Calibration of image plate and back illuminated charge coupled device detectors at the thermal emission band of high Z target laser produced plasmas (80-800 eV).

We present a systematic method to absolutely calibrate detector efficiency vs photon energy using a laser produced plasma broadband x-ray source, a gold standard calibrated detector, and transmission gratings (TGs) as dispersive elements. Calibration uses one calibrated TG and a calibrated gold standard detector on one channel and a second calibrated TG and a detector to be calibrated on the other channel. Both channels simultaneously view the laser-produced plasma x-ray source from the same angle with respect to the laser beam and the planar target normal. Image plate detectors are calibrated for the first time at photon energies below 700 eV. Single shot simultaneous calibration of several detectors is possible, making this method an efficient and practical way to periodically calibrate detectors, using in-house capabilities of laser laboratories.

Laser produced soft x-ray source diagnostics with temporal, spectral, and spatial resolution.

We demonstrate the use of three diagnostic tools which simultaneously view the target from nearly the same direction, and their results are combined to provide temporally, spectrally, and spatially resolved absolutely calibrated target emission information. To demonstrate this capability, Au targets were irradiated by 1.8 kJ, 3 ns laser pulses to produce broadband soft x-ray emission in the 0.1-3.5 keV spectral range. Target diagnostics included a time-resolved x-ray diode array, each measured a partial spectral band, time-integrated spectrally resolved absolutely calibrated transmission grating spectrometer, and static and time-resolved soft x-ray imagers coupled to a charge-coupled device camera and to a streak camera, respectively, measuring spatially and temporally resolved radiation at the main Au target emission bands. The combined temporally, spectrally, and spatially resolved absolutely calibrated target emission result can be compared to simulations and be used to design and analyze experiments in which the source emission is used as a drive for various physical processes.

Time-dependent soft and hard x-ray measurements using streak and x-ray diode array diagnostic systems.

High-temperature, high-density experiments require a simultaneous understanding of temporal and spectral regions. The spectral x-ray streak camera (SXSC) is a new high-temporal-resolution spectral x-ray diagnostic system that allows researchers to differentiate between soft and hard x-ray regions. The diagnostic offers three spectral channels with a wide spectral range, one direct channel that includes a filter and two indirect channels that include both mirrors and filters. The opto-mechanical design positions the filtered radiation at three different locations along the streak photo-cathode (PC) slit to provide time-dependent spectral channels with pico-second temporal resolution. A moderate spatial resolution (150-700 µm) is achieved using slits perpendicular to the PC slit, while the slit width is optimized according to the central channel wavelength (for each channel). The diagnostic system covers a spectral range of 30-500 eV for the mirror channels and >1300 eV for the direct channel. The temporal and spatial axes of the streak camera are calibrated with respect to a sequence of x-ray pulses. The SXSC diagnostic system is tested and analyzed using Marshak-wave emission from an SiO2 foam that was heated by a laser-beam irradiated halfraum. The SXSC results are compared to measurements from an x-ray diode array with similar spectral channels.

Measurement of L-shell emission from mid-Z targets under non-LTE conditions using Transmission Grating Spectrometer and DANTE power diagnostics.

In this work, we present the measurement of L-band emission from buried Sc/V targets in experiments performed at the OMEGA laser facility. The goal of these experiments was to study non-local thermodynamic equilibrium plasmas and benchmark atomic physics codes. The L-band emission was measured simultaneously by the time resolved DANTE power diagnostic and the recently fielded time integrated Soreq-Transmission Grating Spectrometer (TGS) diagnostic. The TGS measurement was used to support the spectral reconstruction process needed for the unfolding of the DANTE data. The Soreq-TGS diagnostic allows for broadband spectral measurement in the 120 eV-2000 eV spectral band, covering L- and M-shell emission of mid- and high-Z elements, with spectral resolution λ/Δλ = 8-30 and accuracy better than 25%. The Soreq-TGS diagnostic is compatible with ten-inch-manipulator platforms and can be used for a wide variety of high energy density physics, laboratory astrophysics, and inertial confinement fusion experiments.

Enhanced accuracy of x-ray spectra reconstruction from filtered diode array measurements by adding a time integrated spectrometer.

A new approach for the spectral reconstruction of time-dependent emission of soft x-ray sources based on the measurement of filtered x-ray diode array systems is suggested. Two reconstruction methods, based on this approach, are demonstrated using both simulated and measured data. The methods use the filtered x-ray diode measurement together with a co-aligned, time-integrated, spectrally resolved measurement, such as transmission grating spectroscopy. The additional experimental information allows for high accuracy spectral reconstruction, even for plasmas far from local thermodynamic equilibrium where the traditional reconstruction methods may miss some important source spectral features. For the demonstrated cases, the accuracy of the new reconstruction methods is better than 10% for the energy dependent flux and 1% of the total flux, which is higher than the accuracy of previous methods and better than the accuracy of the measurement itself.

Effect of triple antibiotic paste with or without ethylenediaminetetraacetic acid on surface loss and surface roughness of radicular dentine.

This study aimed to compare the effect of two concentrations of triple antibiotic paste (TAP) with or without ethylenediaminetetraacetic acid (EDTA) on surface loss and surface roughness of radicular dentine. Human radicular dentine specimens were randomized into six experimental groups (n = 16 per group). The first and second groups were treated with 1,000 mg/mL or 1 mg/mL of TAP for 4 weeks. The third and fourth groups were treated with 1,000 mg/mL or 1 mg/mL of TAP for 4 weeks followed by 17 % EDTA for 5 min. The fifth group was treated with 17 % EDTA for 5 min and the sixth group received no treatment (control). Dentine surface loss and surface roughness were quantified after various treatments using optical and contact profilometry, respectively. One-way ANOVA followed by Fisher's protected least significant differences was used for statistical analyses. All treatment groups showed significantly higher surface loss compared to the untreated dentine. Dentine treated with 1,000 mg/mL had significant increase in surface loss and surface roughness compared to dentine treated with 1 mg/mL of TAP. The use of EDTA after both concentrations of TAP did not have significant additive effect on surface loss and surface roughness of dentine. The clinically used concentration of TAP (1,000 mg/mL) caused significantly higher surface loss and surface roughness of radicular dentine compared to the use of 1 mg/mL of TAP. Furthermore, the substantial amount of dentine surface loss and surface roughness detected in the current study may be attributed to TAP rather than EDTA.

Single-shot calibration of soft x-ray mirrors using a sinusoidal transmission grating.

Calibration of soft x-ray diagnostics is a challenge due to the lack of laboratory-size calibrated sources. An in situ calibration method for newly developed x-ray mirrors, is presented. The x-ray source is produced by laser-matter interaction, and twin transmission gratings which create two identical dispersion lines. The gratings have a sinusoidal transmission function, which produces a highly precise high-orders free spectrum. An x-ray mirror interacts with one of the dispersion lines, and the mirror efficiency curve as a function of wavelength is extracted. Mirror efficiency shows good agreement with the literature, and evidence of water layer may justify the need of in situ calibration.

Development of new antiatherosclerotic and antithrombotic drugs utilizing F11 receptor (F11R/JAM-A) peptides.

Peptides with enhanced resistance to proteolysis, based on the amino acid sequence of the F11 receptor molecule (F11R, aka JAM-A/Junctional adhesion molecule-A), were designed, prepared, and examined as potential candidates for the development of anti-atherosclerotic and anti-thrombotic therapeutic drugs. A sequence at the N-terminal of F11R together with another sequence located in the first Ig-loop of this protein, were identified to form a steric active-site operating in the F11R-dependent adhesion between cells that express F11R molecules on their external surface. In silico modeling of the complex between two polypeptide chains with the sequences positioned in the active-site was used to generate peptide-candidates designed to inhibit homophilic interactions between surface-located F11R molecules. The two lead F11R peptides were modified with D-Arg and D-Lys at selective sites, for attaining higher stability to proteolysis in vivo. Using molecular docking experiments we tested different conformational states and the putative binding affinity between two selected D-Arg and D-Lys-modified F11R peptides and the proposed binding pocket. The inhibitory effects of the F11R peptide 2HN-(dK)-SVT-(dR)-EDTGTYTC-CONH2 on antibody-induced platelet aggregation and on the adhesion of platelets to cytokine-inflammed endothelial cells are reported in detail, and the results point out the significant potential utilization of F11R peptides for the prevention and treatment of atherosclerotic plaques and associated thrombotic events.

Bioactive nanofibrous scaffolds for regenerative endodontics.

Here we report the synthesis, materials characterization, antimicrobial capacity, and cytocompatibility of novel antibiotic-containing scaffolds. Metronidazole (MET) or Ciprofloxacin/(CIP) was mixed with a polydioxanone (PDS)polymer solution at 5 and 25 wt% and processed into fibers. PDS fibers served as a control. Scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), tensile testing, and high-performance liquid chromatography (HPLC) were used to assess fiber morphology, chemical structure, mechanical properties, and drug release, respectively. Antimicrobial properties were evaluated against those of Porphyromonas gingivalis/Pg and Enterococcus faecalis/Ef. Cytotoxicity was assessed in human dental pulp stem cells (hDPSCs). Statistics were performed, and significance was set at the 5% level. SEM imaging revealed a submicron fiber diameter. FTIR confirmed antibiotic incorporation. The tensile values of hydrated 25 wt% CIP scaffold were significantly lower than those of all other groups. Analysis of HPLC data confirmed gradual, sustained drug release from the scaffolds over 48 hrs. CIP-containing scaffolds significantly (p < .00001) inhibited biofilm growth of both bacteria. Conversely, MET-containing scaffolds inhibited only Pg growth. Agar diffusion confirmed the antimicrobial properties against specific bacteria for the antibiotic-containing scaffolds. Only the 25 wt% CIP-containing scaffolds were cytotoxic. Collectively, this study suggests that polymer-based antibiotic-containing electrospun scaffolds could function as a biologically safe antimicrobial drug delivery system for regenerative endodontics.

Advanced experimental applications for x-ray transmission gratings spectroscopy using a novel grating fabrication method.

A novel fabrication method for soft x-ray transmission grating and other optical elements is presented. The method uses focused-ion-beam technology to fabricate high-quality free standing grating bars on transmission electron microscopy grids. High quality transmission gratings are obtained with superb accuracy and versatility. Using these gratings and back-illuminated CCD camera, absolutely calibrated x-ray spectra can be acquired for soft x-ray source diagnostics in the 100-3000 eV spectral range. Double grating combinations of identical or different parameters are easily fabricated, allowing advanced one-shot application of transmission grating spectroscopy. These applications include spectroscopy with different spectral resolutions, bandwidths, dynamic ranges, and may serve for identification of high-order contribution, and spectral calibrations of various x-ray optical elements.

Outcome analysis of patients with transformed teratoma to primitive neuroectodermal tumor.

BACKGROUND: The emergence of a primitive neuroectodermal tumor (PNET) within a germ-cell tumor (GCT) is rare. We assess the prognosis and response to treatment. PATIENTS AND METHODS: Eighty-one patients were identified. Selected patients were treated with cyclophosphamide 1200 mg/m(2), doxorubicin 75 mg/m(2), and vincristine 2 mg i.v. alternating with ifosfamide 1.8 g/m(2) x 5 days plus etoposide 100 mg/m(2) x 5 days (CAV/IE). Ewing's sarcoma (EWS) translocation was assessed using a FISH-based method. RESULTS: Median follow-up was 41 months. Seventy-six patients had PNET in the primary tumor or in initial metastasis. Five harbored PNET only at relapse. Twenty-six of 76 underwent primary retroperitoneal lymph node dissection, 13 of whom had retroperitoneal PNET and four are dead of disease (DOD). Fifty of 76 were initially treated with GCT chemotherapy (n = 49) or CAV/IE (n = 1). Twenty-seven of these 50 underwent complete postchemotherapy resection of residual PNET and 17 are DOD. Ten patients received CAV/IE. Eight achieved an objective response, and five are currently alive. One of the 14 specimens examined carried the EWS translocation. CONCLUSIONS: PNET of GCT origin is associated with an adverse outcome. For low-volume disease, surgery is the optimal initial therapy. CAV/IE may have a role in patients with unresectable disease.

Characteristics and clinical significance of bacterial colonization of ureteral double-J stents in children.

OBJECTIVE: To determine the frequency, type of pathogen and clinical significance of bacterial colonization of double-J stents after pyeloplasty in children. PATIENTS AND METHODS: The medical files of 82 consecutive children (22 girls, 60 boys) who underwent pyeloplasty at a tertiary pediatric medical center in 2000-2007 were reviewed. Additional inclusion criteria were sterile urine preoperatively and placement of an indwelling double-J stent during surgery. Intravenous gentamicin was administered prior to pyeloplasty and stent removal; cephalexin was administered postoperatively until discharge. Children with a postoperative urinary tract infection (UTI) received full-dose antimicrobial treatment followed by prophylaxis until stent removal. RESULTS: Median patient age at surgery was 11 months (1 month-17.5 years). Forty-nine stents were inserted on the left side, 32 on the right, and one bilaterally. Cultures showed bacterial colonization in 58 cases (70.7%); 15 (25.8%) grew Staphylococcus (coagulase negative and positive). Eight children had febrile UTI postoperatively; in four the stent was colonized by Enterococci and in one by Proteus; three were sterile. There was no statistically significant association between positive stent culture and febrile UTI, patient age or sex, or stent laterality. The study was potentially limited by its observational design, small sample size, and the selective antibiotic treatment of patients with UTI which may have affected stent bacterial resistance. CONCLUSION: Bacterial colonization is not uncommon in double-J stents retained for several weeks after pyeloplasty, but is usually not clinically significant. Enterococcus is the most frequent pathogen.

The effect of sildenafil on ocular blood flow.

Sildenafil is a potent phosphodiesterase (PDE) 5 inhibitor that is used for patients with erectile dysfunction. Sildenafil induces vasodilation in selected smooth muscle via increased levels of guanosine 3', 5' cyclic monophosphate and increase in nitric oxide. The vasodilatory effects of the PDE 5 inhibitors led us to review its effect on the ocular vasculature. Sildenafil appears to increase blood flow velocity significantly in the retrobulbar and choroidal circulation. Most studies suggest an increase in choroidal blood flow, with a lesser effect on the retinal vasculature.

Early initiation of aspirin after prostate and transurethral bladder surgeries is not associated with increased incidence of postoperative bleeding: a prospective, randomized trial.

PURPOSE: Lower urinary tract operations are being increasingly performed in elderly patients, in whom aspirin intake is common for preventing cardiovascular disease. We determined the safety of early aspirin re-initiation after lower urinary tract surgeries. MATERIALS AND METHODS: A randomized, open label clinical trial was done. The study cohort included patients referred for transurethral prostatectomy, open prostatectomy and transurethral resection of bladder tumor while receiving aspirin prophylaxis. After controlling for surgical modality patients were randomized into 2 arms, including aspirin treatment initiation 24 hours after discontinuing of bladder irrigation (early treatment group) and aspirin treatment initiation 3 weeks after surgery (late treatment group). Primary end points were pre-discharge hematuria necessitating the restoration of bladder irrigation or the cessation of aspirin treatment and late hematuria treated in an urgent care setting, requiring hospital admission or compelling the cessation of aspirin treatment. RESULTS: A total of 120 patients were enrolled, including 60 per treatment group. There were no significant differences between the groups in surgery related factors that could have affected postoperative bleeding. Primary end points were attained by 16 of the 120 patients (13.6%), including 10 of the 60 (16.7%) in the early treatment group and 6 (10%) in the late treatment group (p = 0.28). Time to catheter removal and persistent hematuria duration were similar in the 2 groups. Cardiovascular morbidity was noted in 3 of 120 patients, of whom all were assigned to the early treatment group. CONCLUSIONS: Early aspirin initiation after lower urinary tract surgeries does not appear to carry an increased risk of postoperative bleeding. Thus, it may be considered in patients at high risk for cardiovascular morbidity.

Clinical implication of routine stone culture in percutaneous nephrolithotomy--a prospective study.

OBJECTIVES: To evaluate the correlation between preoperative urine culture (UC) and intraoperative stone culture (SC) and the impact of SC findings on clinical decisions. METHODS: UC and intraoperative fragmented SC were prospectively obtained in all patients undergoing percutaneous nephrolithotomy between January 2004 and March 2005. Patients with a positive UC received a full course of antibiotics before surgery. All postoperative systemic inflammatory response syndrome (SIRS) events were recorded, as was the antibiotic regimen used and any changes in antibiotic treatment secondary to the SC results. RESULTS: The study group consisted of 75 consecutive patients. Of these 75 patients, 33 (49%) had sterile UC and SC results. Both urine and renal stones were colonized in 17 patients (24%); in 6 of them, the UC and SC showed different pathogens. A colonized SC associated with a sterile UC was found in 19 patients (25%). The calculated UC sensitivity, specificity, and positive and negative predictive value for the detection of stone colonization was 30%, 94%, and 84% and 58%, respectively. Seventeen patients (22%) had postoperative SIRS. In 13 of them, a change in antibiotic treatment was made according to the SC findings. On univariate analysis, the incidence of SIRS was not related to the length of the operation, stone-free rate, or supracostal or infracostal access. The relative risk of SIRS when the SC was positive was 3.6. CONCLUSIONS: Renal calculi pathogens are one of the predisposing factors for infectious events; however, preoperative UC often fails to grow stone-colonizing bacteria. Intraoperative SC may be essential in directing the antibiotic regimen postoperatively and should be routinely used.

Genomic structure, organization and promoter analysis of the human F11R/F11 receptor/junctional adhesion molecule-1/JAM-A.

The F11-receptor (F11R) (a.k.a. JAM-1, JAM-A, CD321) is a cell adhesion molecule of the immunoglobulin superfamily involved in platelet adhesion, secretion and aggregation. In addition, the F11R plays a critical role in the function of endothelial cells and in platelet adhesion to inflamed endothelium. In the present study, we used partial sequences of the human F11R gene, F11R cDNAs, and information in unannotated human genome databases, to delineate the F11R gene. We found that the F11R gene is composed of 13 exons (E1a, 1b, 1c, E1-E10) encoding two groups of mRNAs differing in length and sequence at their 5' UTRs, referred to as type 1 and type 2 messages. Type 1 cDNAs are shorter at the 5' end and contain a region not found within type 2 messages. Type 1 mRNAs are present in endothelial cells (EC), platelets, white blood cells and in the cell lines CMK, HeLa, K562, HOG and A549, while type 2 messages are limited to EC. Type 1 messages contain exons E1-E10 whereas type 2 messages usually contain exons E1a, 1c, part of E1 and E2-E10. The translation start site is localized in the 3' end of E1, common for both type 1 and type 2 messages. Expression of these messages is regulated by two alternative promoters, P1 and P2. P1 is a TATA-less promoter containing an initiator element, multiple transcription start sites, several GC and CCAAT boxes, and GATA, NF-kappaB and ets consensus sequences. The cloned P1 drives efficient expression of the luciferase reporter gene. A high level of similarity between human P1 and its rat and mouse counterparts was observed. Promoter P2, located upstream of P1, contains a TATA box, GC boxes, a CCAAT box and GATA and ets consensus sequences. 3' RACE provided evidence for variability in the 3' UTR due to the presence of two polyadenylation signals. The finding of multiple regulatory sites in the promoters supplements the biochemical evidence that the F11R has several different roles in the functional repertoire of endothelial cells, platelets and other cells. In particular, the presence of NF-kappaB provides additional evidence to the significance of the F11R function in the initiation of inflammatory thrombosis.

Limited efficiency of a silver selenogallate optical parametric oscillator caused by two-photon absorption.

The nonresonant two-photon absorption (TPA) coefficient in silver selenogallate (AgGaSe(2)) crystals was measured for both ordinary and extraordinary polarizations in the 1300-1600-nm wavelength range. We found a cutoff wavelength for the TPA at between 1400 and 1500 nm, which corresponds to half of the bandgap energy of the AgGaSe(2) crystal. Below the cutoff wavelength we measured the TPA coefficient to be approximately 0.035 cm/MW for the extraordinary polarization and two to three times lower for the ordinary polarization. We compared the AgGaSe(2) samples from two manufacturers and observed a factor of 2 difference in the TPA coefficients. Because of the high TPA, the 1.32-mum pumped AgGaSe(2) optical parametric oscillator conversion efficiency was clipped at a low level.

On the in vitro vasoactivity of bile acids.

We compared the vasorelaxant action of nine different bile acids and correlated their vasorelaxant activity with their individual indices for hydrophobicity or lipophilicity. Vasorelaxant activity correlated with the relative lipid solubility of bile acids with lipophilic bile acids exhibiting the greatest vasorelaxant activity with modest to no vasorelaxant activity exhibited by hydrophilic bile acids. We also investigated whether bile acid-induced vasorelaxation is mediated by antagonism of a prototypal contractile receptor, the alpha(1)-adrenoceptor, by stimulation of a bile acid surface membrane receptor, by the release of endothelium-derived relaxant factors, by promoting the generation of reactive oxygen species and increasing the extent of lipid peroxidation, or by modifying membrane fluidity. Lipophilic bile acids induce vasorelaxation possibly by antagonizing alpha(1)-adrenoceptors, a phenomenon that manifests itself as a lowering of the affinity of vascular alpha(1)-adrenoceptors. Bile acid-induced vasorelaxation was not dependent upon stimulation of a bile acid surface membrane receptor or the release of endothelium-derived relaxant factors. Lipophilic bile acids can also increase the extent of lipid peroxidation with a subtle reduction in the fluidity of rat vascular smooth muscle membranes not associated with loss of membrane cholesterol or phospholipid. We have concluded that lipophilic bile acids are non-selective vasorelaxants whose mechanism of action is a multifaceted process involving antagonism of contractile surface membrane receptors possibly effected by an increased extent of lipid peroxidation and/or membrane fluidity but occurs independent of the release of endothelial-derived relaxant factors or stimulation of a surface membrane bile acid binding site.

Identification of ecto-PKC on surface of human platelets: role in maintenance of latent fibrinogen receptors.

Human platelets express a protein phosphorylation system on their surface. A specific protein kinase C (PKC) antibody, monoclonal antibody (MAb) 1.9, which binds to the catalytic domain of PKC and inhibits its activity, causes the aggregation of intact platelets while inhibiting the phosphorylation of platelet surface proteins. Photoaffinity labeling with 100 nM 8-azido-[alpha(32)P]ATP identified this ecto-PKC as a single surface protein of 43 kDa sensitive to proteolysis by extracellular 0.0005% trypsin. Inhibition of the binding of 8-azido-[alpha(32)P]ATP to the 43-kDa surface protein by MAb 1.9 identified this site as the active domain of ecto-PKC. Covalent binding of the azido-ATP molecule to the 43-kDa surface protein inhibited the phosphorylative activity of the platelet ecto-PKC. Furthermore, PKC pseudosubstrate inhibitory peptides directly induced the aggregation of platelets and inhibited azido-ATP binding to the 43-kDa protein. Platelet aggregation induced by MAb 1.9 and by PKC inhibitory peptides required the presence of fibrinogen and resulted in an increase in the level of intracellular free calcium concentration. This increase in intracellular free calcium concentration induced by MAb 1.9 was found to be dependent on the binding of fibrinogen to activated GPIIb/IIIa integrins, suggesting that MAb 1.9 causes Ca(2+) flux through the fibrinogen receptor complex. We conclude that a decrease in the state of phosphorylation of platelet surface proteins caused by inhibition of ecto-PKC results in membrane rearrangements that can induce the activation of latent fibrinogen receptors, leading to platelet aggregation. Accordingly, the maintenance of a physiological steady state of phosphorylation of proteins on the platelet surface by ecto-PKC activity appears to be one of the homeostatic mechanisms that maintain fibrinogen receptors of circulating platelets in a latent state that cannot bind fibrinogen.

Bone-like tissue growth in the root canal of immature permanent teeth after traumatic injuries.

Following a severe traumatic incident to permanent immature teeth, the growth of calcified tissue in the pulp space may occasionally occur. This calcified tissue may be diffuse or in intimate contact with the dentine. It has been suggested that a wide open apex, severe damage to the root sheath, and the absence of infection are only some of the predisposing factors leading to this metaplasia of pulp tissue into bone-like tissue. Five cases are described.