Vernier effect-based tunable mid-infrared sensor using silicon-on-insulator cascaded rings.

Vernier effect has been captivated as a promising approach to achieve high-performance photonic sensors. However, experimental demonstration of such sensors in mid-infrared (MIR) range, which covers abundant absorption fingerprints of molecules, is still lacking. Here, we report Vernier effect-based thermally tunable photonic sensors using cascaded ring resonators fabricated on the silicon-on-insulator (SOI) platform. The radii and the coupling gaps in two rings are investigated as key design parameters. By applying organic liquids on our device, we observe an envelope shift of 48 nm with a sensitivity of 3000 nm/RIU and an intensity drop of 6.7 dB. Besides, our device can be thermally tuned with a sensitivity of 0.091 nm/mW. Leveraging the characteristic molecular absorption in the MIR, our work offers new possibilities for complex index sensing, which has wide applications in on-chip photonic sensors.

Coexistence of air and dielectric modes in single nanocavity.

A deterministic design method and experimental demonstration of single photonic crystal nanocavity supporting both air and dielectric modes in the mid-infrared wavelength region are reported here. The coexistence of both modes is realized by a proper design of photonic dispersion to confine air and dielectric bands simultaneously. By adding central mirrors to make the resonance modes be confined at the bandgap edges, high experimental Q-factors of 2.32 × 104 and 1.59 × 104 are achieved at the resonance wavelength of about 3.875µm and 3.728µm for fundamental dielectric and air modes, respectively. Moreover, multiple sets of air and dielectric modes can be realized by introducing central aperiodic mirrors with multiple bandgaps. The realization of coexistence of air and dielectric modes in single nanocavity will offer opportunities for multifunctional devices, paving the way to integrated multi-parameter sensors, filters, nonlinear devices, and compact light sources.

Thermal annealing study of the mid-infrared aluminum nitride on insulator (AlNOI) photonics platform.

Aluminum nitride on insulator (AlNOI) photonics platform has great potential for mid-infrared applications thanks to the large transparency window, piezoelectric property, and second-order nonlinearity of AlN. However, the deployment of AlNOI platform might be hindered by the high propagation loss. We perform thermal annealing study and demonstrate significant loss improvement in the mid-infrared AlNOI photonics platform. After thermal annealing at 400°C for 2 hours in ambient gas environment, the propagation loss is reduced by half. Bend loss and taper coupling loss are also investigated. The performance of multimode interferometer, directional coupler, and add/drop filter are improved in terms of insertion loss, quality factor, and extinction ratio. Fourier-transform infrared spectroscopy, Raman spectroscopy, and X-ray diffraction spectroscopy suggest the loss improvement is mainly attributed to the reduction of extinction coefficient in the silicon dioxide cladding. Apart from loss improvement, appropriate thermal annealing also helps in reducing thin film stress.

Aluminum nitride on insulator (AlNOI) platform for mid-infrared photonics.

We report an aluminum nitride on insulator platform for mid-infrared (MIR) photonics applications beyond 3 µm. Propagation loss and bending loss are studied, while functional devices such as directional couplers, multimode interferometers, and add/drop filters are demonstrated with high performance. The complementary metal-oxide-semiconductor-compatible aluminum nitride offers advantages ranging from a large transparency window, high thermal and chemical resistance, to piezoelectric tunability and three-dimensional integration capability. This platform can have synergy with other photonics platforms to enable novel applications for sensing and thermal imaging in MIR.

Diagnosing ovarian cancer by identifying SCC-antigen on a multiwalled carbon nanotube-modified dielectrode sensor.

Ovarian cancer starts in the ovaries in its earlier stages and then spreads to the pelvis, uterus, and abdominal region. The success of an ovarian cancer treatment depends on the stage of the cancer and the diagnostic system. Squamous cell carcinoma antigen (SCC-Ag) is one of the most efficient cancer biomarkers, and elevated levels of SCC-Ag in ovarian cancer cells have been used to identify ovarian cancer. Carbon is a potential material for biosensing applications due to its thermal, electrical, and physical properties. Multiwalled carbon nanotubes (MWCNTs) are carbon-based materials that can be used here to detect SCC-Ag. Anti-SCC-Ag antibody was immobilized on the amine-modified MWCNT dielectric sensing surface to detect SCC-Ag. The uniformity of the surface structure was measured with a 3D nanoprofiler, and the results confirmed the detection of SCC-Ag at ∼80 pM. The specific detection of SCC-Ag was confirmed with two control proteins (factor IX and human serum albumin), and the system did not show biofouling. This experimental set-up with MWCNTs a dielectric sensing surface can lead to the detection of ovarian cancer in its initial stages.

Deterministic aperiodic photonic crystal nanobeam supporting adjustable multiple mode-matched resonances.

We investigate nanocavities in deterministic aperiodic photonic crystal (PhC) nanobeams. We reveal that even a single nanocavity can support multiple mode-matched resonances, which show an almost perfect field overlap in the cavity region. The unique property is enabled by the existence of adjustable multiple bandgaps in deterministic aperiodic PhC nanobeams. Our investigation may inspire related studies on low threshold lasers, integrated nonlinear devices, optical filters, and on-chip sensors.

Potential deficit from decreased cerebellar granule cell migration in serine racemase-deficient mice is reversed by increased expression of GluN2B and elevated levels of NMDAR agonists.

Inward migration of cerebellar granule cells (CGCs) after birth is critical for lamination in the cerebellar cortex. N-methyl-d-aspartate (NMDA) subtype of glutamate receptor (NMDAR) tethering CGCs into Bergmann glial fibers mediates the inward movement during the glial-dependent migratory phase. Activation of NMDAR depends on simultaneous binding of the GluN2 subunit by glutamate, and of the GluN1 subunit by d-serine or glycine; d-serine is believed to be an endogenous ligand of NMDAR. We hypothesized that lamination of the cerebellar cortex may be compromised in Srr (the gene for serine racemase (SR)) mutated mice (Srrnull) because of significantly low levels of d-serine per se. Indeed, the external germinal cell layer (EGL) in Srrnull was thicker than in sibling wild-type (WT) mice on postnatal day7 (P7), which accords with decreased CGC migration in Srrnull mice. However, the cerebellar laminar structure in Srrnull mice was normal on P12 and later. Feeding d-serine to pregnant mice abrogated the increased EGL thickness in Srrnull mice on P7. To determine the underlying mechanism of abnormal laminar structure during cerebellar development in Srrnull mice, we examined NMDAR subunits and their ligands. We found increased GluN2B on P10 and increased glycine during P7-12 in the cerebellar homogenates from Srrnull mice compared with the corresponding values from sibling WT mice. In summary, the study revealed how the potential defect in early cerebellar development caused by Srr mutation is circumvented by a compensatory mechanism. This knowledge advances understanding of the adaptation of cerebellar development under the condition of Srr mutation.

Loss-of-function mutation of serine racemase attenuates excitotoxicity by intravitreal injection of N-methyl-D-aspartate.

Convincing data demonstrate that D-serine, a racemized product of serine racemase (SR), contributes to neurotoxicity. Furthermore, a line of evidence suggests that SR/D-serine contributes to retinal neurodegeneration in a diabetic retinopathy rat model and diabetic retinopathy patients. However, the connection between SR/D-serine and retinal neurodegeneration remains unclear. Herein, we report that intravitreal injection of N-methyl-D-aspartate (NMDA) induces excitotoxicity in rodent retina; this retinal neurodegeneration was attenuated in retina carrying a loss-of-function of mutation in Srr, the gene for SR, termed Srr(ochre269). Under the condition of NMDA injection, either posterior pole or middle - but not peripheral - retina from Srr(ochre269) mice was found to retain more retinal ganglion cells (RGC) than the counterpart from w/t (RGCs were identified with retrograde labeling). Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining further demonstrated reduced RGC apoptosis from Srr(ochre269) compared to w/t mice under the condition of NMDA injection. Collectively, our studies demonstrate a pivotal role of SR/D-serine in retinal neurotoxicity. We demonstrated that loss-of-function mutation of the gene encoding serine racemase significantly attenuates excitotoxicity in retina; excitotoxicity accounts for retinal ganglion cell (RGC) demise in diabetic retinopathy (DR). We think that our findings deepen the current knowledge of the mechanisms of RGC degeneration.

The Effects of Single-Bout Exercise Interventions with Different Exercise Modalities on Executive Function in Youths.

BACKGROUND: This study aimed to investigate how single-bout open-skill exercise (OSE), closed-skill exercise (CSE), and mixed-skill exercise intervention (MSE) influence executive function. METHOD: A total of 120 students aged between 18 and 25 were separated into three groups: closed-skill exercise, open-skill exercise, and mixed-skill exercise. A task-switching test was performed before and after a single bout of exercise intervention. The simple reaction time, choice reaction time, switch cost, and correction rate were tested in a task-switching test. The results were analyzed via a two-way analysis of variance, with a significance level of α = 0.05, to compare the effects of the intervention. RESULTS: Only open-skill exercise exhibited a significant effect on the simple reaction time (p < 0.05). In terms of choice reaction time and switch cost, all three intervention groups exhibited significant improvements, with no significant differences observed between the three groups (p < 0.05). The correction rate did not show a significant effect post-intervention, and no significant differences were observed between the groups. The correction rate showed no significant effect after the intervention or between groups. CONCLUSION: All three types of exercise can shorten choice reaction time and switch cost, but only OSE can reduce simple reaction time.

Upconversion nanoparticle-based fluorescence resonance energy transfer sensing of programmed death ligand 1 using sandwich epitope-imprinted polymers.

Programmed death ligand 1 (PD-L1) has been shown to suppress the anti-tumor immune response of some lung cancer patients, and thus PD-L1 expression may be a valuable predictor of the efficacy of anti-PD-1/PD-L1 monoclonal therapy in such patients. In this work, a sandwich approach to fluorescence resonance energy transfer (FRET) was used with green-emitting Yb3+/Ho3+-doped upconversion nanoparticles (UCNPs) and a rhodamine-conjugated conductive polymer as donor and acceptor, respectively. Yb3+/Ho3+-doped UCNPs were synthesized and then coated with poly(ethylene-co-vinyl alcohol), pEVAL, imprinted with PD-L1 peptide. Epitope-imprinted composite nanoparticles were characterized by dynamic light scattering, superconducting quantum interference magnetometry, and atomic force microscopy. Poly(triphenylamine rhodamine-3-acetic acid-co-3,4-ethoxylenedioxythiophene)s copolymers (p(TPAR-co-EDOT)) were imprinted with various epitopes of PD-L1 by in situ electrochemical polymerization. The epitope-imprinted polymer-coated electrodes were then characterized by scanning electron microscopy, atomic force microscopy, and X-ray photoelectron spectroscopy. Finally, the sandwich sensing of various PD-L1 concentrations with peptide-imprinted p(TPAR-co-EDOT)-coated substrate and UCNP-containing magnetic peptide-imprinted pEVAL nanoparticles by FRET was conducted to measure the concentration of PD-L1 in A549 lung cancer cell lysate.

No primexine and plasma membrane undulation is essential for primexine deposition and plasma membrane undulation during microsporogenesis in Arabidopsis.

Primexine deposition and plasma membrane undulation are the initial steps of pollen wall formation. However, little is known about the genes involved in this important biological process. Here, we report a novel gene, NO PRIMEXINE AND PLASMA MEMBRANE UNDULATION (NPU), which functions in the early stage of pollen wall development in Arabidopsis (Arabidopsis thaliana). Loss of NPU function causes male sterility due to a defect in callose synthesis and sporopollenin deposition, resulting in disrupted pollen in npu mutants. Transmission electronic microscopy observation demonstrated that primexine deposition and plasma membrane undulation are completely absent in the npu mutants. NPU encodes a membrane protein with two transmembrane domains and one intracellular domain. In situ hybridization analysis revealed that NPU is strongly expressed in microspores and the tapetum during the tetrad stage. All these results together indicate that NPU plays a vital role in primexine deposition and plasma membrane undulation during early pollen wall development.

Investigation of Asian Dyes and Pigments from the Artifact of "Murongzhi" and the Silk Road in China.

In this paper, a series of modern analysis methods, including Raman spectroscopy, X-ray diffraction, UV-vis spectrophotometry, and ultra-high-pressure liquid chromatography coupled with a thermoelectric LTQ-Orbitrap XL ETD mass spectrometer (UHPLC-MS/MS), were applied to analyze and accurately identify the chemical composition of plant dyes and the mineral pigment from the samples collected from grave goods. As a result, the textiles were dyed by the madder, Kermes, Phellodendron chinense, indigo, Lithospermum L., and so forth. In addition, the mineral pigment, charcoal, hematite, minium, cinnabar, azurite, and malachite were used to paint the exquisite artifacts in the tomb of Murongzhi. This research demonstrates the profound impact on cultural transmission and fusion in the "Tuyuhong" dynasty and explores the Silk Road in Tang dynasty.

Photoelectrochemical biosensor based on SiW12@CdS quantum dots for the highly sensitive detection of HPV 16 DNA.

A highly sensitive biosensor for detecting HPV 16 DNA was prepared based on Keggin-type polyoxometalate (SiW12)-grafted CdS quantum dots (SiW12@CdS QDs) and colloidal gold nanoparticles (Au NPs), which exhibited remarkable selectivity and sensitivity upon target DNA detection because of its excellent photoelectrochemical (PEC) response. Here, an enhanced photoelectronic response ability was achieved with the strong association of SiW12@CdS QDs by polyoxometalate modification, which was developed through a convenient hydrothermal process. Furthermore, on Au NP-modified indium tin oxide slides, a multiple-site tripodal DNA walker sensing platform coupled with T7 exonuclease was successfully fabricated with SiW12@CdS QDs/NP DNA as a probe for detecting HPV 16 DNA. Due to the remarkable conductivity of Au NPs, the photosensitivity of the as-prepared biosensor was improved in an I3-/I- solution and avoided the use of other regents toxic to living organisms. Finally, under optimized conditions, the as-prepared biosensor protocol demonstrated wide linear ranges (15-130 nM), with a limit of detection of 0.8 nM and high selectivity, stability, and reproducibility. Moreover, the proposed PEC biosensor platform offers a reliable pathway for detecting other biological molecules with nano-functional materials.

Identification of genes involved in Listeria monocytogenes biofilm formation by mariner-based transposon mutagenesis.

Listeria monocytogenes is a ubiquitous food-borne pathogen, whose distribution and survival in food-processing environments are associated with the ability to form biofilms. The process of biofilm formation is complex and its molecular mechanism is relatively poorly understood in L. monocytogenes. To better understand the genetics of this process, a mariner-based transposon mutagenesis strategy was used to identify genes involved in biofilm formation of L. monocytogenes. A library of 6,500 mutant colonies was screened for reduced biofilm formation using a microtiter plate biofilm assay. Forty biofilm-deficient mutants of L. monocytogenes were identified based on DNA sequences of the transposon-flanking regions and Southern hybridization with a transposon-based probe. The insertions harbored by these mutants led to the identification of 24 distinct loci, 18 of which, to our knowledge, have not been previously reported to function in the biofilm formation in L. monocytogenes. Genetic complementation confirmed the importance of lmo1386, a gene encoding a putative DNA translocase, for biofilm formation. Molecular analyses of mutants indicated that the majority of the 24 identified genes are related to flagella motility, gene regulation, and cell surface structures.

Low concentration of ethylenediaminetetraacetic acid (EDTA) affects biofilm formation of Listeria monocytogenes by inhibiting its initial adherence.

The distribution and survival of the food-borne pathogen Listeria monocytogenes is associated with its biofilm formation ability, which is affected by various environmental factors. Here we present the first evidence that EDTA at low concentration levels inhibits the biofilm formation of L. monocytogenes. This effect of EDTA is not caused by a general growth inhibition, as 0.1 mM EDTA efficiently reduced the biofilm formation of L. monocytogenes without affecting the planktonic growth. Adding 0.1 mM of EDTA at the starting time of biofilm formation had the strongest biofilm inhibitory effect, while the addition of EDTA after 8 h had no biofilm inhibitory effects. EDTA was shown to inhibit cell-to-surface interactions and cell-to-cell interactions, which at least partially contributed to the repressed initial adherence. The addition of sufficient amounts of cations to saturate EDTA did not restore the biofilm formation, indicating the biofilm inhibition was not due to the chelating properties of EDTA. The study suggests that EDTA functions in the early stage of biofilm process by affecting the initial adherence of L. monocytogenes cells onto abiotic surfaces.

The Effects of High-Intensity Power Training versus Traditional Resistance Training on Exercise Performance.

Background: High-intensity interval training (HIIT) features short, repeated bursts of relatively vigorous exercise with intermittent periods of rest or low-intensity exercise. High-intensity power training (HIPT), in combination with HIIT and traditional resistance training (TRT), is characterized as multijoint high-intensity resistance exercises with low interset rest periods. HIPT requires people to finish the exercise as fast as possible, which increases acute physiological demands. The aim of the study was to investigate the differences between eight-week HIPT or TRT on exercise performance. Methods: Twenty-four college students were recruited and randomly assigned to either the HIPT or TRT group in a counterbalanced order. The power of upper and lower limbs (50% 1RM bench press and vertical jump) and anaerobic power were tested before and after the training (weeks 0 and 9). The results were analyzed by two-way analysis of variance (ANOVA) or Friedman's test with a significance level of α = 0.05 to compare the effects of the intervention on exercise performance. Results: There were significant differences in the explosive force of the upper and lower limbs between the pretest and post-test in both the HIPT and TRT groups (p < 0.05). However, only the HIPT group showed a significant difference in the mean power on the Wingate anaerobic test between the pretest and post-test (p < 0.05). Conclusions: Both HIPT and TRT can improve upper and lower limb explosive force. HIPT is an efficient training protocol, which took less time and produced a better improvement in mean anaerobic power.

Heterogeneously Integrated Graphene/Silicon/Halide Waveguide Photodetectors toward Chip-Scale Zero-Bias Long-Wave Infrared Spectroscopic Sensing.

Mid-infrared absorption spectroscopy plays an important role in molecule identification and quantification for widespread applications. Integrated photonics provides opportunities to perform spectroscopic sensing on-chip for the minimization of device size, cost, and power consumption. The integration of waveguides and photodetectors is an indispensable step toward the realization of these on-chip sensing systems. It is desired to extend the operating wavelengths of these on-chip sensing systems to the long-wave infrared (LWIR) range to utilize more molecular absorption fingerprints. However, the development of LWIR waveguide-integrated photodetectors faces challenges from both waveguide platforms due to the bottom cladding material absorption and photodetection technologies due to the low LWIR photon energy. Here, we demonstrate LWIR waveguide-integrated photodetectors through heterogeneous integration of graphene photodetectors and Si waveguides on CaF2 substrates. A high-yield transfer printing method is developed for flexibly integrating the waveguide and substrate materials to solve the bottom cladding material absorption issue. The fabricated Si-on-CaF2 waveguides show low losses in the broad LWIR wavelength range of 6.3-7.1 µm. The graphene photodetector achieves a broadband responsivity of ∼8 mA/W in these low-photon-energy LWIR wavelengths under zero-bias operation with the help of waveguide integration and plasmonic enhancement. We further integrate the graphene photodetector with a Si-on-CaF2 folded waveguide and demonstrate on-chip absorption sensing using toluene as an example. These results reveal the potential of our technology for the realization of chip-scale, low-cost, and low-power-consumption LWIR spectroscopic sensing systems.

Embedded Upconversion Nanoparticles in Magnetic Molecularly Imprinted Polymers for Photodynamic Therapy of Hepatocellular Carcinoma.

In this work, high-temperature pyrolysis was used to prepare both the core and shell of lantha-nide-doped UCNPs with lithium yttrium tetrafluoride (LiYF4) to enhance the green luminescence. Merocyanine 540 (MC540)-grafted magnetic nanoparticles were incorporated in the PD-L1 pep-tide-imprinted poly(ethylene-co-vinyl alcohol) particles, which were formed by precipitation in a non-solvent. UCNPs in the non-solvent bath were thus entrapped in the imprinted particles to generate composite nanoparticles for the targeting and photodynamic therapy of PD-L1 in tumor cells. Finally, the in vitro cytotoxicity of the nanoparticles in HepG2 human liver cancer cells was evaluated with the continuous administration of MC540/MNPs@MIPs/UCNPs under irradiation by an NIR laser. To understand the delivery of the UCNP-embedded molecularly imprinted pol-ymers, the intrinsic and extrinsic pathways were also investigated.

Intravenous patient-controlled analgesia hydromorphone combined with pregabalin for the treatment of postherpetic neuralgia: a multicenter, randomized controlled study.

BACKGROUND: Postherpetic neuralgia (PHN) is the most common complication of acute herpes zoster. The treatment of PHN remains a challenge for clinical pain management. Despite the effectiveness of anticonvulsants, antidepressants, and lidocaine patches in reducing PHN, many patients still face intractable pain disorders. In this randomized controlled study, we evaluated whether hydromorphone through intravenous patient-controlled analgesia (IV PCA) was effective in relieving PHN. METHODS: Patients with PHN were randomly divided into two groups, one group received oral pregabalin with IV normal saline, another group received oral pregabalin with additional IV PCA hydromorphone for two weeks. Efficacy was evaluated at 1, 4, and 12 weeks after the end of the treatments. RESULTS: Two hundred and one patients were followed up for 12 weeks. After treatment, numerical rating scale (NRS) score of patients in the hydromorphone group was significantly lower than that of the control group, and the difference of NRS scores between the two groups was statistically significant at 4 and 12 weeks after treatment. The frequency of breakthrough pain in the hydromorphone group was significantly lower than that in the control group 1 and 4 weeks after treatment. After treatment, the quality of sleep in the hydromorphone group was significantly improved compared with the control group. The most common adverse reactions in the hydromorphone group were dizziness and nausea, with no significant respiratory depression. CONCLUSIONS: IV PCA hydromorphone combined with oral pregabalin provides superior pain relief in patients with PHN, which is worthy of clinical application and promotion.

The impact of diabetes mellitus medication on the incidence of endogenous endophthalmitis.

PURPOSE: This study aimed to evaluate the relationship between diabetic mellitus (DM) treatment and the incidence rate of endogenous endophthalmitis (EE). DESIGN: This study used a matched cohort design. We utilized the Longitudinal Health Insurance Database to identify outpatients and inpatients who were diagnosed with DM and treated with medication from 2000 to 2010. METHODS: Several factors and different DM medications were also investigated. The influence of DM medication on the incidence of EE was examined by using Cox proportional hazards regression models, and the hazard ratios and 95% confidence intervals were determined. RESULTS: The cumulative incidence of EE was lower in DM patients treated with medication than in subjects in the control group (P = 0.002). The adjusted hazard ratio (AHR) was 0.47-fold lower in the treatment group than in the control group (P = 0.004). With respect to DM medication, single-agent therapy with insulin, metformin, gliclazide, glimepiride, or repaglinide and combination therapy with glimepiride/metformin or repaglinide/metformin were associated with decreased AHRs (0.257-0.544, all P<0.05). CONCLUSIONS: Diabetic patients treated with medication had lower AHRs than those in the control group. Further stratification indicated that liver abscess, liver disease DM patients who were treated with medication had a lower risk of developing EE. Several specific DM medications may decrease the incidence of EE.