Long-term seasonal trends of nitrogen, phosphorus, and suspended sediment load from the non-tidal Susquehanna River Basin to Chesapeake Bay

Reduction of nitrogen (N), phosphorus (P), and suspended sediment (SS) load has been a principal focus of Chesapeake Bay Watershed management for decades. To evaluate the progress of management actions in the Bay's largest tributary, the Susquehanna River, we analyzed the long-term seasonal trends of flow-normalized N, P, and SS load over the last two to three decades, both above and below the Lower Susquehanna River Reservoir System. Our results indicate that annual and decadal-scale trends of nutrient and sediment load generally followed similar patterns in all four seasons, implying that changes in watershed function and land use had similar impacts on nutrient and sediment load at all times of the year. Above the reservoir system, the combined loads from the Marietta and Conestoga Stations indicate general trends of N, P, and SS reduction in the Susquehanna River Basin, which can most likely be attributed to a suite of management actions on point, agricultural, and stormwater sources. In contrast, upward trends of SS and particulate-associated P and N were generally observed below the Conowingo Reservoir since the mid-1990s. Our analyses suggest that (1) the reservoirs' capacity to trap these materials has been diminishing over the past two to three decades, and especially so for SS and P since the mid-1990s, and that (2) the Conowingo Reservoir has already neared its sediment storage capacity. These changes in reservoir performance will pose significant new kinds of challenges to attainment of total maximum daily load goals for the Susquehanna River Basin, and particularly if also accompanied by increases in storm frequency and intensity due to climate change. Accordingly, the reservoir issue may need to be factored into the proper establishment of regulatory load requirements and the development of watershed implementation plans.

Research on pitting corrosion of steam generator heat transfer tubes based on acoustic emission

Corrosion of steam generator heat transfer tubes (SGHTT) is one of the important problems which affect safety operation of nuclear power plants (NPP), and the hazard of pitting corrosion of heat transfer tubes is the most serious. With an acoustic emission device, the signals during a corrosion test on SGHTT were collected and analyzed, and the corrosion points in the tubes were located accurately. The results show that pitting corrosion of heat transfer tubes has passed through three periods in its development: expansion phase, stationary phase and rapid developing phase. The corrosion damage of HTT can be found earlier with acoustic emission than any other non-destructive testing methods. Acoustic emission can be used for on-line and real-time monitoring of the safety and operation of the steam generator and has therefore a great significance.

The proprotein convertase furin is required for trophoblast syncytialization

The multinucleated syncytial trophoblast, which forms the outermost layer of the placenta and serves multiple functions, is differentiated from and maintained by cytotrophoblast cell fusion. Deficiencies in syncytial trophoblast differentiation or maintenance likely contribute to intrauterine growth restriction and pre-eclampsia, two common gestational diseases. The cellular and molecular mechanisms governing trophoblast syncytialization are poorly understood. We report here that the proprotein convertase furin is highly expressed in syncytial trophoblast in the first trimester human placentas, and expression of furin in the syncytiotrophoblast is significantly lower in the placentas from pre-eclamptic patients as compared with their gestational age-matched control placentas. Using multiple experimental models including induced fusion of choriocarcinoma BeWo cells and spontaneous fusion of primary cultured cytotrophoblast cells or placental explants, we demonstrate that cytotrophoblast cell fusion and syncytialization are accompanied by furin expression. Furin-specific siRNAs or inhibitors inhibit cell fusion in BeWo cells, as well as trophoblast syncytialization in human placental explants. Furthermore, type 1 IGF receptor (IGF1R) is indicated in this study as a substrate of furin, and processing of IGF1R by furin is an essential mechanism for syncytialization. Finally, using lentivirus-mediated RNAi targeting to mouse trophectoderm, we demonstrate that furin function is required for the development of syncytiotrophoblast structure in the labyrinth layer, as well as for normal embryonic development.

Spectroscopic, diode-pumped laser properties and gamma irradiation effect on Yb, Er, Ho:GYSGG crystals

We demonstrate a diode end-pumped Yb, Er, Ho:Gd(1.17)Y(1.83)Sc(2)Ga(3)O(12) (GYSGG) laser operated at 2.79 μm in continuous-wave mode. Spectral analysis shows that Yb(3+) and Ho(3+) act as sensitizer and deactivator ions, respectively. Pumping with a 967 nm laser diode produces the maximum output power of 411 mW, corresponding to optical-optical conversion and slope efficiencies of 11.6% and 13.1%, respectively. The minimum laser threshold is only 81 mW because of Ho(3+) doping. The laser properties are only slightly influenced by 100 mrad gamma irradiation. The Yb, Er, Ho:GYSGG crystal possesses excellent radiation resistance and is a potential laser gain medium in radiant environments.

Lysosomes involved in the cellular toxicity of nano-alumina: combined effects of particle size and chemical composition

Nowadays, manufactured nano-particles of aluminum oxide (nano-alumina) have been widely used in many fields with the rapidly developed nano-technology, but their basic toxic data are scarce. It is believed that the smaller nano-particles are able to easily cross the bio-membrane and quickly reach cellular compartments rather than micro-size particles, thus showing more toxic effects. The aim of this study was to compare the toxicity of nano- and micro- particles of alumina for detecting particle size related toxicity, and to compare the toxicity of nano-alumina and nano-carbon with the same particle size for determining chemical composition related toxicity. The present study revealed that nano-particles of alumina were much toxic than micro-alumina particles, indicating a particle size related toxicity; and were much more toxic than nano-carbon particles as well, manifesting a chemical related toxicity. The mechanism might be concerned with the involvement of the lysosomes. In conclusion, toxicity of nano-alumina is a combination of the toxic effects of its particle size and chemical composition.

A 4 year prospective study to determine risk factors for severe community acquired pneumonia in children in southern China

BACKGROUND

Pneumonia is the major cause of death under 5 years. With high CAP numbers in China and growing access to PICUs, factors associated with severe CAP need to be determined to optimize care.

OBJECTIVE

To prospectively determine PICU CAP admission features and outcomes.

METHODS

A 4 year prospective study of CAP aged 1 month to <14 years admitted to PICU, Children's Hospital Affiliated to Soochow University, China. All were managed in a standard manner. Clinical, laboratory, and imaging findings were collected systematically. All received antibiotics.

RESULTS

Eight hundred ten (7%) of 10,836 CAP hospital admissions needed PICU. Seven hundred seven (87%) were enrolled. PICU CAP children were young (76% ≤ 12 months) and 33% had co-morbid conditions; 21% congenital heart disease.21% required mechanical ventilation. The average length of PICU stay was 5 days (range, 3-27). The case fatality rate was 5.8%. Viruses were detected in 38%, RSV 24%; bacteria in 23%, Streptococcus pneumoniae 7%, Haemophilus influenza b 4%, Mycoplasma 11%. On single factor analysis, PICU admission respiratory rate >70/min, grunting/groaning, head nodding, cyanosis, and anemia were associated with respiratory failure and with fatality. On multivariate analysis only presence of congenital heart disease, Trisomy 21 and immunodeficiency correlated with fatality; not microbe nor PICU findings.

CONCLUSIONS

Young age and underlying congenital heart disease were associated factors for PICU support in CAP in China. Early referral if altered sensorium, high respiratory rate, head nodding, grunting and anemia, and universal access to conjugated vaccines may decrease morbidity and mortality.

Formation of nanostructure and nano-hardness characterization on the meso-scale workpiece by a novel laser indirect shock forming method

The meso-scale workpiece with greatly enhanced mechanical properties is potential to be widely used in the electronics productions and micro-electro mechanical systems. In this study, it demonstrates that the meso-scale cup-shape workpiece with good geometry can be obtained by a novel laser indirect shock forming method. After the forming process, the mechanical properties and microstructures of the formed workpiece were characterized. By transmission electron microscope observation, it was found that a mixed refined microstructure consisting of nano-scale twins embedded in nano-sized grains was produced at the center of the formed sample. Formation of these nanograins could be mainly attributed to two mechanisms: twin-twin intersections and twin∕matrix lamellae fragmentation. By nanoindentation tests, it reveals that the hardness of the sample has increased greatly after laser shock forming and the hardness increases with the laser energy. The elevated hardness originates from a considerable number of nano-scale twins and nanograins, which possess a pretty high strength due to the significant effects of grain boundary strengthening and twin boundary strengthening.

Etiology of Moldy Core, Core Browning, and Core Rot of Fuji Apple in China

'Fuji' apple fruit were collected in Shaanxi Province, China, and 186 fungal isolates were obtained from the fruit core region. Fungi were isolated from fruit with symptomless core regions, as well as from the core regions of fruit showing browning, typical moldy core, or core rot. Based on phylogenetic and morphological analysis, all fungi were identified to species. Pathogenicity was determined by cutting apple fruit into halves and daubing spore suspensions containing 1 × 10⁴ up to 1 × 10⁸ spores/ml on the carpel in the core region. Pathogenicity varied significantly among genera, with Alternaria and Cladosporium spp. causing core browning at lower spore concentrations and moldy core at higher spore concentrations. Combinations of pathogens initiated more browning and moldy core than the pathogens applied alone. Epicoccum and Phoma spp. predominated in dry core rot, whereas primarily Trichothecium but also Fusarium and Penicillium spp. caused wet core rot. Core browning was introduced as a new type of core symptom, along with moldy core, dry core rot, and wet core rot. Alternaria alternata, A. tenuissima, A. arborescens, Cladosporium cladosporioides, and C. tenuissimum were the main pathogens causing core browning and moldy core.

Reversal of optical binding force by Fano resonance in plasmonic nanorod heterodimer

We present calculations of the optical force on heterodimer of two gold nanorods aligned head-to-tail, under plane wave illumination that is polarized along the dimer axis. It is found that near the dipole-quadrupole Fano resonance, the optical binding force between the nanorods reverses, indicating an attractive to repulsive transition. This is in contrast to homodimer which in similar configuration shows no negative binding force. Moreover, the force spectrum features asymmetric line shape and shifts accordingly when the Fano resonance is tuned by varying the nanorods length or their gap. We show that the force reversal is associated with the strong phase variation between the hybridized dipole and quadrupole modes near the Fano dip. The numerical results may be demonstrated by a near-field optical tweezer and shall be useful for studying "optical matters" in plasmonics.

Decreased expression of microRNA-31 associates with aggressive tumor progression and poor prognosis in patients with bladder cancer

PURPOSE

MicroRNA-31 (miR-31) has different expression patterns in various human cancers. Especially in urothelial carcinoma of the bladder, it has been demonstrated to be decreased expression in the invasive tumors and homozygously deleted. However, its clinical significance in human bladder cancer has not yet been elucidated. Thus, the purpose of this study was to investigate the diagnostic and prognostic values of miR-31 in this disease.

METHODS

Expression levels of miR-31 in 126 pairs of bladder cancer and adjacent normal tissues were detected by real-time quantitative RT-PCR assay. To determine its prognostic value, overall survival (OS) and progression-free survival (PFS) were evaluated using the Kaplan-Meier method, and multivariate analysis was performed using the Cox proportional hazard analysis.

RESULTS

MiR-31 expression in bladder cancer tissues was significantly lower than those in adjacent normal tissues (mean expression level: 2.1 ± 0.9 vs. 3.8 ± 1.2, P < 0.001). When categorized into low vs. high expression, low miR-31 expression was negatively associated with the tumor stage (P = 0.02), the status of recurrence (P = 0.01), progression (P = 0.01), and death (P = 0.006) of patients with bladder cancer. Moreover, low miR-31 expression clearly predicted poorer PFS (P = 0.001) and OS (P < 0.001). In the multivariate analysis, low miR-31 expression was an independent prognostic factor for both PFS (P = 0.01) and OS (P = 0.008).

CONCLUSION

These findings show that miR-31 may contribute to the progression of bladder cancer and its downregulation may be independently associated with unfavorable PFS and OS, suggesting that miR-31 might be a promising marker for further risk stratification in the treatment of this cancer.

Exome sequencing-driven discovery of coding polymorphisms associated with common metabolic phenotypes

AIMS/HYPOTHESIS

Human complex metabolic traits are in part regulated by genetic determinants. Here we applied exome sequencing to identify novel associations of coding polymorphisms at minor allele frequencies (MAFs) >1% with common metabolic phenotypes.

METHODS

The study comprised three stages. We performed medium-depth (8×) whole exome sequencing in 1,000 cases with type 2 diabetes, BMI >27.5 kg/m(2) and hypertension and in 1,000 controls (stage 1). We selected 16,192 polymorphisms nominally associated (p < 0.05) with case-control status, from four selected annotation categories or from loci reported to associate with metabolic traits. These variants were genotyped in 15,989 Danes to search for association with 12 metabolic phenotypes (stage 2). In stage 3, polymorphisms showing potential associations were genotyped in a further 63,896 Europeans.

RESULTS

Exome sequencing identified 70,182 polymorphisms with MAF >1%. In stage 2 we identified 51 potential associations with one or more of eight metabolic phenotypes covered by 45 unique polymorphisms. In meta-analyses of stage 2 and stage 3 results, we demonstrated robust associations for coding polymorphisms in CD300LG (fasting HDL-cholesterol: MAF 3.5%, p = 8.5 × 10(-14)), COBLL1 (type 2 diabetes: MAF 12.5%, OR 0.88, p = 1.2 × 10(-11)) and MACF1 (type 2 diabetes: MAF 23.4%, OR 1.10, p = 8.2 × 10(-10)).

CONCLUSIONS/INTERPRETATION

We applied exome sequencing as a basis for finding genetic determinants of metabolic traits and show the existence of low-frequency and common coding polymorphisms with impact on common metabolic traits. Based on our study, coding polymorphisms with MAF above 1% do not seem to have particularly high effect sizes on the measured metabolic traits.

Risk factors for male patients with gonorrhoea complicated by inflammation of the paraurethral glands around the external urethral orifice

Gonococcal inflammation of paraurethral glands around the external urethral orifice is a local complication of gonorrhoea in men. To investigate the risk factors for this complication we compared prepuce factors, Chlamydia trachomatis infection, demographic data and behavioural indicators of gonorrhoeal patients with and without this complication. Results showed that a prolonged disease course of gonorrhoea, sexual intercourse during gonorrhoea, repeated squeezing of the penis and a redundant prepuce were risk factors for this complication.

L-Cysteine promotes the proliferation and differentiation of neural stem cells via the CBS/H₂S pathway

Growing evidence has suggested that hydrogen sulfide (H₂S) acts as a novel neuro-modulator and neuroprotective agent; however, it remains to be investigated whether H2S has a direct effect on neural stem cells (NSCs). We report here that NSCs expressed cystathionine β synthase (CBS) and addition of exogenous H2S donor, L-cysteine, stimulated proliferation and increased the differentiation potential of NSCs to neurons and astroglia. Moreover, pre-treatment with aminooxyacetic acid, the inhibitor of CBS or knockdown of CBS in using siRNA, significantly attenuated the effects of L-cysteine on elevated H₂S levels and the cell proliferation; it also effectively suppressed L-cysteine-induced neurogenesis and astrocytogenesis. Further analysis revealed that L-cysteine-induced proliferation was associated with phosphorylation of extracellular signal-regulated kinases 1/2 and differentiation with altered expression of differentiation-related genes. Taken together, the present data suggest that L-cysteine can enhance proliferation and differentiation of NSCs via the CBS/H2S pathway, which may serve as a useful inference for elucidating its role in regulating the fate of NSCs in physiological and pathological settings.

Garnet-to-perovskite transition in Gd3Sc2Ga3O12 at high pressure and high temperature

The structural phase transition of gadolinium-scandium-gallium garnet (Gd(3)Sc(2)Ga(3)O(12), GSGG) has been studied at high pressure and high temperature using the synchrotron X-ray diffraction technique in a laser-heated diamond anvil cell. The GSGG garnet transformed to an orthorhombic perovskite structure at approximately 24 GPa after laser heating to 1500-2000 K. The garnet-to-perovskite phase transition is associated with an ∼8% volume reduction and an increase in the coordination number of the Ga(3+) or Sc(3+) ion. The orthorhombic perovskite GSGG has bulk modulus B(0) = 194(15) GPa with B(0)' = 5.3(8), exhibiting slightly less compression than the cubic garnet structure of GSGG with B(0) = 157(15) GPa and B(0)' = 6.5(10). Upon compression at room temperature, the cubic GSGG garnet became amorphous at ∼65 GPa. Coupled with the amorphous-to-perovskite phase transition in Y(3)Fe(5)O(12) and Gd(3)Ga(5)O(12) at high-pressure-temperature conditions, we conclude that amorphization should represent a new thermodynamic state resulting from hindrance of the garnet-to-perovskite phase transition, whereas the garnet-to-amorphous transition in rare-earth garnets should be kinetically hindered at room temperature.

Superconductivity with extremely large upper critical fields in Nb2Pd0.81S5

Here, we report the discovery of superconductivity in a new transition metal-chalcogenide compound, i.e. Nb2Pd0.81S5, with a transition temperature Tc is approximately equal to 6.6 K. Despite its relatively low Tc, it displays remarkably high and anisotropic superconducting upper critical fields, e.g. μ0Hc2 (T → 0 K) > 37 T for fields applied along the crystallographic b-axis. For a field applied perpendicularly to the b-axis, μ0Hc2 shows a linear dependence in temperature which coupled to a temperature-dependent anisotropy of the upper critical fields, suggests that Nb2Pd0.81S5 is a multi-band superconductor. This is consistent with band structure calculations which reveal nearly cylindrical and quasi-one-dimensional Fermi surface sheets having hole and electron character, respectively. The static spin susceptibility as calculated through the random phase approximation, reveals strong peaks suggesting proximity to a magnetic state and therefore the possibility of unconventional superconductivity.

Fanconi anemia pathway--the way of DNA interstrand cross-link repair

The study of rare genetic diseases usually inspires the research of cancer biology. Fanconi anemia (FA), is a rare cancer susceptibility syndrome with an incidence of only 1 per 350,000 births. FA is an autosomal recessive disease with three main features: chromosome instability, hypersensitivity to DNA cross-linking agents such as mitomycin C (MMC), cisplatin and so on, and susceptible to a number of cancer types, mainly leukemia and squamous cell carcinomas of the head and neck or gynecologic system. DNA crosslinking agents may led to DNA cross-linking lesion, and Fanconi anemia pathway plays a key role in repairing its cross-linking. However, FA pathway is closely linked with carcinogenesis and tumor drug resistance. This paper mainly focuses on the FA pathway and its progress in cancer research.