Periodontal disease and preterm delivery: a nationwide population-based cohort study of Taiwan.

Preterm delivery of low-birth weight infants is considered a leading cause of morbidity and mortality among neonates. Various studies have reported a positive correlation between periodontal disease (PD) and premature birth (PB) and yet no population-based study has assessed the impact of PD severity and treatments on premature birth. This cohort study used Taiwan's national medical records (1999-2012, included 1,757,774 pregnant women) to investigate the association between PD severity and PB. Women with PD during the 2-year period prior for giving birth were more likely to have PB (11.38%) than those without PD (10.56%; p < 0.001). After variables adjustment, the advanced PD group had OR of 1.09 (95% CI 1.07-1.11) for PB, the mild PD group had OR of 1.05 (95% CI 1.04-1.06), while no-PD group had OR of 1. Increased PD severity was related to higher risk of PB. When stratified by age, the highest ORs for PB were those aged from 31 to 35 years in both mild PD group (OR = 1.09, 95% CI 1.07-1.11) and advanced PD group (OR = 1.13, 95% CI 1.09-1.17). Improving periodontal health before or during pregnancy may prevent or reduce the occurrence of adverse pregnancy outcomes and therefore maternal and perinatal morbidity and mortality.

Dental care and infection-control procedures during the COVID-19 pandemic: The experience in Taipei City Hospital, Taiwan.

Coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has now widely spread globally. The main transmission routes of SARS-CoV-2 comprise human-to-human droplet infection, including inhalation and contact infection of patient's saliva, blood and other body fluids through oral mucosa, nasal mucosa, and the eyes, and orofecal transmission. Dental treatment necessitates close-proximity, face-to-face practices and can generate droplets or aerosols containing water, saliva, blood, microorganisms, and other debris during the procedure. Therefore, dental professionals are at a high risk of SARS-CoV-2 infection. To prevent nosocomial SARS-CoV-2 spread during dental procedures, Taipei City Hospital established a dental patient triage and workflow algorithm for the provision of dental services during the COVID-19 pandemic. Given the highly contagious nature of SARS-CoV-2, it is imperative to institute an appropriate standard procedural policy for patient management and recommendation of dental treatment at hospitals during the COVID-19 pandemic.

Romantic Story or Raman Scattering? Rose Petals as Ecofriendly, Low-Cost Substrates for Ultrasensitive Surface-Enhanced Raman Scattering.

In this Article, we present a facile approach for the preparation of ecofriendly substrates, based on common rose petals, for ultrasensitive surface-enhanced Raman scattering (SERS). The hydrophobic concentrating effect of the rose petals allows us to concentrate metal nanoparticle (NP) aggregates and analytes onto their surfaces. From a systematic investigation of the SERS performance when using upper and lower epidermises as substrates, we find that the lower epidermis, with its quasi-three-dimensional (quasi-3D) nanofold structure, is the superior biotemplate for SERS applications. The metal NPs and analytes are both closely packed in the quasi-3D structure of the lower epidermis, thereby enhancing the Raman signals dramatically within the depth of focus (DOF) of the Raman optical system. We have also found the effect of the pigment of the petals on the SERS performance. With the novel petal-based substrate, the SERS measurements reveal a detection limit for rhodamine 6G below the femtomolar regime (10(-15) M), with high reproducibility. Moreover, when we employ an upside-down drying process, the unique effect of the Wenzal state of the hydrophobic petal surface further concentrate the analytes and enhanced the SERS signals. Rose petals are green, natural materials that appear to have great potential for use in biosensors and biophotonics.

Incident angle-tuned, broadband, ultrahigh-sensitivity plasmonic antennas prepared from nanoparticles on imprinted mirrors.

We have used a direct imprint-in-metal method that is cheap and rapid to prepare incident angle-tuned, broadband, ultrahigh-sensitivity plasmonic antennas from nanoparticles (NPs) and imprinted metal mirrors. By changing the angle of incidence, the nanoparticle-imprinted mirror antennas (NIMAs) exhibited broadband electromagnetic enhancement from the visible to the near-infrared (NIR) regime, making them suitable for use as surface-enhanced Raman scattering (SERS)-active substrates. Unlike other SERS-active substrates that feature various structures with different periods or morphologies, the NIMAs achieved broadband electromagnetic enhancement from single configurations. The enhancement of the electric field intensity in the NIMAs originated from coupling between the localized surface plasmon resonance of the NPs and the periodic structure-excited surface plasmon resonance (SPR) of the imprinted mirror. Moreover, the coupling wavelengths could be modulated because the SPR wavelength was readily tuned by changing the angle of the incident light. Herein, we demonstrate that such NIMAs are robust substrates for visible and NIR surface-enhanced resonance Raman scattering under multiple laser lines (532, 633, and 785 nm) of excitation. In addition, we have found that NIMAs are ultrasensitive SERS-active substrates that can detect analytes (e.g., rhodamine 6G) at concentrations as low as 10(-15) M.

Single-shot laser treatment provides quasi-three-dimensional paper-based substrates for SERS with attomolar sensitivity.

In this study, an eco-friendly and ultrasensitive paper substrate is developed for surface-enhanced Raman scattering (SERS) with performance approaching single molecule detection. By exploiting the laser-induced photothermal effect, paper fibrils with hybrid micro- and nanostructures can facilitate the formation of highly dense metal nanoparticles (NPs) after a single shot of laser illumination. Metal films deposited on the paper substrates feature discontinuous morphologies, with the fragments acting as multiple nucleation sites. Because thermal conductivity is low on the broken films and the underlying paper fibrils, the incident energy is absorbed efficiently. Moreover, the quasi-three-dimensional distribution of NPs on the SERS paper greatly enhances the SERS signals within the effective collection volume of a Raman microscope. As a result of the large number of highly effective hot spots and the condensation effect, the hydrophobic SERS paper provides SERS signals with stable and uniform reproducibility throughout the detection area. The limits of detection when using the paper substrates reach the attomolar (10(-18) M) level, thereby approaching single molecule detection.

Plasmonic nanoparticle-film calipers for rapid and ultrasensitive dimensional and refractometric detection.

In this study, we develop an ultrasensitive nanoparticle (NP)-film caliper that functions with high resolution (angstrom scale) in response to both the dimensions and refractive index of the spacer sandwiched between the NPs and the film. The anisotropy of the plasmonic gap mode in the NP-film caliper can be characterized readily using spectroscopic ellipsometry (SE) without the need for further optical modeling. To the best of our knowledge, this paper is the first to report the use of SE to study the plasmonic gap modes in NP-film calipers and to demonstrate that SE is a robust and convenient method for analyzing NP-film calipers. The high sensitivity of this system originates from the plasmonic gap mode in the NP-film caliper, induced by electromagnetic coupling between the NPs and the film. The refractometric sensitivity of this NP-film caliper reaches up to 314 nm per RIU, which is superior to those of other NP-based sensors. The NP-film caliper also provides high dimensional resolution, down to the angstrom scale. In this study, the shift in wavelength in response to the change in gap spacing is approximately 9 nm Å(-1). Taking advantage of the ultrasensitivity of this NP-film caliper, we develop a platform for discriminating among thiol-containing amino acids.

Laser-induced jets of nanoparticles: exploiting air drag forces to select the particle size of nanoparticle arrays.

In this study, we developed a new method-based on laser-induced jets of nanoparticles (NPs) and air drag forces-to select the particle size of NP arrays. First, the incident wavelength of an excimer laser was varied to ensure good photo-to-thermal energy conversion efficiency. We then exploited air drag forces to select NPs with sizes ranging from 5 to 50 nm at different captured distances. Controlling the jet distances allowed us to finely tune the localized surface plasmon resonance (LSPR) wavelength. The shifting range of the LSPR wavelengths of the corresponding NP arrays prepared using the laser-induced jet was wider than that of a single NP or an NP dimer. We further calculated the relationship between the air drag force and the diameter of the NPs to provide good control over the mean NP size (capture size ≧ 300 µm) by varying the capture distance. Laser-induced jets of NPs could also be used to fabricate NP arrays on a variety of substrates, including Si, glass, plastic, and paper. This method has the attractive features of rapid, large-area preparation in an ambient environment, no need for further thermal annealing treatment, ready control over mean particle size, and high selectivity in the positioning of NP arrays. Finally, we used this method to prepare large NP arrays for acting hot spots on surface-enhanced Raman scattering-active substrates, and 10(-12) M R6G can be detected. Besides, we also prepare small NP arrays to act as metal catalysts for constructing low-reflection, broadband light trapping nanostructures on Si substrates.