosis of breast cancer: a nationwide multicenter retrospective study in China.

Background: Several studies have indicated possible associations between age and the prognosis of breast cancer (BC), but limited data are available from hospital-based multicenter studies in China. This study aimed to explore the associations between age at initial diagnosis of BC and the risk of recurrence or metastasis among Chinese women with newly diagnosed advanced breast cancer (ABC) and provide treatment decision support for BC patients of different ages to medical workers. Methods: The medical records of patients newly diagnosed with ABC were obtained from 21 hospitals in seven geographic regions in China from 2012 to 2014. Patients' general information, clinicopathological features at first diagnosis, treatment information, and prognosis were retrospectively collected based on the self-designed case report form (CRF). Cox proportional hazards regression models were used to determine hazard ratios (HR) and 95% confidence intervals (CI) for the associations between age groups and the risk of recurrence and metastasis. Results: A total of 1,852 cases were included in the final analysis. Age at initial diagnosis was shown to be significantly related to hormone receptor status, human epidermal growth factor receptor 2 (HER2) status, molecular subtypes, and the number of lymph node metastasis (all P<0.05). Patients aged <35 years were more likely to have bone metastasis (45.6%). Patients aged ≥65 years had a lower percentage of receiving surgery (87.1%), adjuvant chemotherapy (61.3%), adjuvant radiotherapy (35.5%), and adjuvant endocrine therapy (30.6%) than the other groups (all P<0.05). Compared with patients aged <35 years, the risk of recurrence or metastasis in those aged 55-64 years was significantly higher (HRage 55-64 =1.24, 95% CI: 1.04-1.47), and the risk of bone metastasis and lung metastasis in those aged 35-44 years was lower (HRbone metastasis =0.74, 95% CI: 0.59-0.93; HRlung metastasis =0.70, 95% CI: 0.53-0.93). After adjusting for stage, grade, and molecular subtype, surgery, neoadjuvant chemotherapy, adjuvant chemotherapy, adjuvant radiotherapy, adjuvant endocrine therapy, and family history of BC, patients aged 35-44 years still had a significantly reduced risk of bone metastasis and lung metastasis by 31% and 52%, respectively (HRbone metastasis =0.69, 95% CI: 0.48-0.98; HRlung metastasis =0.48, 95% CI: 0.31-0.74). Conclusions: Age at initial diagnosis is related to the clinicopathological characteristics and treatment pattern. Although the risk of site-specific metastasis varies by age, age is not an independent factor influencing the risk of total recurrence and metastasis. In accordance with current clinical practice guidelines for BC, however, precise treatment shall be chosen personally for patients whose ages at initial diagnosis are different.

Monolithic 6 × 6 transmitter-router with simultaneous sub-nanosecond port and wavelength switching.

A monolithic 6 × 6 transmitter-router with both port and wavelength switching at sub-nanosecond speed is proposed and experimentally demonstrated. Based on an intra-cavity cyclic echelle diffraction grating router (EDGR) and semiconductor optical amplifier (SOA) arrays, each selectable output port can realize a selected multi-wavelength laser (MWL) output. The measurement results show that all 36 input-output combinations have a single-mode emission spectrum with a sidemode suppression ratio (SMSR) over 30 dB. Simultaneous switching of six laser wavelengths is achieved together with the switching of the output port by a single electrode selection. The switching time is less than 1 ns. It can offer a cost-effective solution to multi-wavelength multi-port optical transmitter-routers for fast distributed optical switching in datacenters and high-performance computers (HPCs).

Dielectric Properties of Fluorinated Aromatic Polyimide Films with Rigid Polymer Backbones.

Fluorinated aromatic polyimide (FAPI) films with rigid polymer backbones have been prepared by chemical imidization approach. The polyimide films exhibited excellent mechanical properties including elastic modulus of up to 8.4 GPa and tensile strength of up to 326.7 MPa, and outstanding thermal stability including glass transition temperature (Tg) of 346.3-351.6 °C and thermal decomposition temperature in air (Td5) of 544.1-612.3 °C, as well as high colorless transmittance of >81.2% at 500 nm. Moreover, the polyimide films showed stable dielectric constant and low dielectric loss at 10-60 GHz, attributed to the close packing of rigid polymer backbones that limited the deflection of the dipole in the electric field. Molecular dynamics simulation was also established to describe the relationship of molecular structure and dielectric loss.

Comparisons of Treatment for HER2-Positive Breast Cancer between Chinese and International Practice: A Nationwide Multicenter Epidemiological Study from China.

OBJECTIVE: To better understand the status of medical treatment for human epidermal growth factor receptor 2 (HER2)-positive breast cancer and the differences between the Chinese and the international clinical practice. METHODS: This was a retrospective, nationwide, multicenter, epidemiological study of advanced breast cancer patients from China. Between January 01, 2012, and December 31, 2014, a total of 3649 patients, covering 7 geographic regions and 21 institutions, participated in this series of studies. HER2-positive breast cancer was selected among the group and adopted into this study. In comparison, we summarized the demographics and clinical characteristics of HER2-positive breast cancer from the Surveillance, Epidemiology, and End Results (SEER) database. RESULTS: A total of 918 patients diagnosed as HER2-positive breast cancer patients were included. The median age at diagnosis was 46 years (ranging, 23 to 78) with a single-peak incidence. The proportions of stages II-IV at diagnosis and distance metastasis in viscera were more than half of the participants. In comparison, the prevalence of estrogen or progesterone receptor-positive expression and luminalB subtype was relatively lower than that of the United States. The receipt of chemotherapy was fairly higher, while the usage of targeted therapy was seriously insufficient. Tumor size was in significantly positive associations with the duration of targeted therapy (Kendall's correlation coefficient = 0.3, P < 0.0001), while no prohibitive variables among clinical characteristics were detected. CONCLUSION: Our study suggested that HER2-positive breast cancer patients were characterized as a younger trend, a lower prevalence of hormonal receptor (HR)-positive expression, and less accessible to anti-HER2 targeted therapy with insufficient duration over the past few years in China. Concerted efforts should be exerted for promising survival benefits in the future. The trial registration number is https://clinicaltrials.gov/ct2/show/NCT03047889.

[Evaluation of Air Pollution Characteristics and Air Quality Improvement Effect in Beijing and Chengdu].

In recent years, China's air quality has been improving, and the concentration of atmospheric particulate matter has decreased significantly. In this study, the pollution characteristics and trends of two typical representative cities (Beijing and Chengdu) were analyzed. The geographical locations, pollution emissions, and meteorological diffusion conditions of the two cities were compared, to evaluate the relative contribution of meteorological conditions and pollution reduction regulations in decreasing fine particulate matter (PM2.5) concentrations. The results showed that the number of heavily polluted days and pollution episodes in Beijing and Chengdu decreased significantly from 2013 to 2018, and the concentration of SO2 and PM2.5 decreased substantially. Compared to 2013, SO2 concentration in Beijing and Chengdu has decreased by 77.8% and 70.9%, whereas PM2.5 concentration has decreased by 42.7% and 48.5%, respectively. The largest reduction appeared in winter, when PM2.5 decreased at an annual rate of 13.5 µg ·m-3 for Beijing and 14.1 µg ·m-3 for Chengdu. During the study period, the wind speed in Chengdu was less than that in Beijing, temperature was approximately 3℃ higher, and static wind in winter was more frequent. A significantly lower mixed-layer height, atmospheric capacity index, and ventilation coefficient in Chengdu resulted in more unfavorable atmospheric diffusion conditions. The static and stable weather index and the environmental meteorological index (EMI) also showed that the atmospheric diffusion conditions were better in Beijing than in Chengdu. The EMI of the two cities showed a decreasing trend during the study period, and the decline in EMI in Chengdu was the most significant in 2018, indicating an evident improvement in meteorological conditions. In 2018, emission reductions are estimated to have contributed 33.5% and 24% to the decrease in PM2.5 in Beijing and Chengdu, respectively, and meteorological conditions contributed 7.2% and 11.1% to the reduction in these two cities. In winter, emission reductions respectively contributed 31.7% and 32.5% to reduction in Beijing and Chengdu, while meteorological conditions made a larger contribution.

Clinicopathological characteristics and treatment of young women with breast cancer in China: a nationwide multicenter 10-year retrospective study.

BACKGROUND: Breast cancer is currently the most common female malignancy in China. However, the clinical features and overall prognosis of young women diagnosed with this malignancy remain unclear. This study aimed to describe the clinicopathological characteristics of young patients (≤34 years of age) with breast cancer and explore the current treatment approaches used in China. METHODS: This was a hospital-based, multicenter, retrospective study of women with breast cancer across seven Chinese hospitals from 1999 to 2008. A total of 295 young (≤34 years of age) patients (research group) and 2,119 women aged 35 to 49 years (control group) were included in the study. Patient epidemiology, pre-operative examinations, clinical pathology, and treatment were analyzed. RESULTS: The percentage of young patients with breast cancer in the study group was 7.01%. These young women had a lower body mass index (BMI), a higher level of education, a lower number of previous births, and a lower history of breastfeeding than the control group (P<0.05). Increasingly, pre-operative use of ultrasound and magnetic resonance imaging are being used to diagnose breast cancer in young women in China. In young women with breast cancer, breast cancer not otherwise specified (NOS) was the primary pathology. The carcinoma in young women was more prone to lymph node metastasis, showed less progesterone receptor (PR) expression, and was more advanced than observed in the control group (P<0.05). We found that the number of young breast cancer patients undergoing breast-conserving surgery in China is increasing. CONCLUSIONS: Young breast cancer patients display unique clinicopathological features, including tumors of a higher grade than those aged 35 years or older. As breast cancer is more aggressive in younger women, prevention and early diagnosis are critical, and new policies should be developed in line with these findings.

Profile and outcome of receptor conversion in breast cancer metastases: a nation-wide multicenter epidemiological study.

Although receptor status including estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2) of the primary breast tumors was related to the prognosis of breast cancer patients, little information is yet available on whether patient management and survival are impacted by receptor conversion in breast cancer metastases. Using data from the nation-wide multicenter clinical epidemiology study of advanced breast cancer in China (NCT03047889), we report the situation of retesting ER, PR and HER2 status for breast cancer metastases and evaluate the patient management and prognostic value of receptor conversion. In total, 3295 patients were analyzed and 1583 (48.0%) patients retesting receptor status for metastasis. Discordance in one or more receptors between the primary and the metastatic biopsy was found in 37.7% of women. Patients who remained hormone receptor (HR) positive in their metastases had similar progression-free survival of first-line and second-line treatment compared to patients with HR conversion (P > .05). In multivariate analysis, patients who showed ER conversion from negative to positive had longer disease-free survival (DFS) than patients who remained negative in their metastases (hazard ratio, 2.05; 95% confidence interval [CI], 1.45-2.90; P < .001). Patients with PR remained positive and had longer DFS than patients with PR conversion from negative to positive (hazard ratio, 0.56; 95% CI, 0.38-0.83; P = .004). Patients with PR conversion have shorter overall survival than patients with PR remained positive or negative (P = .016 and P = .041, respectively). Our findings showed that the receptors' conversions were common in metastatic breast cancer, and the conversion impacted the survival.

Thermo-Optical Tuning Cascaded Double Ring Sensor with Large Measurement Range.

In this paper, a thermo-optic tuning optical waveguide sensor system based on a cascaded double micro-ring resonator is investigated. The system consists of a micro-ring resonator with the microheater as a reference ring and a micro-ring resonator with removing the upper cladding layers as a sensing ring, combined with a microfluidic control. The refractive index change of the sample is measured by the electric power change of the microheater. The experimental results show that the sensitivity of the thermo-optic tuning is 34.231 W/RIU (refractive index units), and the measurement range is 4.325 × 10-3 RIU, almost eight times larger than that of the cascaded double micro-ring resonator without thermo-optic tuning for the intensity interrogation.

Independent risk factors for axillary lymph node metastasis in breast cancer patients with one or two positive sentinel lymph nodes.

BACKGROUND: The benefit of axillary lymph node dissection (ALND) in breast cancer patients with one or two positive sentinel lymph nodes (SLNs) remains inconclusive. The purpose of this study was to identify risk factors independently associated with axillary lymph node (ALN) metastasis. METHODS: We retrospectively analyzed data from 389 Chinese breast cancer patients with one or two positive SLNs who underwent ALND. Univariate and multivariate logistic regression analyses were performed to identify ALN metastasis-associated risk factors. RESULTS: Among the 389 patients, 174 (44.7%) had ALN metastasis, while 215 (55.3%) showed no evidence of ALN metastasis. Univariate analysis revealed significant differences in age (< 60 or ≥ 60 years), human epidermal growth factor receptor-2 (Her-2) status, and the ratio of positive to total SLNs between the ALN metastasis and non-metastasis groups (P < 0.05). The multivariate analysis indicated that age, the ratio of positive to total SLNs, and occupations were significantly different between the two groups. Lastly, younger age (< 60 years), a higher ratio of positive to total SLNs, and manual labor jobs were independently associated with ALN metastasis (P < 0.05). CONCLUSIONS: The risk of ALN metastasis in breast cancer patients with one or two positive SLNs can be further increased by younger age, manual labor jobs, and a high ratio of positive to total SLNs. Our findings may also aid in identifying which patients with one or two positive SLNs may not require ALND.

Mid-infrared widely tunable single-mode interband cascade lasers based on V-coupled cavities.

We demonstrate widely tunable single-mode V-coupled-cavity lasers emitting at wavelengths near 3 µm based on a type-II interband cascade (IC) structure. The mode selection is achieved using a half-wave V-coupler designed for the IC structure in the mid-infrared range. The laser waveguides and cavity structure are deeply etched in a single etching step, without any grating. By changing the injection current at a fixed heat-sink temperature, a tuning range over 35 nm can be achieved with a side-mode suppression-ratio up to 28 dB. The tuning range can be extended to 60 nm when combined with the adjustments of the heat-sink temperature.

Associations between clinical-pathological parameters and biomarkers, HER-2, TYMS, RRMI, and 21-gene recurrence score in breast cancer.

BACKGROUND: Chemotherapy is the predominant treatment option for patients with breast cancer. Selection of patients according to biomarker will improve chemotherapy efficacy. In the present study, we examined the relations of the expression of candidate genes and 21-recurrence score (RS) results to patients' demographic characteristics, histopathological factors, and outcomes. METHODS: A total of 146 patients were enrolled in this study. The patients underwent 21-gene RS testing. In addition, expressions of candidate genes, TYMS, RRM1, TUBB3, TOP2A, PTEN, were detected. Information was obtained on age, tumor size, TMN stage, tumor grade, and status of Ki-67, HER2, ER and PR. The treatment information on the type of endocrine therapy was also obtained. RESULTS: Results clearly showed that the 21-gene RS significantly correlated with the TNM stage of breast cancer (P = 0.047). The RS also correlated with the number of sentinel lymph node (P = 0.038). The pathological type of tumors was strongly associated with the expression of RRM1 (P < 0.015), and slightly correlated with TYMS (P = 0.095) and tumor size (P = 0.061). Further analysis showed that TYMS and RRM1 were two independent factors affecting the disease progression of patients. Besides, for HER-2 stain, staining of grade 2 or above significantly increased the risk of disease progression. CONCLUSION: Our studies showed that TNM stage and sentinel lymph node were important clinical parameters correlated with 21-gene RS results. Also, RRM1, TYMS and HER2 expressions were independent factors associated with disease progression in breast cancer patients. Future study is warranted to investigate the usefulness of these genes in treatment efficacy.

Tunable coupled-cavity semiconductor laser based on a half-wave bow-tie coupler.

We propose and experimentally demonstrate a widely tunable coupled-cavity semiconductor laser based on a novel half-wave bow-tie coupler. The laser comprises two resonate cavities connected through the bow-tie coupler consisting of two back-to-back corner reflectors connected with a short waveguide, which produces a half-wave cross-coupling phase with an optimum coupling coefficient for achieving high mode selectivity. No complex grating or multiple epitaxial growth is needed. By tuning a single electrode at a fixed temperature, 29.6 nm wavelength tuning covering 38 channels with 100 GHz frequency spacing is achieved experimentally, with a side-mode suppression ratio of over 35 dB.

Uniform-loss cyclic arrayed waveguide grating router using a mode-field converter based on a slab coupler and auxiliary waveguides.

We designed and fabricated a silica-based 16×16 cyclic arrayed waveguide grating router (AWGR) with improved channel loss uniformity using a simple mode-field converter composed of a slab coupling region and auxiliary waveguides placed at the interface between the arrayed waveguides and the output star coupler of the AWGR. The mode-field converter transforms the fundamental Gaussian-shaped mode in the arrayed waveguides to a complex mode field which produces a flat-top far field at the image plane of the output star coupler. It does not change the overall construction of the AWGR and does not increase the device size. The experimental results show that loss non-uniformity for a 16×16 AWGR with 1.6 nm wavelength channel spacing is reduced from 3 to 0.5 dB after adapting the mode-field converter, and the crosstalk is improved by about 2 dB.

Temperature-insensitive waveguide sensor using a ring cascaded with a Mach-Zehnder interferometer.

We demonstrate a temperature-insensitive waveguide sensor based on a silicon-on-insulator platform. The sensor consists of a ring resonator and a Mach-Zehnder interferometer (MZI). A free spectral range of the sensing ring is designed to be slightly different from that of the MZI; hence, the Vernier effect can be employed to improve sensitivity. By optimizing structural parameters of the MZI, the envelope peak position of a cascaded transmission spectrum can be immune to the temperature variation, and only dependent on analyte change in the sensing area. The experimental results show that bulk refractive index (RI) sensitivity of the proposed sensor is 3552 nm/RI unit, while its temperature sensitivity is less than 4 pm/K, which is two orders of magnitude smaller than the conventional cascaded sensor structure without temperature compensation. The proposed temperature-insensitive waveguide sensor does not need polymer cladding or extra thermal stabilization, making it more robust in practical applications.