Socially-supported sleep in older adults aged 50 and older: a concept analysis.

Introduction: The population of older adults is growing disproportionately, constituting 13% of the global population in 2022, and is expected to double by 2050. One of public health's priorities is healthy aging, the maintenance of functional ability aligned with well-being. As many as 50% of older adults report poor sleep quality, leading to an increased risk of morbidity and mortality. The quality and quantity of social relationships may broadly benefit sleep in older adults. However, the concept of socially-supported sleep is underdeveloped as a basis for intervention. Methods: Existing literature was searched without time restriction in PubMed, CINAHL, PsycINFO, and Scopus ending in August 2022. Thematic analysis was used to determine the defining attributes, antecedents, and consequences of socially-supported sleep guided by Rodgers' evolutionary concept analysis. Results: Twenty-nine articles written in English, peer-reviewed, and examined social support and sleep in participants aged ≥50 were included. The defining attributes reflect dimensions of sleep quality. The antecedents are safe and secure, belonging and connection, and warmth and comfort. The consequences of socially-supported sleep include improved regulatory capabilities, physical and emotional well-being, and quality of life. Conclusion: Socially-supported sleep has the potential to inform interventions that promote sleep in older adults. Ongoing research is needed to address the antecedents and mechanisms through which socially-supported sleep may promote sleep quality for healthy aging.

The fate and transport of neonicotinoid insecticides and their metabolites through municipal wastewater treatment plants in South China.

Neonicotinoid insecticides (NEOs) have gained widespread usage as the most prevalent class of insecticides globally and are frequently detected in the environment, posing potential risks to biodiversity and human health. Wastewater discharged from wastewater treatment plants (WWTPs) is a substantial source of environmental NEOs. However, research tracking NEO variations in different treatment units at the WWTPs after being treated by the treatment processes remains limited. Therefore, this study aimed to comprehensively investigate the fate of nine parent NEOs (p-NEOs) and five metabolites in two municipal WWTPs using distinct treatment processes. The mean concentrations of ∑NEOs in influent (effluent) for the UNITANK, anaerobic-anoxic-oxic (A2/O), and cyclic activated sludge system (CASS) processes were 189 ng/L (195 ng/L), 173 ng/L (177 ng/L), and 123 ng/L (138 ng/L), respectively. Dinotefuran, imidacloprid, thiamethoxam, acetamiprid, and clothianidin were the most abundant p-NEOs in the WWTPs. Conventional wastewater treatment processes were ineffective in removing NEOs from wastewater (-4.91% to -12.1%), particularly major p-NEOs. Moreover, the behavior of the NEOs in various treatment units was investigated. The results showed that biodegradation and sludge adsorption were the primary mechanisms responsible for eliminating NEO. An anoxic or anaerobic treatment unit can improve the removal efficiency of NEOs during biological treatment. However, the terminal treatment unit (chlorination disinfection tank) did not facilitate the removal of most of the NEOs. The estimated total amount of NEOs released from WWTPs to receiving waters in the Pearl River of South China totaled approximately 6.90-42.6 g/d. These findings provide new insights into the efficiency of different treatment processes for removing NEOs in current wastewater treatment systems.

Contamination of neonicotinoid insecticides in source water and their fate during drinking water treatment in the Dongguan section of the Pearl River.

Neonicotinoid insecticides (NEOs) as well as their metabolites are highly mobile on the subsurface and can potentially contaminate drinking water sources; however, their pollution status and fate in the drinking water system remains ambiguous. In this study, six parent NEOs and two characteristic metabolites were measured in drinking water source protection area (source water, n = 52) and two related drinking water treatment plants (DWTPs) (n = 88) located in the Dongguan section of the Pearl River. The ubiquitous of NEOs was observed in source water with the mean concentration of total NEOs (ΣNEOs) at 240 ng/L. Although advanced DWTP (A-DWTP; range: 26 % to 100 %) showed better removals of ΣNEOs and all individual NEOs rather than those in conventional DWTP (C-DWTP; range: -53 % to 28 %), the removals were still low for acetamiprid (ACE, 26 %), thiacloprid (THD, 59 %), thiamethoxam (THM, 56 %) and N-desmethyl-acetamiprid (N-dm-ACE, 45 %) in A-DWTP. Removal rates were positive in chlorination (48 %), final stage of sedimentation (F-Sed, 24 %), and granular activated carbon (GAC) filter effluent (19 %) in A-DWTP. It worthy to note that ΣNEOs has high negative removal rates at the start stage of sedimentation (S-Sed, -83 %), middle stage of sedimentation (M-Sed, -47 %), and sand filter effluent (-42 %) water in C-DWTP, which resulted in negative removals of ΣNEOs (-9.6 %), imidacloprid (IMI, -22 %), clothianidin (CLO, -37 %), flupyradifurone (FLU, -76 %), and N-dm-ACE (-29 %) in C-DWTP. Residual levels of NEOs were high in source water, and their low or negative removals in DWTPs should be highly concerning. Results would fill the existing knowledge gap of NEOs in aquatic environment and provide a scientific dataset for policy-making on pollution control and environmental protection.

Dietary fiber during gestation improves lactational feed intake of sows by modulating gut microbiota.

BACKGROUND: The feed intake of sows during lactation is often lower than their needs. High-fiber feed is usually used during gestation to increase the voluntary feed intake of sows during lactation. However, the mechanism underlying the effect of bulky diets on the appetites of sows during lactation have not been fully clarified. The current study was conducted to determine whether a high-fiber diet during gestation improves lactational feed intake (LFI) of sows by modulating gut microbiota. METHODS: We selected an appropriate high-fiber diet during gestation and utilized the fecal microbial transplantation (FMT) method to conduct research on the role of the gut microbiota in feed intake regulation of sows during lactation, as follows: high-fiber (HF) diet during gestation (n = 23), low-fiber (LF) diet during gestation (n = 23), and low-fiber diet + HF-FMT (LFM) during gestation (n = 23). RESULTS: Compared with the LF, sows in the HF and LFM groups had a higher LFI, while the sows also had higher peptide tyrosine tyrosine and glucagon-like peptide 1 on d 110 of gestation (G110 d). The litter weight gain of piglets during lactation and weaning weight of piglets from LFM group were higher than LF group. Sows given a HF diet had lower Proteobacteria, especially Escherichia-Shigella, on G110 d and higher Lactobacillus, especially Lactobacillus_mucosae_LM1 and Lactobacillus_amylovorus, on d 7 of lactation (L7 d). The abundance of Escherichia-Shigella was reduced by HF-FMT in numerically compared with the LF. In addition, HF and HF-FMT both decreased the perinatal concentrations of proinflammatory factors, such as endotoxin (ET), lipocalin-2 (LCN-2), tumor necrosis factor-α (TNF-α), and interleukin-1ß (IL-1ß). The concentration of ET and LCN-2 and the abundance of Proteobacteria and Escherichia-Shigella were negatively correlated with the LFI of sows. CONCLUSION: The high abundance of Proteobacteria, especially Escherichia-Shigella of LF sows in late gestation, led to increased endotoxin levels, which result in inflammatory responses and adverse effects on the LFI of sows. Adding HF during gestation reverses this process by increasing the abundance of Lactobacillus, especially Lactobacillus_mucosae_LM1 and Lactobacillus_amylovorus.

A Pilot Nationwide Survey on the Concentrations of Neonicotinoids and Their Metabolites in Indoor Dust from China: Application for Human Exposure.

The present study assessed the residue levels of six parent neonicotinoids (p-NEOs) and four metabolites (m-NEOs) in indoor dust collected from 12 cities of China. Acetamiprid (ACE) and imidacloprid (IMI) were the predominated p-NEOs (detection rates: 98%) with the median values at 4.54 and 7.48 ng/g dry weight (dw), respectively. N-demethyl-acetamiprid (N-dm-ACE) was the most important m-NEO with the median value at 0.69 ng/g dw, while other m-NEOs were rarely detected (detection rates: < 15%). Significant correlation between ACE and thiacloprid (THD) was observed (p < 0.01), indicating their probably concurrent applications. ACE was significantly correlated to N-dm-ACE (p < 0.01), implicating the degradation of ACE in indoor environment. The estimated daily intake (EDIing) of NEOs via dust ingestion were far lower than the acceptable daily intake for NEOs. To our knowledge, this study provided a baseline nationwide investigation on the occurrence of NEOs in indoor dust of China.

Effects of Corn and Broken Rice Extrusion on the Feed Intake, Nutrient Digestibility, and Gut Microbiota of Weaned Piglets.

In this study, we investigated the effects of corn and rice extrusion diets on feed intake, nutrient digestibility, and gut microbiota in weaned piglets. Animals were divided into four dietary groups and fed a controlled diet containing (1) 62.17% corn (CORN), 15% soybean, 10% extruded full-fat soybean, and 6% fishmeal (2) half the corn replaced by extruded corn (ECORN), (3) broken rice (RICE), and (4) extruded broken rice (ERICE) for 28 days. Rice supplementation increased dry matter total tract digestibility and gross energy. Extruded cereals generated a lower average daily feed intake (ADFI) at 15-28 and 1-28 days, decreased average daily growth (ADG) at 15-28 and 1-28 days, and a lowered body weight (BW) on day 28, regardless of cereal type. Dietary extruded cereals increased the appetite-regulating hormones glucagon-like peptide-1 (GLP-1) and peptide YY (PYY). Piglets fed extruded cereals displayed low short-chain fatty acid (SCFA) levels in plasma and low Lactobaillaceae and Bifidobateriaceae levels in feces, whereas a higher abundance of the potential pathogens Sarcina, Clostridium_sensu_strictio_1 and Terrisporobacter was observed. Piglets fed extruded cereals displayed significantly lower gas and SCFA levels during in vitro fermentation. Combined, 50% corn substituted with extruded corn or broken rice decreased piglet growth performance, possibly by altering their microbiota.

Long-term maternal intake of inulin exacerbated the intestinal damage and inflammation of offspring rats in a DSS-induced colitis model.

This study aimed to investigate the effects of long-term maternal intake of inulin on intestinal morphology, permeability, inflammation and microbiota of offspring rats treated with dextran sulfate sodium (DSS). Sixteen female adult Sprague-Dawley rats were assigned to two groups receiving the fiber-free diet (FFD) or inulin diet (INU, 5% inulin) for three parities. The offspring weaned rats (third-parity) were fed with the same diet for four weeks until receiving 6% DSS for 7 days; the four groups were as follows: FFD, FFD + DSS, INU and INU + DSS. The results showed that maternal intake of inulin increased the histopathology score and activity of diamine oxidase (DAO) in serum, and the highest histopathology scores and activity of DAO were observed in INU + DSS rats. Maternal intake of inulin increased the activity of myeloperoxidase (MPO), mRNA expressions of inflammatory factors and protein expression of IL-1ß in colonic tissues. Likewise, INU + DSS rats had the highest activity of MPO and mRNA expressions of inflammatory factors in colonic tissues. Maternal intake of inulin increased the abundances of Bacteroidetes, Bacteroides and Parasutterella, which were the highest enriched in INU + DSS rats. The level of acetate in the colonic digesta of INU + DSS rats was lower than that in FFD and INU rats. These results indicated that long-term maternal intake of inulin exacerbated the intestinal damage and inflammation of DSS-induced offspring rats, associated with the decreased level of acetate and altered intestinal microbiota.

Maternal Long-Term Intake of Inulin Improves Fetal Development through Gut Microbiota and Related Metabolites in a Rat Model.

Adequate dietary fiber intake during gestation is critical for maternal-fetal health. This experiment aims to uncover the impacts of maternal long-term intake of inulin on fetal development and its underlying mechanism. Eighty female Sprague-Dawley rats were randomly assigned to two groups receiving either a fiber-free diet or an inulin diet (inulin) for three parities. On the 19th day of pregnancy in the third parity, blood, intestinal, placental, and colonic digesta samples were collected. Results showed that maternal intake of inulin significantly decreased the within-litter birth weight variation in parities 2 and 3. Inulin intake modified the gut microbiome profiles and elevated the colonic contents of short chain fatty acids (propionate and butyrate). Inulin decreased the serotonin (5-HT) concentration in the colon, whereas it increased the 5-HT concentrations in serum and placenta and the number of 5-HT+ enterochromaffin cells in the colon. The protein expression of melatonin-synthesizing enzyme (arylalkylamine N-acetyltransferase) and the melatonin concentration in the placenta were also increased by inulin. Inulin improved the placental redox status and nutrient transport. These findings indicated that maternal long-term intake of inulin improves fetal development by altering the intestinal microbiota and related metabolites in rats.

An integrated ICP-MS-based analytical approach to fractionate and characterize ionic and nanoparticulate Ce species.

Cerium dioxide nanoparticles (CeO2 NPs) are widely used in various fields, leading to concern about their effect on human health. When conducting in vivo investigations of CeO2 NPs, the challenge is to fractionate ionic Ce and CeO2 NPs and to characterize CeO2 NPs without changing their properties/state. To meet this challenge, we developed an integrated inductively coupled plasma-mass spectrometry (ICP-MS)-based analytical approach in which ultrafiltration is used to fractionate ionic and nanoparticulate Ce species while CeO2 NPs are characterized by single particle-ICP-MS (sp-ICP-MS). We used this technique to compare the effects of two sample pretreatment methods, alkaline and enzymatic pretreatments, on ionic Ce and CeO2 NPs. Results showed that enzymatic pretreatment was more efficient in extracting ionic Ce or CeO2 NPs from animal tissues. Moreover, results further showed that the properties/states of all ionic and nanoparticulate Ce species were well preserved. The rates of recovery of both species were over 85%; the size distribution of CeO2 NPs was comparable to that of original NPs. We then applied this analytical approach, including the enzymatic pretreatment and ICP-MS-based analytical techniques, to investigate the bioaccumulation and biotransformation of CeO2 NPs in mice. It was found that the thymus acts as a "holding station" in CeO2 NP translocation in vivo. CeO2 NP biotransformation was reported to be organ-specific. This is the first study to evaluate the impact of enzymatic and alkaline pretreatment on Ce species, namely ionic Ce and CeO2 NPs. This integrated ICP-MS-based analytical approach enables us to conduct in vivo biotransformation investigations of CeO2 NPs.

Effects of Melatonin Supplementation during Pregnancy on Reproductive Performance, Maternal-Placental-Fetal Redox Status, and Placental Mitochondrial Function in a Sow Model.

Melatonin (MT) is a bio-antioxidant that has been widely used to prevent pregnancy complications, such as pre-eclampsia and IUGR during gestation. This experiment evaluated the impacts of dietary MT supplementation during pregnancy on reproductive performance, maternal-placental-fetal redox status, placental inflammatory response, and mitochondrial function, and sought a possible underlying mechanism in the placenta. Sixteen fifth parity sows were divided into two groups and fed each day of the gestation period either a control diet or a diet that was the same but for 36 mg of MT. The results showed that dietary supplementation with MT increased placental weight, while the percentage of piglets born with weight < 900 g decreased. Meanwhile, serum and placental MT levels, maternal-placental-fetal redox status, and placental inflammatory response were increased by MT. In addition, dietary MT markedly increased the mRNA levels of nutrient transporters and antioxidant-related genes involved in the Nrf2/ARE pathway in the placenta. Furthermore, dietary MT significantly increased ATP and NAD+ levels, relative mtDNA content, and the protein expression of Sirt1 in the placenta. These results suggested that MT supplementation during gestation could improve maternal-placental-fetal redox status and reproductive performance by ameliorating placental antioxidant status, inflammatory response, and mitochondrial dysfunction.

Live yeast supplementation during late gestation and lactation affects reproductive performance, colostrum and milk composition, blood biochemical and immunological parameters of sows.

This study was conducted to evaluate the effects of dietary live yeast (LY) supplementation during late gestation and lactation on reproductive performance, colostrum and milk composition, blood biochemical and immunological parameters of sows. A total of 40 multiparous sows were randomly fed either the control (CON) diet or the CON diet supplemented with LY at 1 g/kg from d 90 of gestation to weaning. Results showed that the number of stillborn piglets and low BW piglets were significantly decreased in the LY-supplemented sows compared with sows in the CON group (P < 0.05). Moreover, the concentrations of protein, lactose and solids-not-fat were increased in the colostrum of LY-supplemented sows (P < 0.05). Interestingly, the plasma activities of aspartate aminotransferase (AST), alkaline phosphatase (ALP), gamma-glutamyl transpeptidase (γ-GGT) at d 1 of lactation and alanine aminotransferase (ALT) at weaning day were decreased by feeding LY diet (P < 0.05). Meanwhile, sows fed LY diet had higher plasma concentration of immunoglobulin G compared with sows fed CON diet at d 1 of lactation (P < 0.05). In conclusion, LY supplementation in maternal diets decreased the number of stillborn piglets and low BW piglets, improved colostrum quality and health status of sows.

Triclosan and triclocarbon in maternal-fetal serum, urine, and amniotic fluid samples and their implication for prenatal exposure.

Triclosan (TCS) and Triclocarbon (TCC) are chlorinated synthetic antimicrobial agents formaternal urinelated in quantities of consumer products. However, the biomonitoring of direct exposure reflection for fetuses are rare. In this study, we determine the concentrations of TCS and TCC in paired maternal serum, cord serum, maternal urine, and amniotic fluid samples collected from a cohort of 95 expecting mother-fetal pairs in Southern China. TCS and TCC are detected widely (detection rates: >76.9%) in maternal serum, cord serum, maternal urine, and amniotic fluid samples. TCS is found to be the predominant antimicrobial agent with median concentrations in maternal serum (1.5 ng/mL) and cord serum (1.8 ng/mL) that are one order of magnitude higher than those of tcc in maternal serum (0.085 ng/mL) and cord serum (0.052 ng/mL), respectively. Cord serum concentrations of tcs and tcc correlated well with the concentrations in maternal serum, which reflect the mothers' contribution to fetal exposure. The higher median ratio of cord serum/maternal serumTCS (0.95) compared to that of cord serum/maternal serumTCC (0.53) indicates high placental transmission ability of TCS. Moreover, the facility to penetrate the placental barrier and hard to depurate characteristics lead to the long residence of TCS in the fetal environment, causing great concern over the prenatal exposure risks during the critical window of fetal development. This study provides a novel contribution by increasing existing knowledge on the exposure assessment of TCS and TCC during pregnancy through the exploration of matched maternal-fetal samples.

Urinary Metabolites of Neonicotinoid Insecticides: Levels and Recommendations for Future Biomonitoring Studies in China.

Neonicotinoids (NEOs) are insecticides that are widely used around the world. Following exposure, NEOs get metabolized in human bodies. The biomarkers to assess human NEO exposure are not well described because of the lack of information on the metabolites of NEOs (m-NEOs). In this study, five m-NEOs including N-desmethyl-acetamiprid (N-dm-ACE), 5-hydroxy-imidacloprid (5-OH-IMI), olefin-imidacloprid (Of-IMI), 1-methyl-3-(tetrahydro-3-furylmethyl) guanidine (DIN-G), and 1-methyl-3-(tetrahydro-3-furylmethyl) (DIN-U) were measured in 275 urine samples collected from 10 cities in China. All of the m-NEOs were frequently detected in urine samples with the median concentrations ranging from 0.42 (DIN-G) to 1.02 (5-OH-IMI) ng/mL. The urinary concentrations of N-dm-ACE and 5-OH-IMI measured in China were higher than those reported from Japan and the USA. In comparison to the parent NEO (i.e., acetamiprid, ACE; imidacloprid, IMI; and dinotefuran, DIN) concentrations reported in the same set of samples by our research group, the median ratios of m-NEO to the corresponding parent NEO (m-NEO/NEO) ranged from 4.95 (DIN-G/DIN) to 37.7 (N-dm-ACE/ACE), indicating that NEOs are mainly present as metabolites rather than the parent forms. Furthermore, the ratio of Σm-NEOs/ΣNEOs was significantly (p < 0.01) higher in females than in males, suggesting that NEOs are more readily metabolized in females or females are more highly exposed to m-NEOs. To our knowledge, this is the first study to measure Of-IMI, DIN-G, and DIN-U levels in urine samples from China. We recommend biomonitoring studies to include N-dm-ACE, 5-OH-IMI, and DIN-U (and DIN-G) for clear understanding of human exposure to ACE, IMI, and DIN, respectively.

Novel and legacy poly- and perfluoroalkyl substances (PFASs) in indoor dust from urban, industrial, and e-waste dismantling areas: The emergence of PFAS alternatives in China.

With the phase out of perfluorooctanesulfonate (PFOS) and perfluorooctanoic acid (PFOA), the composition profiles of poly- and perfluoroalkyl substance (PFAS) in our living environment are unclear. In this study, 25 PFASs were analyzed in indoor dust samples collected from urban, industrial, and e-waste dismantling areas in China. PFOS alternatives, including 6:2 chlorinated polyfluorinated ether sulfonate (6:2 Cl-PFESA) (median: 5.52 ng/g) and 8:2 chlorinated polyfluorinated ether sulfonate (8:2 Cl-PFESA) (1.81 ng/g), were frequently detected. By contrast, PFOA alternatives, such as hexafluoropropylene oxide dimer acid (HPFO-DA, Gen-X) and ammonium 4,8-dioxa-3H-perfluorononanoate (ADONA), were not found in any of the dust samples. As expected, all legacy PFASs were widely observed in indoor dust, and 4 PFAS precursors were also detected. Dust concentrations of 6:2 Cl-PFESA were strongly correlated (p < 0.05) with those of 8:2 Cl-PFESA regardless of sampling sites. 6:2 Cl-PFESA was also significantly associated with that of PFOS in industrial and e-waste (p < 0.01) areas. Association analysis suggested that the sources of PFOS and its alternatives are common or related. Although ∑Cl-PFESA concentration was lower than that of PFOS (17.4 ng/g), industrial areas had the highest 6:2 Cl-PFESA/PFOS ratio (0.63). Composition profiles of PFASs in the industrial area showed the forefront of fluorine change. Thus, the present findings suggested that Cl-PFESAs are widely used as PFOS alternatives in China, and high levels of human Cl-PFESA exposure are expected in the future. Short-chain PFASs (C4-C7) were the predominant PFASs found in dust samples, contributing to over 40% of ∑total PFASs. Furthermore, perfluoro-1-butanesulfonate/PFOS and perfluoro-n-butanoic acid (PFBA)/PFOA ratios were 2.8 and 0.72, respectively. These findings suggested shifting to the short-chain PFASs in the environment in China. To the authors knowledge this is the first study to document the levels of 6:2 Cl-PFESA, 8:2 Cl-PFESA in indoor dust.

Occurrence and transfer of benzophenone-type ultraviolet filters from the pregnant women to fetuses.

Benzophenone (BP)-type ultraviolet (UV) filters are widely used in personal care products. Some of them have been identified as endocrine disrupting chemicals. However, little is known about the occurrence of BP-type UV filters in paired maternal-fetal samples. In this study, we investigated the occurrence of eight BP-type UV filters in paired maternal-fetal samples collected from Southern China. Among target analytes, only benzophenone-3 (BP-3) was frequently (detection rate > 80%) detected in maternal-fetal samples, i.e., maternal serum (MS), cord serum (CS), maternal urine (MU) and amniotic fluid (AF). BP-3 was the dominant compound in MS (median: 0.14 ng/mL), CS (0.16) and AF (0.12); whereas MU was dominated by benzophenone-1 (BP-1, 2.85). The median CS/MS ratios (i.e., placental transfer rates) of 4-hydroxy benzophenone (4-OH-BP, 2.35), BP-1 (1.52), benzophenone-4 (BP-4, 1.06), and BP-3 (1.03) were higher than 1.0, suggesting that exposure levels of these chemicals in fetuses were greater than those in mothers. Significant positive correlations (r = 0.667, p < 0.001) of BP-3 concentrations were found between MS and CS, which suggested that MS could be an indicator of fetal exposure to BP-3. Furthermore, the CS/MS ratios of 4-OH-BP, BP-1, BP-3, and benzophenone-8 (BP-8) increased with decreasing molecular weight or log Kow. Passive diffusion may play an important role in placental transfer of these BP type UV filters. The MU/MSBP-3 ratio (5.86) was relatively higher than that of MU/MSBP-1 (0.89), which indicated that BP-3 excretes rapidly in urine. The present study documents the occurrence of eight BP-type UV filters in matched MS, CS, MU and AF samples for the first time in China.

Integration of sub-organ quantitative imaging LA-ICP-MS and fractionation reveals differences in translocation and transformation of CeO2 and Ce3+ in mice.

Information on the risk of exposure to cerium oxide (CeO2) nanoparticles (NPs) is limited. To assess risk, we must know where and how such NPs are distributed to the body after exposure, both short- and long-term. In this work, an integrated approach of quantitative LA-ICP-MS bioimaging and fractionation was employed to study the translocation and transformation of CeO2 and Ce3+ in mouse spleen and liver. The complementary information retrieved by the two techniques above on the accumulation of Ce and dissolution/aggregation were found consistent. In brief, a detailed fine scanning of a region of interest in the organ was performed after fast-screening at low spatial resolution. In the spleen, after short-term high-dose exposure, CeO2 NPs was found mainly in the marginal zone and caused an up-regulation of Zn in the white pulp. After long-term low-dose exposure, CeO2 was found in the marginal zone and white pulp. In the liver, CeO2 NPs were mainly distributed in the Kupffer cells and lobule periphery. The high spatial resolution LA maps of H&E-stained liver sections allowed imaging close to cell level; this enabled an estimation of Ce content in Kupffer cells. Furthermore, fractionation by ultrafiltration was also employed to differentiate the ionic and NP species in the organs. This fractionation showed aggregation of Ce ions in spleen, supporting the LA-ICP-MS results. Transmission electron microscopy revealed that long-term CeO2 exposure triggered an immune response to infection in the spleen and confirmed the differential deposition of Ce in the marginal zone. The integrated analyses based on ICP-MS together with histology and TEM investigation suggests that long-term low doses of CeO2 NPs may cause toxicity in the liver and impair functions of the immune system.

Cavity spatial mode-locking and high controllability of radial output coupling for circular/square plasmonic nano-resonator lasers.

We proposed and investigated a novel output coupling scheme for a circular and a square plasmonic nano-ring laser based on a T-shaped radial coupler that is easier to realize than a tangential coupler. The amount of coupling efficiency is shown to be highly controllable from a few percent to tens of percents. This is due to the fact that the standing-wave lasing mode pattern will rotate to give the minimal cavity loss at the T-coupler's location, making the amount of output coupling surprisingly low and hence, controllable. For a non-circular cavity, other symmetry-breaking and geometry-induced scattering could result in separate mode-pattern locking. These give a few main ways to control and optimize the coupling efficiency: via widening/narrowing or rotating the T-coupler's waveguide, or, for the case of a non-circular cavity, via shifting the location of the T-coupler. We observed increased unidirectional lasing induced by either rotating the waveguide or shifting it (for non-circular cases). We simulated the coupling using Maxwell's equations based on the multi-level multi-electron FDTD (MLME-FDTD) method to realistically model the lasing and output coupling behaviors of such plasmonic semiconductor lasers.

Silicon/III-V laser with super-compact diffraction grating for WDM applications in electronic-photonic integrated circuits.

We have demonstrated a heterogeneously integrated III-V-on-Silicon laser based on an ultra-large-angle super-compact grating (SCG). The SCG enables single-wavelength operation due to its high-spectral-resolution aberration-free design, enabling wavelength division multiplexing (WDM) applications in Electronic-Photonic Integrated Circuits (EPICs). The SCG based Si/III-V laser is realized by fabricating the SCG on silicon-on-insulator (SOI) substrate. Optical gain is provided by electrically pumped heterogeneous integrated III-V material on silicon. Single-wavelength lasing at 1550 nm with an output power of over 2 mW and a lasing threshold of around 150 mA were achieved.