Metasurface-enabled on-chip multiplexed diffractive neural networks in the visible.

Replacing electrons with photons is a compelling route toward high-speed, massively parallel, and low-power artificial intelligence computing. Recently, diffractive networks composed of phase surfaces were trained to perform machine learning tasks through linear optical transformations. However, the existing architectures often comprise bulky components and, most critically, they cannot mimic the human brain for multitasking. Here, we demonstrate a multi-skilled diffractive neural network based on a metasurface device, which can perform on-chip multi-channel sensing and multitasking in the visible. The polarization multiplexing scheme of the subwavelength nanostructures is applied to construct a multi-channel classifier framework for simultaneous recognition of digital and fashionable items. The areal density of the artificial neurons can reach up to 6.25 × 106 mm-2 multiplied by the number of channels. The metasurface is integrated with the mature complementary metal-oxide semiconductor imaging sensor, providing a chip-scale architecture to process information directly at physical layers for energy-efficient and ultra-fast image processing in machine vision, autonomous driving, and precision medicine.

Electrically Tunable Multifunctional Polarization-Dependent Metasurfaces Integrated with Liquid Crystals in the Visible Region.

Metasurfaces open up new avenues for designing planar optics, enabling compact dynamic metadevices. Numerous dynamic strategies have been proposed, among which liquid crystal (LC) based metasurfaces are expected due to the maturity of LC materials. However, existing schemes rarely exploit the polarization manipulation capabilities of metasurfaces and the limited performance hinders the development of practical addressable devices. Here, we demonstrate an electrically tunable multifunctional polarization-dependent metasurface integrated with LCs in the visible range. By a combination of the helicity-dependent metasurface and the birefringent LCs, continuous intensity tuning and switching of two helicity channels are realized. Electrically tunable mono- and multicolor switchable metaholograms and dynamic varifocal metalenses are demonstrated with a simple and performance-enhancing integration scheme. Further, electrically addressable dynamic metasurfaces are achieved. The proposed modulation and integration schemes pave the way for addressable dynamic metasurface devices in various applications, such as space light modulators, light detection and ranging systems, and holographic displays.

Capecitabine plus bevacizumab versus capecitabine in maintenance treatment for untreated characterised KRAS exon 2 wild-type metastatic colorectal cancer: a retrospective analysis in Chinese postmenopausal women.

BACKGROUND: Capecitabine plus bevacizumab (CAP-B) maintenance treatment after 6 cycles of capecitabine, oxaliplatin, and bevacizumab (CAPOXB) has demonstrated clinical activity and failure to compromise quality of life in patients with metastatic colorectal cancer (MCC) in a previous phase 3 CAIRO3 study. The objective of this study is to evaluate the efficacy and safety of CAP-B versus CAP in maintenance treatment after 6-cycle CAPOXB induction therapy in Chinese postmenopausal women with untreated characterised KRAS exon 2 wild-type MCC. METHODS: During 2012-2016, prospectively maintained databases were reviewed to evaluate cohorts with untreated characterised KRAS exon 2 wild-type MCC and stable disease or better after 6-cycle CAPOXB induction treatment. After induction treatment, all patients received either CAP-B or capecitabine (CAP) as maintenance treatment. Median progression-free survival (mPFS) and median overall survival (mOS) were the primary endpoints. Safety was the secondary endpoint. RESULTS: A total of 263 women with untreated characterised KRAS exon 2 wild-type MCC and stable disease or better after 6-cycle CAPOXB induction treatment were included for the evaluation of efficacy and safety (CAP-B-treated cohort, n = 130 and CAP-treated cohort, n = 133). The mPFS was 11.5 months (95% confidence interval [CI], 5.6-17.4) and 9.2 months (95% CI, 3.6-14.8) for the CAP-B-treated and CAP-treated cohorts, respectively (HR 0.54, 95% CI 0.32~0.85; P = 0.013). The mOS was 16.2 months (95% CI, 11.4-18.7) and 12.4 months (95% CI, 10.6-15.5) for the CAP-B- and CAP-treated cohorts, respectively (HR 0.72, 95% CI 0.51~0.94; P = 0.022). The CAP-B-treated cohort experienced significantly more grade 3 or 4 diarrhoea (P < 0.001) than the CAP-treated cohort. CONCLUSIONS: CAP-B maintenance treatment after 6-cycle CAPOX-B in Chinese postmenopausal women with untreated KRAS exon 2 wild-type MCC is poorer tolerated but has a more modest, if any, benefit compared with that of CAP maintenance treatment.

Poor outcomes for osteoporotic patients undergoing conversion total hip arthroplasty following prior failed dynamic hip screw fixation: a nationwide retrospective cohort study.

OBJECTIVES: This study was performed to compare the long-term clinical and radiological outcomes of conversion total hip arthroplasty (CTHA) following prior failed InterTan nail (IT) fixation or dynamic hip screw (DHS) fixation in Asian patients with osteoporotic intertrochanteric hip fractures (IHFs) and to clarify which implant tends to be more favourable for CTHA. METHODS: Records of consecutive Asian patients with osteoporosis who underwent conversion of failed primary unilateral IT or DHS fixation to THA from 2010 to 2013 were extracted from the comprehensive database of the China Pacific Insurance Company Ltd. All consecutive procedures were managed by high-volume surgeons. The primary endpoint was the clinical outcome. The secondary endpoint was the radiological outcome. RESULTS: In total, 447 Asian patients with osteoporotic IHFs (DHS, n = 223; IT, n = 224) were assessed during a median follow-up of 46 months (range, 39-53 months). The two groups showed a significant difference in the Harris hip score at final follow-up and in the orthopaedic complication rate (DHS, 20.2%; IT, 9.8%). CONCLUSION: Conversion to THA following prior failed DHS fixation tends to be associated with poorer clinical and radiological outcomes in Asian patients with osteoporotic IHFs than that following prior failed IT fixation.

Comparing the vascular thromboembolic events following arteriovenous fistula in Chinese population with end-stage renal diseases receiving Clopidogrel versus Beraprost sodium therapy: a retrospective cohort study.

BACKGROUND: To assess the time to first on-study vascular thromboembolic events (VTEs) of clopidogrel (CL) or beraprost sodium (BPS) in Chinese population with end-stage renal disease (ESRD) treated with arteriovenous fistula (AVF) surgery. METHODS: From Jan 2009 to May 2015, 346 ESRD cases suffering an AVF surgery and undergoing oral administration of 75 mg CL (initial dose of 300 mg), 1 time/day, for 4 weeks or 40 µg BPS, 3 times/day, for 4 weeks were retrospectively assessed. The primary outcome was time to first on-study VTE. RESULTS: In total, 222 ESRD cases (CL, n = 112; BPS, n = 110) were assessed, with a median follow-up time of 38.1 months (range, 37-40 months). The mean time to first on-study VTE was 1.2 weeks (0.5-2.3) and 1.8 weeks (1.2-3.8) for CL and BPS, respectively (HR 0.27, 95% CI 0.16-1.45; P = 0.00). An increased incidence of VTEs was found during the 1th-month follow-up, with rates of 14.2 and 5.5% for CL and BPS, respectively (P = 0.03). The difference persisted over time, with rates of 24.1 and 11.8% at final follow-up, respectively (P = 0.02). CONCLUSION: CL with an increased risk of VTEs tended to have a VTE within the 1st month after cessation compared with BPS.