Single-molecule Detection in Nanogap-embedded Plasmonic Gratings

We introduce nanogap-embedded silver plasmonic gratings for single-molecule (SM) visualization using an epifluorescence microscope. This silver plasmonic platform was fabricated by a cost-effective nano-imprint lithography technique, using an HD DVD template. DNA/RNA duplex molecules tagged with Cy3/Cy5 fluorophores were immobilized on SiO2-capped silver gratings. Light was coupled to the gratings at particular wavelengths and incident angles to form surface plasmons. The SM fluorescence intensity of the fluorophores at the nanogaps showed approximately a 100-fold mean enhancement with respect to the fluorophores observed on quartz slides using an epifluorescence microscope. This high level of enhancement was due to the concentration of surface plasmons at the nanogaps. When nanogaps imaged with epifluorescence mode were compared to quartz imaged using total internal reflection fluorescence (TIRF) microscopy, more than a 30-fold mean enhancement was obtained. Due to the SM fluorescence enhancement of plasmonic gratings and the correspondingly high emission intensity, the required laser power can be reduced, resulting in a prolonged detection time prior to photobleaching. This simple platform was able to perform SM studies with a low-cost epifluorescence apparatus, instead of the more expensive TIRF or confocal microscopes, which would enable SM analysis to take place in most scientific laboratories

Epidemiology of birth defects based on a birth defects surveillance system in southwestern China and the associated risk factors

BackgroundBirth defects (BDs) are associated with many potential risk factors, and its causes are complex.ObjectivesThis study aimed to explore the epidemiological characteristics of BDs in Guangxi of China and the associated risk factors of BDs.MethodsBDs data of perinatal infants (PIs) were obtained from the Guangxi birth defects monitoring network between 2016 and 2020. Univariate Poisson regression was used to calculate the prevalence-rate ratios (PRR) to explore the changing trends of BDs prevalence by year and the correlation between the regarding of characteristics of BDs (including infant gender, maternal age, and quarter) and BDs. Clinical characteristics of PIs with BDs and general characteristics of their mothers were documented, and Spearman correlation analysis was used to explore the potential associated risk factors of BDs.ResultsBetween 2016 and 2020, 44,146 PIs with BDs were monitored, with an overall BDs prevalence of 121.71 (95% CI: 120.58–122.84) per 10,000 PIs, showing a significant increase trend (PRR = 1.116, 95% CI: 1.108–1.123), especially the prevalence of congenital heart defects (CHDs) that most significantly increased (PRR = 1.300, 95% CI: 1.283–1.318). The 10 most common BDs were CHDs, polydactyly, congenital talipes equinovarus, other malformation of external ear, syndactyly, hypospadias, cleft lip with cleft palate, cleft lip, hemoglobin Bart's hydrops fetalis syndrome (BHFS), and congenital atresia of the rectum and anus. BDs were positively correlated with pregnant women's age (R = 0.732, P < 0.01) and education level (R = 0.586, P < 0.05) and having pre-gestational diabetes mellitus (PGDM)/gestational diabetes mellitus (GDM) (R = 0.711, P < 0.01), while when the pregnant women had a family history of a dead fetus (R = −0.536, P < 0.05) and a birth of a fetus with BDs (R = −0.528, P < 0.05) were negatively correlated with BDs.ConclusionA significant increase in the prevalence of BDs was detected between 2016 and 2020 in Guangxi, especially the prevalence of CHDs that most significantly increased. Older maternal age, higher maternal education level, and having PGDM before pregnancy or GDM in early pregnancy were the risk factors for BDs

Distribution, degradation and dynamics of dissolved organic carbon and its major compound classes in the Pearl River estuary, China

We investigated the distribution, degradation and dynamics of organic carbon and its major compound classes, carbohydrates and amino acids, based upon a cruise in the Pearl River estuary in April 2007. Dissolved oxygen (DO), nutrients, particulate organic carbon (POC), chlorophyll a (Chl a), dissolved organic carbon (DOC), total dissolved carbohydrates (TCHO, including monosaccharides, MCHO, and polysaccharides, PCHO) as well as total dissolved amino acids (TAA, both dissolved free, DFAA, and combined components. DCAA) were measured along a salinity gradient. Community respiration and biodegradable DOC were also determined via both short term (within 3 days) and long term (lasting 30 days) incubation. DOC, MCHO, TCHO, DFAA and TAA concentrations were high in the upper reach of the Pearl River estuary and decreased rapidly downstream. Anthropogenic sewage input appeared to be an important source of the DOC pool in the upper estuary. DOC distribution was non-conservative during the estuarine mixing, showing a net consumption of DOC in the upper reach and in the low salinity (S<20) region of the Pearl River estuary. Changes in the relative compositions of carbohydrates (MCHO vs. PCHO) and amino acids (DFAA vs. DCAA) along the salinity gradient further indicated that different processes (biodegradation, flocculation, and phytoplankton production) had different influences on distributions of organic compound classes in this estuarine system. Our one-month incubation experiment further revealed that a substantial portion (15-45%) of DOC from the estuary was biodegradable. Bacterial respiration rates were much higher (0.12-5.8 mu mol O-2 L-1 h(-1)) than the DOC consumption rates, suggesting that there were other oxygen consumption processes, such as nitrification besides the aerobic respiration of organic matter in the Pearl River estuary, as inferred by the distribution of NH4+ and NO3-. We estimated that 5.3 x 10(8) g C d(-1) of DOC can be exported out from the Lingdingyang Bay (a major subestuary of the Pearl River estuary) to the continental shelf of the South China Sea during this low flow season. (C) 2009 Elsevier B.V. All rights reserved.Natural Science Foundation of China [40576036, 90711005, 40821063

Genome encode analyses reveal the basis of convergent evolution of fleshy fruit ripening

Altres ajuts: Generalitat de Catalunya/CERCA ProgrammeFleshy fruits using ethylene to regulate ripening have developed multiple times in the history of angiosperms, presenting a clear case of convergent evolution whose molecular basis remains largely unknown. Analysis of the fruitENCODE data consisting of 361 transcriptome, 71 accessible chromatin, 147 histone and 45 DNA methylation profiles reveals three types of transcriptional feedback circuits controlling ethylene-dependent fruit ripening. These circuits are evolved from senescence or floral organ identity pathways in the ancestral angiosperms either by neofunctionalisation or repurposing pre-existing genes. The epigenome, H3K27me3 in particular, has played a conserved role in restricting ripening genes and their orthologues in dry and ethylene-independent fleshy fruits. Our findings suggest that evolution of ripening is constrained by limited hormone molecules and genetic and epigenetic materials, and whole-genome duplications have provided opportunities for plants to successfully circumvent these limitations

Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat

Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat

Correction to: Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

The original version of this article unfortunately contained a mistake

Plasmonic platform for super-resolution imaging and applications in biological and nanoenergetic systems

Field of study: Electrical and computer engineering.Dr. Shubhra Gangopadhyay, Dr. Matthew R. Maschmann, Dissertation Supervisors.Includes vita."December 2017."Plasmonics, taking advantages of coupling photons to free electrons in metals, enables prominent electromagnetic field enhancements by concentrating light into subwavelength scales, allowing super resolution imaging, enhancement of fluorescence and photothermal heating. In this dissertation, a plasmonic grating platform prepared by nano-imprint lithography was introduced for imagingnanostructures, biological materials, and diagnostics of nanoenergetic systems. First, a glancing angledeposition technique was developed to combine periodic gratings with nano-protrusion for single moleculesuper-resolution imaging for dye-labeled DNA/RNA duplex in wide dye concentrations. The combination of the plasmonic probes and localization microscopy can resolve features as small as 65 nm. Then, the subwavelength nanoparticles with various shapes were studied by different super-resolution approaches. Further, the plasmonic grating microchips facilitate a robust in-situ diagnostic platform for the laser-induced photothermal heating and combustion of aluminum nanoparticles (Al NPs)-fluoropolymer nanoenergetic films. A fluorescence-based temperature sensor with temperature-sensitive dye was developed for dynamic thermal mapping at the nanoscale. The plasmonic grating enables visualization and initialization of localized nano-flames whose temperatures were obtained by two-color pyrometry. Scattering measurements enabled precise identification of individual Al NPs over a large field of view, leading to 3D reconstruction of combustion eventsIncludes bibliographical references (pages 201-208)

Bagged Tree Model to Retrieve Planetary Boundary Layer Heights by Integrating Lidar Backscatter Profiles and Meteorological Parameters

The planetary boundary layer (PBL) is the part of the troposphere in which the soil’s influence is noticeable. It plays an important role in the fields of air pollution, meteorology, weather forecasting, and climate. Continuous observation of lidar makes obtaining the day–night PBL height (PBLH) with a high temporal resolution possible. A high-precision PBLH retrieval method is the key to achieving this goal. In this study, we propose a new method based on a bagged tree model to retrieve the PBLH from micro-lidar backscatter profiles. With the radiosonde measurements taken as the true reference, lidar features (the ten maximum slopes identified by the maximum gradient method) and four meteorological parameters (atmospheric pressure, temperature, relative humidity, and wind speed) serve as characteristic variables. The PBLH retrieval model is evaluated using a 10-fold cross-validation (CV) method and then compared with the four traditional methods (i.e., maximum gradient, maximum standard deviation, wavelet covariance, and the ideal profile method). The correlation coefficient (R) between the retrieved PBLHs and the radiosonde measurements is 0.89, which is much bigger than the R (0.2–0.48) from the four traditional methods. Moreover, the root mean square error and mean absolute error for the retrieved PBLH are 0.3 km and 0.2 km, respectively, which are lower than those of the four traditional methods (0.5~0.6 km for RMSE and 0.4–0.5 for MAE). Cases with different conditions show that this new method is almost undisturbed by cloud and suspended/thick aerosol layers. It can also be used to retrieve shallow PBL in cases in which using traditional methods would be difficult. Long-term analysis of averaged PBLHs retrieved by the proposed model from 2013 to 2016 shows that the hourly PBLH rises at sunrise and sets at sunset, and that the monthly PBLH in summer is higher than that in winter. The results suggest that the proposed method is better than the four traditional methods and available for use in conditions such as existing cloud layers and multiple-layers