Metal-Organic Framework Derived Bi-O-Sn/C Nanostructure: Tailoring the Adsorption Site of Dominant Intermediate for Highly Efficient CO2 Electroreduction to Formate.

Electrochemical CO2 reduction into high-value-added formic acid/formate is an attractive strategy to mitigate global warming and achieve energy sustainability. However, the adsorption energy of most catalysts for the key intermediate *OCHO is usually weak, and how to rationally optimize the adsorption of *OCHO is challenging. Here, an effective Bi-Sn bimetallic electrocatalyst (Bi1 -O-Sn1 @C) where a Bi-O-Sn bridge-type nanostructure is constructed with O as an electron bridge is reported. The electronic structure of Sn is precisely tuned by electron transfer from Bi to Sn through O bridge, resulting in the optimal adsorption energy of intermediate *OCHO on the surface of Sn and the enhanced activity for formate production. Thus, the Bi1 -O-Sn1 @C exhibits an excellent Faradaic efficiency (FE) of 97.7% at -1.1 V (vs RHE) for CO2 reduction to formate (HCOO- ) and a high current density of 310 mA cm-2 at -1.5 V, which is one of the best results catalyzed by Bi- and Sn-based catalysts reported previously. Impressively, the FE exceeds 93% at a wide potential range from -0.9 to -1.4 V. In-situ ATR-FTIR, in-situ Raman, and DFT calculations confirm the unique role of the bridge-type structure of Bi-O-Sn in highly efficient electrocatalytic reduction of CO2 into formate.

Soliton Microcombs Multiplexing Using Intracavity-Stimulated Brillouin Lasers.

Solitons in microresonators have spurred intriguing nonlinear optical physics and photonic applications. Here, by combining Kerr and Brillouin nonlinearities in an over-modal microcavity, we demonstrate spatial multiplexing of soliton microcombs under a single external laser pumping operation. This demonstration offers an ideal scheme to realize highly coherent dual-comb sources in a compact, low-cost and energy-efficient manner, with uniquely low beating noise. Moreover, by selecting the dual-comb modes, the repetition rate difference of a dual-comb pair could be flexibly switched, ranging from 8.5 to 212 MHz. Beyond dual-comb, the high-density mode geometry allows the cascaded Brillouin lasers, driving the co-generation of up to 5 space-multiplexing frequency combs in distinct mode families. This Letter offers a novel physics paradigm for comb interferometry and provides a widely appropriate tool for versatile applications such as comb metrology, spectroscopy, and ranging.

General learning ability in perceptual learning.

Developing expertise in any field usually requires acquisition of a wide range of skills. Most current studies on perceptual learning have focused on a single task and concluded that learning is quite specific to the trained task, and the ubiquitous individual differences reflect random fluctuations across subjects. Whether there exists a general learning ability that determines individual learning performance across multiple tasks remains largely unknown. In a large-scale perceptual learning study with a wide range of training tasks, we found that initial performance, task, and individual differences all contributed significantly to the learning rates across the tasks. Most importantly, we were able to extract both a task-specific but subject-invariant component of learning, that accounted for 38.6% of the variance, and a subject-specific but task-invariant perceptual learning ability, that accounted for 36.8% of the variance. The existence of a general perceptual learning ability across multiple tasks suggests that individual differences in perceptual learning are not "noise"; rather, they reflect the variability of learning ability across individuals. These results could have important implications for selecting potential trainees in occupations that require perceptual expertise and designing better training protocols to improve the efficiency of clinical rehabilitation.

Confirmation of Natural Hybridization between Kengyilia (StStYYPP) and Campeiostachys (StStYYHH) (Triticeae: Poaceae) Based on Morphological and Molecular Cytogenetic Analyses.

Natural hybridization has been frequently observed in Triticeae; however, few studies have investigated the origin of natural intergeneric Triticeae hybrids. In the present study, we discovered three putative hybrid Triticeae plants in the Western Sichuan Plateau of China. Morphologically, the putative hybrids were intermediate between Kengyilia melanthera (2n = 6x = 42; StStYYPP) and Campeiostachys dahurica var. tangutorum (2n = 6x = 42; StStYYHH) with greater plant height and tiller number. Cytological analyses demonstrated that the hybrids were hexaploid with 42 chromosomes (2n = 6x = 42). At metaphase I, 12.10-12.58 bivalents and 13.81-14.18 univalents per cell were observed in the hybrid plants. Genomic in situ hybridization demonstrated that the hybrids had StStYYHP genomes. Phylogenetic analysis of Acc1 sequences indicated that the hybrids were closely related to K. melanthera and C. dahurica var. tangutorum. Our morphological, cytological, and molecular analyses indicate that these hexaploid natural hybrid plants may be hybrids of K. melanthera and C. dahurica var. tangutorum.

High energy and low noise soliton fiber laser comb based on nonlinear merging of Kelly sidebands.

Optical solitons in mode-locked laser cavities with dispersion-nonlinearity interaction, delivers pulses of light that retain their shape. Due to the nature of discretely distributed dispersion and nonlinearity, optical solitons can emit Kelly-sidebands via the frequency coupling of soliton and dispersive waves. In this paper, we generate a high-energy femtosecond laser comb, by using the intracavity Kelly radiations and 3rd order nonlinearities. By increasing the intracavity power, the soliton envelop and the Kelly-sidebands merge together via four-wave-mixing, forming a super-continuum spectrum, obtaining 3.18 nJ pulse energy. A supercontinuum span covering from 1100 nm to 2300 nm for further self-referenced f-2f stabilization can be directly achieved by using an amplification-free external supercontinuum technique. Our finding not only demonstrates a non-trivial frequency-time evolution based on 'erbium + χ(3)' nonlinear gains, but also offers a new opportunity to develop practically compact fiber frequency combs for frequency metrology or spectroscopy.

Identifying Long- and Short-Term Processes in Perceptual Learning.

Practice makes perfect in almost all perceptual tasks, but how perceptual improvements accumulate remains unknown. Here, we developed a multicomponent theoretical framework to model contributions of both long- and short-term processes in perceptual learning. Applications of the framework to the block-by-block learning curves of 49 adult participants in seven perceptual tasks identified ubiquitous long-term general learning and within-session relearning in most tasks. More importantly, we also found between-session forgetting in the vernier-offset discrimination, face-view discrimination, and auditory-frequency discrimination tasks; between-session off-line gain in the visual shape search task; and within-session adaptation and both between-session forgetting and off-line gain in the contrast detection task. The main results of the vernier-offset discrimination and visual shape search tasks were replicated in a new experiment. The multicomponent model provides a theoretical framework to identify component processes in perceptual learning and a potential tool to optimize learning in normal and clinical populations.

Clinical-pathological characteristics and prognostic factors for malignant peritoneal mesothelioma in the elderly.

BACKGROUND: Malignant peritoneal mesothelioma (MPM) is a rare disease characterized by atypical symptoms, difficult diagnosis, variable course and poor prognosis, and it develops mainly in elderly individuals. The authors aimed to identify the clinical-pathological characteristics, prognosis, and prognostic factors in elderly MPM patients. METHODS: From the National Cancer Institute Surveillance Epidemiology End Results (SEER) database, 1492 patients with MPM from 1975 to 2016 were selected and divided into the elderly group (≥ 65) and the adult group (< 65). We compared the clinical-pathological characteristics and treatment methods of the elderly group (N = 665) and the adult group (N = 827). At the same time, we analysed specific selected clinicopathological parameters and prognostic factors for elderly MPM patients. RESULTS: Compared with the adult group, the elderly group had higher percentages of male patients (P = 0.017) and white patients (P = 0.043) and lower proportions of insured patients (P < 0.001) married patients (P < 0.001), patients with peritoneal tumours (P = 0.006) and patients who underwent surgery (P < 0.001) and chemotherapy (P < 0.001). There was a significant difference in the differentiation grade between the two groups (P = 0.003). Elderly patients had a shorter median survival time than adult patients (6 months vs. 19 months). Uninsured (hazard ratio (HR): 5.187, P = 0.005), sarcomatoid type (HR 3.913, P < 0.001), poorly differentiated (HR 3.900, P < 0.001), distant metastasis (HR 1.735, P = 0.001), no cancer-directed surgery (HR 1.733, P < 0.001), and no chemotherapy (HR 1.532, P < 0.001) were independently associated with poorer prognosis in elderly MPM patients. CONCLUSION: Compared with adult patients, elderly MPM patients had a higher male ratio, poor differentiation and relatively conservative treatment. The cancer-specific survival (CSS) rate of elderly MPM patients was significantly lower than that of adult patients. Insurance status, histology type, differentiation grade, stage, surgery status, and chemotherapy status were all independent prognostic factors for elderly MPM patients.

Analysis of Grapevine's Somatic Embryogenesis Receptor Kinase (SERK) Gene Family: VqSERK3/BAK1 Overexpression Enhances Disease Resistance.

The somatic embryogenesis receptor kinase (SERK) gene family has been intensively studied in several plant species. Here we confirmed the existence of five SERK genes in grapevine (Chinese wild grapevine Vitis quinquangularis) and named them VqSERK1, VqSERK2, VqSERK3, VqSERK4, and VqSERK5. Analysis of the predicted structures of these SERK proteins revealed they include a signal peptide domain, a leucine zipper domain, a Ser-Pro-Pro domain, a single transmembrane domain, different leucine-rich repeats, and an intracellular kinase activity domain. The SERK genes of grapevine showed different gene expression patterns when treated with powdery mildew (Erysiphe necator) and hormones (salicylic acid, jasmonic acid, abscisic acid, and ethylene). Subcellular localization assays confirmed that VqSERK family proteins localized to the cell membrane. Moreover, we cloned the SERK3/BAK1 gene from the Chinese wild grapevine V. quinquangularis clone 'Shang-24'. Heterologous VqSERK3/BAK1 expression in the Arabidopsis bak1-4 mutant lines restored control of cell death, increased resistance to powdery mildew, and strengthened stomatal immunity. Our work may provide the foundation for further studies of SERK genes for pathogen resistance and hormone treatment in grapevine.

Untargeted metabolomics and lipidomics analysis identified the role of FOXA1 in remodeling the metabolic pattern of BaP-transformed 16HBE cells.

Benzo[a]pyrene (BaP) is a strong carcinogen for lung cancer, and forkhead-box A1 (FOXA1) plays an oncogenic role in BaP-transformed cell THBEc1. To explore the remodeling of metabolic pattern caused by BaP-induced transformation and the possible role FOXA1 might play in it, we compared metabolic patterns between THBEc1 cells and control using untargeted metabolomics and lipidomics analysis, and determined the effects of FOXA1 knockout on the metabolic pattern of THBEc1 cells. Metabolomics and lipidomics identified a total of 15 and 46 differential metabolites and lipids between THBEc1 and 16HBE cells, respectively, and a total of 4 and 1 differential metabolites and lipids between FOXA1 knockout cell THBEc1-ΔFOXA1-c34 and control cell THBEc1-ctrl, respectively. Analysis results of metabolites and metabolic pathways indicated the metabolic pattern remodeling may be related to the alteration in glucose metabolism during BaP-induced transformation. Western blotting revealed the up-regulation of enolase-2 (ENO2), pyruvate carboxylase (PCB), aconitase-2 (ACO2) and phosphorylated extracellular signal-regulated kinase 1/2 (p-ERK1/2) (Thr202/Tyr204), the down-regulation of succinate dehydrogenase complex subunit A (SDHA) and phosphoenolpyruvate carboxykinase 2 (PCK2) in THBEc1 cells. The detection results of metabolites related to glucose metabolism demonstrated the decreasing of lactic acid content in cells, lactic acid production in culture medium and citric acid content in mitochondria, and the increasing of ATP production of THBEc1 cells. FOXA1 knockout partially reversed the changes of ENO2, SDHA, PCK2 and p-ERK1/2 (Thr202/Tyr204) levels, lactic acid release, citric acid content in mitochondria of THBEc1 cells. In conclusion, FOXA1 knockout partially reversed the remodeling of glucose metabolism caused by BaP-induced malignant transformation. Our findings provide a clue for the possible role of FOXA1 in glucose metabolism regulation.

Label-free quantitative proteomic analysis identifies the oncogenic role of FOXA1 in BaP-transformed 16HBE cells.

Lung cancer has been the leading cause of cancer incidence and mortality in China for years. Benzo[a]pyrene (BaP) is a well-known carcinogen for lung cancer. To understand alternation of key proteins and their role in BaP-induced lung cancer, we compared proteome profiles between BaP-transformed 16HBE cell line T-16HBE-C1 (THBEc1) cells and control using label-free quantitative proteomic analysis. Forkhead box protein A1 (FOXA1) was selected and evaluated for its potential role in BaP-induced carcinogenesis in vitro and in vivo. Relationship between FOXA1 expression and survival of lung cancer patients were examined via The Cancer Genome Atlas (TCGA) database. A total of 183 differentially expressed proteins were identified, with 67 proteins including FOXA1 up-regulated and 116 proteins down-regulated in THBEc1 cells. Differentially expressed proteins mainly functioned in basic cellular metabolism, tumor related pathways and regulation of transcription factors. FOXA1 knockout inhibited colony formation and migration of THBEc1 cells in vitro. FOXA1 knockout inhibited tumor growth and metastasis in BALB/c-nude mice after subcutaneous and tail vein injection of FOXA1 knockout THBEc1 cells, respectively. FOXA1 mRNA expression was higher in tumor tissues for patients with lung squamous cell carcinoma, but not associated with survival of lung cancer patients. Our findings revealed oncogenic role of FOXA1 in BaP-induced lung cancer and improved understanding of mechanism in BaP-induced carcinogenesis.

High reward enhances perceptual learning.

Studies of perceptual learning have revealed a great deal of plasticity in adult humans. In this study, we systematically investigated the effects and mechanisms of several forms (trial-by-trial, block, and session rewards) and levels (no, low, high, subliminal) of monetary reward on the rate, magnitude, and generalizability of perceptual learning. We found that high monetary reward can greatly promote the rate and boost the magnitude of learning and enhance performance in untrained spatial frequencies and eye without changing interocular, interlocation, and interdirection transfer indices. High reward per se made unique contributions to the enhanced learning through improved internal noise reduction. Furthermore, the effects of high reward on perceptual learning occurred in a range of perceptual tasks. The results may have major implications for the understanding of the nature of the learning rule in perceptual learning and for the use of reward to enhance perceptual learning in practical applications.

[L-carnitine protects the motion parameters and mitochondrial function of human sperm in cryopreservation].

OBJECTIVE: To study the effects of L-carnitine (LC) on cryopreserved human sperm. METHODS: Ten semen samples were collected from normal sperm donors, each divided into six groups, fresh ejaculate (FE), non-LC cryopreservation (non-LC), and cryopreservation with LC at 1 mmol/L (LC-1), 2.5 mmol/L (LC-2), 5 mmol/L (LC-3) and 10 mmol/L (LC-4), respectively. The optimal concentration of LC was identified based on the motility and motion parameters of the post-thaw sperm. The plasma membrane integrity (PMI) of the sperm was assessed by eosin-nigrosin staining, their mitochondrial membrane potential (MMP) monitored by JC-1 assay, and the level of sperm ROS measured by the fluorescent probe DCFH-DA, followed by analysis of the mechanisms of LC protecting sperm against cryopreservation injury. RESULTS: Compared with the sperm in the FE group, the post-thaw sperm in the non-LC and LC groups showed significantly decreased progressive motility, average path velocity (VAP), straight line velocity (VSP) and curvilinear velocity (VCP) (P < 0.05). In comparison with the non-LC group, the LC-3 group exhibited a remarkably higher percentage of progressively motile sperm (ï¼»41.9 ± 4.6ï¼½ vs ï¼»47.0 ± 4.3ï¼½%, P = 0.0261) and VAP (ï¼»34.9 ± 2.6ï¼½ vs ï¼»38.9 ± 4.2ï¼½ µm/s, P = 0.0152), indicating that the optimal concentration of LC was 5 mmol/L. Both PMI and MMP were significantly lower in the non-LC than in the FE group (ï¼»52.7 ± 5.7ï¼½ vs ï¼»75.5 ± 5.4ï¼½%, P < 0.01 and ï¼»44.5 ± 3.5ï¼½ vs ï¼»57.3 ± 4.4ï¼½%, P < 0.01), but higher in the LC groups (ï¼»70.1 ± 8.2ï¼½% and ï¼»50.3 ± 3.4ï¼½%) than in the non-LC group (P < 0.01 and P < 0.05). The level of sperm ROS, however, was markedly higher in the non-LC than in the FE group (ï¼»12.5 ± 3.9ï¼½ vs ï¼»6.8 ± 2.4ï¼½, P < 0.01) but lower in the LC groups (ï¼»8.4 ± 5.3ï¼½%) than in the non-LC group (P = 0.05). CONCLUSIONS: L-carnitine can improve the motility and motion parameters of cryopreserved human sperm by reducing sperm ROS, enhancing sperm mitochondrial membrane potential and protecting the sperm plasma membrane.

Frequency-dependent changes in the amplitude of low-frequency fluctuations in patients with Wilson's disease: a resting-state fMRI study.

To investigate the frequency-dependent changes in the amplitude of low-frequency fluctuations (ALFF) in patients with Wilson's disease (WD). Resting-state function magnetic resonance imaging (R-fMRI) were employed to measure the amplitude of ALFF in 28 patients with WD and 27 matched normal controls. Slow-5 (0.01-0.027 Hz) and slow-4 (0.027-0.073 Hz) frequency bands were analyzed. Apart from the observation of atrophy in the cerebellum, basal ganglia, occipital gyrus, frontal gyrus, precentral gyrus, and paracentral lobule, we also found widespread differences in ALFF of the two bands in the medial frontal gyrus, inferior temporal gyrus, insula, basal ganglia, hippocampus/parahippocampal gyrus, and thalamus bilaterally. Compared to normal controls, WD patients had increased ALFF in the posterior lobe of the cerebellum, inferior temporal gyrus, brain stem, basal ganglia, and decreased ALFF in the anterior lobe of the cerebellum and medial frontal gyrus. Specifically, we observed that the ALFF abnormalities in the cerebellum and middle frontal gyrus were greater in the slow-5 than in the slow-4 band. Correlation analysis showed consistently positive correlations between urinary copper excretion (Cu), serum ceruloplasmin (CP) and ALFFs in the cerebellum. Our study suggests the accumulation of copper profoundly impaired intrinsic brain activity and the impairments seem to be frequency-dependent. These results provide further insights into the understanding of the pathophysiology of WD.

[Increase of apoptosis and decrease of sperm motility induced by oxidative stress after exposed to butyl p-hydroxybenzoate].

OBJECTIVE: To explore the effect and mechanism of butyl phydroxybenzoate( BP) on sperm motility, oxidative stress and apoptosis. METHODS: Semen samples from 20 healthy sperm donors were randomly divided into four groups:group control, BP 200 µmol/L, BP 400 µmol/L and BP 800 µmol/L, each group had five parallel samples. The spermatozoa were cultured with BP for 4 h in vitro, with the exposed concentration of BP at 0, 200, 400 and 800 µmol/L, respectively. The influence of BP on spermatozoa were analyzed by sperm activity, cytotoxicity, the rate of reactive oxygen species( ROS) positive cell and apoptosis. RESULTS: The total sperm activity in group BP200 µmol/L, BP 400 µmol/L and BP 800 µmol/L were( 47. 67 ± 3. 93) %, ( 32. 79 ±2. 90) %, ( 10. 51 ± 5. 88) % respectively, which were significantly lower than control( 26. 44 ± 7. 83) %. Compared with the control group, the survival rate of sperm in the three experiment groups were( 63. 36 ± 9. 08) %, ( 49. 72 ± 7. 15) %, ( 29. 91 ±5. 93) % respectively. Rate of ROS positive cells in the three experiment groups were( 24. 67 ± 0. 50) %, ( 54. 50 ± 3. 40) %, ( 59. 93 ± 3. 47) % respectively, which were significantly higher than control( 8. 63 ± 0. 57) %. The rate of late stage apoptosis were( 11. 8 ± 1. 74) %, ( 12. 87 ± 0. 25) %, ( 14. 60 ± 0. 87) % respectively, which were significantly higher than control( 9. 63 ± 1. 00) %. The level of sperm ROS and the late stage apoptosis rate were negatively correlated with the total sperm motility, correlation coefficient were- 0. 727 and- 0. 688 respectively( P < 0. 05). CONCLUSION: BP has cytotoxicity and can reduce sperm motility and promote the production of sperm ROS.

[Effects of Early Enteral Immunonutrition on Postoperative Immune Function and Rehabilitation of Patients with Gastric Cancer and Nutritional Risk].

OBJECTIVES: To investigate the effects of early enteral immunonutrition on postoperative immune function and rehabilitation of gastric cancer patients with nutritional risk. METHODS: New hospitalized patients with gastric cancer were evaluated the nutrient status based on NRS 2002. The patients who scored between 3 to 5 points were randomized into two groups(30 cases for each group), and those in experimental group were given 7-d early postoperative enteral immune nutrition, those in control group were given normal nutrition. The immune indexes (CD3+, CD4+, CD8+ and CD4+/CD8+) and nutritional indexes(transferrin, pre-albumin, albumin) were measured before operation and at the 3rd and 7th day postoperatively. In addition, the first flatus time, gastrointestinal adverse reactions and complications, length of hospital stays were compared between the two groups. RESULTS: The level of CD4+/CD8+ and transferrin, pre-albumin, albumin in experimental group were significantly higher than those in control group at the third and seventh day postoperatively (P<0.05).Compared with the control group, the experimental group had shorter first flatus time after surgery, which were (63.5±7.3) h vs. (72.8±8.6 ) h respectively (P<0.05).There were no statistically difference on pneumonia, anastomosis leakage, severe abdominal distension, inflammatory bowel obstruction and total postoperative hospitalization time between the two groups (P>0.05). CONCLUSIONS: Early enteral immunonutrition can effectively promote the recovery of nutritional status and immune function in gastric cancer patients with nutrition risk.

n-butylparaben induces male reproductive disorders via regulation of estradiol and estrogen receptors.

It is well known that inappropriate exposure to exogenous hormones during fetal or neonatal life, such as testosterone (T) and estradiol (E2 ), leads to adverse reproductive outcomes. In our previous study, the reproductive dysfunction of male rats was characterized by an E2 increase and T decrease after in utero and lactation exposures to n-butylparaben (n-BP). In this study, we investigated the synthesis and metabolism pathways of steroid hormones, hormone receptors and the epigenetic modification of male offspring on postnatal day (PND) 21 and PND90 to explore the possible mechanisms of endocrine and reproductive disorders. The expression of steroidogenic acute regulatory protein (StAR), cytochrome cholesterol side-chain cleavage enzyme (P450scc), estrogen sulfotransferase (SULT1E1) and androgen receptor (AR) in the testes was significantly decreased at the transcript and protein levels; in addition, aromatase (CYP19) and estrogen receptor α (ERα) expression was significantly increased and the methylation rate of the ERα promoter was significantly decreased. These results suggest that increased CYP19 expression and decreased SULT1E1 expression are responsible for the E2 increase. This effect promotes the expression of ERα, which plays a pivotal role in regulating reproductive and endocrine disorders of male rats exposed to n-BP. Furthermore, the epigenetic hypomethylation of ERα is involved in this regulation processes. Our study is the first to report on the possible mechanism of male rat reproductive disorders induced by the xenoestrogenic chemical n-BP. Copyright © 2016 John Wiley & Sons, Ltd.

The Seroprevalence of Some Pathogen Specific IgM in Children with Acute Respiratory Tract Infections in Guangzhou Region, 2011 - 2012.

BACKGROUND: Acute respiratory tract infections (ARTIs) are the leading cause of morbidity and death in children < 5 years worldwide. The aim of this study is to analyze the seroprevalence of nine pathogen specific IgMs in children with ARTIs with respect to gender, age, and seasonality in the Guangzhou region. METHODS: Serum samples were collected from 20160 children with ARTIs admitted to the Guangzhou Women and Children's Medical Center between 2011 and 2012. Serum-specific IgM antibodies to nine respiratory pathogens, Mycoplasma pneumonia (MP), Legionella pneumophila (LP), Coxiella burnetii (C. burnetii), Chlamydophila pneumonia (CP), adenovirus (ADV), respiratory syncytial virus (RSV), type A and type B influenza virus (IVA and IVB), and parainfluenza virus (PIV), were detected using immunofluorescence assay. RESULTS: The male-to-female ratio of all patients was 1.9:1. The median age was 3 years and 8 months with a significant difference in seropositivity to respiratory tract pathogens between children from different age groups. Seropositivity was detected in 43.53% of the children with the top three pathogens being MP (33.15%), RSV (10.27%), and ADV (6.63%), followed by IVB (2.63%), LP (2.25%), IVA (1.59%), PIV (1.57%), CP (0.27%), and C. burnetii (0.13%). The prevalence of single, double, and triple seropositivity was 70.20% (6160/8775), 25.22% (2213/8775), and 4.57% (401/8775), respectively. The total IgM seropositivity for any kind of pathogen in the nine kinds of pathogens peaked in winter (46.53%), while the nadir was observed in summer (41.97%). CONCLUSIONS: The top three seroprevalence of nine kinds of pathogen specific IgM was MP, followed by RSV and ADV. The epidemic pathogen specific IgM had a season-specific seropositivity distribution. Seroprevalence of the pathogen should be a focus of attention.

Exposure characteristics of ferric oxide nanoparticles released during activities for manufacturing ferric oxide nanomaterials.

The exposure characteristics of Fe2O3 nanoparticles (NPs) released in a factory were investigated, as exposure data on this type of NP is absent. The nature of the particles was identified in terms of their concentrations [i.e. number concentration (NC(20-1000 nm)), mass concentration (MC(100-1000 nm)), surface area concentration (SAC(10-1000 nm))], size distribution, morphology and elemental composition. The relationships between different exposure metrics were determined through analyses of exposure ranking (ER), concentration ratios (CR), correlation coefficients and shapes of the particle concentration curves. Work activities such as powder screening, material feeding and packaging generated higher levels of NPs as compared to those of background particles (p < 0.01). The airborne Fe2O3 NPs exhibited a unimodal size distribution and a spindle-like morphology and consisted predominantly of the elements O and Fe. Periodic and activity-related characteristics were noticed in the temporal variations in NC(20-1000 nm) and SAC(10-1000 nm). The modal size of the Fe2O3 NPs remained relatively constant (ranging from 10 to 15 nm) during the working periods. The ER, CR values and the shapes of NC(20-1000 nm) and SAC(10-1000 nm) curves were similar; however, these were significantly different from those for MC(100-1000 nm). There was a high correlation between NC(20-1000 nm) and SAC(10-1000 nm), and relatively lower correlations between the two and MC(100-1000 nm). These findings suggest that the work activities during the manufacturing processes generated high levels of primary Fe2O3 NPs. The particle concentrations exhibited periodicity and were activity dependent. The number and SACs were found to be much more relevant metrics for characterizing NPs than was the mass concentration.

Perceptual learning improves neural processing in myopic vision.

Visual performance is jointly determined by the quality of optical transmission of the eye and neural processing in the visual system. An open question is: Can effects of optical defects be compensated by perceptual learning in neural processing? To address this question, we conducted a perceptual learning study on 23 observers with myopic vision, targeting high frequency deficits by training them in a monocular grating detection task in the non-dominant eye near their individual cutoff spatial frequencies. The contrast sensitivity function and visual acuity in both eyes (without optical correction) were assessed for all the observers in the training group before and after training, and for all the observers in the control group twice with a 10-day interval between the tests. In addition, the threshold versus external noise contrast function was measured for five observers in the training group before and after training. We found that (a) training significantly improved contrast sensitivity at the trained spatial frequency, visual acuity, and contrast sensitivity over a wide range of spatial frequencies in both eyes; (b) training did not lead to any significant refractive changes; (c) the mechanism of improvements was a combination of internal additive noise reduction and external noise exclusion; and (d) the improvements in visual acuity and contrast sensitivity were almost fully retained for at least four months in the three observers tested. These results suggest that perceptual learning may provide a potential noninvasive procedure to compensate for optical defects in mild to modest myopia.

Broad bandwidth of perceptual learning in second-order contrast modulation detection.

Comparing characteristics of learning in first- and second-order systems might inform us about different neural plasticity in the two systems. In the current study, we aim to determine the properties of perceptual learning in second-order contrast modulation detection in normal adults. We trained nine observers to detect second-order gratings at an envelope modulation spatial frequency of 8 cycles/° with their nondominant eyes. We found that, although training generated the largest improvements around the trained frequency, contrast sensitivity over a broad range of spatial frequencies also improved, with a 4.09-octave bandwidth of perceptual learning, exhibiting specificity to the trained spatial frequency as well as a relatively large degree of generalization. The improvements in the modulation sensitivity function (MSF) were not significantly different between the trained and untrained eyes. Furthermore, training did not significantly change subjects' ability in detecting first-order gratings. Our results suggest that perceptual learning in second-order detection might occur at the postchannel level in binocular neurons, possibly through reducing the internal noise of the visual system.