CXCR3 expression and activation of eosinophils: role of IFN-gamma-inducible protein-10 and monokine induced by IFN-gamma

CXC chemokine receptor 3 (CXCR3), predominately expressed on memory/activated T lymphocytes, is a receptor for both IFN-gamma-inducible protein-10 (gamma IP-10) and monokine induced by IFN-gamma (Mig). We report a novel finding that CXCR3 is also expressed on eosinophils. gamma IP-10 and Mig induce eosinophil chemotaxis via CXCR3, as documented by the fact that anti-CXCR3 mAb blocks gamma IP-10- and Mig-induced eosinophil chemotaxis. gamma IP-10- and Mig-induced eosinophil chemotaxis are up- and down-regulated by IL-2 and IL-10, respectively. Correspondingly, CXCR3 protein and mRNA expressions in eosinophils are up- and down-regulated by IL-2 and IL-10, respectively, as detected using flow cytometry, immunocytochemical assay, and a real-time quantitative RT-PCR technique. gamma IP-10 and Mig act eosinophils to induce chemotaxis via the cAMP-dependent protein kinase A signaling pathways. The fact that gamma IP-10 and Mig induce an increase in intracellular calcium in eosinophils confirms that CXCR3 exists on eosinophils. Besides induction to chemotaxis, gamma IP-10 and Mig also activate eosinophils to eosinophil cationic protein release. These results indicate that CXCR3-gamma IP-10 and -Mig receptor-ligand pairs as well as the effects of IL-2 and IL-10 on them may be especially important in the cytokine/chemokine environment for the pathophysiologic events of allergic inflammation, including initiation, progression, and termination in the processes.

Redox transformations of arsenic and iron in water treatment sludge during aging and TCLP extraction

Laboratory experiments and modeling studies were performed to investigate the redox transformations of arsenic and iron in water treatment sludge during aging, and to evaluate the impact of those transformations on the leachability of arsenic determined with the U.S. EPA toxicity characteristic leaching procedure (TCLP). When the backwash suspension samples collected from a California surface water treatment plant were aged in closed containers for a few weeks, soluble arsenic increased from less than 5 microg/L to as high as 700 microg/L and then decreased dramatically because of biotic reduction of arsenate [As(V)], ferric oxyhydroxide, and sulfate. The experimental results and the thermodynamic models showed that arsenic mobility can be divided into three redox zones: (a) an adsorption zone at pe > 0, which is characterized by strong adsorption of As(V) on ferric oxyhydroxide; (b) a mobilization (transition) zone at -4.0 < pe < 0, where arsenic is released because of reduction of ferric oxyhydroxide to ferrous iron and As(V) to arsenite [As(III)]; and (c) a reductive fixation zone at pe < -4.0, where arsenic is immobilized by pyrite and other reduced solid phases. The TCLP substantially underestimated the leachability of arsenic in the anoxic sludge collected from sludge ponds because of the oxidation of Fe(II) and As(III) by oxygen. The leaching test should be performed in zero-headspace vessels or under nitrogen to minimize the transformations of the redox-sensitive chemical species.

Identification of microRNAs associated with lymphangiogenesis in human gastric cancer

PURPOSE

Lymphatic metastasis is a primary cause of gastric cancer-related death, yet factors governing tumor cell lymphatic metastasis have not been fully elucidated. MicroRNAs (miRNAs) are a recently discovered class of regulatory, non-coding RNAs, some of which are involved in gastric cancer progression. However, little is known about which miRNA contributes to the lymphatic metastasis in human gastric cancer. This prompted us to find the significant miRNAs associated with lymphangiogenesis in human gastric cancer.

METHODS

We screened vascular endothelial growth factor C (VEGF-C) expression in several gastric cancer cell lines as well as in the immortalized human gastric mucosal cell line GES-1, by real-time reverse transcriptase PCR (qRT-PCR). The gastric cancer cell lines MKN-45 and SGC-7901, which have commonly been cultured with human lymphatic endothelial cells (HLECs) in vitro, promoted tube formation of HLECs following transformation with a VEGF-C expression vector. Using microarrays, we identified a panel of differentially expressed miRNAs in HLECs that had been co-cultured with VEGF-C-transformed gastric cancer cells compared with non-transformed gastric cancer cells. A subset of miRNAs was further validated using qRT-PCR.

RESULTS

We found altered expression of miRNAs in HLECs co-cultured with lymphangiogenesis-inducing VEGF-C-transformed gastric cancer cells, with 47 up-regulated and 42 down-regulated miRNAs. These findings were confirmed by qRT-PCR of selected miRNAs. Furthermore, several miRNAs were differentially expressed in patients with positive lymphatic metastasis of the primary gastric tumor. Up-regulated miRNAs included miR-648, miR-5002-3p, miR-4754, miR-4760-5p, miR-4491, miR-4252, miR-5007-3p, and miR-647; and down-regulated miRNAs included miR-3178, miR-593-5p, miR-4485, miR-135a-3p, miR-17, miR-1469, and miR-124-5p.

CONCLUSIONS

Several lymphangiogenesis-related miRNAs are significantly altered during lymphatic metastasis of gastric cancer.

Cutaneous mast cells are altered in normal healthy volunteers sitting in front of ordinary TVs/PCs--results from open-field provocation experiments

BACKGROUND

Considerable controversy has surrounded the question of possible biological responses to electromagnetic fields (EMFs) generated from visual display terminals (VDTs), such as personal computers (PCs) and ordinary television sets (TVs). The cellular and molecular mechanisms for such potential harmful health hazards have not yet been understood, although clues from the literature include mast cells and histamine. The aim of this study was therefore to investigate possible biological mast cell responses to TV/PC screens.

METHODS

Using the indirect immunofluorescence technique, we studied the presence of histamine-containing mast cells in the dermis of healthy volunteers. Cutaneous biopsies taken before and after exposure to ordinary TV/PC screens for 2 or 4 h were investigated in 13 healthy subjects.

RESULTS

Our present in vivo study indicates that normal cutaneous mast cells could be altered by exposure from ordinary TV/PC screens. To our great surprise, we found the number of mast cells in the papillary and reticular dermis to increase, to varying degrees, in 5 out the 13 subjects after such an exposure. A migration of mast cells towards the uppermost dermis appeared as the most important event. Thus, the normally upper "empty zone" of the dermis disappeared, and instead, a higher density of mast cells were found in this zone. These cells also seemed to have a tendency to increase in number towards the epidermal-dermal junctional zone and some of them lost their granular content and the cytoplasm shrunk (=degranulation). These findings could only be seen in the exposed skin. Two of the 13 cases instead showed a decrease in mast cell number, but the shift in mast cells towards the upper dermis was still visible. Twenty-four h after the provocation, the cellular number and location were normalized in all subjects.

CONCLUSIONS

By definition, normal healthy volunteers are assumed not to react to a TV/PC screen provocation. To our great surprise, this proved not to be true. The present results might lay a foundation to understand the underlying cause of so-called "screen dermatitis" with special reference to mast cells. However, blind or double-blind experiments using patients ought to be further investigated in order to find out the exact cause for the observed changes. Such causes include the effects of surrounding airborne chemicals, stress factors, etc.

Review of soluble uranium removal by nanoscale zero valent iron

Uranium (U) has been released to surface soil and groundwater through military and industrial activities. Soluble forms of U transferred to drinking water sources and food supplements can potentially threaten humans and the biosphere due to its chemical toxicity and radioactivity. The immobilization of aqueous U onto iron-based minerals is one of the most vital geochemical processes controlling the transport of U. As a consequence, much research has been focused on the use of iron-based materials for the treatment of U contaminated waters. One material currently being tested is nanoscale zero-valent iron (nZVI). However, understanding the removal mechanism of U onto nZVI is crucial to develop new technologies for contaminated water resources. This review article aims to provide information on the removal mechanism of U onto nZVI under different conditions (pH, U concentration, solution ion strength, humic acid, presence of O₂ and CO₂, microorganism effect) pertinent to environmental and engineered systems, and to provide risk or performance assessment results with the stability of nZVI products after removal of U in environmental restoration.

Chemokine stromal cell-derived factor 1alpha activates basophils by means of CXCR4

BACKGROUND

The CXC chemokine receptor 4 (CXCR4) is predominantly expressed on inactivated naive T lymphocytes, B lymphocytes, dendritic cells, and endothelial cells. CXC chemokine stromal cell-derived factor 1alpha (SDF-1alpha) is the only known ligand for CXCR4. To date, the CXCR4 expression and function of SDF-1alpha in basophils are unknown.

OBJECTIVE

The purpose of this study was to investigate the expression of CXCR4 and functions of SDF-1alpha in basophils and to characterize the role of the CXCR4-SDF-1alpha receptor ligand pair in the allergic inflammation.

METHODS

Basophil purification, flow cytometry, real-time quantitative RT-PCR assay, Northern blotting, intracellular free Ca(2+) change, chemotaxis assay, and histamine release assay were used.

RESULTS

CXCR4 is abundantly expressed on peripheral blood resting basophils (91%). Likewise, CXCR4 messenger (m)RNA is expressed in resting basophils (3.2 x 10(3) copies per 2 x 10(2) cells). The existence of CXCR4 mRNA was also confirmed in basophils by means of Northern blot analysis. SDF-1alpha induces an increase in intracellular free Ca(2+) in basophils. SDF-1alpha activates basophils to chemotaxis (chemotactic index = 3.8) and histamine release (36% of total content) through CXCR4 on the cells. The chemokines SDF-1alpha, eotaxin, RANTES, monocyte chemoattractant protein (MCP) 1, and macrophage inflammatory protein (MIP) 1alpha have been demonstrated at different potencies in induction of chemotaxis (eotaxin > SDF-1alpha > RANTES congruent with MCP-1 >> MIP-1alpha) and histamine release (MCP-1 congruent with SDF-1alpha > eotaxin > RANTES > MIP-1alpha). The optimal concentration seen for SDF-1alpha effects (chemotaxis and histamine release) on basophils was 100 ng/mL.

CONCLUSION

These results indicate that the CXCR4-SDF-1alpha receptor ligand pair may be important for the recruitment and activation of the basophils, which is a characteristic effector cell of the allergic inflammation.

Elevated expression of calcium-binding protein p9Ka is associated with increasing malignant characteristics of rat prostate carcinoma cells

Northern and Western blotting techniques were used to study expression of the mRNA and corresponding protein product of the S100-related calcium-binding molecule p9Ka in 6 different metastatic cell lines of the Dunning R3327 rat prostate cancer model. In cells with the lowest metastatic capability (G cells), p9Ka mRNA was barely detectable. In 2 weakly metastatic cell lines (AT-1 and AT-2), p9Ka transcript amounts were, respectively, 6.29 +/- 0.74 and 5.55 +/- 1.11 times that detected in the G cells. In 3 highly metastatic cell lines (AT-3, MAT-LyLu and MAT-Lu), the amounts of p9Ka mRNA were, respectively, 12.85 +/- 2.82, 13.06 +/- 1.69 and 11.62 +/- 1.81 times that expressed in the G cells. Western blot analyses detected no p9Ka protein in the G cells. The amounts of p9Ka protein expressed by tumour cells of intermediate metastatic capability (AT-1 and AT-2) were 3.4 +/- 1.3 microg and 3.3 +/- 1.4 microg, respectively, per 1 x 10(6) cells. The amounts of p9Ka protein expressed by the tumour cells of highest metastatic capability (AT-3, MAT-LyLu and MAT-Lu) were 8.3 +/- 1.1 microg, 8.7 +/- 1.6 microg and 9.6 +/- 1.7 microg, respectively, per 1 x 10(6) cells. Our data reveal a direct association between the elevated expression of mRNA and the p9Ka protein amounts and the increased metastatic capability of individual prostatic cancer cell lines. We suggest that calcium-binding protein p9Ka may play an important role in the metastatic behaviour of rat prostate cancer.

Experimental demonstration of energy-chirp compensation by a tunable dielectric-based structure

A tunable energy-chirp compensator was used to remove a correlated energy chirp from the 60-MeV beam at the Brookhaven National Laboratory Accelerator Test Facility. The compensator operates through the interaction of the wakefield of the electron bunch with itself and consists of a planar structure comprised of two alumina bars with copper-plated backs separated by an adjustable beam aperture. By changing the gap size, the correlated energy chirp of the electron bunch was completely removed. Calculations show that this device, properly scaled to account for the electron bunch charge and length, can be used to remove residual correlated energy spread at the end of the linacs used for free-electron lasers. The experimental results are shown to be in good agreement with numerical simulations. Application of this technique can significantly simplify linac design and improve free-electron lasers performance.

Effects of fulvic acid on the bioavailability of rare earth elements and GOT enzyme activity in wheat (Triticum aestivum)

Fulvic acid (FA) was extracted and purified from natural soil and the effects of such FA on the bioaccumulation of rare earth elements (REEs, La3+, Gd3+ and Y3+) in wheat seedling were investigated. The results indicated that low concentration of FA (<0.4 mg C/l to root, <0.7 mg C/l to tops (stem and leaves)) could increase the bioaccumulation values of REEs in wheat, but when the concentration of FA was high (>0.4 mg C/l to root, >1.5 mg C/l to tops) the bioaccumulation values were decreased. Kinetic experimental results suggested that bioaccumulation values of REEs in roots for 30 days were correlated with the kinetic linear growth equation, and correlation coefficients were higher than 0.861. The kinetic bioaccumulation pattern of REEs in tops was different from that in root. The bioaccumulation values of REEs in wheat root were much higher than in wheat tops. Variations of glutamic oxaloacetic transaminase (GOT) enzyme activities in wheat root and tops were determined. A good correlation existed between the bioaccumulation values of REEs and GOT enzyme activities, and the correlation coefficients were higher than 0.922. GOT is an important parameter influencing the bioavailability of REEs.

CXCR3 expression on CD34(+) hemopoietic progenitors induced by granulocyte-macrophage colony-stimulating factor: II. Signaling pathways involved

CXCR3, known to have four ligands (IFN-gamma inducible protein 10 (gamma IP-10), monokine induced by IFN-gamma (Mig), I-TAC, and 6Ckine), is predominantly expressed on memory/activated T lymphocytes. We recently reported that GM-CSF induces CXCR3 expression on CD34(+) hemopoietic progenitors, in which gamma IP-10 and Mig induce chemotaxis and adhesion. Here we further report that stimulation with GM-CSF causes phosphorylation of Syk protein kinase, but neither Casitas B-lineage lymphoma (Cbl) nor Cbl-b in CD34(+) hemopoietic progenitors can be blocked by anti-CD116 mAb. Specific Syk blocking generated by PNA antisense completely inhibits GM-CSF-induced CXCR3 expression in CD34(+) progenitors at both mRNA and protein as well as at functional levels (chemotaxis and adhesion). Cbl and Cbl-b blocking have no such effects. Thus, GM-CSF binds to its receptor CD116, and consequently activates Syk phosphorylation, which leads to induce CXCR3 expression. gamma IP-10 and Mig can induce Syk, Cbl, and Cbl-b phosphorylation in CD34(+) progenitors by means of CXCR3. gamma IP-10 or Mig has induced neither chemotaxis nor adhesion in GM-CSF-stimulated Cbl-b-blocked CD34(+) hemopoietic progenitors, whereas SDF-1alpha induces both chemotaxis and adhesion in these cells. Interestingly, gamma IP-10 and Mig can induce chemotaxis and adhesion in GM-CSF-stimulated Syk- or Cbl-blocked CD34(+) hemopoietic progenitors. Thus, Cbl-b, but not Syk and Cbl phosphorylation, is essential for gamma IP-10- and Mig-induced chemotaxis and adhesion in CD34(+) hemopoietic progenitors. This study provides a useful insight into novel signaling transduction pathways of the functions of CXCR3/gamma IP-10 and Mig, which may be especially important in the cytokine/chemokine environment for mobilization, homing, and recruitment during proliferation, differentiation, and maturation of hemopoietic progenitor cells.

Dietary sodium and potassium and risk of diabetes: A prospective study using data from the China Health and Nutrition Survey

AIMS

Dietary sodium and potassium intakes are well-known risk factors for cardiovascular outcomes. However, the associations between dietary sodium and potassium and diabetes are still controversial. Our study aimed to examine whether dietary sodium, potassium and the sodium-potassium ratio are associated with the risk of diabetes, based on a large sample of Chinese adults.

METHODS

The study data were from the 2004-2009 China Health and Nutrition Survey (CHNS), and 5867 participants were eligible for analysis. Sodium and potassium intakes were estimated based on three consecutive 24-h recalls at an individual level combined with a food inventory at a household level performed over the same 3-day period. Diabetes was defined as fasting glucose ≥7.0mmol/L (≥126mg/dL), HbA_1c ≥6.5% or use of antidiabetic drugs.

RESULTS

Over a mean follow-up of 4.7 years, there were 611 (10.4%) incident cases of diabetes. Participants in the higher quartiles (Q3 and Q4) of sodium intake had significantly higher risks of diabetes than those with the lowest sodium intake [Q3, RR: 1.41, 95% CI: 1.06-1.86 and Q4, RR: 1.35, 95% CI: 1.02-1.80; P<0.001 for trend]. In addition, high sodium intakes were significantly associated with levels of fasting glucose and HbA_1c (P<0.05 for trend), with similar associations also found with sodium-potassium ratios (P<0.05 for trend), but not for potassium intakes.

CONCLUSION

This study found that higher sodium intakes and sodium-potassium ratios were significantly associated with a higher risk of diabetes. Further clinical research is now necessary to confirm these results.

The role of testicular nuclear receptor 4 in chemo-resistance of docetaxel in castration-resistant prostate cancer

Docetaxel-based therapy is one of the first-line options for castration-resistant prostate cancer (CRPC). However, a large proportion of CRPC patients show different extents of docetaxel resistance. The current study aims to investigate the role of testicular nuclear receptor 4 (TR4) in docetaxel resistance in CRPC. TR4 expression level in prostate biopsy samples from CRPC patients treated with docetaxel was measured by immunohistochemistry (IHC). Alternation of TR4 expression in prostate cancer (PCa) cell line PC3 was applied to find out the influence of TR4 on half-maximal inhibitory concentration (IC50), cell viability and cell apoptosis. Patients who failed to achieve prostate-specific antigen (PSA) response (<50% PSA reduction from baseline) after docetaxel-based chemotherapy had a comparatively higher TR4 expression than those who achieved PSA response (⩾50% PSA reduction from baseline). Knocking down TR4 in PC3 cells led to a lower IC50 dose, poorer cell viability and more cell apoptosis when treated with docetaxel, whereas overexpression of TR4 in PC3 led to a higher IC50 dose, better cell viability and less cell apoptosis. TR4 enhances the chemo-resistance of docetaxel in CRPC. It may serve as a biomarker to determine the prognosis of docetaxel-based therapy and as a potential therapy target to combine with docetaxel to better suppress CRPC.

Association between interleukin gene polymorphisms and risk of recurrent oral ulceration

We conducted a case-control study to investigate the association between the functional IL-1β+3954 (C/T), IL-6-174 (G/C), IL-10-1082 (G/A), and IL-10-819C/T genetic polymorphisms and risk of recurrent oral ulceration (ROU) in a Chinese population. Polymorphisms of IL-1β+3954C/T, IL-6-174G/C, IL-10-1082A/G and IL-10-819C/T were assessed by polymerase chain reaction-restriction fragment length polymorphism. The genotype distributions of the IL-1β+3954 C/T and IL-10-819C/T were in Hardy-Weinberg equilibrium in the control group. Conditional logistic regression analyses showed that subjects carrying the IL-1β+3954CC and IL-10-1082AA genotypes had a significantly increased risk of ROU, with adjusted ORs (95%CI) of 2.86 (1.37-6.33) and 1.72 (1.02-2.89), respectively. In summary, we found that IL-1β+3954C/T and IL-10-1082A/G polymorphisms are associated with an increased risk of ROU.

Structural difference analysis of adult's intestinal flora basing on the 16S rDNA gene sequencing technology

OBJECTIVE

Through 16S rDNA technology, we aimed at separating adults aging 20-50 years old into a few groups and processing the high-throughput sequencing analysis, in order to explore the features and differences of intestinal flora in each age group in a microcosmic perspective.

PATIENTS AND METHODS

120 stool specimens were collected strictly in accordance with acceptance criteria and exclusion criteria. 49 subjects aging 20-29 years old (Group AGE1), 51 subjects aging 30-39 years old (Group AGE2), and 20 subjects aging 40-49 years old (Group AGE3) were divided into 3 groups. Bacteria DNA from fresh stool specimens of 3 groups were abstracted. Illumina MiSeq high-throughput sequencing platform was applied to process 16S rDNA sequencing in Area 338F_806R for intestinal flora detection. I-Sanger Bio-cloud platform was applied for the analysis of intestinal flora structure changes in phylum level and genus level.

RESULTS

Among the age of 20-50, with older age, the abundance of intestinal flora decreased among healthy adults more than 40 years old. In addition, the diversity and sample dispersion of intestinal flora is significantly different from people among 20-40 years old. The decrease ratio of Firmicutes/Bacteroidetes indicated that as the age grows, glucose tolerance might decrease. Comparing with people among 20-40 years old, the amount of Bifidobacterium and Eubacterium in people over 40 years old have significantly decreased. The decrease of Bifidobacterium and Eubacterium may increase the risks of cognitive impairment and lower the anti-inflammation and anti-cancer efficacy in human body, respectively. Subdoligranulum relates to poor metabolism and chronic inflammation and it happens more in people aged over 40 than young people who are among 20-40 years old.

CONCLUSIONS

There are differences in the intestinal flora of healthy adults aged 20-50. Effective intervention of the intestinal flora may play a role in delaying aging and preventing diseases.

Systematic comparison of gene expression through analysis of cDNA fragments within or near to the protein-coding region

Life is controlled by the timely and ordered expression of genes. Identification of important genes involved in specific physiological and pathological conditions requires efficient methods to analyse differential gene expression. We describe a novel strategy, namely complete comparison of gene expression (CCGE), for a systematic assessment of differentially expressed genes. Using the CCGE method, double-stranded cDNA is digested with two restriction enzymes that cut with different frequencies, the representative cDNA fragments are generated within or near to the protein-coding region. After being flanked by two different types of adapters, and amplified by a nested suppression PCR, the selected cDNA fragments, representing entire cDNA population, can be divided into 256 subsets; amplified and compared in a systematic manner.

Observation of enhanced transformer ratio in collinear wakefield acceleration

One approach to future high energy particle accelerators is based on the wakefield principle: a leading high-charge drive bunch is used to excite fields in an accelerating structure or plasma that in turn accelerates a trailing low-charge witness bunch. The transformer ratio R is defined as the ratio of the maximum energy gain of the witness bunch to the maximum energy loss of the drive bunch. In general, R<2 for this configuration. A number of techniques have been proposed to overcome the transformer ratio limitation. We report here the first experimental study of the ramped bunch train (RBT) technique in a dielectric based accelerating structure. A single drive bunch was replaced by two bunches with charge ratio of 1:2.5 and a separation of 10.5 wavelengths of the fundamental mode. An average measured transformer ratio enhancement by a factor of 1.31 over the single drive bunch case was obtained.

Modic type III lesions and Schmorl's nodes are the same pathological changes?

INTRODUCTION

Degenerative disc disease (DDD) is a major health problem worldwide. Both Modic lesions and Schmorl's nodes are considered to correlate with DDD such as low back pain. Modic lesions are the changes of degenerative vertebral endplate and adjacent bone marrow observed on magnetic resonance imaging and are divided into three types. Modic type III lesions are thought to represent extensive subchondral bone sclerosis within the bone marrow of adjacent endplate. The pathological performance of Schmorl's nodes is cystic lesions around indistinct sclerotic margins and beneath the cartilaginous endplate. Coincidently, there are many similarities between Modic type III lesions and Schmorl's nodes including pathological appearances, pathogenetic location and related diseases.

HYPOTHESIS

We hypothesize that Modic type III lesions and Schmorl's nodes are the same pathological changes, and Modic type III lesions may be the quiescent or incipient pathology phrase of Schmorl's nodes. The clinical symptoms of DDD are also accompanied by emergence of these pathological changes.

TESTING

A longitudinal study could be used to test this hypothesis. We could measure and analyze whether Modic type III lesions have increased in size or evolved into Schmorl's nodes as time goes on.

SIGNIFICANCE

This hypothesis explains the possible pathologic process of Modic type III lesions and Schmorl's nodes. If the hypothesis were conformed, Modic type III lesions and Schmorl's nodes will be rediscovered, which provides the new basis for the clinical treatment of DDD. In additions, this hypothesis also has crucial significances for the classification of Modic lesions.

Experimental observation of energy modulation in electron beams passing through terahertz dielectric wakefield structures

We report the observation of a strong wakefield induced energy modulation in an energy-chirped electron bunch passing through a dielectric-lined waveguide. This modulation can be effectively converted into a spatial modulation forming microbunches with a periodicity of 0.5-1 ps and, hence, capable of driving coherent terahertz radiation. The experimental results agree well with theoretical predictions.

The application of illite supported nanoscale zero valent iron for the treatment of uranium contaminated groundwater

In this study, nanoscale zero valent iron I-NZVI was investigated as a remediation strategy for uranium contaminated groundwater from the former Cimarron Fuel Fabrication Site in Oklahoma, USA. The 1 L batch-treatment system was applied in the study. The result shows that 99.9% of uranium in groundwater was removed by I-NZVI within 2 h. Uranium concentration in the groundwater stayed around 27 μg/L, and there was no sign of uranium release into groundwater after seven days of reaction time. Meanwhile the release of iron was significantly decreased compared to NZVI which can reduce the treatment impact on the water environment. To study the influence of background pH of the treatment system on removal efficiency of uranium, the groundwater was adjusted from pH 2-10 before the addition of I-NZVI. The pH of the groundwater was from 2.1 to 10.7 after treatment. The removal efficiency of uranium achieved a maximum in neutral pH of groundwater. The desorption of uranium on the residual solid phase after treatment was investigated in order to discuss the stability of uranium on residual solids. After 2 h of leaching, 0.07% of the total uranium on residual solid phase was leached out in a HNO₃ leaching solution with a pH of 4.03. The concentration of uranium in the acid leachate was under 3.2 μg/L which is below the EPA's maximum contaminant level of 30 μg/L. Otherwise, the concentration of uranium was negligible in distilled water leaching solution (pH = 6.44) and NaOH leaching solution (pH = 8.52). A desorption study shows that an acceptable amount of uranium on the residuals can be released into water system under strong acid conditions in short terms. For long term disposal management of the residual solids, the leachate needs to be monitored and treated before discharge into a hazardous landfill or the water system. For the first time, I-NZVI was applied for the treatment of uranium contaminated groundwater. These results provide proof that I-NZVI has improved performance compared to NZVI and is a promising technology for the restoration of complex uranium contaminated water resources.

Interaction of an Ultrarelativistic Electron Bunch Train with a W-Band Accelerating Structure: High Power and High Gradient

Electron beam interaction with high frequency structures (beyond microwave regime) has a great impact on future high energy frontier machines. We report on the generation of multimegawatt pulsed rf power at 91 GHz in a planar metallic accelerating structure driven by an ultrarelativistic electron bunch train. This slow-wave wakefield device can also be used for high gradient acceleration of electrons with a stable rf phase and amplitude which are controlled by manipulation of the bunch train. To achieve precise control of the rf pulse properties, a two-beam wakefield interferometry method was developed in which the rf pulse, due to the interference of the wakefields from the two bunches, was measured as a function of bunch separation. Measurements of the energy change of a trailing electron bunch as a function of the bunch separation confirmed the interferometry method.

Subpicosecond bunch train production for a tunable mJ level THz source

A strong energy modulation in an electron bunch passing through a dielectric-lined waveguide was recently demonstrated in Antipov et al., Phys. Rev. Lett. 108, 144801 (2012). In this Letter, we demonstrate a successful conversion of this energy modulation into a beam density modulation, and the formation of a series of microbunches with a subpicosecond periodicity by means of magnetic optics (chicane). A strong coherent transition radiation signal produced by the microbunches is obtained and the tunability of its carrier frequency in the 0.68-0.9 THz range by regulating the energy chirp in the incoming electron bunch is demonstrated using infrared interferometry. A tabletop, compact, tunable, and narrowband source of intense THz radiation based on this technology is proposed.

Cut-offs for defining uterine prolapse using transperineal ultrasound in Chinese women: prospective multicenter study

OBJECTIVE

Transperineal ultrasound is a simple and highly repeatable method that has been used increasingly in the quantification of pelvic organ prolapse, but abnormal uterine descent on ultrasound in Chinese women is still poorly defined. We aimed to determine the optimal cut-off to define abnormal uterine descent on transperineal ultrasound in Chinese women.

METHODS

This prospective multicenter study recruited women who were examined in tertiary-level gynecological centers, due to symptoms of lower urinary tract and/or pelvic floor dysfunction, between February 2017 and September 2018. All recruited women underwent a standardized interview, pelvic organ prolapse quantification (POP-Q) examination, and four-dimensional transperineal ultrasound examination. On ultrasound, uterine descent was measured relative to the posteroinferior margin of the symphysis pubis during maximum Valsalva maneuver. The optimal cut-off value for definition of abnormal uterine descent was selected as the value with the highest Youden index and the diagnostic performance of this cut-off for the prediction of prolapse symptoms and POP-Q stage was assessed and compared by means of the area under the receiver-operating-characteristics curve (AUC).

RESULTS

In total, 538 Chinese women, with a mean age of 39.4 (range, 18-81) years, were enrolled into the study. Both uterine descent on transperineal ultrasound (P < 0.001) and POP-Q stage (P < 0.001) were associated strongly with presence of prolapse symptoms. Uterine descent on ultrasound was associated significantly with POP-Q stage for apical compartment prolapse (P < 0.001). The optimal cut-off value for the definition of abnormal uterine descent on transperineal ultrasound during maximum Valsalva maneuver in the prediction of prolapse symptoms was 4.79 mm above the symphysis pubis (AUC, 0.75 (95% CI, 0.71-0.78)), while the optimal cut-off values in the prediction of prolapse of POP-Q Stage ≥ 1 and POP-Q Stage ≥ 2 were 6.63 mm above the symphysis pubis (AUC, 0.83 (95% CI, 0.80-0.86)) and 8.42 mm below the symphysis pubis (AUC, 0.85 (95% CI, 0.82-0.88)), respectively.

CONCLUSIONS

The optimal cut-off value to define abnormal uterine descent on transperineal ultrasound during maximum Valsalva maneuver for the prediction of prolapse symptoms in this population of Chinese women was 4.79 mm above the symphysis pubis, close to that for predicting apical compartment prolapse of POP-Q Stage ≥ 1 (6.63 mm above the symphysis pubis). These are somewhat different from values described previously in mainly Caucasian populations. Ethnic differences should be taken into account in the evaluation of pelvic organ prolapse using transperineal ultrasound. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Observation of High Transformer Ratio of Shaped Bunch Generated by an Emittance-Exchange Beam Line

Collinear wakefield acceleration has been long established as a method capable of generating ultrahigh acceleration gradients. Because of the success on this front, recently, more efforts have shifted towards developing methods to raise the transformer ratio (TR). This figure of merit is defined as the ratio of the peak acceleration field behind the drive bunch to the peak deceleration field inside the drive bunch. TR is always less than 2 for temporally symmetric drive bunch distributions and therefore recent efforts have focused on generating asymmetric distributions to overcome this limitation. In this Letter, we report on using the emittance-exchange method to generate a shaped drive bunch to experimentally demonstrate a TR≈5 in a dielectric wakefield accelerator.