Preparation of near-infrared photoacoustic imaging and photothermal treatment agent for cancer using a modifiable acid-triggered molecular platform.

Ratiometric near-infrared fluorescent pH probes with various pKa values were innovatively designed and synthesized based on cyanine with a diamine moiety. The photochemical properties of these probes were thoroughly evaluated. Among the series, IR-PHA exhibited an optimal pKa value of approximately 6.40, closely matching the pH of cancerous tissues. This feature is particularly valuable for real-time pH monitoring in both living cells and living mice. Moreover, when administered intravenously to tumor-bearing mice, IR-PHA demonstrated rapid and significant enhancement of near-infrared fluorescence and photoacoustic signals within the tumor region. This outcome underscores the probe's exceptional capability for dual-modal cancer imaging utilizing near-infrared fluorescence (NIRF) and photoacoustic (PA) modalities. Concurrently, the application of a continuous-wave near-infrared laser efficiently ablated cancer cells in vivo, attributed to the photothermal effect induced by IR-PHA. The results strongly indicate that IR-PHA is well-suited for NIRF/PA dual-modality imaging and photothermal therapy of tumors. This makes it a promising candidate for theranostic applications involving small molecules.

Unravelling the Flotation Performance of 1-Hydroxy-2-naphthyl hydroxamic Acid and Styrene Phosphonic Acid Collectors on Monazite Using Experiments and DFT Calculations.

The atomic-level structure and electronic properties of monazite were investigated using a first-principles method based on density functional theory (DFT). First, the geometric structure of monazite was optimized, followed by calculations of its Mulliken population, electron density, and density of states, which were subsequently analyzed. The findings of this analysis suggest that monazite is highly susceptible to cleavage along the {100} plane during crushing and grinding. When SPA was utilized as the collector, the recovery rate of monazite was higher than that when LF-P8 was used. The zeta potential and adsorption energy results indicated that the zeta potential after SPA adsorption tended towards negativity, and the adsorption energy was smaller, indicating that SPA exhibited stronger adsorption performance. LF-P8 was stably adsorbed on the monazite (100) surface via mononuclear double coordination. SPA was stably adsorbed on the surface of monazite (100) via binuclear double coordination. The results of this study provide valuable insights into the adsorption of monazite by commonly used flotation collectors. These findings are of substantial importance for future endeavors in designing flotation collectors capable of achieving selective monazite flotation.

Application an internet facilitation in a community-based cervical cancer screening project.

OBJECTIVE: To evaluate the feasibility of an internet-facilitated community model for cervical cancer screening using self-collected HPV testing as primary screening. METHOD: A population-based cervical cancer screening program was conducted in the suburb of Shenzhen, China, from September 2014 to July 2017. Women with 25-60 years of age and no pregnancy were eligible for participation. Participants could register for screening by logging in a website by themselves or with the aids of local community workers. A unique barcode was issued to each applicant upon successful registration. After registration, women could get sampling kits from community screening site/study clinic, collect vaginal samples privately or in group, and provide their sample for Hr-HPV tests on Cobas4800 and SeqHPV assays. Testing reports were checkable through personal account for all participant and phone calls were given to all women positive of Hr-HPV. Participants positive of both or either the 2 assays were identified as the positives. The positives could return the study clinic for triage or search medical care in other clinics. Colposcopy directed or ramdom biopsies were performed on all positives who returned to the study clinics. RESULTS: A total of 10,792 community women registered for screening, among whom, 10,010 provided their vaginal samples for tests. 99.5% of the participants were confirmed to have correct personal identifiable information and samples, and 98.9% of them got HPV testing results from both or either assays. No adverse event was reported. CONCLUSION: When self-collected HPV testing is used as the primary testing, the internet-based data platform facilitates the screening in registration, data collection, and data tracking, and increases the screening coverage. Internet-facilitated community model is promising to cervical cancer control and applicable in regions with variety of resources.

The effect of MicroRNAs variants on idiopathic recurrent pregnancy loss.

BACKGROUND: Although the importance of miRNA variants in female reproductive disorders has been frequently reported, the association between miRNA polymorphisms and recurrent pregnancy loss (RPL) has been poorly studied. In this study, we aimed to assess the correlation of four different miRNA variants to unexplained RPL. METHODS AND RESULTS: The prevalence of four SNPs including miR-21 rs1292037, miR-155-5p rs767649, miR-218-2 rs11134527, and miR-605 rs2043556 in 280 cases with iRPL and 280 controls was performed. The DNA was extracted from all subjects and the SNPs were genotyped using RFLP-PCR methods. The data revealed that rs1292037 and rs767649 were significantly associated with higher rates of iRPL in patients compared with controls while rs11134527 and rs2043556 showed no association with increased rates of iRPL among patients. The haplotypes T-A-G-G and T-A-G-A were the most frequent in both cases and controls. Three haplotypes including T-T-G-A, C-T-G-G, and T-A-A-A showed significantly different frequencies in patients in comparison to healthy females. CONCLUSION: This study suggests that rs1292037 and rs767649 could be risk factors for increased rates of iRPL.

Fabrication of Superhydrophobic Gully-Structured Surfaces by Femtosecond Laser and Imprinting for High-Efficiency Self-Cleaning Rain Collection.

Freshwater is considered an essential need for humanity. Moreover, it is important to collect and make full use of rainwater. This work utilizes a femtosecond laser to fabricate micro-nanostructures on aluminum alloy substrates as molds. Then, the structures are imprinted on cheap and wildly used polypropylene (PP) materials. The just-imprinted PP surfaces with instinctive surface energy and replicated micro-nanostructures have an excellent superhydrophobic property with contact angles greater than 160° and anisotropic sliding angles smaller than 5° in parallel directions and smaller than 10° in the vertical directions. A small-scale rain collection device formed by a combination of the superhydrophobic PP surfaces is used to investigate the effects of the rain collection efficiency and total surface area relating to manufacturing cost. The rain collection device formed by the imprinted PP surfaces has high rain collection efficiency in terms of the volume of the collected water per square centimeter. For the light rain, the rain collection efficiency can reach an approximated maximum of 90%, more than 100% efficiency improvement of the device formed by flat PP surfaces in some cases. Therefore, the rain collection device is helpful in collecting water from rains in arid areas.

[Multilevel study on the effects of dietary nutrients on body mass index of Chinese children and adolescents aged 7-17].

OBJECTIVE: Analyze the relationship between dietary nutrients and body mass index of children and adolescents aged 7-17 in China. METHODS: The data comes from the "China Health and Nutrition Survey", and 5562 children and adolescents aged 7-17 who participated in at least one round(2000, 2006, 2011 and 2015) of the survey and had complete dietary and physical measurement survey data were selected as the research objects. A three-level(community-individual-observation level) linear random intercept mixed effect model of body mass index was constructed to analyze the influence of dietary nutrient intake of children and adolescents of different genders in urban and rural areas on their body mass index(BMI).24 hours for 3 consecutive days and family weight accounting were used to evaluate the dietary nutrient intake. RESULTS: BMI of urban children and adolescents is higher than that of rural children and adolescents. The BMI of children and adolescents aged 12-17 is higher than that of children and adolescents aged 7-11. BMI of boys was higher than that of girls, but the difference was statistically significant only in 2011 and 2015. After controlling for confounding factors such as individual level(survey year, age, physical activity and family per capita income) and community level(community urbanization index), the three-level model showed that the BMI of rural boys increased with the increase of cholesterol intake(P<0.01). BMI of urban girls increased with the increase of vitamin B_1 intake(P<0.05) and iron intake(P<0.01). BMI of rural girls increased with the increase of vitamin E intake(P<0.001) and sodium intake(P<0.05). CONCLUSION: There are some differences in dietary nutrients that affect the BMI level of 7-17 years old children and adolescents between urban and rural areas.

[Trends of overweight and obesity among children and adolescents aged 7-17 in 16 provinces of China from 2000 to 2018].

OBJECTIVE: To analyze the distribution characteristics and trends of overweight and obesity in children and adolescents aged 7-17 years in 16 provinces of China. METHODS: Data were collected from China health and nutrition survey in 2000, 2006, 2011, 2015 and 2018, 8398 children and adolescents aged 7-17 with complete data were selected as the research objects. Overweight and obesity were classified by body mass index(BMI) reference norm for screening overweight and obesity in Chinese children and adolescents. The distribution and trend of overweight and obesity among children and adolescents aged 7-17 in 16 provinces of China were analyzed by using Cochran-Armitage trend test and two-level random intercept model. RESULTS: The prevalence of overweight and obesity in children and adolescents aged 7-17 in China showed an upward trend from 2000 to 2018(P<0.05). The prevalence of overweight increased from 5.42% in 2000 to 12.92% in 2018, and the prevalence of obesity increased from 2.45% in 2000 to 12.36% in 2018. The result of multilevel model analysis showed that gender and urban and rural areas had significant effects on centralized BMI(P<0.05), the BMI increase value of boys was greater than that of girls(ß=0.2824), the BMI increase value of children and adolescents in rural areas was greater than that in urban areas(ß=0.5902). CONCLUSION: The prevalence of overweight and obesity among children and adolescents aged 7-17 in 16 provinces of China are increasing.

Ultrabroadband, compact, polarization independent and efficient metasurface-based power splitter on lithium niobate waveguides.

We propose a metasurface-based Lithium Niobate waveguide power splitter with an ultrabroadband and polarization independent performance. The design consists of an array of amorphous silicon nanoantennas that partially converts the input mode to multiple output modes creating multimode interference such that the input power is equally split and directed to two branching waveguides. FDTD simulation results show that the power splitter operates with low insertion loss (< 1dB) over a bandwidth of approximately 800 nm in the near-infrared range, far exceeding the O, E, S, C, L and U optical communication bands. The metasurface is ultracompact with a total length of 2.7 µm. The power splitter demonstrates a power imbalance of less than 0.16 dB for both fundamental TE and TM modes. Our simulations show that the device efficiency exhibits high tolerance to possible fabrication imperfections.

Distinguishing monomer and nanoparticle contributions to high-harmonic emission from laser-ablated plumes.

Nano-clusters and nano-particles (NPs) are attractive media for high-harmonic generation (HHG) since they combine the advantages of using atomic media (for the low average density) and bulk solid media (for the high local density). Recently, laser ablated plumes from metal nano-powders have been used as HHG media and it has been often assumed that the harmonics mainly come from the NPs in the plumes but not by the isolated atoms/ions. However, this assumption is yet to be fully justified. Here, we show that in fact both NPs and isolated monomers could dominate the harmonic spectrum, depending on which part of the plume is interacting with the driving laser. From the ablated plume of indium NPs, it is found that the harmonic spectra from the region where monomers dominate are distinctively different from the region where NPs dominate. Our results demonstrate that accurately capturing the contribution of NPs in HHG processes requires precise selection of the laser-plasma interaction region, a factor that had not been carefully considered in previous studies.

Spectrally resolved wedged reversal shearing interferometer.

In this Letter, we introduce a technique to fully determine the spatio-temporal electric field E(x,y,t) of an arbitrary ultrashort pulse. By passing the beam through a wedged reversal shearing interferometer followed by a scanning Michelson interferometer, the field autocorrelation of the shearing interferograms is measured. The spectrum of the shearing interferograms is obtained after a Fourier transform by the Whittaker-Shannon sampling theorem, yielding the amplitude and wavefront information at every wavelength. With the addition of the phase information of a single point, we are able to directly reconstruct the spatio-temporal electric field E(x,y,t) of an arbitrary ultrashort pulse.

Compact vectorial optical field generator using a single phase-only spatial light modulator.

In this study, we demonstrate a compact vectorial optical field generator for any coherent light, including femtosecond laser beams. The apparatus utilizes a single Köster prism for both beam splitting and recombining. A phase-only spatial light modulator is used as a diffractive optical element to encode the two complex fields that recombine after being converted to orthogonal polarizations, generating an arbitrary vectorial optical field. We apply this setup to shape focused femtosecond pulses in producing patterned structures.

Resonance-enhanced high harmonic in metal ions driven by elliptically polarized laser pulses.

Resonance enhancement of a single order harmonic has been a main attractive feature in high-harmonic generation from laser ablated plumes of metals. Although it has been extensively investigated experimentally and theoretically, studies so far have focused only on linearly polarized driving fields. In this Letter, we study the dependence of the resonant harmonic yield in tin ions on the driving laser ellipticity. We find that the resonance leads to a less rapid decay of the harmonic yield as a function of driving ellipticity, and it is qualitatively reproduced by quantum mechanical simulations. To the best of our knowledge, our findings provide a new type of evidence for supporting previously proposed mechanisms for enhancement.

Phase change material-based nano-cavity as an efficient optical modulator.

Structural phase transition induced by temperature or voltage in phase change materials has been used for many tunable photonic applications. Exploiting reversible and sub-ns fast switching in antimony trisulfide (Sb2S3) from amorphous (Amp) to crystalline (Cry), we introduced a reflection modulator based on metal-dielectric-metal structure. The proposed design exhibits tunable, perfect, and multi-band absorption from visible to the near-infrared region. The reflection response of the system shows >99% absorption of light at normal incidence. The maximum achievable modulation efficiency with a narrow line width is ∼98%. Interestingly, the designed cavity supports critical resonance in an ultrathin (∼λ/15) Sb2S3 film with perfect, broadband, and tunable absorption. Finally, we proposed a novel hybrid cavity design formed of Cry and Amp Sb2S3 thin films side-by-side to realize an optical modulator via relative motion between the incident light beam and cavity. The proposed lithographic free structure can be also used for filtering, optical switching, ultrathin photo-detection, solar energy harvesting, and other energy applications.

Significantly enhanced electrocatalytic activity of copper for hydrogen evolution reaction through femtosecond laser blackening.

In this work, we report on the creation of a black copper via femtosecond laser processing and its application as a novel electrode material. We show that the black copper exhibits an excellent electrocatalytic activity for hydrogen evolution reaction (HER) in alkaline solution. The laser processing results in a unique microstructure: microparticles covered by finer nanoparticles on top. Electrochemical measurements demonstrate that the kinetics of the HER is significantly accelerated after bare copper is treated and turned black. At -0.325 V (v.s. RHE) in 1 M KOH aqueous solution, the calculated area-specific charge transfer resistance of the electrode decreases sharply from 159 Ω cm2 for the untreated copper to 1 Ω cm2 for the black copper. The electrochemical surface area of the black copper is measured to be only 2.4 times that of the untreated copper and therefore, the significantly enhanced electrocatalytic activity of the black copper for HER is mostly a result of its unique microstructure that favors the formation and enrichment of protons on the surface of copper. This work provides a new strategy for developing high-efficient electrodes for hydrogen generation.

A Highly Sensitive Single Crystal Perovskite-Graphene Hybrid Vertical Photodetector.

Organolead trihalide perovskites have attracted significant attention for optoelectronic applications due to their excellent physical properties in the past decade. Generally, both grain boundaries in perovskite films and the device structure play key roles in determining the device performance, especially for horizontal-structured device. Here, the first optimized vertical-structured photodetector with the perovskite single crystal MAPbBr3 as the light absorber and graphene as the transport layer is shown. The hybrid device combines strong photoabsorption characteristics of perovskite and high carrier mobility of flexible graphene, exhibits excellent photoresponse performance with high photoresponsivity (≈1017.1 A W-1 ) and high photodetectivity (≈2.02 × 1013 Jones) in a low light intensity (0.66 mW cm-2 ) under the actuations of 3 V bias and laser irradiation at 532 nm. In particular, an ultrahigh photoconductive gain of ≈2.37 × 103 is attained because of fast charge transfer in the graphene and large recombination lifetime in the perovskite single crystal. The vertical architecture combining perovskite crystal with highly conductive graphene offers opportunities to fulfill the synergistic effect of perovskite and 2D materials, is thus promising for developing high-performance electronic and optoelectronic devices.

Boosting Perovskite Photodetector Performance in NIR Using Plasmonic Bowtie Nanoantenna Arrays.

Triple-cation mixed metal halide perovskites are important optoelectronic materials due to their high photon to electron conversion efficiency, low exciton binding energy, and good thermal stability. However, the perovskites have low photon to electron conversion efficiency in near-infrared (NIR) due to their weak intrinsic absorption at longer wavelength, especially near the band edge and over the bandgap wavelength. A plasmonic functionalized perovskite photodetector (PD) is designed and fabricated in this study, in which the perovskite ((Cs0.06 FA0.79 MA0.15 )Pb(I0.85 Br0.15 )3 ) active materials are spin-coated on the surface of Au bowtie nanoantenna (BNA) arrays substrate. Under 785 nm laser illumination, near the bandedge of perovskite, the fabricated BNA-based plasmonic PD exhibits ≈2962% enhancement in the photoresponse over the Si/SiO2 -based normal PD. Moreover, the detectivity of the plasmonic PD has a value of 1.5 × 1012 with external quantum efficiency as high as 188.8%, more than 30 times over the normal PD. The strong boosting in the plasmonic PD performance is attributed to the enhanced electric field around BNA arrays through the coupling of localized surface plasmon resonance. The demonstrated BNA-perovskite design can also be used to enhance performance of other optoelectronic devices, and the concept can be extended to other spectral regions with different active materials.

Rapid fabrication of anti-corrosion and self-healing superhydrophobic aluminum surfaces through environmentally friendly femtosecond laser processing.

The development of superhydrophobic metals has found many applications such as self-cleaning, anti-corrosion, anti-icing, and water transportation. Recently, femtosecond laser has been used to create nano/microstructures and wetting property changes. However, for some of the most common metals, such as aluminum, a relatively long aging process is required to obtain stable hydrophobicity. In this work, we introduce a combination of femtosecond laser ablation and heat treatment post-process, without using any harsh chemicals. We turn aluminum superhydrophobic within 30 minutes of heat treatment following femtosecond laser processing, and this is significantly shorter compared to conventional aging process of laser-ablated aluminum. The superhydrophobic surfaces maintain high contact angles greater than 160° and low sliding angles smaller than 5° over two months after the heat treatment. Moreover, the samples exhibit strong superhydrophobicity for various types of liquids (milk, coffee, CuPc, R6G, HCl, NaOH and CuCl2). The samples also show excellent self-healing and anti-corrosion properties. The mechanism for fast wettability conversion time is discussed. Our technique is a rapid process, reproducible, feasible for large-area fabrication, and environment-friendly.

Plasmonic analogue of geometric diodes realizing asymmetric optical transmission.

Geometric diodes represent a relatively new class of diodes used in rectennas that rely on the asymmetry of a conducting thin film. Here, we numerically investigate a plasmonic analogue of geometric diodes to realize nanoscale optical asymmetric transmission. The device operates based on spatial symmetry breaking that relies on a unique property of surface plasmon polaritons (SPPs), namely, adiabatic nanofocusing. We show that the structure can realize on-chip asymmetric electromagnetic transmission with a total dimension of ∼2µm×6µm. We demonstrate a signal contrast of 0.7 and an asymmetric optical transmission ratio of 4.77 dB. We investigate the origin of the asymmetric transmission and show that it is due mainly to asymmetric out-coupling of SPPs to far-field photons. We highlight the role of evanescent field coupling of SPPs in undermining the asymmetric transmission efficiency and show that by adjusting the plasmonic waveguide dimensions, a signal contrast of 0.94 and an asymmetric optical transmission ratio of 5.18 dB can be obtained. Our work presents a new paradigm for on-chip nanoscale asymmetric optical transmission utilizing the unique properties of SPPs.

Producing anomalous uniform periodic nanostructures on Cr thin films by femtosecond laser irradiation in vacuum.

We report on producing unprecedentedly uniform periodic structures on chromium thin films in vacuum conditions with irradiation of femtosecond laser pulses. In sharp contrast to the observations in air, the achieved surface structures of the ablated groove arrays are surprisingly found to have not only an extraordinarily uniform distribution but also a deep-subwavelength period of 360 nm. The measured both width and depth of the ablated periodic grooves are 150 and 120 nm, respectively, showing a large depth-to-width ratio and sharp-edge profiles. Remarkably, such well-organized nanostructures can be enabled to robustly extend into an infinitely long range via the sample scanning and even have a large-area production with a cylindrical lens. Raman spectral analyses reveal that the regular formation of such nanostructures benefits from avoiding the material oxidation and thermal disturbance of the air plasma on the sample surface.

Dynamic control of spontaneous emission rate using tunable hyperbolic metamaterials.

We numerically investigate the dynamic control over the spontaneous emission rate of quantum emitters using tunable hyperbolic metamaterials (HMMs). The dispersion of a metal-dielectric thin-film stack at a given frequency can undergo a topological transition from an elliptical to a hyperbolic dispersion by incorporating a tunable metal or dielectric film in the HMM. This transition modifies the local density of optical states of the emitter and, hence, its emission rate. In the visible range, we use an HMM consisting of TiN and ${{\rm Sb}_2}{{\rm S}_3}$Sb2S3 and show considerable tunability in the Purcell enhancement and quantum efficiency as ${{\rm Sb}_2}{{\rm S}_3}$Sb2S3 phase changes from amorphous to crystalline. Similarly, we show tunable Purcell enhancement in the telecommunication wavelength range using a ${\rm TiN}/{{\rm VO}_2}$TiN/VO2- HMM. Finally, tunable spontaneous emission rate in the mid-IR range is obtained using a ${\rm graphene}/{\rm MgF}_2$graphene/MgF2 HMM by modifying the graphene conductivity through changing its chemical potential. We show that using a metal nitride (for the visible and NIR HMMs) and a fluoride (for the mid-IR HMM) is important to get an appreciable change in the effective permittivity of the thin-film multilayer stack.