54 research outputs found

    Reciprocal polarization imaging of complex media

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    The vectorial evolution of polarized light interaction with a medium can reveal its microstructure and anisotropy beyond what can be obtained from scalar light interaction. Anisotropic properties (diattenuation, retardance, and depolarization) of a complex medium can be quantified by polarization imaging by measuring the Mueller matrix. However, polarization imaging in the reflection geometry, ubiquitous and often preferred in diverse applications, has suffered a poor recovery of the medium's anisotropic properties due to the lack of suitable decomposition of the Mueller matrices measured inside a backward geometry. Here, we present reciprocal polarization imaging of complex media after introducing reciprocal polar decomposition for backscattering Mueller matrices. Based on the reciprocity of the optical wave in its forward and backward scattering paths, the anisotropic diattenuation, retardance, and depolarization of a complex medium are determined by measuring the backscattering Mueller matrix. We demonstrate reciprocal polarization imaging in various applications for quantifying complex non-chiral and chiral media (birefringence resolution target, tissue sections, and glucose suspension), uncovering their anisotropic microstructures with remarkable clarity and accuracy. We also highlight types of complex media that Lu-Chipman and differential decompositions of backscattering Mueller matrices lead to erroneous medium polarization properties, whereas reciprocal polar decomposition recovers properly. Reciprocal polarization imaging will be instrumental in imaging complex media from remote sensing to biomedicine and will open new applications of polarization optics in reflection geometry

    Discovery of Novel 2-Aminopyridine Derivatives As ROS1 and ALK Dual Inhibitors to Combat Drug-Resistant Mutants including ROS1G2032R and ALKG1202R

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    Clinical treatment by FDA-approved ROS1/ALK inhibitor Crizotinib significantly improved the therapeutic outcomes. However, the emergence of drug resistance, especially driven by acquired mutations, have become an inevitable problem and worsened the clinical effects of Crizotinib. To combat drug resistance, some novel 2-aminopyridine derivatives were designed rationally based on molecular simulation, then synthesised and subjected to biological test. The preferred spiro derivative C01 exhibited remarkable activity against CD74-ROS1G2032R cell with an IC50 value of 42.3 nM, which was about 30-fold more potent than Crizotinib. Moreover, C01 also potently inhibited enzymatic activity against clinically Crizotinib-resistant ALKG1202R, harbouring a 10-fold potency superior to Crizotinib. Furthermore, molecular dynamic disclosed that introducing the spiro group could reduce the steric hindrance with bulky side chain (Arginine) in solvent region of ROS1G2032R, which explained the sensitivity of C01 to drug-resistant mutant. These results indicated a path forward for the generation of anti Crizotinib-resistant ROS1/ALK dual inhibitors

    Green synthesis of Au-Pd bimetallic nanoparticles: Single-step bioreduction method with plant extract

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    A facile and eco-friendly method for the preparation of Au-Pd bimetallic nanoparticles (similar to 7 nm) has been developed based on simultaneous bioreduction of Au(III) and Pd(II) precursors with Cacumen Platycladi leaf extract in aqueous environment. The morphology, structure, and size were confirmed with the aid of transmission electron microscopy, selected area electron diffraction. UV-vis spectroscopy, X-ray diffraction, and energy dispersive X-ray spectroscopy. The results from Fourier transform infrared spectroscopy showed that the C=O and C-O groups in the plant extract played a critical role in capping the nanoparticles. Importantly, the process can be described as pure "green chemistry" technique since no additional synthetic reagents are used as reductants or stabilizers. (C) 2011 Elsevier B.V. All rights reserved.National Natural Science Foundation of China[21036004, 20976146]; Natural Science Foundation of Fujian Province of China[2010J05032, 2010J01052]WOS:00029506830004

    Geometry and kinematics for a spherical-base integrated parallel mechanism

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    Parallel mechanisms, in general, have a rigid base and a moving platform connected by several limbs. For achieving higher mobility and dexterity, more degrees of freedom are introduced to the limbs. However, very few researchers focus on changing the design of the rigid base and making it foldable and reconfigurable to improve the performance of the mechanism. Inspired by manipulating an object with a metamorphic robotic hand, this paper presents for the first time a parallel mechanism with a reconfigurable base. This novel spherical-base integrated parallel mechanism has an enlarged workspace compared with traditional parallel manipulators. Evolution and structure of the proposed parallel mechanism is introduced and the geometric constraint of the mechanism is investigated based on mechanism decomposition. Further, kinematics of the proposed mechanism is reduced to the solution of a univariate polynomial of degree 8. Moreover, screw theory based Jacobian is presented followed by the velocity analysis of the mechanism

    Perioperative Toripalimab Plus Chemotherapy for Patients With Resectable Non-Small Cell Lung Cancer: The Neotorch Randomized Clinical Trial

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    IMPORTANCE: Adjuvant and neoadjuvant immunotherapy have improved clinical outcomes for patients with early-stage non-small cell lung cancer (NSCLC). However, the optimal combination of checkpoint inhibition with chemotherapy remains unknown. OBJECTIVE: To determine whether toripalimab in combination with platinum-based chemotherapy will improve event-free survival and major pathological response in patients with stage II or III resectable NSCLC compared with chemotherapy alone. DESIGN, SETTING, AND PARTICIPANTS: This randomized clinical trial enrolled patients with stage II or III resectable NSCLC (without EGFR or ALK alterations for nonsquamous NSCLC) from March 12, 2020, to June 19, 2023, at 50 participating hospitals in China. The data cutoff date for this interim analysis was November 30, 2022. INTERVENTIONS: Patients were randomized in a 1:1 ratio to receive 240 mg of toripalimab or placebo once every 3 weeks combined with platinum-based chemotherapy for 3 cycles before surgery and 1 cycle after surgery, followed by toripalimab only (240 mg) or placebo once every 3 weeks for up to 13 cycles. MAIN OUTCOMES AND MEASURES: The primary outcomes were event-free survival (assessed by the investigators) and the major pathological response rate (assessed by blinded, independent pathological review). The secondary outcomes included the pathological complete response rate (assessed by blinded, independent pathological review) and adverse events. RESULTS: Of the 501 patients randomized, 404 had stage III NSCLC (202 in the toripalimab + chemotherapy group and 202 in the placebo + chemotherapy group) and 97 had stage II NSCLC and were excluded from this interim analysis. The median age was 62 years (IQR, 56-65 years), 92% of patients were male, and the median follow-up was 18.3 months (IQR, 12.7-22.5 months). For the primary outcome of event-free survival, the median length was not estimable (95% CI, 24.4 months-not estimable) in the toripalimab group compared with 15.1 months (95% CI, 10.6-21.9 months) in the placebo group (hazard ratio, 0.40 [95% CI, 0.28-0.57], P \u3c .001). The major pathological response rate (another primary outcome) was 48.5% (95% CI, 41.4%-55.6%) in the toripalimab group compared with 8.4% (95% CI, 5.0%-13.1%) in the placebo group (between-group difference, 40.2% [95% CI, 32.2%-48.1%], P \u3c .001). The pathological complete response rate (secondary outcome) was 24.8% (95% CI, 19.0%-31.3%) in the toripalimab group compared with 1.0% (95% CI, 0.1%-3.5%) in the placebo group (between-group difference, 23.7% [95% CI, 17.6%-29.8%]). The incidence of immune-related adverse events occurred more frequently in the toripalimab group. No unexpected treatment-related toxic effects were identified. The incidence of grade 3 or higher adverse events, fatal adverse events, and adverse events leading to discontinuation of treatment were comparable between the groups. CONCLUSIONS AND RELEVANCE: The addition of toripalimab to perioperative chemotherapy led to a significant improvement in event-free survival for patients with resectable stage III NSCLC and this treatment strategy had a manageable safety profile. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04158440

    Inductive Method for Evaluating RFID Security Protocols

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    Authentication protocol verification is a difficult problem. The problem of “state space explosion” has always been inevitable in the field of verification. Using inductive characteristics, we combine mathematical induction and model detection technology to solve the problem of “state space explosion” in verifying the OSK protocol and VOSK protocol of RFID system. In this paper, the security and privacy of protocols in RFID systems are studied and analysed to verify the effectiveness of the combination of mathematical induction and model detection. We design a (r,s,t)-security experiment on the basis of privacy experiments in the RFID system according to the IND-CPA security standard in cryptography, using mathematical induction to validate the OSK protocol and VOSK protocol. Finally, the following conclusions are presented. The OSK protocol cannot resist denial of service attacks or replay attacks. The VOSK protocol cannot resist denial of service attacks but can resist replay attacks. When there is no limit on communication, the OSK protocol and VOSK protocol possess (r,s,t)-privacy; that is to say they can resist denial of service attacks

    Green synthesis of Au/TS-1 catalysts via two novel modes and their surprising performance for propylene epoxidation

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    In this communication, we report on the preparation of active Au/TS-1 catalysts via two green modes, namely, sol-immobilization method and adsorption-reduction method by using plant extract. Experimental results manifested that bioreduction Au/TS-1 catalysts exhibited excellent performance in vapor phase propylene epoxidation with H(2)/O(2) mixture, especially in view of the fact that the optimal propylene conversion (12.6%) and H(2) efficiency (48.9%) are the highest in data reported so far. To our knowledge, this is the first attempt on the preparation of bioreduction Au/TS-1 catalysts for propylene epoxidation. (C) 2011 Elsevier B.V. All rights reserved.National Natural Science Foundation of China[21036004, 20576109, 20776120, 20976146, 30700020]; Natural Science Foundation of Fujian Province of China[2010J05032, 2010J01052, 2008J0169

    A novel internet sampling for HIV surveillance: feasibility of self-sampling and preparation of DBS for delivery detection of HIV total nucleic acid and complementarity to sentinel surveillance

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    Abstract Background To propose a new mode of HIV test and surveillance among population of men who have sex with men (MSM): Internet-based Self-sampling at home plus Laboratory testing of HIV total nucleic acid (TNA) in dried blood spot (DBS) (ISL of DBS TNA). Feasibility of ISL of DBS TNA was studied. Characteristics of the new mode and that of conventional surveillance mode at HIV voluntary counseling and testing clinic (VCT) were compared. Methods A non-governmental organization (NGO) published the recruitment information on the WeChat public account. MSM filled in the questionnaire online, applied for self-sampling service package, and mailed the self made DBS to professional laboratory. The laboratory performed HIV TNA test and submitted the test results to online platform. Participants queried test results online with their unique ID. Center for Disease Control and Prevention (CDC) followed up participants with positive nucleic acid results using IDs and contact information. Rates were compared by using the Chi-Square test or Fisher's exact test. Results Four hundred twenty-three questionnaires were completed. 423 self-sampling service packages were sent out and 340 DBSs were returned to professional laboratory within one month with qualified rate of sampling as high as 95.0% (323/340). Seven samples were found to be TNA positive. Comparing ISL of DBS TNA with sentinel surveillance, it was found that there was a significant difference in the composition ratio of the two modes of surveillance population (P < 0.05). HIV prevalence of ISL of DBS as 2.17% was significantly lower than sentinel site as 8.96% (χ 2  = 14.953, P = 0.000 < 0.05). Conclusions ISL of DBS TNA proposed is feasible and has a high self-sampling qualification rate, good confidentiality. It is an effective supplement to routine sentinel surveillance and has important promotion value

    Energy and spectral analysis of confined solar flares from radio and X-ray observations

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    International audienceThe energy and spectral shape of radio bursts may help us understand the generation mechanism of solar eruptions, including solar flares, coronal mass ejections, eruptive filaments, and various scales of jets. The different kinds of flares may have different characteristics of energy and spectral distribution. In this work, we selected 10 mostly confined flare events during October 2014 to investigate their overall spectral behaviour and the energy emitted in microwaves by using radio observations from microwaves to interplanetary radio waves, and X-ray observations of GOES, RHESSI, and Fermi/GBM. We found that: all the confined flare events were associated with a microwave continuum burst extending to frequencies of 9.4 ∼ 15.4 GHz, and the peak frequencies of all confined flare events are higher than 4.995 GHz and lower than or equal to 17 GHz. The median value is around 9 GHz. The microwave burst energy (or fluence) and the peak frequency are found to provide useful criteria to estimate the power of solar flares. The observations imply that the magnetic field in confined flares tends to be stronger than that in 412 flares studied by Nita et al. (2004). All 10 events studied did not produce detectable hard X-rays with energies above ∼300 keV indicating the lack of efficient acceleration of electrons to high energies in the confined flares
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