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Sample records for underwent gold weight

  1. Predictors of weight regain in patients who underwent Roux-en-Y gastric bypass surgery.

    Science.gov (United States)

    Shantavasinkul, Prapimporn Chattranukulchai; Omotosho, Philip; Corsino, Leonor; Portenier, Dana; Torquati, Alfonso

    2016-11-01

    Roux-en-Y gastric bypass (RYGB) is a highly effective treatment for obesity and results in long-term weight loss and resolution of co-morbidities. However, weight regain may occur as soon as 1-2 years after surgery. This retrospective study aimed to investigate the prevalence of weight regain and possible preoperative predictors of this phenomenon after RYGB. An academic medical center in the United States. A total of 1426 obese patients (15.8% male) who underwent RYGB during January 2000 to 2012 and had at least a 2-year follow-up were reviewed. We included only patients who were initially successful, having achieved at least 50% excess weight loss at 1 year postoperatively. Patients were then categorized into either the weight regain group (WR) or sustained weight loss (SWL) group based upon whether they gained≥15% of their 1-year postoperative weight. Weight regain was observed in 244 patients (17.1%). Preoperative body mass index was similar between groups. Body mass index was significantly higher and percent excess weight loss was significantly lower in the WR group (Pweight regain was 19.5±9.3 kg and-.8±8.5 in the WR and SWL groups, respectively (Pweight loss. Moreover, a longer duration after RYGB was associated with weight regain. Multivariate analysis revealed that younger age was a significant predictor of weight regain even after adjusting for time since RYGB. The present study confirmed that a longer interval after RYGB was associated with weight regain. Younger age was a significant predictor of weight regain even after adjusting for time since RYGB. The findings of this study underscore the complexity of the mechanisms underlying weight loss and regain after RYGB. Future prospective studies are needed to further explore the prevalence, predictors, and mechanisms of weight regain after RYGB. Copyright © 2016 American Society for Bariatric Surgery. Published by Elsevier Inc. All rights reserved.

  2. GOLD WEIGHTS IN FACIAL PARALYSIS (REVISITED)

    NARCIS (Netherlands)

    ZECHA, PJ; ROBINSON, PH; VANOORT, RP; COENRAADS, PJ

    A retrospective study of 11 patients with facial paralysis was undertaken. Correction of lagophthalmos was accomplished by inserting a dental gold weight into the upper eyelid. All weights were assessed and adjusted to fit the patient's individual need. The primary objective was to achieve adequate

  3. [Rehabilitation of the eye in patients with facial paralyses: indications and results of gold weight implantation].

    Science.gov (United States)

    Linder, T; Linstrom, C; Robert, Y

    1997-05-01

    Upper-lid gold weight insertions in patients with long-standing facial palsy allow closure of the eye through an increased gravitational pull on the relaxed eyelid and complete opening without restriction of the peripheral visual field. Between 1990 and 1995, 45 patients underwent eyelid rehabilitation for facial nerve paralysis at the New York Eye & Ear Infirmary. Their charts and outcomes were reviewed retrospectively. Twelve patients were followed prospectively at the University Hospital Zurich since December 1995. One gold weight extruded twice in one patient. Delayed infections 1-3 months after surgery occurred in 6.6% and could be treated without removal of the gold weight. Tarsorrhaphies were necessary in 11%. Overall one third of all patients had their gold weight removed during this 5-year observation period. They all had return of their facial movements and did not require further lid loading. All prospectively evaluated patients had a marked improvement of their dry eye symptoms and a better quality of life. The analysis of 57 patients indicates, that gold weight insertions are a simple, reliable, reversible and successful technique for early rehabilitation of the paralyzed eyelid, often combined with lower lid shortening procedures. We favor early implantation in patients with severe facial nerve injury, concomitant Vth nerve palsy, inadequate patient compliance, in patients with one eye only or with disturbing dry eye symptoms.

  4. Eyelid lymphoma in a patient with a gold weight implant.

    Science.gov (United States)

    Di Nisio, L A; Croxatto, J O; Mansur, M C; Aldecoa, J P; Weil, D

    2017-04-01

    A male patient with an exposure keratopathy caused by lagophthalmos. A gold weight was implanted in the right upper eyelid. Eight months later, he presented with erythema and swelling of right upper eyelid. An incisional biopsy was performed, reporting extranodal marginal zone B cell lymphoma. when a tumour at the site of a gold weight implant is refractory to treatment, it is essential to perform an incisional biopsy to establish the histopathological diagnosis. Ocular adnexal lymphomas are relatively common. The presence of foreign material can cause chronic inflammation that could be the stimulus for the development of a lymphoproliferative disorder. Copyright © 2016 Sociedad Española de Oftalmología. Publicado por Elsevier España, S.L.U. All rights reserved.

  5. A single FTO gene variant rs9939609 is associated with body weight evolution in a multiethnic extremely obese population that underwent bariatric surgery.

    Science.gov (United States)

    Rodrigues, Gisele K; Resende, Cristina M M; Durso, Danielle F; Rodrigues, Lorena A A; Silva, José Luiz P; Reis, Rodrigo C; Pereira, Solange S; Ferreira, Daniela C; Franco, Gloria R; Alvarez-Leite, Jacqueline

    2015-01-01

    The rs9939609 single nucleotide polymorphism (SNP) in the fat mass and obesity-associated (FTO) gene is involved in obesity. Few studies have been conducted on patients who underwent bariatric surgery. The aim of this study was to evaluate the influence of FTO SNPs on body weight, body composition, and weight regain during a 60-mo follow-up period after bariatric surgery. The rs9939609 was genotyped in 146 individuals using a real-time polymerase chain reaction TaqMan assay. Data for lifestyle, comorbidities, body weight, body mass index (BMI), excess weight loss (EWL), and body composition were obtained before and 6, 12, 18, 24, 36, 48, and 60 mo after surgery. Data were analyzed by comparing two groups of patients according to rs9939609 FTO gene polymorphism. Mixed-regression models were constructed to evaluate the dynamics of body weight, BMI, and EWL over time in female patients. No differences were observed between the groups during the first 24 mo after surgery. After 36, 48, and 60 mo, body weight, fat mass, and BMI were higher, whereas fat-free mass and EWL were lower in the FTO-SNP patient group. Weight regain was more frequent and occurred sooner in the FTO-SNP group. There is a different evolution of weight loss in obese carriers of the FTO gene variant rs9939609 after bariatric surgery. However, this pattern was evident at only 2 y postbariatric surgery, inducing a lower proportion of surgery success and a greater and earlier weight regain. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. Eyelid reanimation with gold weight implant and tendon sling suspension: evaluation of excursion and velocity using the FACIAL CLIMA system.

    Science.gov (United States)

    Hontanilla, Bernardo; Marre, Diego

    2013-04-01

    This study aims to analyse the efficacy of static techniques, namely gold weight implant and tendon sling, in the reanimation of the paralytic eyelid. Upper eyelid rehabilitation in terms of excursion and blinking velocity is performed using the automatic motion capture system, FACIAL CLIMA. Seventy-four patients underwent a total of 101 procedures including 58 upper eyelid gold weight implants and 43 lower eyelid tendon suspension with 27 patients undergoing both procedures. The presence of lagophtalmos, eye dryness, corneal ulcer, epiphora and lower lid ptosis/ectropion was assessed preoperatively. The Wilcoxon signed-rank test was used to compare preoperative versus postoperative measurements of upper eyelid excursion and blinking velocity determined with FACIAL CLIMA. Significance was set at p CLIMA revealed significant improvement of eyelid excursion and velocity of blinking (p CLIMA system is a reliable method to quantify upper eyelid excursion and blinking velocity and to detect the exact position of the lower eyelid. Copyright © 2012 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

  7. Task-based evaluation of segmentation algorithms for diffusion-weighted MRI without using a gold standard.

    Science.gov (United States)

    Jha, Abhinav K; Kupinski, Matthew A; Rodríguez, Jeffrey J; Stephen, Renu M; Stopeck, Alison T

    2012-07-07

    In many studies, the estimation of the apparent diffusion coefficient (ADC) of lesions in visceral organs in diffusion-weighted (DW) magnetic resonance images requires an accurate lesion-segmentation algorithm. To evaluate these lesion-segmentation algorithms, region-overlap measures are used currently. However, the end task from the DW images is accurate ADC estimation, and the region-overlap measures do not evaluate the segmentation algorithms on this task. Moreover, these measures rely on the existence of gold-standard segmentation of the lesion, which is typically unavailable. In this paper, we study the problem of task-based evaluation of segmentation algorithms in DW imaging in the absence of a gold standard. We first show that using manual segmentations instead of gold-standard segmentations for this task-based evaluation is unreliable. We then propose a method to compare the segmentation algorithms that does not require gold-standard or manual segmentation results. The no-gold-standard method estimates the bias and the variance of the error between the true ADC values and the ADC values estimated using the automated segmentation algorithm. The method can be used to rank the segmentation algorithms on the basis of both the ensemble mean square error and precision. We also propose consistency checks for this evaluation technique.

  8. Innate stimulatory capacity of high molecular weight transition metals Au (gold) and Hg (mercury).

    Science.gov (United States)

    Rachmawati, Dessy; Alsalem, Inás W A; Bontkes, Hetty J; Verstege, Marleen I; Gibbs, Sue; von Blomberg, B M E; Scheper, Rik J; van Hoogstraten, Ingrid M W

    2015-03-01

    Nickel, cobalt and palladium ions can induce an innate immune response by triggering Toll-like receptor (TLR)-4 which is present on dendritic cells (DC). Here we studied mechanisms of action for DC immunotoxicity to gold and mercury. Next to gold (Na3Au (S2O3)2⋅2H2O) and mercury (HgCl2), nickel (NiCl2) was included as a positive control. MoDC activation was assessed by release of the pro-inflammatory mediator IL-8. Also PBMC were studied, and THP-1 cells were used as a substitution for DC for evaluation of cytokines and chemokines, as well as phenotypic, alterations in response to gold and mercury. Our results showed that both Na3Au (S2O3)2⋅2H2O and HgCl2 induce substantial release of IL-8, but not IL-6, CCL2 or IL-10, from MoDc, PBMC, or THP-1 cells. Also gold and, to a lesser extent mercury, caused modest dendritic cell maturation as detected by increased membrane expression of CD40 and CD80. Both metals thus show innate immune response capacities, although to a lower extent than reported earlier for NiCl2, CoCl2 and Na2 [PdCl4]. Importantly, the gold-induced response could be ascribed to TLR3 rather than TLR4 triggering, whereas the nature of the innate mercury response remains to be clarified. In conclusion both gold and mercury can induce innate immune responses, which for gold could be ascribed to TLR3 dependent signalling. These responses are likely to contribute to adaptive immune responses to these metals, as reflected by skin and mucosal allergies. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Protein adsorption on well-characterized polyethylene oxide brushes on gold: dependence on molecular weight and grafting density.

    Science.gov (United States)

    Taylor, Warren; Jones, Richard A L

    2013-05-21

    The adsorption of lysozyme protein was measured ex situ on well-characterized gold surfaces coated by end-tethered polyethylene oxide brushes of various molecular weights and controlled grafting densities. The adsorbed amount of protein for different molecular weight brushes was found to collapse onto one master curve when plotted against brush coverage. We interpret this relationship in terms of a model involving site-blocking of the adsorption of proteins at the substrate and discuss the role of the physical attraction of PEO segments to gold. We account for our observation of a simple exponential relationship between protein adsorption and normalized brush coverage with a simple protein adsorption model. In contrast to other studies in similar systems, we do not observe protein adsorption on brushes at high grafting density, and we suggest that this discrepancy may be due to the solubility effects of salt upon the brushes, influencing their protein binding affinity, in the limit of high grafting density and high brush volume fraction.

  10. Periocular and anterior orbital necrosis after upper eyelid gold weight loading: operation-related or self-inflicted?

    Directory of Open Access Journals (Sweden)

    Schwartz R

    2014-04-01

    Full Text Available Roy Schwartz,1 Ran Ben Cnaan,1 Ophir Schein,2 Michael Giladi,3 Michal Raz,4 Igal Leibovitch11Oculoplastic and Orbital Institute, Department of Ophthalmology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel; 2Department of Plastic Surgery, Assaf Harofeh Medical Center, Tzrifin, Israel; 3Infectious Disease Unit, 4Pathology Unit, Tel Aviv Sourasky Medical Center, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, IsraelAbstract: A 44-year-old woman, who had undergone gold-weight implantation due to facial palsy and lagophthalmos, arrived at the ophthalmology ward with eyelid swelling and erythema, which rapidly deteriorated under intravenous antibiotics to a necrotic process involving the periocular tissues, the eye, and the anterior orbit. Despite prompt removal of the gold weight, the patient's ocular and systemic condition continued to deteriorate, necessitating evisceration and debridement of necrotic tissue. Cultures showed growth of Staphylococcus epidermidis, Staphylococcus capitis, Candida glabrata, and Candida albicans, and histopathology demonstrated an acute nonspecific necrotizing panophthalmitis. Later on, the patient was admitted to a plastic surgery ward with recurrent severe burns of her thigh, which were highly suggestive of being self-induced, raising the possibility of self-induced damage.Keywords: evisceration, factitious disorder, lagophthalmos

  11. Mass Spectrometry Imaging of low Molecular Weight Compounds in Garlic (Allium sativum L.) with Gold Nanoparticle Enhanced Target.

    Science.gov (United States)

    Misiorek, Maria; Sekuła, Justyna; Ruman, Tomasz

    2017-11-01

    Garlic (Allium sativum) is the subject of many studies due to its numerous beneficial properties. Although compounds of garlic have been studied by various analytical methods, their tissue distributions are still unclear. Mass spectrometry imaging (MSI) appears to be a very powerful tool for the identification of the localisation of compounds within a garlic clove. Visualisation of the spatial distribution of garlic low-molecular weight compounds with nanoparticle-based MSI. Compounds occurring on the cross-section of sprouted garlic has been transferred to gold-nanoparticle enhanced target (AuNPET) by imprinting. The imprint was then subjected to MSI analysis. The results suggest that low molecular weight compounds, such as amino acids, dipeptides, fatty acids, organosulphur and organoselenium compounds are distributed within the garlic clove in a characteristic manner. It can be connected with their biological functions and metabolic properties in the plant. New methodology for the visualisation of low molecular weight compounds allowed a correlation to be made between their spatial distribution within a sprouted garlic clove and their biological function. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  12. Diagnostic accuracy of diffusion weighted magnetic resonance imaging in malignant breast lesions, keeping histopathology as gold standard

    International Nuclear Information System (INIS)

    Sidiq, T.; Ullah, H.

    2017-01-01

    Objective: To determine the diagnostic accuracy of Diffusion Weighted Magnetic Resonance Imaging/Apparent and Diffusion Coefficient (DWI/ADC sequences) in malignant breast lesions taking histopathology as gold standard. Study Design: Cross-sectional validation study. Place and Duration of Study: Combined Military Hospitals Quetta & Peshawar, from Sep 2013 to Mar 2015 and Armed Forces Institute of Radiology and Imaging Rawalpindi, from Apr 2015 to Dec 2015. Material and Methods: After informed consent, patients scheduled for biopsy of a suspicious breast lesion on sonomammography and/or mammography (BIRADS IV & V), fulfilling the inclusion criteria were evaluated with breast MRI including Diffusion Weighted Imaging (DWI) sequence using b-values of 0 & 750 mm2/sec. Apparent Diffusion Coefficient (ADC) values for the breast lesions were also calculated. MRI findings were correlated with histopathological results. Results: A total of 299 cases were included in the study. Mean age of the study population was 45.73 years (SD ± 15.02) with a range of 18 to 89 years. On histopathology 77.9% (n=233) lesions turned to be malignant and 22.1% (n=66) were benign. On DWI 73% (n=219) lesions showed restricted diffusion and were labeled malignant while 27% (n=80) lesions showed facilitated diffusion and were considered benign. The mean apparent diffusion coefficient value of the malignant breast lesions was significantly lower than that of the benign breast lesions (p-value<0.001). The calculated sensitivity, specificity, positive predictive value and negative predictive values of DWI/ADC mapping in differentiating between malignant and benign lesions were 92.2%, 93.9%, 98.1% and 77.5% respectively. The diagnostic accuracy was found to be 92.6%. Conclusion: DWI is a non-invasive diagnostic modality for diagnosing malignant breast lesions. It can be used to reduce the number of unnecessary biopsies and it may help in reaching a definite diagnosis in cases where a suspicious breast

  13. The interplay of plasma treatment and gold coating and ultra-high molecular weight polyethylene: On the cytocompatibility

    Czech Academy of Sciences Publication Activity Database

    Novotná, Z.; Rimpelová, S.; Juřík, P.; Veselý, M.; Kolská, Z.; Hubáček, Tomáš; Ruml, T.; Švorčík, V.

    2017-01-01

    Roč. 71, FEB (2017), s. 125-131 ISSN 0928-4931 R&D Projects: GA MŠk LM2015075 Institutional support: RVO:60077344 Keywords : UHMWPE * plasma treatment * gold sputtering * atomic force microscopy Subject RIV: JJ - Other Materials OBOR OECD: Materials engineering Impact factor: 4.164, year: 2016

  14. Inkjet-printed gold nanoparticle surfaces for the detection of low molecular weight biomolecules by laser desorption/ionization mass spectrometry.

    Science.gov (United States)

    Marsico, Alyssa L M; Creran, Brian; Duncan, Bradley; Elci, S Gokhan; Jiang, Ying; Onasch, Timothy B; Wormhoudt, Joda; Rotello, Vincent M; Vachet, Richard W

    2015-11-01

    Effective detection of low molecular weight compounds in matrix-assisted laser desorption/ionization (MALDI) mass spectrometry (MS) is often hindered by matrix interferences in the low m/z region of the mass spectrum. Here, we show that monolayer-protected gold nanoparticles (AuNPs) can serve as alternate matrices for the very sensitive detection of low molecular weight compounds such as amino acids. Amino acids can be detected at low fmol levels with minimal interferences by properly choosing the AuNP deposition method, density, size, and monolayer surface chemistry. By inkjet-printing AuNPs at various densities, we find that AuNP clusters are essential for obtaining the greatest sensitivity. Graphical Abstract ᅟ.

  15. Poly(glycidyl ether)-Based Monolayers on Gold Surfaces: Control of Grafting Density and Chain Conformation by Grafting Procedure, Surface Anchor, and Molecular Weight.

    Science.gov (United States)

    Heinen, Silke; Weinhart, Marie

    2017-03-07

    For a meaningful correlation of surface coatings with their respective biological response reproducible coating procedures, well-defined surface coatings, and thorough surface characterization with respect to layer thickness and grafting density are indispensable. The same applies to polymeric monolayer coatings which are intended to be used for, e.g., fundamental studies on the volume phase transition of surface end-tethered thermoresponsive polymer chains. Planar gold surfaces are frequently used as model substrates, since they allow a variety of straightforward surface characterization methods. Herein we present reproducible grafting-to procedures performed with thermoresponsive poly(glycidyl ether) copolymers composed of glycidyl methyl ether (GME) and ethyl glycidyl ether (EGE). The copolymers feature different molecular weights (2 kDa, 9 kDa, 24 kDa) and are equipped with varying sulfur-containing anchor groups in order to achieve adjustable grafting densities on gold surfaces and hence control the tethered polymers' chain conformation. We determined "wet" and "dry" thicknesses of these coatings by QCM-D and ellipsometry measurements and deduced anchor distances and degrees of chain overlap of the polymer chains assembled on gold. Grafting under cloud point conditions allowed for higher degrees of chain overlap compared to grafting from a good solvent like ethanol, independent of the used sulfur-containing anchor group for polymers with low (2 kDa) and medium (9 kDa) molecular weights. By contrast, the achieved grafting densities and thus chain overlaps of surface-tethered polymers with high (24 kDa) molecular weights were identical for both grafting methods. Monolayers prepared from an ethanolic solution of poly(glycidyl ether)s equipped with sterically demanding disulfide-containing anchors revealed the lowest degrees of chain overlap. The ratio of the radius of gyration to the anchor distance (2 R g /l) of the latter coating was found to be lower than 1

  16. Gold prices

    OpenAIRE

    Joseph G. Haubrich

    1998-01-01

    The price of gold commands attention because it serves as an indicator of general price stability or inflation. But gold is also a commodity, used in jewelry and by industry, so demand and supply affect its pricing and need to be considered when gold is a factor in monetary policy decisions.

  17. Phage based green chemistry for gold ion reduction and gold retrieval.

    Science.gov (United States)

    Setyawati, Magdiel I; Xie, Jianping; Leong, David T

    2014-01-22

    The gold mining industry has taken its toll on the environment, triggering the development of more environmentally benign processes to alleviate the waste load release. Here, we demonstrate the use of bacteriophages (phages) for biosorption and bioreduction of gold ions from aqueous solution, which potentially can be applied to remediate gold ions from gold mining waste effluent. Phage has shown a remarkably efficient sorption of gold ions with a maximum gold adsorption capacity of 571 mg gold/g dry weight phage. The product of this phage mediated process is gold nanocrystals with the size of 30-630 nm. Biosorption and bioreduction processes are mediated by the ionic and covalent interaction between gold ions and the reducing groups on the phage protein coat. The strategy offers a simple, ecofriendly and feasible option to recover of gold ions to form readily recoverable products of gold nanoparticles within 24 h.

  18. A case that underwent bilateral video-assisted thoracoscopic ...

    African Journals Online (AJOL)

    No Abstract Available A case that underwent bilateral video-assisted thoracoscopic surgical (VATS) biopsy combined with pneumonectomy is presented. The patient developed hypoxia during the contralateral VATS biopsy. His hypoxia was treated with positive expiratory pressure (PEEP) to the dependent lung and apneic ...

  19. Gold Returns

    OpenAIRE

    Robert J. Barro; Sanjay P. Misra

    2013-01-01

    From 1836 to 2011, the average real rate of price change for gold in the United States is 1.1% per year and the standard deviation is 13.1%, implying a one-standard-deviation confidence band for the mean of (0.1%, 2.1%). The covariances of gold's real rate of price change with consumption and GDP growth rates are small and statistically insignificantly different from zero. These negligible covariances suggest that gold's expected real rate of return--which includes an unobserved dividend yiel...

  20. NUTRITION SUPPORT COMPLICATIONS IN PATIENT WHO UNDERWENT CARDIAC SURGERY

    OpenAIRE

    Krdžalić, Alisa; Kovčić, Jasmina; Krdžalić, Goran; Jahić, Elmir

    2016-01-01

    Background: The nutrition support complications after cardiac surgery should be detected and treated on time. Aim: To show the incidence and type of nutritional support complication in patients after cardiac surgery. Methods: The prospective study included 415 patients who underwent cardiac surgery between 2010 and 2013 in Clinic for Cardiovascular Disease of University Clinical Center Tuzla. Complications of the delivery system for nutrition support (NS) and nutrition itself were analy...

  1. Gold Museum

    OpenAIRE

    Efraín Sánchez Cabra

    2003-01-01

    On 22 december 1939, the Banco de la República, the Central Bank of Colombia, purchased a 23.5 centimetres high pre-Columbian gold arte fact weighing 777·7 grams that was to become the Gold M useum's foundation stone. Described as a Quimbaya poporo, it is a masterpiece of pre-Hispanic goldwork, an object of beauty whose brightly burnished body and neck, crowned with four sphere-like or naments, rest on an exquisite cast metal tiligree base and which seems to ftoat in a space of its own. The b...

  2. Pigmented Villonodular Synovitis in a Patient who Underwent Hip Arthroplasty

    Directory of Open Access Journals (Sweden)

    Nevzat Dabak

    2014-09-01

    Full Text Available Pigmented villonodular synovitis (PVNS is a rare, benign, but a locally aggressive tumor. It is characterized by the proliferation of synovial membrane, but it can also be seen in tendon sheaths and bursae. Clinical presentation of solitary lesions include compression and locking of the joint suggesting loose bodies in the joint and a subsequent findings of an effusion, whereas diffuse lesions manifest with pain and chronic swelling. In this article, we presented a curious case of PVNS in a female patient who have been followed up due to an acetabular cystic lesion. She underwent total hip arthroplasty for severe osteoarthritis of the hip joint and associated pain. The diagnosis of PVNS was established intraoperatively. (The Me­di­cal Bul­le­tin of Ha­se­ki 2014; 52: 235-7

  3. ALGORITHM FOR MANAGEMENT OF HYPERTENSIVE PATIENTS UNDERWENT UROLOGY INTERVENTIONS

    Directory of Open Access Journals (Sweden)

    S. S. Davydova

    2015-09-01

    Full Text Available Aim. To study the efficacy of cardiovascular non-invasive complex assessment and pre-operative preparation in hypertensive patients needed in surgical treatment of urology dis- eases.Material and methods. Males (n=883, aged 40 to 80 years were included into the study. The main group consisted of patients that underwent laparotomic nephrectomy (LTN group; n=96 and patients who underwent laparoscopic nephrectomy (LSN group; n=53. Dynamics of ambulatory blood pressure monitoring (ABPM data was analyzed in these groups in the immediate postoperative period. The efficacy of a package of non-invasive methods for cardiovascular system assessment was studied. ABPM was performed after nephrectomy (2-nd and 10-th days after surgery in patients with complaints of vertigo episodes or intense general weakness to correct treatment.Results. In LTN group hypotension episodes or blood pressure (BP elevations were observed in 20 (20.8% and 22 (22.9% patients, respectively, on the 2-nd day after the operation. These complications required antihypertensive treatment correction. Patients with hypotension episodes were significantly older than patients with BP elevation and had significantly lower levels of 24-hour systolic BP, night diastolic BP and minimal night systolic BP. Re-adjustment of antihypertensive treatment on the 10-th postoperative day was required to 2 (10% patients with hypotension episodes and to 1 (4.5% patient with BP elevation. Correction of antihypertensive therapy was required to all patients in LSN group on the day 2, and to 32 (60.4% patients on the 10-th day after the operation. Reduction in the incidence of complications (from 1.2% in 2009 to 0.3% in 2011, p<0.001 was observed during the application of cardiovascular non-invasive complex assessment and preoperative preparation in hypertensive patients.Conclusion. The elaborated management algorithm for patients with concomitant hypertension is recommended to reduce the cardiovascular

  4. ALGORITHM FOR MANAGEMENT OF HYPERTENSIVE PATIENTS UNDERWENT UROLOGY INTERVENTIONS

    Directory of Open Access Journals (Sweden)

    S. S. Davydova

    2013-01-01

    Full Text Available Aim. To study the efficacy of cardiovascular non-invasive complex assessment and pre-operative preparation in hypertensive patients needed in surgical treatment of urology dis- eases.Material and methods. Males (n=883, aged 40 to 80 years were included into the study. The main group consisted of patients that underwent laparotomic nephrectomy (LTN group; n=96 and patients who underwent laparoscopic nephrectomy (LSN group; n=53. Dynamics of ambulatory blood pressure monitoring (ABPM data was analyzed in these groups in the immediate postoperative period. The efficacy of a package of non-invasive methods for cardiovascular system assessment was studied. ABPM was performed after nephrectomy (2-nd and 10-th days after surgery in patients with complaints of vertigo episodes or intense general weakness to correct treatment.Results. In LTN group hypotension episodes or blood pressure (BP elevations were observed in 20 (20.8% and 22 (22.9% patients, respectively, on the 2-nd day after the operation. These complications required antihypertensive treatment correction. Patients with hypotension episodes were significantly older than patients with BP elevation and had significantly lower levels of 24-hour systolic BP, night diastolic BP and minimal night systolic BP. Re-adjustment of antihypertensive treatment on the 10-th postoperative day was required to 2 (10% patients with hypotension episodes and to 1 (4.5% patient with BP elevation. Correction of antihypertensive therapy was required to all patients in LSN group on the day 2, and to 32 (60.4% patients on the 10-th day after the operation. Reduction in the incidence of complications (from 1.2% in 2009 to 0.3% in 2011, p<0.001 was observed during the application of cardiovascular non-invasive complex assessment and preoperative preparation in hypertensive patients.Conclusion. The elaborated management algorithm for patients with concomitant hypertension is recommended to reduce the cardiovascular

  5. Green Gold

    International Nuclear Information System (INIS)

    Salamandra Martinez, Carlos

    2004-01-01

    The main purpose of this work is to offer a general panoramic of the processes or experiences pilot that are carried out in the Project Green Gold, as strategy of environmental sustainability and organizational invigoration in Choco, especially in the 12 communities of the municipalities of Tado and Condoto. It is also sought to offer a minimum of information on the techniques of handmade production and to show the possibilities to carry out in a rational way the use and use of the natural resources. The Project Green Gold is carried out by the Corporation Green Gold (COV) and co-financed with resources of international and national character, the intervention of the financial resources it achievement mainly for the use of clean processes in the extraction stages and metals benefit. The project is centered primarily in the absence of use of products or toxic substances as the mercury, fair trade, organizational invigoration, execution of 11 approaches and certification of the metals Gold and Platinum. The COV, it has come executing the proposal from the year 2001 with the premise of contributing to the balance between the rational exploitation of the natural resources and the conservation of the environment in the Choco. In the project they are used technical handmade characteristic of the region framed inside the mining activity and production activities are diversified in the productive family units. Those producing with the support of entities of juridical character, specify the necessary game rules for the extraction and products commercialization

  6. Frequency of Helicobacter pylori in patients underwent endoscopy

    Directory of Open Access Journals (Sweden)

    Ahmet Tay

    2012-06-01

    Full Text Available Objectives: The aim of this study was to investigate thefrequency of Helicobacter pylori in patients underwent endoscopyeastern Anatolia.Materials and methods: The patients whose endoscopicantral biopsies were taken for any reason in our endoscopyunit in February-June 2010 period were includedand retrospectively investigated. The frequency of Helicobacterpylori was determined as separating the patientsaccording to general, sex and the age groups. Antral biopsieswere stained with hematoxylin-eosin and modified giemsamethod and examined under light microscope andreported as (+ mild, (++ moderate, (+++ severe positiveaccording to their intensities.Results: Biopsy specimens of 1298 patients were includedinto the study. The mean age was 47.5 ± 17.5 years(range 14-88 and 607 of these patients (47% were male.Histopathological evaluation revealed that, 918 of the patientswere (71% positive and 379 (29% were negativefor Helicobacter pylori. Approximately 60% of our patientshad mild, 29% had moderate and 11% had severe positivityfor Helicobacter pylori. No significant difference wasfound in the frequency of Helicobacter pylori betweenwomen and men. The frequencies of Helicobacter pyloriwere 73.2%, 71.5%, 68.6% and 70.4%, respectively, inthe age groups of 14-30 years, 31-45 years, 46-60 yearsand 61-88 years.Conclusion: The frequency of Helicobacter pylori was71% in Eastern Anatolia Region. No statistically significantdifference was found between genders and agegroups in term of the frequency of Helicobacter pylori.

  7. The Gold Standard as a `Good Housekeeping Seal of Approval'

    OpenAIRE

    Michael D. Bordo

    1995-01-01

    In this paper we argue that adherence to the gold standard rule of convertibility of national currencies into a fixed weight of gold served as a `good housekeeping seal of approval' which facilitated access by peripheral countries to foreign capital from the core countries of western Europe. We survey the historical background of gold standard adherence in the period 1870-1914 by nine important peripheral countries. The sample includes the full range of commitment to the gold standard from co...

  8. The Gold Standard as a "Good Housekeeping Seal of Approval"

    OpenAIRE

    Hugh Rockoff; Michael D. Bordo

    1996-01-01

    In this paper we argue that adherence to the gold standard rule of convertibility of national currencies into a fixed weight of gold served as `a good housekeeping seal of approval' which facilitated access by peripheral countries to foreign capital from the core countries of western Europe. We survey the historical background of gold standard adherence in the period 1870-1914 by nine important peripheral countries. The sample includes the full range of commitment to the gold standard from co...

  9. Gold in Modern Economy

    Directory of Open Access Journals (Sweden)

    Boryshkevych Olena V.

    2014-01-01

    Full Text Available The article studies the role of gold in modern economy. It analyses dynamics and modern state of the gold market. It studies volumes of contracts in exchange and off-exchange markets. In order to reveal changes of key features of the gold market, it focuses on the study of gold demand volumes, studies volumes and geographical changes in the world gold mining, and analyses volumes of monetary gold of central banks and its share in gold and currency reserves. It analyses price fluctuations in the gold market during 1968 – 2013 and identifies main factors that determine the gold price. It identifies interconnection between the state of the gold market and financial markets of countries. The study showed that namely geopolitical and economic instability restricts the spectrum of financial assets for investing and gold is not only a safe investment object but also a profitable one.

  10. Knowledge-driven GIS modeling technique for gold exploration, Bulghah gold mine area, Saudi Arabia

    Directory of Open Access Journals (Sweden)

    Ahmed A. Madani

    2011-12-01

    Full Text Available This research aims to generate a favorability map for gold exploration at the Bulghah gold mine area using integration of geo-datasets within a GIS environment. Spatial data analyses and integration of different geo-datasets are carried out based on knowledge-driven and weighting technique. The integration process involves the weighting and scoring of different layers affecting the gold mineralization at the study area using the index overlay method within PCI Geomatica environment. Generation of the binary predictor maps for lithology, lineaments, faults and favorable contacts precede the construction of the favorability map. About 100 m buffer zones are generated for favorable contacts, lineaments and major faults layers. Internal weighting is assigned to each layer based on favorability for gold mineralization. The scores for lithology, major faults, lineaments and favorable contacts layers in the constructed favorability map are 50%, 25%, 10% and 15%, respectively. Final favorability map for the Bulghah gold mine area shows the recording of two new sites for gold mineralization located at the northern and southern extensions of tonalite–diorite intrusions. The northern new site is now exploited for gold from the Bulghah North mine. The southern new site is narrow and small; its rocks resemble those of the Bulghah gold mine.

  11. Gold-Mining

    DEFF Research Database (Denmark)

    Raaballe, J.; Grundy, B.D.

    2002-01-01

    of operating gold mines. Asymmetric information on the reserves in the mine implies that, at a high enough price of gold, the manager of high type finds the extraction value of the company to be higher than the current market value of the non-operating gold mine. Due to this under valuation the maxim of market...... value maximization forces the manager of high type to extract the gold.The implications are three-fold. First, all managers (except the lowest type) extract the gold too soon compared to the first-best policy of leaving the gold in the mine forever. Second, a manager of high type extracts the gold......  Based on standard option pricing arguments and assumptions (including no convenience yield and sustainable property rights), we will not observe operating gold mines. We find that asymmetric information on the reserves in the gold mine is a necessary and sufficient condition for the existence...

  12. The in vitro formation of placer gold by bacteria

    Science.gov (United States)

    Southam, Gordon; Beveridge, Terrance J.

    1994-10-01

    A laboratory simulation was developed to provide mechanistic information about placer (nugget) gold development in the natural environment. To initiate the simulation, ionic gold was immobilized to a high capacity by Bacillus subtilis 168 (116.2 μg/mg dry weight bacteria) as fine-grained intracellular colloids (5-50 nm). During the low-temperature diagenesis experiment (60°C), the release of organics due to bacterial autolysis coincided with the in vitro formation of hexagonal-octahedral gold crystals (20 μm). This octahedral gold was observed to aggregate, forming fine-grained placer gold (50 μm). In addition to achieving a fundamental understanding into secondary gold deposition, a significant economic benefit could be realized by employing this environmentally safe procedure to concentrate widely dispersed gold in placer deposits to facilitate mining by conventional methodologies.

  13. The use of gold nanoparticles to enhance radiotherapy in mice

    International Nuclear Information System (INIS)

    Hainfeld, James F; Slatkin, Daniel N; Smilowitz, Henry M

    2004-01-01

    Mice bearing subcutaneous EMT-6 mammary carcinomas received a single intravenous injection of 1.9 nm diameter gold particles (up to 2.7 g Au/kg body weight), which elevated concentrations of gold to 7 mg Au/g in tumours. Tumour-to-normal-tissue gold concentration ratios remained ∼8:1 during several minutes of 250 kVp x-ray therapy. One-year survival was 86% versus 20% with x-rays alone and 0% with gold alone. The increase in tumours safely ablated was dependent on the amount of gold injected. The gold nanoparticles were apparently non-toxic to mice and were largely cleared from the body through the kidneys. This novel use of small gold nanoparticles permitted achievement of the high metal content in tumours necessary for significant high-Z radioenhancement. (note)

  14. Skin contact with gold and gold alloys.

    Science.gov (United States)

    Rapson, W S

    1985-08-01

    3 types of reaction to gold merit discussion. First, there is the effect known as black dermographism, in which stroking with certain metals immediately produces well-defined black lines on the skin. Some gold alloys are amongst such metals. The evidence indicates that the effect is the result of impregnation of the skin with black metallic particles generated by mechanical abrasion of the metal by contaminants of the skin. There is no positive and unequivocal evidence of the ability of metals to mark uncontaminated skin so rapidly that it is possible to write upon it. Secondly there are the 2 related phenomena of the wear of gold jewelry, and the susceptibility to certain individuals to blackening of the skin where it is in contact with such jewelry. The occurrence of smudge, as it is often called, is not very common, but is brought to the attention of most jewelers from time to time. In extreme cases it may make it embarrassing for the person concerned to wear metallic jewelry. It would appear as if gold smudge also results mainly from mechanical abrasion of jewelry, though this may be aided and/or supplemented in some instances by corrosion of gold or gold alloy induced by certain components of the sweat. Finally, there is the question of true allergic responses to contact of the skin with gold and its alloys. Judging from the very few cases which have been recorded, such responses are extremely rare. Some recent observations on the reactions of metallic gold with amino acids and of reaction to contact of the skin with gold on the part of rheumatoid arthritis patients undergoing gold therapy, are, however, relevant in this connection.

  15. Gold in plants

    International Nuclear Information System (INIS)

    Girling, C.A.; Peterson, P.J.

    1980-01-01

    Many plants have the ability to take up gold from the soil and to accumulate it in their tisssue. Advances have been made in understanding these processes to the point where their exploitation in the field of prospecting for gold appears practically feasible. Neutron activation analysis is used for the determination of the small quantities of gold in plants

  16. Estimation of Gold Resources from Exploration Drilling using ...

    African Journals Online (AJOL)

    Estimation of gold resources from exploration drilling has passed through various phases and methods at the AngloGold Ashanti, Iduapriem Mine Limited, Tarkwa in Ghana. From the use of Inverse Distance Weighting (IDW) to the use of Ordinary Kriging (OK) and currently the use of Uniform Conditioning (UC). This is all ...

  17. Phytomining for Artisanal Gold Mine Tailings Management

    Directory of Open Access Journals (Sweden)

    Baiq Dewi Krisnayanti

    2016-08-01

    Full Text Available Mine tailings are generally disposed of by artisanal and small scale gold miners in poorly constructed containment areas and this leads to environmental risk. Gold phytomining could be a possible option for tailings management at artisanal and small-scale gold mining (ASGM locations where plants accumulate residual gold in their above ground biomass. The value of metal recovered from plants could offset some of the costs of environmental management. Getting gold into plants has been repeatedly demonstrated by many research groups; however, a simple working technology to get gold out of plants is less well described. A field experiment to assess the relevance of the technology to artisanal miners was conducted in Central Lombok, Indonesia between April and June 2015. Tobacco was planted in cyanidation tailings (1 mg/kg gold and grown for 2.5 months before the entire plot area was irrigated with NaCN to induce metal uptake. Biomass was then harvested (100 kg, air dried, and ashed by miners in equipment currently used to ash activated carbon at the end of a cyanide leach circuit. Borax and silver as a collector metal were added to the tobacco ash and smelted at high temperature to extract metals from the ash. The mass of the final bullion (39 g was greater than the mass of silver used as a collector (31 g, indicating recovery of metals from the biomass through the smelt process. The gold yield of this trial was low (1.2 mg/kg dry weight biomass concentration, indicating that considerable work must still be done to optimise valuable metal recovery by plants at the field scale. However, the described method to process the biomass was technically feasible, and represents a valid technique that artisanal and small-scale gold miners are willing to adopt if the economic case is good.

  18. Gold induced apoptsis study

    DEFF Research Database (Denmark)

    Laustsen, Christoffer

    2008-01-01

    Introduction   Cancer cells are highly thermo sensitive. On the basis of an article in Nature the idea arose, for a new non-invasive thermotherapy technique, based on radio frequency inductive heating of nano gold particles in an MR-scanner. Thermotherapy is getting considerably attention...... at the moment, especially in the fields of lasers, they though have some problems concerning the placement of the tumor in the human body. Local heating by MR has tremendous advance in comparison too lasers. The first step is to validate the hypothesis of the inductive heating of the gold nano particles trough...... in silico methods are here proposed for apoptosis studies and for AMG studies.   Methods   MR - heating of high concentration micrometer gold and low concentration nano gold.   CSLM of ethidum bromide stained cell lines, with and witout gold and automated image processing.   AMG gold uptake study...

  19. Nanotoxicity of gold and gold-cobalt nanoalloy.

    Science.gov (United States)

    Girgis, E; Khalil, W K B; Emam, A N; Mohamed, M B; Rao, K V

    2012-05-21

    Nanotoxicology test of gold nanoparticles (Au NPs) and gold-cobalt (Au-Co) nanoalloy is an important step in their safety evaluation for biomedical applications. The Au and Au-Co NPs were prepared by reducing the metal ions using sodium borohydride (NaBH(4)) in the presence of polyvinyl pyrrolidone (PVP) as a capping material. The average size and shape of the nanoparticles (NPs) were characterized using high resolution transmission electron microscopy (HRTEM). Cobalt presence in the nanoalloy was confirmed by energy dispersive X-ray spectroscopy (EDX) analysis, and the magnetic properties of these particles were determined using a vibrating sample magnetometer (VSM). The Gold and gold-cobalt NPs of average size 15 ± 1.5 nm were administered orally to mice with a dose of 80, 160, and 320 mg/kg per body weight (bw) using gavages. Samples were collected after 7 and 14 days of the treatment. The results indicated that the Au-Co NPs were able to induce significant alteration in the tumor-initiating genes associated with an increase of micronuclei (MNs) formation and generation of DNA adduct (8-hydroxy-2-deoxyguanosine, 8-OHdG) as well as a reduction in the glutathione peroxidase activity. This action of Au-Co NPs was observed using 160 and 320 mg/kg bw at both time intervals. However, Au NPs had much lower effects than Au-Co NPs on alteration in the tumor-initiating genes, frequency of MNs, and generation of 8-OHdG as well as glutathione peroxidase activity except with the highest dose of Au NPs. This study suggests that the potential to cause in vivo genetic and antioxidant enzyme alterations due to the treatment by Au-Co nanoalloy may be attributed to the increase in oxidative stress in mice.

  20. Gold mineralogy and extraction

    Energy Technology Data Exchange (ETDEWEB)

    Cashion, J.D.; Brown, L.J. [Monash University, Physics Department (Australia)

    1998-12-15

    Several examples are examined in which Moessbauer spectroscopic analysis of gold mineral samples, treated concentrates and extracted species has provided information not obtainable by competing techniques. Descriptions are given of current work on bacterial oxidation of pyritic ores and on the adsorbed species from gold extracted from cyanide and chloride solutions onto activated carbon and polyurethane foams. The potential benefits for the gold mining industry from Moessbauer studies and some limitations on the use of the technique are also discussed.

  1. Gold and uranium extraction

    International Nuclear Information System (INIS)

    James, G.S.; Davidson, R.J.

    1977-01-01

    A process for extracting gold and uranium from an ore containing them both comprising the steps of pulping the finely comminuted ore with a suitable cyanide solution at an alkaline pH, acidifying the pulp for uranium dissolution, adding carbon activated for gold recovery to the pulp at a suitable stage, separating the loaded activated carbon from the pulp, and recovering gold from the activated carbon and uranium from solution

  2. Magnetism in nanocrystalline gold.

    Science.gov (United States)

    Tuboltsev, Vladimir; Savin, Alexander; Pirojenko, Alexandre; Räisänen, Jyrki

    2013-08-27

    While bulk gold is well known to be diamagnetic, there is a growing body of convincing experimental and theoretical work indicating that nanostructured gold can be imparted with unconventional magnetic properties. Bridging the current gap in experimental study of magnetism in bare gold nanomaterials, we report here on magnetism in gold nanocrystalline films produced by cluster deposition in the aggregate form that can be considered as a crossover state between a nanocluster and a continuous film. We demonstrate ferromagnetic-like hysteretic magnetization with temperature dependence indicative of spin-glass-like behavior and find this to be consistent with theoretical predictions, available in the literature, based on first-principles calculations.

  3. Direct formation of gold nanorods on surfaces using polymer-immobilised gold seeds

    Directory of Open Access Journals (Sweden)

    Majid K. Abyaneh

    2016-06-01

    Full Text Available Herein, we present the formation of gold nanorods (GNRs on novel gold–poly(methyl methacrylate (Au–PMMA nanocomposite substrates with unprecedented growth control through the polymer molecular weight (Mw and gold-salt-to-polymer weight ratio. For the first time, GNRs have been produced by seed-mediated direct growth on surfaces that were pre-coated with polymer-immobilised gold seeds. A Au–PMMA nanocomposite formed by UV photoreduction has been used as the gold seed. The influence of polymer Mw and gold concentration on the formation of GNRs has been investigated and discussed. The polymer nanocomposite formed with a lower Mw PMMA and 20 wt % gold salt provides a suitable medium for growing well-dispersed GNRs. In this sample, the average dimension of produced GNRs is 200 nm in length with aspect ratios up to 10 and a distribution of GNRs to nanoparticles of nearly 22%. Suitable characterization techniques such as AFM and SEM have been used to support concept of the proposed growth method.

  4. Subchronic inhalation toxicity of gold nanoparticles

    Directory of Open Access Journals (Sweden)

    Chung Yong

    2011-05-01

    Full Text Available Abstract Background Gold nanoparticles are widely used in consumer products, including cosmetics, food packaging, beverages, toothpaste, automobiles, and lubricants. With this increase in consumer products containing gold nanoparticles, the potential for worker exposure to gold nanoparticles will also increase. Only a few studies have produced data on the in vivo toxicology of gold nanoparticles, meaning that the absorption, distribution, metabolism, and excretion (ADME of gold nanoparticles remain unclear. Results The toxicity of gold nanoparticles was studied in Sprague Dawley rats by inhalation. Seven-week-old rats, weighing approximately 200 g (males and 145 g (females, were divided into 4 groups (10 rats in each group: fresh-air control, low-dose (2.36 × 104 particle/cm3, 0.04 μg/m3, middle-dose (2.36 × 105 particle/cm3, 0.38 μg/m3, and high-dose (1.85 × 106 particle/cm3, 20.02 μg/m3. The animals were exposed to gold nanoparticles (average diameter 4-5 nm for 6 hours/day, 5 days/week, for 90-days in a whole-body inhalation chamber. In addition to mortality and clinical observations, body weight, food consumption, and lung function were recorded weekly. At the end of the study, the rats were subjected to a full necropsy, blood samples were collected for hematology and clinical chemistry tests, and organ weights were measured. Cellular differential counts and cytotoxicity measurements, such as albumin, lactate dehydrogenase (LDH, and total protein were also monitored in a cellular bronchoalveolar lavage (BAL fluid. Among lung function test measurements, tidal volume and minute volume showed a tendency to decrease comparing control and dose groups during the 90-days of exposure. Although no statistically significant differences were found in cellular differential counts, histopathologic examination showed minimal alveoli, an inflammatory infiltrate with a mixed cell type, and increased macrophages in the high-dose rats. Tissue

  5. Medicinal gold compounds

    International Nuclear Information System (INIS)

    Parish, R.V.; Cottrill, S.M.

    1987-01-01

    A major use of gold compounds in the pharmaceutical industry is for anti-arthritic agents. The disease itself is not understood and little is known about the way in which the drugs act, but detailed pictures of the distribution of gold in the body are available, and some of the relevant biochemistry is beginning to emerge. The purpose of this article is to give a survey of the types of compounds presently employed in medicine, of the distribution of gold in the body which results from their use, and of some relevant chemistry. Emphasis is placed on results obtained in the last few years

  6. Accuracy of bone SPECT/CT for identifying hardware loosening in patients who underwent lumbar fusion with pedicle screws

    Energy Technology Data Exchange (ETDEWEB)

    Hudyana, Hendrah; Maes, Alex [AZ Groeninge, Department of Nuclear Medicine, Kortrijk (Belgium); University Hospital Leuven, Department of Morphology and Medical Imaging, Leuven (Belgium); Vandenberghe, Thierry; Fidlers, Luc [AZ Groeninge, Department of Neurosurgery, Kortrijk (Belgium); Sathekge, Mike [University of Pretoria, Department of Nuclear Medicine, Pretoria (South Africa); Nicolai, Daniel [AZ Groeninge, Department of Nuclear Medicine, Kortrijk (Belgium); Wiele, Christophe van de [AZ Groeninge, Department of Nuclear Medicine, Kortrijk (Belgium); University Ghent, Department of Radiology and Nuclear Medicine, Ghent (Belgium)

    2016-02-15

    The aim of this retrospective study was to evaluate the accuracy of bone SPECT (single photon emission computed tomography)/CT (computed tomography) in diagnosing loosening of fixation material in patients with recurrent or persistent back pain that underwent lumbar arthrodesis with pedicle screws using surgery and clinical follow-up as gold standard A total of 48 patients (median age 49 years, range 21-81 years; 17 men) who had undergone lumbar spinal arthrodesis were included in this retrospective analysis. SPECT/CT results were compared to the gold standard of surgical evaluation or clinical follow-up. Positive SPECT/CT results were considered true positives if findings were confirmed by surgery or if clinical and other examinations were completely consistent with the positive SPECT/CT finding. They were considered false positives if surgical evaluation did not find any loose pedicle screws or if symptoms subsided with non-surgical therapy. Negative SPECT/CT scans were considered true negatives if symptoms either improved without surgical intervention or remained stable over a minimum follow-up period of 6 months. Negative SPECT/CT scans were determined to be false negatives if surgery was still required and loosening of material was found. The median length of time from primary surgery to bone SPECT/CT referral was 29.5 months (range 12-192 months). Median follow-up was 18 months (range 6-57) for subjects who did not undergo surgery. Thirteen of the 48 patients were found to be positive for loosening on bone SPECT/CT. Surgical evaluation (8 patients) and clinical follow-up (5 patients) showed that bone SPECT/CT correctly predicted loosening in 9 of 13 patients, while it falsely diagnosed loosening in 4 patients. Of 35 negative bone SPECT/CT scans, 12 were surgically confirmed. In 18 patients, bone SPECT/CT revealed lesions that could provide an alternative explanation for the symptoms of pain (active facet degeneration in 14 patients, and disc and sacroiliac

  7. Axially chiral allenyl gold complexes.

    Science.gov (United States)

    Johnson, Alice; Laguna, Antonio; Gimeno, M Concepción

    2014-09-17

    Unprecedented allenyl gold complexes have been achieved starting from triphenylpropargylphosphonium bromide. Two different coordination modes of the allene isomer of triphenylphosphoniumpropargylide to gold have been found depending on the gold oxidation state. Bromo-, pentafluorophenyl-, and triphenylphosphine-gold(I) allenyl complexes were prepared in which the α carbon coordinates to the gold(I) center. A chiral pentafluorophenyl-gold(III) allenyl complex with the gold atoms coordinated to the γ carbon was also prepared. All the complexes have been structurally characterized by X-ray diffraction showing the characteristic distances for a C═C═C unit.

  8. [Anesthetic Management of an Infant who Underwent Awake-intubation for Her Pharyngeal Injury Caused by a Toothbrush].

    Science.gov (United States)

    Nakano, Yoko; Suzuki, Hiroaki; Arai, Takero; Hashimoto, Yuichi; Okuda, Yasuhisa

    2016-04-01

    A 2-year-and-4-month-old female infant, 12 kg in weight and 90 cm in height fell off from a table, which was about 1 m height with a toothbrush in her mouth without her parents noticing. Urgent CT scan showed that it penetrated the left side of her oropharyngeal wall to the bifurcation of her right carotid artery. According to the initial assessment, carotid artery seemed intact and there seemed to be no sign of CNS involvement. She underwent general anesthesia for further investigation and operation. We could detect vocal code with ease by inserting Glidescope between her tongue and the toothbrush. After the intubation, we administered fentanyl 25 μg rocuronium 15 mg and sevoflulane 3-5% to her, and then she underwent arteriography. The neurosurgeon found no sign of major arterial injury nor traumatic aneurysm nor CNS involvement. She went to the ICU intubated after the removal of the toothbrush. She was extubated 5 days after operation. One of the benefits of the Glidescope is that we can share the visual image, and we chose it this time. When we expect a difficult airway during management for oropharyngeal trauma, we have to consider the way to manage the airway.

  9. Gold nanoprobes for theranostics

    Science.gov (United States)

    Panchapakesan, Balaji; Book-Newell, Brittany; Sethu, Palaniappan; Rao, Madhusudhana; Irudayaraj, Joseph

    2011-01-01

    Gold nanoprobes have become attractive diagnostic and therapeutic agents in medicine and life sciences research owing to their reproducible synthesis with atomic level precision, unique physical and chemical properties, versatility of their morphologies, flexibility in functionalization, ease of targeting, efficiency in drug delivery and opportunities for multimodal therapy. This review highlights some of the recent advances and the potential for gold nanoprobes in theranostics. PMID:22122586

  10. The Gold Standard Programme

    DEFF Research Database (Denmark)

    Neumann, Tim; Rasmussen, Mette; Ghith, Nermin

    2013-01-01

    To evaluate the real-life effect of an evidence-based Gold Standard Programme (GSP) for smoking cessation interventions in disadvantaged patients and to identify modifiable factors that consistently produce the highest abstinence rates.......To evaluate the real-life effect of an evidence-based Gold Standard Programme (GSP) for smoking cessation interventions in disadvantaged patients and to identify modifiable factors that consistently produce the highest abstinence rates....

  11. Biosynthesis of gold nanoparticles using diatoms-silica-gold and EPS-gold bionanocomposite formation

    OpenAIRE

    Schröfel, Adam; Kratošová, Gabriela; Bohunická, Markéta; Dobročka, Edmund; Vávra, Ivo

    2011-01-01

    Novel synthesis of gold nanoparticles, EPS-gold, and silica-gold bionanocomposites by biologically driven processes employing two diatom strains (Navicula atomus, Diadesmis gallica) is described. Transmission electron microscopy (TEM) and electron diffraction analysis (SAED) revealed a presence of gold nanoparticles in the experimental solutions of the diatom culture mixed with tetrachloroaureate. Nature of the gold nanoparticles was confirmed by X-ray diffraction studies. Scanning electron m...

  12. Effect of using pump on postoperative pleural effusion in the patients that underwent CABG

    Directory of Open Access Journals (Sweden)

    Mehmet Özülkü

    2015-08-01

    Full Text Available Abstract Objective: The present study investigated effect of using pump on postoperative pleural effusion in patients who underwent coronary artery bypass grafting. Methods: A total of 256 patients who underwent isolated coronary artery bypass grafting surgery in the Cardiovascular Surgery clinic were enrolled in the study. Jostra-Cobe (Model 043213 105, VLC 865, Sweden heart-lung machine was used in on-pump coronary artery bypass grafting. Off-pump coronary artery bypass grafting was performed using Octopus and Starfish. Proximal anastomoses to the aorta in both on-pump and off-pump techniques were performed by side clamps. The patients were discharged from the hospital between postoperative day 6 and day 11. Results: The incidence of postoperative right pleural effusion and bilateral pleural effusion was found to be higher as a count in Group 1 (on-pump as compared to Group 2 (off-pump. But the difference was not statistically significant [P>0.05 for right pleural effusion (P=0.893, P>0.05 for bilateral pleural effusion (P=0.780]. Left pleural effusion was encountered to be lower in Group 2 (off-pump. The difference was found to be statistically significant (P<0.05, P=0.006. Conclusion: Under the light of these results, it can be said that left pleural effusion is less prevalent in the patients that underwent off-pump coronary artery bypass grafting when compared to the patients that underwent on-pump coronary artery bypass grafting.

  13. Dysphagia among Adult Patients who Underwent Surgery for Esophageal Atresia at Birth

    Directory of Open Access Journals (Sweden)

    Valérie Huynh-Trudeau

    2015-01-01

    Full Text Available BACKGROUND: Clinical experiences of adults who underwent surgery for esophageal atresia at birth is limited. There is some evidence that suggests considerable long-term morbidity, partly because of dysphagia, which has been reported in up to 85% of adult patients who undergo surgery for esophageal atresia. The authors hypothesized that dysphagia in this population is caused by dysmotility and/or anatomical anomalies.

  14. Evolution of elderly patients who underwent cardiac surgery with cardiopulmonary bypass

    Directory of Open Access Journals (Sweden)

    Alain Moré Duarte

    2016-01-01

    Full Text Available Introduction: There is a steady increase in the number of elderly patients with severe cardiovascular diseases who require a surgical procedure to recover some quality of life that allows them a socially meaningful existence, despite the risks.Objectives: To analyze the behavior of elderly patients who underwent cardiac surgery with cardiopulmonary bypass.Method: A descriptive, retrospective, cross-sectional study was conducted with patients over 65 years of age who underwent surgery at the Cardiocentro Ernesto Che Guevara, in Santa Clara, from January 2013 to March 2014.Results: In the study, 73.1% of patients were men; and there was a predominance of subjects between 65 and 70 years of age, accounting for 67.3%. Coronary artery bypass graft was the most prevalent type of surgery and had the longest cardiopulmonary bypass times. Hypertension was present in 98.1% of patients. The most frequent postoperative complications were renal dysfunction and severe low cardiac output, with 44.2% and 34.6% respectively.Conclusions: There was a predominance of men, the age group of 65 to 70 years, hypertension, and patients who underwent coronary artery bypass graft with prolonged cardiopulmonary bypass. Renal dysfunction was the most frequent complication.

  15. Acute myocardial infarctation in patients with critical ischemia underwent lower limb revascularization

    Directory of Open Access Journals (Sweden)

    Esdras Marques Lins

    2013-12-01

    Full Text Available BACKGROUND: Atherosclerosis is the main cause of peripheral artery occlusive disease (PAOD of the lower limbs. Patients with PAOD often also have obstructive atherosclerosis in other arterial sites, mainly the coronary arteries. This means that patients who undergo infrainguinal bypass to treat critical ischemia have a higher risk of AMI. There are, however, few reports in the literature that have assessed this risk properly. OBJECTIVE: The aim of this study was to determine the incidence of acute myocardial infarction in patients who underwent infrainguinal bypass to treat critical ischemia of the lower limbs caused by PAOD. MATERIAL AND METHODS: A total of 64 patients who underwent 82 infrainguinal bypass operations, from February 2011 to July 2012 were studied. All patients had electrocardiograms and troponin I blood assays during the postoperative period (within 72 hours. RESULTS: There were abnormal ECG findings and elevated blood troponin I levels suggestive of AMI in five (6% of the 82 operations performed. All five had conventional surgery. The incidence of AMI as a proportion of the 52 conventional surgery cases was 9.6%. Two patients died. CONCLUSION: There was a 6% AMI incidence among patients who underwent infrainguinal bypass due to PAOD. Considering only cases operated using conventional surgery, the incidence of AMI was 9.6%.

  16. Gold recovery from low concentrations using nanoporous silica adsorbent

    Science.gov (United States)

    Aledresse, Adil

    The development of high capacity adsorbents with uniform porosity denoted 5%MP-HMS (5% Mercaptopropyl-Hexagonal Mesoporous Structure) to extract gold from noncyanide solutions is presented. The preliminary studies from laboratory simulated noncyanide gold solutions show that the adsorption capacities of these materials are among the highest reported. The high adsorption saturation level of these materials, up to 1.9 mmol/g (37% of the adsorbent weight) from gold chloride solutions (potassium tetrachloroaurate) and 2.9 mmol/g (57% of the adsorbent weight) from gold bromide solutions (potassium tetrabromoaurate) at pH = 2, is a noteworthy feature of these materials. This gold loading from [AuC4]- and [AuBr4 ]- solutions corresponds to a relative Au:S molar ratio of 2.5:1 and 3.8:1, respectively. These rates are significantly higher than the usual 1:1 (Au:S) ratio expected for metal ion binding with the material. The additional gold ions loaded have been spontaneously reduced to metallic gold in the mesoporous material. Experimental studies indicated high maximum adsorptions of gold as high as 99.9% recovery. Another promising attribute of these materials is their favourable adsorption kinetics. The MP-HMS reaches equilibrium (saturation) in less than 1 minute of exposure in gold bromide and less than 10 minutes in gold chloride. The MP-HMS materials adsorption is significantly improved by agitation and the adsorption capacity of Au (III) ions increases with the decrease in pH. The recovery of adsorbed gold and the regeneration of spent adsorbent were investigated for MP-HMS adsorbent. The regenerated adsorbent (MP-HMS) maintained its adsorption capacity even after repeated use and all the gold was successfully recovered from the spent adsorbent. For the fist time, a promising adsorbent system has been found that is capable of effectively concentrating gold thiosulphate complexes, whereas conventional carbon-inpulp (CIP) and carbon-in-leach (CIL) systems fail. The

  17. Weight Management in Phenylketonuria

    DEFF Research Database (Denmark)

    Rocha, Julio César; van Rijn, Margreet; van Dam, Esther

    2016-01-01

    . It is becoming evident that in addition to acceptable blood phenylalanine control, metabolic dieticians should regard weight management as part of routine clinical practice. SUMMARY: It is important for practitioners to differentiate the 3 levels for overweight interpretation: anthropometry, body composition...... and frequency and severity of associated metabolic comorbidities. The main objectives of this review are to suggest proposals for the minimal standard and gold standard for the assessment of weight management in PKU. While the former aims to underline the importance of nutritional status evaluation in every...... specialized clinic, the second objective is important in establishing an understanding of the breadth of overweight and obesity in PKU in Europe. KEY MESSAGES: In PKU, the importance of adopting a European nutritional management strategy on weight management is highlighted in order to optimize long...

  18. GOLD IS EARNED FROM THE PRODUCTION OF THAI GOLD LEAF

    Directory of Open Access Journals (Sweden)

    Dirk Bax

    2010-06-01

    Full Text Available Thai people like to cover sacred objects or things dear to them with gold leaf.. Statues of Buddha are sometimes covered with so many layers of gold leaf that they become formless figures, that can hardly be recognized. Portraits of beloved ancestors, statues of elephants and grave tombs are often covered with gold leaf. If one considers the number of Thai people and the popularity of the habit, the amount of gold involved could be considerable.

  19. Activated carbons and gold

    International Nuclear Information System (INIS)

    McDougall, G.J.; Hancock, R.D.

    1980-01-01

    The literature on activated carbon is reviewed so as to provide a general background with respect to the effect of source material and activation procedure on carbon properties, the structure and chemical nature of the surface of the activated carbon, and the nature of absorption processes on carbon. The various theories on the absorption of gold and silver from cyanide solutions are then reviewed, followed by a discussion of processes for the recovery of gold and silver from cyanide solutions using activated carbon, including a comparison with zinc precipitation

  20. Rushing for gold

    DEFF Research Database (Denmark)

    Jønsson, Jesper Bosse; Bryceson, Deborah Fahy

    2009-01-01

    African rural dwellers have faced depressed economic prospects for several decades. Now, in a number of mineral-rich countries, multiple discoveries of gold and precious stones have attracted large numbers of prospective small-scale miners. While their 'rush' to, and activities within, mining sites...... are increasingly being noted, there is little analysis of miners' mobility patterns and material outcomes. In this article, on the basis of a sample survey and interviews at two gold-mining sites in Tanzania, we probe when and why miners leave one site in favour of another. Our findings indicate that movement...

  1. Properties of gold nanostructures sputtered on glass

    Directory of Open Access Journals (Sweden)

    Kolská Zdeňka

    2011-01-01

    Full Text Available Abstract We studied the electrical and optical properties, density, and crystalline structure of Au nanostructures prepared by direct current sputtering on glass. We measured temperature dependence of sheet resistance and current-voltage characteristics and also performed scanning electron microscopy [SEM] analysis of gold nanolayers. It was shown that within the wide range of temperatures, gold nanolayers (<10 nm exhibit both metal and semiconducting-like type of conductivity. UV/Vis analysis proved the semiconducting characteristic of intrinsic Au clusters. SEM analysis showed the initiatory stadium of gold layer formation to be running over isolated islands. Gold density calculated from the weight and effective thickness of the layers is an increasing function of the layer thickness up to approximately 100 nm. In thin layers deposited on solid surface, a lattice expansion is observed, which is manifested in the increase of the lattice parameter and the decrease of metal density. With increasing layer thickness, the lattice parameter and the density approach the bulk values.

  2. Electrochemical growth of two-dimensional gold nanostructures on a thin polypyrrole film modified ITO electrode.

    Science.gov (United States)

    Li, Yin; Shi, Gaoquan

    2005-12-22

    Two-dimensional gold nanostructures have been fabricated by electrochemical deposition of gold nanoparticles onto indium tin oxide (ITO) glass substrate modified with thin polypyrrole film. By controlling the electrodeposition conditions, gold nanoparticles with dendritic rod, sheet, flower-like (consisting of staggered nanosheets), and pinecone-like structures were generated. The flower-like gold nanoparticles showed high catalytic activity on electrochemical reduction of oxygen, and its activity was measured to be approximately 25 times that of gold pinecones and 10(4) times that of gold nanosheets in terms of gold weight. The pinecone-like nanoparticles can form a compact film with nano-/microscale binary structure like a lotus leaf surface. After modification with n-dodecanethiol, the surface showed superhydrophobic properties with a water contact angle of 153.4 degrees and a tilt angle of 4.4 degrees (5 microL droplet).

  3. ['Gold standard', not 'golden standard'

    NARCIS (Netherlands)

    Claassen, J.A.H.R.

    2005-01-01

    In medical literature, both 'gold standard' and 'golden standard' are employed to describe a reference test used for comparison with a novel method. The term 'gold standard' in its current sense in medical research was coined by Rudd in 1979, in reference to the monetary gold standard. In the same

  4. GOLD PRESSURE VESSEL SEAL

    Science.gov (United States)

    Smith, A.E.

    1963-11-26

    An improved seal between the piston and die member of a piston-cylinder type pressure vessel is presented. A layer of gold, of sufficient thickness to provide an interference fit between the piston and die member, is plated on the contacting surface of at least one of the members. (AEC)

  5. Digging for Gold

    Science.gov (United States)

    Waters, John K.

    2012-01-01

    In the case of higher education, the hills are more like mountains of data that "we're accumulating at a ferocious rate," according to Gerry McCartney, CIO of Purdue University (Indiana). "Every higher education institution has this data, but it just sits there like gold in the ground," complains McCartney. Big Data and the new tools people are…

  6. Turning lead into gold

    DEFF Research Database (Denmark)

    Jensen, Steffen Moltrup Ernø

    For years the field of entrepreneurship has been blinded by the alchemical promise of turning lead into gold, of finding the ones most likely to become the next Branson, Zuckerberg or Gates. The promise has been created in the midst of political and scientific agendas where certain individuals...

  7. Gold Nanoparticle Microwave Synthesis

    International Nuclear Information System (INIS)

    Krantz, Kelsie E.; Christian, Jonathan H.; Coopersmith, Kaitlin; Washington II, Aaron L.; Murph, Simona H.

    2016-01-01

    At the nanometer scale, numerous compounds display different properties than those found in bulk material that can prove useful in areas such as medicinal chemistry. Gold nanoparticles, for example, display promise in newly developed hyperthermia therapies for cancer treatment. Currently, gold nanoparticle synthesis is performed via the hot injection technique which has large variability in final particle size and a longer reaction time. One underdeveloped area by which these particles could be produced is through microwave synthesis. To initiate heating, microwaves agitate polar molecules creating a vibration that gives off the heat energy needed. Previous studies have used microwaves for gold nanoparticle synthesis; however, polar solvents were used that partially absorbed incident microwaves, leading to partial thermal heating of the sample rather than taking full advantage of the microwave to solely heat the gold nanoparticle precursors in a non-polar solution. Through this project, microwaves were utilized as the sole heat source, and non-polar solvents were used to explore the effects of microwave heating only as pertains to the precursor material. Our findings show that the use of non-polar solvents allows for more rapid heating as compared to polar solvents, and a reduction in reaction time from 10 minutes to 1 minute; this maximizes the efficiency of the reaction, and allows for reproducibility in the size/shape of the fabricated nanoparticles.

  8. Gold Nanoparticle Microwave Synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Krantz, Kelsie E. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Christian, Jonathan H. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Coopersmith, Kaitlin [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Washington, II, Aaron L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Murph, Simona H. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-07-27

    At the nanometer scale, numerous compounds display different properties than those found in bulk material that can prove useful in areas such as medicinal chemistry. Gold nanoparticles, for example, display promise in newly developed hyperthermia therapies for cancer treatment. Currently, gold nanoparticle synthesis is performed via the hot injection technique which has large variability in final particle size and a longer reaction time. One underdeveloped area by which these particles could be produced is through microwave synthesis. To initiate heating, microwaves agitate polar molecules creating a vibration that gives off the heat energy needed. Previous studies have used microwaves for gold nanoparticle synthesis; however, polar solvents were used that partially absorbed incident microwaves, leading to partial thermal heating of the sample rather than taking full advantage of the microwave to solely heat the gold nanoparticle precursors in a non-polar solution. Through this project, microwaves were utilized as the sole heat source, and non-polar solvents were used to explore the effects of microwave heating only as pertains to the precursor material. Our findings show that the use of non-polar solvents allows for more rapid heating as compared to polar solvents, and a reduction in reaction time from 10 minutes to 1 minute; this maximizes the efficiency of the reaction, and allows for reproducibility in the size/shape of the fabricated nanoparticles.

  9. Voiding patterns of adult patients who underwent hypospadias repair in childhood.

    Science.gov (United States)

    Jaber, Jawdat; Kocherov, Stanislav; Chertin, Leonid; Farkas, Amicur; Chertin, Boris

    2017-02-01

    This study aimed at evaluating the voiding patterns of adult patients who underwent hypospadias repair in childhood. Following IRB approval 103 (22.7%) of 449 adult patients who underwent hypospadias repair between 1978 and 1993 responded to the following questionnaires: International Prostate Symptom Score (I-PSS) and Short Form 12 questionnaire (SF-12). Uroflowmetry (UF) was performed for all patients. The patients were divided into three groups according to the primary meatus localization. Group I had 63 patients (61.5%) treated for glanular hypospadias, group II had 19 patients (18.4%) treated for distal hypospadias, and group III comprised the remaining 21 patients (20.4%) treated for proximal hypospadias. The mean ± SD I-PSS score for all patients who responded to the questionnaire was 2.3 ± 2.4, and UF was 21.1 ± 4.3 mL/s. The patients from groups I and III had fewer urinary symptoms compared with those of the group II: 1.3 ± 1.5, 5.5 ± 2.4, and 1.6 ± 1.4, respectively (p hypospadias repair in childhood had normal or mild voiding disturbance, with no effects on their physical or mental status. Copyright © 2016 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.

  10. [Prognostic Analysis of Breast Cancer Patients Who Underwent Neoadjuvant Chemotherapy Using QOL-ACD].

    Science.gov (United States)

    Fukui, Yasuhiro; Kashiwagi, Shinichiro; Takada, Koji; Goto, Wataru; Asano, Yuka; Morisaki, Tamami; Noda, Satoru; Takashima, Tsutomu; Onoda, Naoyoshi; Hirakawa, Kosei; Ohira, Masaichi

    2017-11-01

    We investigated into association of quality of life(QOL)and prognosis of breast cancer patients who underwent neoadjuvant chemotherapy(NAC). We retrospectively studied 228 patients with breast cancer who were performed NAC during a period between 2007 and 2015. TheQ OL score was measured with"The QOL Questionnaire for Cancer Patients Treated with Anticancer Drugs(QOL-ACD)". We evaluate association between QOL score with antitumor effect and prognosis. Changes in the QOL score between before and after NAC were compared as well. We divided 2 groups by QOL-ACD scoreinto high and low groups. Therapeautic effect of NAC on 75 patients were pathological complete response(pCR). QOL-ACD score was not significantly associated with pCR rate in both high and low groups(p=0.199). High group was significantly associated with higher survival rate in both of disease free survival(p=0.009, logrank)and overall survival(p=0.040, logrank). QOLACD score decreased after NAC in both of pCR and non-pCR patients. In conclusion, QOL evaluation using QOL-ACD could be an indicator of breast cancer patients' prognosis who underwent NAC.

  11. HLA-G regulatory haplotypes and implantation outcome in couples who underwent assisted reproduction treatment.

    Science.gov (United States)

    Costa, Cynthia Hernandes; Gelmini, Georgia Fernanda; Wowk, Pryscilla Fanini; Mattar, Sibelle Botogosque; Vargas, Rafael Gustavo; Roxo, Valéria Maria Munhoz Sperandio; Schuffner, Alessandro; Bicalho, Maria da Graça

    2012-09-01

    The role of HLA-G in several clinical conditions related to reproduction has been investigated. Important polymorphisms have been found within the 5'URR and 3'UTR regions of the HLA-G promoter. The aim of the present study was to investigate 16 SNPs in the 5'URR and 14-bp insertion/deletion (ins/del) polymorphism located in the 3'UTR region of the HLA-G gene and its possible association with the implantation outcome in couples who underwent assisted reproduction treatments (ART). The case group was composed of 25 ART couples. Ninety-four couples with two or more term pregnancies composed the control group. Polymorphism haplotype frequencies of the HLA-G were determined for both groups. The Haplotype 5, Haplotype 8 and Haplotype 11 were absolute absence in ART couples. The HLA-G*01:01:02a, HLA-G*01:01:02b alleles and the 14-bp ins polymorphism, Haplotype 2, showed an increased frequency in case women and similar distribution between case and control men. However, this susceptibility haplotype is significantly presented in case women and in couple with failure implantation after treatment, which led us to suggest a maternal effect, associated with this haplotype, once their presence in women is related to a higher number of couples who underwent ART. Copyright © 2012. Published by Elsevier Inc.

  12. Sarcopenia: a new predictor of postoperative complications for elderly gastric cancer patients who underwent radical gastrectomy.

    Science.gov (United States)

    Zhou, Chong-Jun; Zhang, Feng-Min; Zhang, Fei-Yu; Yu, Zhen; Chen, Xiao-Lei; Shen, Xian; Zhuang, Cheng-Le; Chen, Xiao-Xi

    2017-05-01

    A geriatric assessment is needed to identify high-risk elderly patients with gastric cancer. However, the current geriatric assessment has been considered to be either time-consuming or subjective. The present study aimed to investigate the predictive effect of sarcopenia on the postoperative complications for elderly patients who underwent radical gastrectomy. We conducted a prospective study of patients who underwent radical gastrectomy from August 2014 to December 2015. Computed tomography-assessed lumbar skeletal muscle, handgrip strength, and gait speed were measured to define sarcopenia. Sarcopenia was present in 69 of 240 patients (28.8%) and was associated with lower body mass index, lower serum albumin, lower hemoglobin, and higher nutritional risk screening 2002 scores. Postoperative complications significantly increased in the sarcopenic patients (49.3% versus 24.6%, P sarcopenia (odds ratio: 2.959, 95% CI: 1.629-5.373, P Sarcopenia, presented as a new geriatric assessment factor, was a strong and independent risk factor for postoperative complications of elderly patients with gastric cancer. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Circulating S100B and Adiponectin in Children Who Underwent Open Heart Surgery and Cardiopulmonary Bypass

    Directory of Open Access Journals (Sweden)

    Alessandro Varrica

    2015-01-01

    Full Text Available Background. S100B protein, previously proposed as a consolidated marker of brain damage in congenital heart disease (CHD newborns who underwent cardiac surgery and cardiopulmonary bypass (CPB, has been progressively abandoned due to S100B CNS extra-source such as adipose tissue. The present study investigated CHD newborns, if adipose tissue contributes significantly to S100B serum levels. Methods. We conducted a prospective study in 26 CHD infants, without preexisting neurological disorders, who underwent cardiac surgery and CPB in whom blood samples for S100B and adiponectin (ADN measurement were drawn at five perioperative time-points. Results. S100B showed a significant increase from hospital admission up to 24 h after procedure reaching its maximum peak (P0.05 have been found all along perioperative monitoring. ADN/S100B ratio pattern was identical to S100B alone with the higher peak at the end of CPB and remained higher up to 24 h from surgery. Conclusions. The present study provides evidence that, in CHD infants, S100B protein is not affected by an extra-source adipose tissue release as suggested by no changes in circulating ADN concentrations.

  14. Effect of different pneumoperitoneum pressure on stress state in patients underwent gynecological laparoscopy

    Directory of Open Access Journals (Sweden)

    Ai-Yun Shen

    2016-10-01

    Full Text Available Objective: To observe the effect of different CO2 pneumoperitoneum pressure on the stress state in patients underwent gynecological laparoscopy. Methods: A total of 90 patients who were admitted in our hospital from February, 2015 to October, 2015 for gynecological laparoscopy were included in the study and divided into groups A, B, and C according to different CO2 pneumoperitoneum pressure. The changes of HR, BP, and PetCO2 during the operation process in the three groups were recorded. The changes of stress indicators before operation (T0, 30 min during operation (T1, and 12 h after operation (T2 were compared. Results: The difference of HR, BP, and PetCO2 levels before operation among the three groups was not statistically significant (P>0.05. HR, BP, and PetCO2 levels 30 min after pneumoperitoneum were significantly elevated when compared with before operation (P0.05. PetCO2 level 30 min after pneumoperitoneum in group B was significantly higher than that in group A (P0.05. Conclusions: Low pneumoperitoneum pressure has a small effect on the stress state in patients underwent gynecological laparoscopy, will not affect the surgical operation, and can obtain a preferable muscular relaxation and vision field; therefore, it can be selected in preference.

  15. Weight Management

    Science.gov (United States)

    ... Health Information Weight Management English English Español Weight Management Obesity is a chronic condition that affects more ... Liver (NASH) Heart Disease & Stroke Sleep Apnea Weight Management Topics About Food Portions Bariatric Surgery for Severe ...

  16. 16 CFR Appendix to Part 23 - Exemptions Recognized in the Assay for Quality of Gold Alloy, Gold Filled, Gold Overlay, Rolled...

    Science.gov (United States)

    2010-01-01

    ... Quality of Gold Alloy, Gold Filled, Gold Overlay, Rolled Gold Plate, Silver, and Platinum Industry...—Exemptions Recognized in the Assay for Quality of Gold Alloy, Gold Filled, Gold Overlay, Rolled Gold Plate... in any assay for quality of a karat gold industry product include springs, posts, and separable backs...

  17. Carotid intima-media thickness and ınsulin resistance changes in patients who underwent sleeve gastrectomy: A prospective study.

    Science.gov (United States)

    Yorulmaz, G; Cilekar, M; Bilge, U; Akcan, E; Akalin, A

    2016-01-01

    Our aim was to examine changes in insulin resistance, Carotid Intima-Media Thickness (CIMT), in morbid obese patients without any known associated chronic diseases who underwent sleeve gastrectomy. The subjects of this study were patients with minimum BMI of 40, who did not have any known chronic diseases. Sleeve gastrectomy was performed and perioperative control endoscopy was performed. The following values were measured before the operation and after follow-up period after the operation: Fasting blood glucose and insulin, lipid profile, BMI, liver function tests, right and left CIMT. Furthermore, the patients' insulin resistance was calculated by HOMA method, and the values of 2.7. Six-teen patients (14 women and 2 men, average age: 39.12 ± 10.63 years), who did not have a known additional chronic disease, took part in the study. There was a significant difference between baseline and follow-up values of the patients, and the mean weight loss was 20.5%. Given the statistical evaluation of baseline and follow-up values, there was a significant difference in BMI, insulin resistance rates and right and left CIMT values. Bariatric surgery may provide some additional advantages for the management of cardiovascular risks in obese patients. However, it should be kept in mind that the most important components of fight against obesity are appropriate diet and exercise programs.

  18. Moessbauerspectroscopy on Gold Ruby Glass

    International Nuclear Information System (INIS)

    Haslbeck, S.

    2005-01-01

    In this thesis, the chemical states of gold and the physical mechanisms of the growing process of the particles under the influence of additional ingredients like tin, lead, antimony and selenium before, during and after the colouring process are investigated by using the Moessbauer spectroscopy on 197 Au, 119 Sn and 121 Sb, optical spectroscopy and X-ray-diffraction. Gold in an unnealed, colourless state of the glasses consists of monovalent forming linear bonds to two neighbouring oxygen atoms. The Lamb-Moessbauer factor of these gold oxide bondings is observed as 0.095 at 4.2 K. The gold in it's oxide state transforms to gold particles with a diameter of 3 nm to 60 nm. The size of the gold particles is quite definable within the optical spectra and certain sizes are also discernable within the Moessbauer spectra. One component of the Moessbauer spectra is assigned to the surface layer of the gold particles. By comparing this surface component with the amount of the bulk metallic core, one can calculate the size of the gold particles. In the Moessbauer spectra of the colourless glass one also can find parts of bulk metallic gold. Investigations with X-ray diffraction show that these are gold particles with a diameter of 100 nm to 300 nm and therefore have no additional colouring effect within the visible spectrum. The Moessbauer spectra on gold of the remelt glasses are similar to those which have been measured on the initial colourless glasses

  19. For the love of gold

    International Nuclear Information System (INIS)

    Young, J.E.

    1993-01-01

    Gold is found in minute quantities and gold mining generates enormous amounts of waste materials and long history of environmental destruction: mercury in tailing, eroded land, and acid mine drainage are legacies of the past. The problem has become worse in recent years in North America, Australia, the Amazon basin, Philippines. This paper describes the economics of gold and the changes in the world economy which has precipitated the new gold rushes. Current technology uses a cyanide solution for leaching small amounts of gold from tons of waste, and mercury remains a toxic waste of gold mining. Both short and long term results of gold mining, on the environment and on indiginous populations are described

  20. A Pregnant Woman Who Underwent Laparoscopic Adrenalectomy due to Cushing’s Syndrome

    Directory of Open Access Journals (Sweden)

    Halit Diri

    2014-01-01

    Full Text Available Cushing’s syndrome (CS may lead to severe maternal and fetal morbidities and even mortalities in pregnancy. However, pregnancy complicates the diagnosis and treatment of CS. This study describes a 26-year-old pregnant woman admitted with hypertension-induced headache. Hormonal analyses performed due to her cushingoid phenotype revealed a diagnosis of adrenocorticotropic hormone- (ACTH- independent CS. MRI showed a 3.5 cm adenoma in her right adrenal gland. After preoperative metyrapone therapy, she underwent a successful unilateral laparoscopic adrenalectomy at 14-week gestation. Although she had a temporary postoperative adrenal insufficiency, hormonal analyses showed that she has been in remission since delivery. Findings in this patient, as well as those in previous patients, indicate that pregnancy is not an absolute contraindication for laparoscopic adrenalectomy. Rather, such surgery should be considered a safe and efficient treatment method for pregnant women with cortisol-secreting adrenal adenomas.

  1. Clinical outcomes for 14 consecutive patients with solid pseudopapillary neoplasms who underwent laparoscopic distal pancreatectomy.

    Science.gov (United States)

    Nakamura, Yoshiharu; Matsushita, Akira; Katsuno, Akira; Yamahatsu, Kazuya; Sumiyoshi, Hiroki; Mizuguchi, Yoshiaki; Uchida, Eiji

    2016-02-01

    The postoperative results of laparoscopic distal pancreatectomy for solid pseudopapillary neoplasm of the pancreas (SPN), including the effects of spleen-preserving resection, are still to be elucidated. Of the 139 patients who underwent laparoscopic pancreatectomy for non-cancerous tumors, 14 consecutive patients (average age, 29.6 years; 1 man, 13 women) with solitary SPN who underwent laparoscopic distal pancreatectomy between March 2004 and June 2015 were enrolled. The tumors had a mean diameter of 4.8 cm. Laparoscopic spleen-preserving distal pancreatectomy was performed in eight patients (spleen-preserving group), including two cases involving pancreatic tail preservation, and laparoscopic spleno-distal pancreatectomy was performed in six patients (standard resection group). The median operating time was 317 min, and the median blood loss was 50 mL. Postoperatively, grade B pancreatic fistulas appeared in two patients (14.3%) but resolved with conservative treatment. No patients had postoperative complications, other than pancreatic fistulas, or required reoperation. The median postoperative hospital stay was 11 days, and the postoperative mortality was zero.None of the patients had positive surgical margins or lymph nodes with metastasis. The median follow-up period did not significantly differ between the two groups (20 vs 39 months, P = 0.1368). All of the patients are alive and free from recurrent tumors without major late-phase complications. Laparoscopic distal pancreatectomy might be a suitable treatment for patients with SPN. A spleen-preserving operation is preferable for younger patients with SPN, and this study demonstrated the non-inferiority of the procedure compared to spleno-distal pancreatectomy. © 2015 Japan Society for Endoscopic Surgery, Asia Endosurgery Task Force and John Wiley & Sons Australia, Ltd.

  2. [Patients with astigmatism who underwent cataract surgery by phacoemulsification: toric IOL x asferic IOL?].

    Science.gov (United States)

    Torres Netto, Emilio de Almeida; Gulin, Marina Carvalho; Zapparoli, Marcio; Moreira, Hamilton

    2013-01-01

    Compare the visual acuity of patients who underwent cataract surgery by phacoemulsification with IOL AcrySof(®) toric implantation versus AcrySof(®) IQ and evaluate the reduction of cylindrical diopters (CD) in the postoperative period. Analytical and retrospective study of 149 eyes with 1 or more diopters of regular symmetrical keratometric astigmatism, which underwent cataract surgery by phacoemulsification. The eyes were divided into two groups: the toric group with 85 eyes and the non-toric group with 64 eyes. In the pre-operative phase, topographic data and refraction of each eye to be operated were assessed. In the postoperative phase, refraction and visual acuity with and without correction were measured. The preoperative topographic astigmatism ranged from 1.00 to 5.6 DC in both groups. Average reduction of 1.37 CD (p<0.001) and 0.16 CD (p=0.057) was obtained for the toric and non-toric group when compared to the refractive astigmatism, respectively. Considering visual acuity without correction (NCVA), the toric group presented 44 eyes (51.7%) with NCVA of 0 logMAR (20/20) or 0.1 logMAR (20/25) and the toric group presented 7 eyes (10.93%) with these same NCVA values. The results show that patients with a significant keratometric astigmatism presented visual benefits with the toric IOL implantation. The reduction of the use of optical aids may be obtained provided aberrations of the human eye are corrected more accurately. Currently, phacoemulsification surgery has been used not only for functional improvement, but also as a refraction procedure.

  3. Enteral nutrition is superior to total parenteral nutrition for pancreatic cancer patients who underwent pancreaticoduodenectomy.

    Science.gov (United States)

    Liu, Changli; Du, Zhi; Lou, Cheng; Wu, Chenxuan; Yuan, Qiang; Wang, Jun; Shu, Guiming; Wang, Yijun

    2011-01-01

    To determine the effects of total parenteral nutrition (TPN) and enteral nutrition (EN) on biochemical and clinical outcomes in pancreatic cancer patients who underwent pancreaticoduodenectomy. From the year 2006 to 2008, 60 patients who underwent pancreaticoduodenectomy in Tianjin Third Central Hospital were enrolled in this study. They were randomly divided into the EN group and the TPN group. The biochemical and clinical parameters were recorded and analyzed between the two groups. There was no significant difference in the nutritional status, liver and kidney function, and blood glucose levels between the TPN and EN groups on the preoperative day, the 1st and 3 rd postoperative days. However, on the 7th postoperative day, there was significant difference between the two groups in 24 h urinary nitrogen, serum levels of, total protein (TP), transferrin (TF), alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), and γ-glutamyl transpeptadase (GGT), blood urea nitrogen (BUN) and creatinine (Cr). On the 14th postoperative day, there was a significant difference between the two groups in terms of urinary levels of 24 h nitrogen, TP, TF, retinol binding protein, ALT, AST, ALP, GGT, total bilirubin, direct bilirubin, BUN, Cr, and glucose. The incidence of delayed gastric emptying in the EN and TPN groups was 0% and 20%, respectively. Moreover, the incidence of pancreatic fistulas and hemorrhages in the EN group were 3.6% and 3.6%, versus 26.7% and 30% in the TPN group, respectively. EN is better than TPN for pancreatic cancer patients who received pancreaticoduodenectomy.

  4. Gold Nanoparticles Cytotoxicity

    Science.gov (United States)

    Mironava, Tatsiana

    Over the last two decades gold nanoparticles (AuNPs) have been used for many scientific applications and have attracted attention due to the specific chemical, electronic and optical size dependent properties that make them very promising agents in many fields such as medicine, imagine techniques and electronics. More specifically, biocompatible gold nanoparticles have a huge potential for use as the contrast augmentation agent in X-ray Computed Tomography and Photo Acoustic Tomography for early tumor diagnostic as well these nanoparticles are extensively researched for enhancing the targeted cancer treatment effectiveness such as photo-thermal and radiotherapy. In most biomedical applications biocompatible gold nanoparticles are labeled with specific tumor or other pathology targeting antibodies and used for site specific drug delivery. However, even though gold nanoparticles poses very high level of anti cancer properties, the question of their cytotoxicity ones they are released in normal tissue has to be researched. Moreover, the huge amount of industrially produced gold nanoparticles raises the question of these particles being a health hazard, since the penetration is fairly easy for the "nano" size substances. This study focuses on the effect of AuNPs on a human skin tissue, since it is fall in both categories -- the side effects for biomedical applications and industrial workers and users' exposure during production and handling. Therefore, in the present project, gold nanoparticles stabilized with the biocompatible agent citric acid were generated and characterized by Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM). The cytotoxic effect of AuNPs release to healthy skin tissue was modeled on 3 different cell types: human keratinocytes, human dermal fibroblasts, and human adipose derived stromal (ADS) cells. The AuNPs localization inside the cell was found to be cell type dependent. Overall cytotoxicity was found to be dependent

  5. Susceptibility weighted imaging depicts retinal hemorrhages in abusive head trauma

    Energy Technology Data Exchange (ETDEWEB)

    Zuccoli, Giulio [Children' s Hospital of Pittsburgh of UPMC, Department of Pediatric Radiology, Pittsburgh, PA (United States); Children' s Hospital of Pittsburgh of UPMC, Department of Radiology, Pittsburgh, PA (United States); Panigrahy, Ashok; Haldipur, Anshul; Willaman, Dennis [Children' s Hospital of Pittsburgh of UPMC, Department of Pediatric Radiology, Pittsburgh, PA (United States); Squires, Janet; Wolford, Jennifer [Children' s Hospital of Pittsburgh of UPMC, Division of Child Advocacy, Pittsburgh, PA (United States); Sylvester, Christin; Mitchell, Ellen; Lope, Lee Ann [Children' s Hospital of Pittsburgh of UPMC, Eye Center, Pittsburgh, PA (United States); Nischal, Ken K. [Children' s Hospital of Pittsburgh of UPMC, Eye Center, Pittsburgh, PA (United States); Children' s Hospital of Pittsburgh of UPMC, Division of Pediatric Ophthalmology, Strabismus, and Adult Motility, Eye Center, Pittsburgh, PA (United States); Berger, Rachel P. [Children' s Hospital of Pittsburgh of UPMC, Division of Child Advocacy, Pittsburgh, PA (United States); University of Pittsburgh Medical Center, Safar Center for Resuscitation Research, Pittsburgh, PA (United States)

    2013-07-15

    This study aims to evaluate the capability of magnetic resonance imaging (MRI) susceptibility weighted images (SWI) in depicting retinal hemorrhages (RH) in abusive head trauma (AHT) compared to the gold standard dilated fundus exam (DFE). This is a retrospective, single institution, observational study on 28 patients with suspected AHT, who had a DFE and also underwent brain MRI-SWI as part of routine diagnostic protocol. Main outcome measures involved evaluation of patients to determine whether the RH could be identified on standard and high-resolution SWI sequences. Of the 21 subjects with RH on DFE, 13 (62 %) were identified by using a standard SWI sequence performed as part of brain MRI protocols. Of the 15 patients who also underwent an orbits SWI protocol, 12 (80 %) were positive for RH. None of the seven patients without RH on of DFE had RH on either standard or high-resolution SWI. Compared with DFE, the MRI standard protocol showed a sensitivity of 75 % which increased to 83 % for the orbits SWI protocol. Our study suggests the usefulness of a tailored high-resolution orbits protocol to detect RH in AHT. (orig.)

  6. Susceptibility weighted imaging depicts retinal hemorrhages in abusive head trauma

    International Nuclear Information System (INIS)

    Zuccoli, Giulio; Panigrahy, Ashok; Haldipur, Anshul; Willaman, Dennis; Squires, Janet; Wolford, Jennifer; Sylvester, Christin; Mitchell, Ellen; Lope, Lee Ann; Nischal, Ken K.; Berger, Rachel P.

    2013-01-01

    This study aims to evaluate the capability of magnetic resonance imaging (MRI) susceptibility weighted images (SWI) in depicting retinal hemorrhages (RH) in abusive head trauma (AHT) compared to the gold standard dilated fundus exam (DFE). This is a retrospective, single institution, observational study on 28 patients with suspected AHT, who had a DFE and also underwent brain MRI-SWI as part of routine diagnostic protocol. Main outcome measures involved evaluation of patients to determine whether the RH could be identified on standard and high-resolution SWI sequences. Of the 21 subjects with RH on DFE, 13 (62 %) were identified by using a standard SWI sequence performed as part of brain MRI protocols. Of the 15 patients who also underwent an orbits SWI protocol, 12 (80 %) were positive for RH. None of the seven patients without RH on of DFE had RH on either standard or high-resolution SWI. Compared with DFE, the MRI standard protocol showed a sensitivity of 75 % which increased to 83 % for the orbits SWI protocol. Our study suggests the usefulness of a tailored high-resolution orbits protocol to detect RH in AHT. (orig.)

  7. The RHIC gold rush

    CERN Document Server

    Schäfer, T

    2003-01-01

    Physicists are colliding gold nuclei to recreate the fireball that existed in the very early universe, and they may have found evidence for quark-gluon plasma. What happens to ordinary matter as you heat it to higher and higher temperatures, or compress it to greater and greater densities? This simple question underpins a major effort to create extreme conditions in the lab, which has recently taken the shape of the Relativistic Heavy Ion Collider (RHIC). This machine has been colliding gold nuclei since 2000, and has produced tantalizing hints that a new state of matter - the quark-gluon plasma - is created in the reactions. But it has also sparked surprises that are sending researchers back to the drawing board. (U.K.)

  8. Radioactive gold ring dermatitis

    Energy Technology Data Exchange (ETDEWEB)

    Miller, R.A.; Aldrich, J.E. (Dalhousie Univ., Halifax, Nova Scotia (Canada))

    1990-08-01

    A superficial squamous cell carcinoma developed in a woman who wore a radioactive gold ring for more than 30 years. Only part of the ring was radioactive. Radiation dose measurements indicated that the dose to basal skin layer was 2.4 Gy (240 rad) per week. If it is assumed that the woman continually wore her wedding ring for 37 years since purchase, she would have received a maximum dose of approximately 4600 Gy.

  9. Radioactive gold ring dermatitis

    International Nuclear Information System (INIS)

    Miller, R.A.; Aldrich, J.E.

    1990-01-01

    A superficial squamous cell carcinoma developed in a woman who wore a radioactive gold ring for more than 30 years. Only part of the ring was radioactive. Radiation dose measurements indicated that the dose to basal skin layer was 2.4 Gy (240 rad) per week. If it is assumed that the woman continually wore her wedding ring for 37 years since purchase, she would have received a maximum dose of approximately 4600 Gy

  10. Direct evidence of oxidized gold on supported gold catalysts.

    Science.gov (United States)

    Fu, L; Wu, N Q; Yang, J H; Qu, F; Johnson, D L; Kung, M C; Kung, H H; Dravid, V P

    2005-03-10

    Supported gold catalysts have drawn worldwide interest due to the novel properties and potential applications in industries. However, the origin of the catalytic activity in gold nanoparticles is still not well understood. In this study, time-of-flight secondary ion mass spectroscopy (TOF-SIMS) has been applied to investigate the nature of gold in Au (1.3 wt %)/gamma-Al2O3 and Au (2.8 wt %)/TiO2 catalysts prepared by the deposition-precipitation method. The SIMS spectrum of the supported gold catalysts presented AuO-, AuO2-, and AuOH- ion clusters. These measurements show direct evidence for oxidized gold on supported gold catalysts and may be helpful to gaining better understanding of the origin of the catalytic activity.

  11. Return and volatility transmission between gold and stock sectors: Application of portfolio management and hedging effectiveness

    Directory of Open Access Journals (Sweden)

    Dilip Kumar

    2014-03-01

    Full Text Available The paper investigates the first and second orders moment transmission between gold and Indian industrial sectors with an application of portfolio design and hedging effectiveness using generalised VAR-ADCC-BVGARCH model. Our findings indicate unidirectional significant return spillover from gold to stock sectors. The negative values of estimated time varying conditional correlations are mainly observed during periods of market turbulence and crisis indicating the scope of portfolio diversification and hedging during these periods. We also estimate optimal weights, hedge ratios, and hedging effectiveness for the stock-gold portfolios. Our findings suggest that stock-gold portfolio provides better diversification benefits than stock portfolios.

  12. Study of the seroma volume changes in the patients who underwent Accelerated Partial Breast Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dae Ho; Son, Sang Jun; Mun, Jun Ki; Seo, Seok Jin; Lee, Je Hee [Dept. of Radiation Oncology, Seoul National University Hospital, Seoul (Korea, Republic of)

    2016-06-15

    By analyzing seroma volume changes in the patients who underwent Partial breast radiation therapy after breast conserving surgery, we try to contribute to the improvement of radiotherapy effect. Enrolled 20 patients who underwent partial breast radiation therapy by ViewRay MRIdian System were subject. After seeking for the size of the removed sample in the patients during surgery and obtained seroma volume changes on a weekly basis. On the Basis of acquired volume, it was compared with age, term from start of the first treatment after surgery, BMI (body mass index) and the extracted sample size during surgery. And using the ViewRay MRIdian RTP System, the figure was analyzed by PTV(=seroma volume + margin) to obtain a specific volume of the Partial breast radiation therapy. The changes of seroma volume from MR simulation to the first treatment (a week) is 0~5% in 8, 5~10% in 3, 10 to 15% in 2, and 20% or more in 5 people. Two patients(A, B patient) among subjects showed the biggest change. The A patient's 100% of the prescribed dose volume is 213.08 cc, PTV is 181.93 cc, seroma volume is 15.3 cc in initial plan. However, while seroma volume decreased 65.36% to 5.3 cc, 100% of the prescribed dose volume was reduced to 3.4% to 102.43 cc and PTV also did 43.6% to 102.54 cc. In the case of the B patient, seroma volume decreased 42.57% from 20.2 cc to 11.6 cc. Because of that, 100% of the prescribed dose volume decreased 8.1% and PTV also did to 40%. As the period between the first therapy and surgery is shorter, the patient is elder and the size of sample is smaller than 100 cc, the change grow bigger. It is desirable to establish an adaptive plan according to each patient's changes of seroma volume through continuous observation. Because partial breast patients is more sensitive than WBRT patients about dose conformity in accordance with the volume change.

  13. Synthesis of a stable gold hydrosol by the reduction of chloroaurate ...

    Indian Academy of Sciences (India)

    occur at ≈150°C (2% weight loss) and 350°C (1⋅2% weight loss). These weight losses are attributed to desorption of surface-bound aspartic acid molecules and indicates that there are two modes of binding of the amino acid to the gold nanoparticle surface. We have observed a similar behaviour from alkylamine capped ...

  14. Estimation of Reminant Gold Resources of Old Underground ...

    African Journals Online (AJOL)

    The lack of geological control and old underground development at AngloGold Ashanti (Bibiani mine) in Ghana was a major setback for the conventional methods of resource estimation to produce accurate estimates of the deposit. Consequently, inverse distance weighting of indicator variables were used. This estimation ...

  15. Comparative analysis of pain in patients who underwent total knee replacement regarding the tourniquet pressure

    Directory of Open Access Journals (Sweden)

    Marcos George de Souza Leão

    Full Text Available ABSTRACT OBJECTIVES: To evaluate through the visual analog scale (VAS the pain in patients undergoing total knee replacement (TKR with different pressures of the pneumatic tourniquet. METHODS: An observational, randomized, descriptive study on an analytical basis, with 60 patients who underwent TKR, divided into two groups, which were matched: a group where TKR was performed with tourniquet pressures of 350 mmHg (standard and the other with systolic blood pressure plus 100 mmHg (P + 100. These patients had their pain assessed by VAS at 48 h, and at the 5th and 15th days after procedure. Secondarily, the following were also measured: range of motion (ROM, complications, and blood drainage volume in each group; the data were subjected to statistical analysis. RESULTS: After data analysis, there was no statistical difference regarding the incidence of complications (p = 0.612, ROM (p = 0.202, bleeding after 24 and 48 h (p = 0.432 and p = 0.254 or in relation to VAS. No correlation was observed between time of ischemia compared to VAS and bleeding. CONCLUSIONS: The use of the pneumatic tourniquet pressure at 350 mmHg or systolic blood pressure plus 100 mmHg did not influence the pain, blood loss, ROM, and complications. Therefore the pressures at these levels are safe and do not change the surgery outcomes; the time of ischemia must be closely observed to avoid major complications.

  16. Assessment of quality of life in patients who underwent minimally invasive cosmetic procedures.

    Science.gov (United States)

    de Aquino, Marcello Simão; Haddad, Alessandra; Ferreira, Lydia Masako

    2013-06-01

    There are increasingly more patients seeking minimally invasive procedures, which have become more effective and safer in reducing the signs of facial aging. This study included 40 female adult patients who voluntarily underwent selected minimally invasive procedures (filling with hyaluronic acid and botulinum toxin injection) for facial rejuvenation. All patients were followed for a period of 6 months. They were evaluated with the use of questionnaires, a quality-of-life questionnaire (DLQI), the self-esteem scale of Rosenberg (EPM/Rosenberg), and a pain scale. The minimally invasive procedures resulted in improvement in quality of life and self-esteem, which were stronger the first 3 months after the procedures but remained at a higher level than that before treatment, even after 6 months. Hyaluronic acid with lidocaine in the formula is more comfortable for the patient as it makes the injection less painful. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

  17. Assessment of Patients Who Underwent Nasal Reconstruction After Non-Melanoma Skin Cancer Excision.

    Science.gov (United States)

    Uzun, Hakan; Bitik, Ozan; Kamburoğlu, Haldun Onuralp; Dadaci, Mehmet; Çaliş, Mert; Öcal, Engin

    2015-06-01

    Basal and squamous cell carcinomas are the most common malignant cutaneous lesions affecting the nose. With the rising incidence of skin cancers, plastic surgeons increasingly face nasal reconstruction challenges. Although multiple options exist, optimal results are obtained when "like is used to repair like". We aimed to introduce a simple algorithm for the reconstruction of nasal defects with local flaps, realizing that there is always more than one option for reconstruction. We retrospectively reviewed 163 patients who underwent nasal reconstruction after excision of non-melanoma skin cancer between March 2011 and April 2014. We analyzed the location of the defects and correlated them with the techniques used to reconstruct them. There were 66 males and 97 females (age, 21-98 years). Basal cell carcinoma was diagnosed in 121 patients and squamous cell carcinoma in 42. After tumor excision, all the defects were immediately closed by either primary closure or local flap options such as Limberg, Miter, glabellar, bilobed, nasolabial, V-Y advancement, and forehead flaps. Obtaining tumor-free borders and a pleasing aesthetic result are major concerns in nasal reconstruction. Defect reconstruction and cosmesis are as important as rapid recovery and quick return to normal daily activities, and these should be considered before performing any procedure, particularly in elderly patients.

  18. [A survey of perioperative asthmatic attack among patients with bronchial asthma underwent general anesthesia].

    Science.gov (United States)

    Ie, Kenya; Yoshizawa, Atsuto; Hirano, Satoru; Izumi, Sinyuu; Hojo, Masaaki; Sugiyama, Haruhito; Kobayasi, Nobuyuki; Kudou, Kouichirou; Maehara, Yasuhiro; Kawachi, Masaharu; Miyakoshi, Kouichi

    2010-07-01

    We investigated the risk factor of perioperative asthmatic attack and effectiveness of preventing treatment for asthmatic attack before operation. We performed retrospective chart review of one hundred eleven patients with asthma underwent general anesthesia and surgical intervention from January 2006 to October 2007 in our hospital. The rate of perioperative asthmatic attack were as follows; 10.2% (5 in 49 cases) in no pretreatment group, 7.5% (3 in 40 cases) in any pretreatments except for systemic steroid, and 4.5% (1 in 22 cases) in systemic steroid pretreatment group. Neither preoperative asthma severity nor duration from the last attack had significant relevancy to perioperative attack rate. The otolaryngological surgery, especially those have nasal polyp and oral surgery had high perioperative asthma attack rate, although there was no significant difference. We recommend the systemic steroid pretreatment for asthmatic patients, especially when they have known risk factor such as administration of the systemic steroid within 6 months, or possibly new risk factor such as nasal polyp, otolaryngological and oral surgery.

  19. Influence of perioperative administration of amino acids on thermoregulation response in patients underwent colorectal surgical procedures

    Directory of Open Access Journals (Sweden)

    Zeba Snježana

    2007-01-01

    Full Text Available Background. Hypothermia in the surgical patients can be the consequence of long duration of surgical intervention, general anesthesia and low temperature in operating room. Postoperative hypothermia contributes to a number of postoperative complications such as arrhythmia, myocardial ischemia, hypertension, bleeding, wound infection, coagulopathy, prolonged effect of muscle relaxants. External heating procedures are used to prevent this condition, but some investigations reported that infusion of aminoacids during surgery can induce thermogenesis and prevent postoperative hypothermia. Case report. We reported two males who underwent major colorectal surgery for rectal carcinoma. One patient received Aminosol 15% solution, 125 ml/h, while the other did not. The esophageal temperatures in both cases were measured every 30 minutes during the operation and 60 minutes after in Intensive Care Unit. We were monitoring blood pressure, heart rate, ECG, and shivering. Patient who received aminoacids showed ameliorated postoperative hypothermia without hypertension, arrhythmia, or shivering, while the other showed all symptoms mentioned above. Conclusion. According to literature data, as well as our findings, we can conclude that intraoperative intravenous treatment with amino acid solution ameliorates postoperative hypothermia along with its complications. .

  20. Congenital hydrocele: prevalence and outcome among male children who underwent neonatal circumcision in Benin City, Nigeria.

    Science.gov (United States)

    Osifo, O D; Osaigbovo, E O

    2008-06-01

    To determine the prevalence and spontaneous resolution of congenital hydrocele diagnosed in male neonates who underwent circumcision at our centre. All male neonates presented for circumcision at the University of Benin Teaching Hospital, Benin City, Nigeria between January 2002 and December 2006 were examined for the presence of hydrocele. Those diagnosed with this condition were recruited and followed up in a surgical outpatient clinic for 2 years. The number of cases of spontaneous resolution and age at which this occurred were documented on a structured pro forma. A total of 2715 neonates were circumcised and 128 (4.7%) were diagnosed with 163 cases of hydrocele, while 27 cases in 25 (0.9%) children failed to resolve at the age of 2 years. Neonatal hydrocele was bilateral in 112 (68.7%), and there were 20 (12.3%) right and 31 (19.0%) left. Among those with hydrocele, 28.1% were delivered preterm and resolution was spontaneous in many of them, with no observed significant statistical difference to those delivered full term (P=0.4740). Of the 163 hydrocele cases, 136 (83.4%) resolved spontaneously by age 18 months with peak resolution at 4-6 months. No spontaneous resolution occurred after 18 months and no hydrocele-related complication occurred during follow up. Neonates with congenital hydrocele should be observed for spontaneous resolution for at least 18 months before being subjected to surgery.

  1. Stress and Quality of Life for Taiwanese Women Who Underwent Infertility Treatment.

    Science.gov (United States)

    Cheng, Ching-Yu; Stevenson, Eleanor Lowndes; Yang, Cheng-Ta; Liou, Shwu-Ru

    2018-04-28

    To describe the psychological stress and quality of life experienced by women who underwent fertility treatment in Taiwan. Cross-sectional, correlational study. Recruitment was conducted and questionnaires administered at a reproductive medicine center in Chiayi City, Taiwan. Informed consent to participate was obtained from 126 women who sought fertility treatment at the center. The Chinese Fertility Problem Inventory and Fertility Quality of Life scale were used to measure participants' levels of fertility-related stress and fertility-related quality of life. Descriptive statistics, correlation, and regression analysis were used. Overall, participants reported low levels of fertility-related stress and fertility-related quality of life; however, they had relatively high levels of stress related to need for parenthood. Women who were older, had greater body mass indexes, and consumed coffee regularly had lower fertility-related quality of life. Social and relationship concerns and stress related to need for parenthood were significant predictors of low fertility-related quality of life. In a culture in which childbearing is generally an expectation and an important part of family life, women who experience infertility are at risk to experience fertility-related stress. Social support and family consultation might be offered to improve women's fertility-related quality of life. Copyright © 2018 AWHONN, the Association of Women’s Health, Obstetric and Neonatal Nurses. Published by Elsevier Inc. All rights reserved.

  2. Gold--a controversial sensitizer

    DEFF Research Database (Denmark)

    Bruze, M; Andersen, Klaus Ejner

    1999-01-01

    of clinical relevance, i.e., causing or aggravating a contact dermatitis. In this paper, these steps are discussed with regard to gold. With our present knowledge of contact allergy-allergic contact dermatitis, we do not recommend including gold sodium thiosulfate in the standard series. It should be applied......Until recently, gold allergy was considered to be extremely rare. Gold has been used and worshipped for thousands of years without any obvious complaints of skin problems, either in those participating in mining and other ways of prospecting, or in those wearing jewellery. When studies on contact...... allergy to gold sodium thiosulfate were published at the beginning of the 1990s, the allergic nature of the reported positive patch test reactions to gold was questioned. The major argument for such questioning was the lack of demonstrable clinical relevance in most positive reactors. A major reason...

  3. Immunological properties of gold nanoparticles.

    Science.gov (United States)

    Dykman, Lev A; Khlebtsov, Nikolai G

    2017-03-01

    In the past decade, gold nanoparticles have attracted strong interest from the nanobiotechnological community owing to the significant progress made in robust and easy-to-make synthesis technologies, in surface functionalization, and in promising biomedical applications. These include bioimaging, gene diagnostics, analytical sensing, photothermal treatment of tumors, and targeted delivery of various biomolecular and chemical cargos. For the last-named application, gold nanoparticles should be properly fabricated to deliver the cargo into the targeted cells through effective endocytosis. In this review, we discuss recent progress in understanding the selective penetration of gold nanoparticles into immune cells. The interaction of gold nanoparticles with immune cell receptors is discussed. As distinct from other published reviews, we present a summary of the immunological properties of gold nanoparticles. This review also summarizes what is known about the application of gold nanoparticles as an antigen carrier and adjuvant in immunization for the preparation of antibodies in vivo . For each of the above topics, the basic principles, recent advances, and current challenges are discussed. Thus, this review presents a detailed analysis of data on interaction of gold nanoparticles with immune cells. Emphasis is placed on the systematization of data over production of antibodies by using gold nanoparticles and adjuvant properties of gold nanoparticles. Specifically, we start our discussion with current data on interaction of various gold nanoparticles with immune cells. The next section describes existing technologies to improve production of antibodies in vivo by using gold nanoparticles conjugated with specific ligands. Finally, we describe what is known about adjuvant properties of bare gold or functionalized nanoparticles. In the Conclusion section, we present a short summary of reported data and some challenges and perspectives.

  4. Bats, cyanide, and gold mining

    Science.gov (United States)

    Clark, Donald R.

    1991-01-01

    Although the boom days of prospectors and gold nuggets are long gone, modern technology enables gold to continue to be extracted from ore. Unfortunately, the extraction method has often been disastrous for bats and other wildlife, an issue I first became aware of in early 1989. Phone calls from Drs. Merlin Tuttle and Elizabeth Pierson, a BCI member and bat researcher from Berkeley, California, alerted me that bats were dying from apparent cyanide poisoning at gold mines in the western United States.

  5. Long-term outcomes of four patients with tracheal agenesis who underwent airway and esophageal reconstruction.

    Science.gov (United States)

    Tazuke, Yuko; Okuyama, Hiroomi; Uehara, Shuichiro; Ueno, Takehisa; Nara, Keigo; Yamanaka, Hiroaki; Kawahara, Hisayoshi; Kubota, Akio; Usui, Noriaki; Soh, Hideki; Nomura, Motonari; Oue, Takaharu; Sasaki, Takashi; Nose, Satoko; Saka, Ryuta

    2015-12-01

    The aim of this study was to evaluate the long-term outcomes of four patients with tracheal agenesis who underwent airway and esophageal/alimentary reconstruction. We reviewed the medical records of four long-term survivors of tracheal agenesis and collected the following data: age, sex, type of tracheal agenesis, method of reconstruction, nutritional management, and physical and neurological development. The patients consisted of three boys and one girl, who ranged in age from 77 to 109months. The severity of their condition was classified as Floyd's type I (n=2), II (n=1), or III (n=1). Mechanical respiratory support was not necessary in any of the cases. Esophageal/alimentary reconstruction was performed using the small intestine (n=2), a gastric tube (n=1), and the esophagus (n=1). The age at esophageal reconstruction ranged from 41 to 55months. All of the cases required enteral nutrition via gastrostomy. Three of the patients were able to swallow a small amount of liquid and one was able to take pureed food orally. The physical development of the subjects was moderately delayed-borderline in childhood. Neurological development was normal in two cases and slightly delayed in two cases. None of the long-term survivors of tracheal agenesis required the use of an artificial respirator, and their development was close to normal. Future studies should aim to elucidate the optimal method for performing esophageal reconstruction to allow tracheal agenesis patients to achieve their full oral intake. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. Evaluation of patients who underwent resympathectomy for treatment of primary hyperhidrosis.

    Science.gov (United States)

    de Campos, José Ribas Milanez; Lembrança, Lucas; Fukuda, Juliana Maria; Kauffman, Paulo; Teivelis, Marcelo Passos; Puech-Leão, Pedro; Wolosker, Nelson

    2017-11-01

    Video thoracoscopic sympathectomy is the recommended surgical treatment for primary hyperhidrosis and has a high success rate. Despite this high success rate, some patients are unresponsive and eventually need a resympathectomy. Few studies have previously analysed exclusively the results of these resympathectomies in patients with primary hyperhidrosis. None of the studies have objectively evaluated the degree of response to surgery or the improvement in quality of life after resympathectomies. This is a retrospective study, evaluating 15 patients from an initial group of 2300 patients who underwent resympathectomy after failure of the primary surgical treatment. We evaluated sympathectomy levels of resection, technical difficulties, surgical complications preoperative quality of life, response to treatment and quality-of-life improvement 30 days after each surgery. Regarding gender, 11 (73.3%) patients were women. The average age was 23.2 with SD of 5.17 years, and the mean body mass index was 20.9 (SD 2.12). Ten patients had major complaints about their hands (66%) and 5 (33%) patients about their forearms. A high degree of response to sympathectomy occurred in 73% of patients. In 11 of these patients, the improvement in quality of life was considered high, 3 showed a mild improvement and 1 did not improve. No major complications occurred; the presence of adhesions was reported in 11 patients and pleural drainage was necessary in 4 patients. Resympathectomy is an effective procedure, and it improves the quality of life in patients with primary hyperhidrosis who failed after the first surgery. © The Author 2017. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

  7. Surgical outcomes of 380 patients with double outlet right ventricle who underwent biventricular repair.

    Science.gov (United States)

    Li, Shoujun; Ma, Kai; Hu, Shengshou; Hua, Zhongdong; Yang, Keming; Yan, Jun; Chen, Qiuming

    2014-09-01

    The study objective was to report the outcomes of biventricular repair in patients with double outlet right ventricle. Patients with double outlet right ventricle who underwent biventricular repair at Fuwai Hospital from January 2005 to December 2012 were included. Patients were excluded if double outlet right ventricle was combined with atrioventricular septal defect, heterotaxy syndrome, atrioventricular discordance, or univentricular physiology. A total of 380 consecutive patients with a mean age of 1.9 ± 2.1 years (range, 1 month to 6 years) were included. Varied types of biventricular repair were customized individually. Follow-up was 90.4% complete, and the mean follow-up time was 3.4 ± 3.9 years. There were 17 (4.5%) early deaths and 7 (2.1%) late deaths. Preoperative pulmonary hypertension was the only risk factor for early mortality. Postoperative significant left ventricular outflow tract obstruction was present in 9 survivors. Patients with noncommitted ventricular septal defect had a longer crossclamp time, longer cardiopulmonary bypass time, and higher incidence of postdischarge left ventricular outflow tract obstruction. There were 4 reoperations, all of which were caused by subaortic left ventricular outflow tract obstruction. All of the pressure gradients were decreased to less than 20 mm Hg after the modified Konno procedure with an uneventful postoperative course. Optimal results of varied types of biventricular repair for double outlet right ventricle have been acquired. Although noncommitted ventricular septal defect is technically difficult, the outcomes of patients are favorable. Late-onset left ventricular outflow tract obstruction is the main reason for reoperation but can be successfully relieved by the modified Konno procedure. Copyright © 2014 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.

  8. Newly Developed Sarcopenia as a Prognostic Factor for Survival in Patients who Underwent Liver Transplantation.

    Directory of Open Access Journals (Sweden)

    Ja Young Jeon

    Full Text Available The relationship between a perioperative change in sarcopenic status and clinical outcome of liver transplantation (LT is unknown. We investigated whether post-LT sarcopenia and changes in sarcopenic status were associated with the survival of patients.This retrospective study was based on a cohort of 145 patients from a single transplant center who during a mean of 1 year after LT underwent computed tomography imaging evaluation. The cross-sectional area of the psoas muscle of LT patients was compared with that of age- and sex-matched healthy individuals. The Cox proportional hazards regression model was used to determine whether post-LT sarcopenia and changes in sarcopenic status affect post-LT survival.The mean age at LT of the 116 male and 29 female patients was 50.2 ± 7.9 years; the mean follow-up duration was 51.6 ± 32.9 months. All pre-LT patients with sarcopenia still had sarcopenia 1 year after LT; 14 (15% patients had newly developed sarcopenia. The mean survival duration was 91.8 ± 4.2 months for non-sarcopenic patients and 80.0 ± 5.2 months for sarcopenic patients (log-rank test, p = 0.069. In subgroup analysis, newly developed sarcopenia was an independent negative predictor for post-LT survival (hazard ratio: 10.53, 95% confidence interval: 1.37-80.93, p = 0.024.Sarcopenia in LT recipients did not improve in any of the previously sarcopenic patients and newly developed within 1 year in others. Newly developed sarcopenia was associated with increased mortality. Newly developed sarcopenia can be used to stratify patients with regard to the risk of post-LT mortality.

  9. Healthy Weight

    Science.gov (United States)

    ... Weight Gain Losing Weight Getting Started Improving Your Eating Habits Keeping It Off Healthy Eating for a Healthy ... or "program". It's about lifestyle changes in daily eating and exercise habits. Success Stories They did it. So can you! ...

  10. The extractive metallurgy of gold

    Energy Technology Data Exchange (ETDEWEB)

    Kongolo, K.; Mwema, M.D. [University of Lubumbashi, Zaire, Gecamines Metallurgical Research Centre, Likasi, Zaire, c/o Gecamines Brussels (Belgium)

    1998-12-15

    Moessbauer spectroscopy has been successfully used in investigation of the gold compounds present in ores and the gold species which occur during the process metallurgy of this metal. This paper is a survey of the basic recovery methods and techniques used in extractive metallurgy of gold. Process fundamentals on mineral processing, ore leaching, zinc dust cementation, adsorption on activated carbon, electrowinning and refining are examined. The recovery of gold as a by-product of the copper industry is also described. Alternative processing methods are indicated in order to shed light on new interesting research topics where Moessbauer spectroscopy could be applied.

  11. The extractive metallurgy of gold

    International Nuclear Information System (INIS)

    Kongolo, K.; Mwema, M.D.

    1998-01-01

    Moessbauer spectroscopy has been successfully used in investigation of the gold compounds present in ores and the gold species which occur during the process metallurgy of this metal. This paper is a survey of the basic recovery methods and techniques used in extractive metallurgy of gold. Process fundamentals on mineral processing, ore leaching, zinc dust cementation, adsorption on activated carbon, electrowinning and refining are examined. The recovery of gold as a by-product of the copper industry is also described. Alternative processing methods are indicated in order to shed light on new interesting research topics where Moessbauer spectroscopy could be applied

  12. Surface-stabilized gold nanocatalysts

    Science.gov (United States)

    Dai, Sheng [Knoxville, TN; Yan, Wenfu [Oak Ridge, TN

    2009-12-08

    A surface-stabilized gold nanocatalyst includes a solid support having stabilizing surfaces for supporting gold nanoparticles, and a plurality of gold nanoparticles having an average particle size of less than 8 nm disposed on the stabilizing surfaces. The surface-stabilized gold nanocatalyst provides enhanced stability, such as at high temperature under oxygen containing environments. In one embodiment, the solid support is a multi-layer support comprising at least a first layer having a second layer providing the stabilizing surfaces disposed thereon, the first and second layer being chemically distinct.

  13. Determining gold content

    International Nuclear Information System (INIS)

    Clayton, C.G.; Wormald, M.R.

    1981-01-01

    A method for determining the gold content of a material, comprises irradiating a body of the material with neutrons and determining the intensity of γ-rays having an energy of 279 keV arising from the reaction 179 Au(nn') 179 Au → 279 keV. The apparatus has means for conveying the materials past an assembly, which has a neutron source, which does not produce neutrons having sufficient energy to excite fast neutron reactions in non-auriferous constituents. (author)

  14. 31 CFR 100.4 - Gold coin and gold certificates in general.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 1 2010-07-01 2010-07-01 false Gold coin and gold certificates in... EXCHANGE OF PAPER CURRENCY AND COIN In General § 100.4 Gold coin and gold certificates in general. Gold coins, and gold certificates of the type issued before January 30, 1934, are exchangeable, as provided...

  15. Determination of Gold from Gold Matrix of North Western Nigeria ...

    African Journals Online (AJOL)

    The research paper presents analytical results of Au, Mn and V concentrations of some Nigerian gold ores using two techniques: epithermal neutron activation analysis (ENAA) and proton induced X-ray emission (PIXE). Fourteen samples were collected from gold fields of North Western Nigeria, prepared separately to a ...

  16. Activation analysis in gold industry

    International Nuclear Information System (INIS)

    Kist, A. A.

    2003-01-01

    Nuclear techniques and methods were, are, and will be very important for many fields of science, agriculture, industry, etc. Among other examples one can remember role of the nuclear medicine (radiotherapy and radiodiagnostic methods) or semiconductors (communication, computing, information, etc.) which industrial production has been on initial stage based on activation analysis. One of very illustrative examples is application of nuclear methods in gold industry. This is given by favorable nuclear properties of gold. Uzbekistan is one of the main producers of gold. Open-cast mining and hydro metallurgic extraction (using leaching by cyanide and sorption by ion-exchange resin) is the mostly used technology. The typical gold ores are sulfide and contain elevated concentration of As and Sb. That needs special technology of gold extraction. Importance of gold for Uzbekistan economy is a reason why for many years there are carried out studies concerning to gold production. These studies include also nuclear methods and their results are successfully used in gold industry. The present paper gives a brief overview for period of 25 years. For many reasons most of these studies were not published before completely. Despite some results are obtained decades ago we decided to present the overview as an example how nuclear methods can cover requirements of the whole process. We are trying to sort these studies according to methods and applications

  17. Gold content of ectomycorrhizal and saprobic macrofungi - an update

    International Nuclear Information System (INIS)

    Borovika, J; Randa; Jelinek, E

    2006-01-01

    Species of macrofungi growing in the wild were collected from non-auriferous and unpolluted areas, and analyzed for gold. In addition, preliminary results of samples originated from an auriferous area are presented. Gold was determined using long-term instrumental neutron activation analysis (INAA). In total, 108 samples, including 49 species of ectomycorrhizal fungi and 30 species of terrestrial saprobes, were examined. The highest concentrations (expressed in dry weight) were found in ectomycorrhizal species Russula nigricans (235 ng g -1 ) and Suillus variegatus (1070 ng g -1 ). Among the saprobic macrofungi, an extraordinary high value 2250 ng g -1 was found in Lepiota cf. clypeolaria. Gold content of saprobic macrofungi originated from the auriferous area was obviously higher than that of macrofungi from non-auriferous areas. The highest contents were found in Agaricus silvaticus (4230 ng g -1 ) and in two samples of Lycoperdon perlatum (6955 and 7739 ng g -1 )

  18. Stealing the Gold

    International Nuclear Information System (INIS)

    Whittington, S G

    2005-01-01

    Stealing the Gold presents a survey of some of the most exciting topics in condensed matter physics today, from the perspective of the pioneering work of Sam Edwards. Original articles from leaders in the field, including several Nobel laureates, highlight the historical development as well as new and emerging areas. This book would be of interest to graduate students and researchers in condensed matter physics, statistical physics and theoretical physics. Over the course of nearly half a century, Sam Edwards has led the field of condensed matter physics in new directions, ranging from the electronic and statistical properties of disordered materials to the mechanical properties of granular materials. Along the way he has provided seminal contributions to fluid mechanics, polymer science, surface science and statistical mechanics. This volume celebrates the immense scope of his influence by presenting a collection of original articles by recognized leaders in theoretical physics, including two Nobel laureates and a Fields medalist, which describe the genesis, evolution and future prospects of the various sub-fields of condensed matter theory, along with reprints of a selection of Edwards' seminal papers that helped give birth to the subject. Stealing the Gold, Edwards' favourite caricature of the relationship between theoretical physicists and nature, will be of singular interest to graduate students looking for an overview of some of the most exciting areas of theoretical physics, as well as to researchers in condensed matter physics looking for a comprehensive, broad and uniquely incisive snapshot of their subject at the dawn of the 21st century. (book review)

  19. NUTRITIONAL ASPECTS AND THE USE OF NUTRITIONAL SUPPLEMENTS BY WOMEN WHO UNDERWENT GASTRIC BYPASS.

    Science.gov (United States)

    Trindade, Elisangela Mara; Gebara, Telma Souza E Silva; Cambi, Maria Paula Carlini; Baretta, Giorgio Alfredo Pedroso

    2017-01-01

    Bariatric surgery is deemed one of the most effective procedures for the treatment of obesity and it aims at the reduction and maintenance of weight loss in long term, as the control of the related comorbidities. Quantify the occurrence of alterations of the gastrointestinal tract, suggestive signs of nutritional deficiencies and the use of supplements in a group of women undergoing bariatric surgery. The sample consisted of women aged 20-65 years submitted to Roux-en-Y gastric bypass with monitoring equal to or higher than 24 months. For the qualitative analysis, the Feeding Frequency Questionnaire was used. In the postoperative period, alopecia was the most reported (79.3%), followed by changes in the texture of the nails, both considered predictive of nutritional deficiencies. Changes in the gastrointestinal tract were described in 86.2%, and episodes of dumping were reported in 65.5%. Qualitative analysis has shown reduced daily consumption of sources of animal and plant proteins. After bariatric surgery can occur flatulence, vomiting and dumping syndrome as the most frequent representative symptoms of digestive functional disorders. Alopecia and nail changes are the most important signs of nutritional deficiency. The use of dietary supplements in the postoperative period is scarce and sporadic. A cirurgia bariátrica é considerada um dos procedimentos mais eficazes para tratamento da obesidade e objetiva a redução e manutenção da perda de peso em longo prazo, assim como, o controle das comorbidades associadas. Quantificar a ocorrência de alterações funcionais do trato gastrointestinal, sinais sugestivos de carências nutricionais e o uso de suplementos em um grupo de mulheres submetidas à cirurgia bariátrica. A amostra foi constituída por mulheres com idades entre 20-65 anos submetidas ao bypass gástrico em Y-de-Roux com seguimento igual ou superior a 24 meses. Para análise qualitativa foi utilizado o Questionário de Frequência Alimentar. No per

  20. pH induced protein-scaffold biosynthesis of tunable shape gold nanoparticles

    Science.gov (United States)

    Zhang, Xiaorong; He, Xiaoxiao; Wang, Kemin; Ren, Fang; Qin, Zhihe

    2011-09-01

    In this paper, a pH-inductive protein-scaffold biosynthesis of shape-tunable crystalline gold nanoparticles at room temperature has been developed. By simple manipulation of the reaction solution's pH, anisotropic gold nanoparticles including spheres, triangles and cubes could be produced by incubating an aqueous solution of sodium tetrachloroaurate with Dolichomitriopsis diversiformis biomasses after immersion in ultrapure Millipore water overnight. A moss protein with molecular weight of about 71 kDa and pI of 4.9 was the primary biomolecule involved in the biosynthesis of gold nanoparticles. The secondary configuration of the proteins by CD spectrum implied that the moss protein could display different secondary configurations including random coil, α-helix and intermediate conformations between random coil and α-helix for the experimental pH solution. The growth process of gold nanoparticles further showed that the moss protein with different configurations provided the template scaffold for the shape-controlled biosynthesis of gold nanoparticles. The constrained shape of the gold nanoparticles, however, disappeared in boiled moss extract. The gold nanoparticles with designed morphology were successfully reconstructed using the moss protein purified from the gold nanoparticles. Structural characterizations by SEM, TEM and SAED showed that the triangular and cubic gold nanoparticles were single crystalline.

  1. pH induced protein-scaffold biosynthesis of tunable shape gold nanoparticles

    International Nuclear Information System (INIS)

    Zhang Xiaorong; He Xiaoxiao; Wang Kemin; Ren Fang; Qin Zhihe

    2011-01-01

    In this paper, a pH-inductive protein-scaffold biosynthesis of shape-tunable crystalline gold nanoparticles at room temperature has been developed. By simple manipulation of the reaction solution's pH, anisotropic gold nanoparticles including spheres, triangles and cubes could be produced by incubating an aqueous solution of sodium tetrachloroaurate with Dolichomitriopsis diversiformis biomasses after immersion in ultrapure Millipore water overnight. A moss protein with molecular weight of about 71 kDa and pI of 4.9 was the primary biomolecule involved in the biosynthesis of gold nanoparticles. The secondary configuration of the proteins by CD spectrum implied that the moss protein could display different secondary configurations including random coil, α-helix and intermediate conformations between random coil and α-helix for the experimental pH solution. The growth process of gold nanoparticles further showed that the moss protein with different configurations provided the template scaffold for the shape-controlled biosynthesis of gold nanoparticles. The constrained shape of the gold nanoparticles, however, disappeared in boiled moss extract. The gold nanoparticles with designed morphology were successfully reconstructed using the moss protein purified from the gold nanoparticles. Structural characterizations by SEM, TEM and SAED showed that the triangular and cubic gold nanoparticles were single crystalline.

  2. Weighted Clustering

    DEFF Research Database (Denmark)

    Ackerman, Margareta; Ben-David, Shai; Branzei, Simina

    2012-01-01

    the partitional and hierarchical settings, characterizing the conditions under which algorithms react to weights. Extending a recent framework for clustering algorithm selection, we propose intuitive properties that would allow users to choose between clustering algorithms in the weighted setting and classify...

  3. Shape evolution of gold nanoparticles

    International Nuclear Information System (INIS)

    Wang, Y. Q.; Liang, W. S.; Geng, C. Y.

    2010-01-01

    The tetraoctylammonium bromide-stabilized gold nanoparticles have been successfully fabricated. The shape evolution of these nanoparticles under different annealing temperatures has been investigated using high-resolution transmission electron microscopy. After an annealing at 100 o C for 30 min, the average diameters of the gold nanoparticles change a little. However, the shapes of gold nanoparticles change drastically, and facets appear in most nanoparticles. After an annealing at 200 o C for 30 min, not only the size but also the shape changes a lot. After an annealing at 300 o C for 30 min, two or more gold nanoparticles coalesce into bigger ones. In addition, because of the presence of Cu grid during the annealing, some gold particles become the nucleation sites of Cu 2 O nanocubes, which possess a microstructure of gold-particle core/Cu 2 O shell. These Au/Cu 2 O heterostructure nanocubes can only be formed at a relatively high temperature (≥300 o C). The results can provide some insights on controlling the shapes of gold nanoparticles.

  4. Directed Assembly of Gold Nanoparticles

    DEFF Research Database (Denmark)

    Westerlund, Axel Rune Fredrik; Bjørnholm, Thomas

    2009-01-01

    As a complement to common "top-down" lithography techniques, "bottom-up" assembly techniques are emerging as promising tools to build nanoscale structures in a predictable way. Gold nanoparticles that are stable and relatively easy to synthesize are important building blocks in many such structures...... due to their useful optical and electronic properties. Programmed assembly of gold nanoparticles in one, two, and three dimensions is therefore of large interest. This review focuses on the progress from the last three years in the field of directed gold nanoparticle and nanorod assembly using...

  5. GOLD and the fixed ratio

    Directory of Open Access Journals (Sweden)

    Vestbo J

    2012-09-01

    Full Text Available Jørgen VestboUniversity of Manchester, Manchester, UKI read with interest the paper entitled "Diagnosis of airway obstruction in the elderly: contribution of the SARA study" by Sorino et al in a recent issue of this journal.1 Being involved in the Global Initiative for Obstructive Lung Diseases (GOLD, it is nice to see the interest sparked by the GOLD strategy document. However, in the paper by Sorino et al, there are a few misunderstandings around GOLD and the fixed ratio (forced expiratory volume in 1 second/forced volume vital capacity < 0.70 that need clarification.View original paper by Sorino and colleagues.

  6. Differential uptake of gold nanoparticles by 2 species of tadpole, the wood frog (Lithobates sylvaticus) and the bullfrog (Lithobates catesbeianus).

    Science.gov (United States)

    Thompson, Lucas B; Carfagno, Gerardo L F; Andresen, Kurt; Sitton, Andrea J; Bury, Taylor; Lee, Laura L; Lerner, Kevin T; Fong, Peter P

    2017-12-01

    Engineered nanoparticles are aquatic contaminants of emerging concern that exert ecotoxicological effects on a wide variety of organisms. We exposed cetyltrimethylammonium bromide-capped spherical gold nanoparticles to wood frog and bullfrog tadpoles with conspecifics and in combination with the other species continuously for 21 d, then measured uptake and localization of gold. Wood frog tadpoles alone and in combination with bullfrog tadpoles took up significantly more gold than bullfrogs. Bullfrog tadpoles in combination with wood frogs took up significantly more gold than controls. The rank order of weight-normalized gold uptake was wood frogs in combination > wood frogs alone > bullfrogs in combination > bullfrogs alone > controls. In all gold-exposed groups of tadpoles, gold was concentrated in the anterior region compared with the posterior region of the body. The concentration of gold nanoparticles in the anterior region of wood frogs both alone and in combination with bullfrogs was significantly higher than the corresponding posterior regions. We also measured depuration time of gold in wood frogs. After 21 d in a solution of gold nanoparticles, tadpoles lost >83% of internalized gold when placed in gold-free water for 5 d. After 10 d in gold-free water, tadpoles lost 94% of their gold. After 15 d, gold concentrations were below the level of detection. Our finding of differential uptake between closely related species living in similar habitats with overlapping geographical distributions argues against generalizing toxicological effects of nanoparticles for a large group of organisms based on measurements in only one species. Environ Toxicol Chem 2017;36:3351-3358. © 2017 SETAC. © 2017 SETAC.

  7. Grafting of Gold Nanoparticles on Glass Using Sputtered Gold Interlayers

    OpenAIRE

    Kvítek, Ondřej; Hendrych, Robin; Kolská, Zdeňka; Švorčík, Václav

    2014-01-01

    Three-step preparation of nanostructured Au layer on glass substrate is described. The procedure starts with sputtered gold interlayer, followed by grafting with dithiols and final coverage with gold nanoparticles (AuNPs). Successful binding of dithiols on the sputtered Au film was confirmed by X-ray photoelectron spectroscopy measurement. AuNPs bound to the surface were observed using atomic force microscopy. Both single nanoparticles and their aggregates were observed. UV-Vis spectra show b...

  8. Low rate of asymptomatic cerebral embolism and improved procedural efficiency with the novel pulmonary vein ablation catheter GOLD: results of the PRECISION GOLD trial.

    Science.gov (United States)

    De Greef, Yves; Dekker, Lukas; Boersma, Lucas; Murray, Stephen; Wieczorek, Marcus; Spitzer, Stefan G; Davidson, Neil; Furniss, Steve; Hocini, Mélèze; Geller, J Christoph; Csanádi, Zoltan

    2016-05-01

    This prospective, multicentre study (PRECISION GOLD) evaluated the incidence of asymptomatic cerebral embolism (ACE) after pulmonary vein isolation (PVI) using a new gold multi-electrode radiofrequency (RF) ablation catheter, pulmonary vein ablation catheter (PVAC) GOLD. Also, procedural efficiency of PVAC GOLD was compared with ERACE. The ERACE study demonstrated that a low incidence of ACE can be achieved with a platinum multi-electrode RF catheter (PVAC) combined with procedural manoeuvres to reduce emboli. A total of 51 patients with paroxysmal atrial fibrillation (AF) (age 57 ± 9 years, CHA2DS2-VASc score 1.4 ± 1.4) underwent AF ablation with PVAC GOLD. Continuous oral anticoagulation using vitamin K antagonists, submerged catheter introduction, and heparinization (ACT ≥ 350 s prior to ablation) were applied. Cerebral magnetic resonance imaging (MRI) scans were performed within 48 h before and 16-72 h post-ablation. Cognitive function assessed by the Mini-Mental State Exam at baseline and 30 days post-ablation. New post-procedural ACE occurred in only 1 of 48 patients (2.1%) and was not detectable on MRI after 30 days. The average number of RF applications per patient to achieve PVI was lower in PRECISION GOLD (20.3 ± 10.0) than in ERACE (28.8 ± 16.1; P = 0.001). Further, PVAC GOLD ablations resulted in significantly fewer low-power (GOLD in combination with established embolic lowering manoeuvres results in a low incidence of ACE. Pulmonary vein ablation catheter GOLD demonstrates improved biophysical efficiency compared with platinum PVAC. ClinicalTrials.gov NCT01767558. © The Author 2016. Published by Oxford University Press on behalf of the European Society of Cardiology.

  9. Kuantitas dan kualitas telur ayam arab (Gallus turcicus silver dan gold

    Directory of Open Access Journals (Sweden)

    M. H. Yumna

    2014-03-01

    Full Text Available This research was conducted to examine egg quantity and quality of Silver and Gold Arabic chicken (Gallus turcicus. The materials used in this study were 30 Silver and 30 Gold Arabic chicken aged 8-9 months which had mean of initial body weight were 1,93±0,13 and 2,00±0,15 kg respectively. The method was experiment on two groups of Arabic chicken based on feather color (Silver and Gold. Data was analyzed by unpaired t test. The study shows that egg weight of Gold Arabic chicken (46.81±2.41 g was significantly heavier (P<0.01 than that of Silver Arabic chicken (42.75±2.22 g. However, there were no significant difference on egg number, egg index, yolk color eggs, yolk protein content, yolk fat content, and Haugh units among these two chickens. It could be concluded that Gold Arabic chicken could produce heavier egg weight than the Silver one although there were no differences on egg number, egg index, yolk color eggs, yolk protein content, yolk fat content, and Haugh units. The study suggests breeding Gold Arabic chickens due to its egg weight production. Keywords: Arabic chicken, feather color, quantity and quality eggs

  10. 41 CFR 101-45.002 - Gold.

    Science.gov (United States)

    2010-07-01

    ... 41 Public Contracts and Property Management 2 2010-07-01 2010-07-01 true Gold. 101-45.002 Section... PERSONAL PROPERTY § 101-45.002 Gold. (a) Gold will be sold in accordance with this section and part 102-38 of the Federal Management Regulation. (b) Sales of gold shall be processed to— (1) Use the sealed bid...

  11. Size fraction assaying of gold bearing rocks (for gold extraction) by ...

    African Journals Online (AJOL)

    A novel method has been developed for processing and extraction of gold from gold bearing rocks for use by small-scale gold miners in Ghana. The methodology involved crushing of gold bearing hard rocks to fine particles to form a composite sample and screening at a range of sizes. Gold distribution in the composite ...

  12. Optical trapping of gold aerosols

    DEFF Research Database (Denmark)

    Schmitt, Regina K.; Pedersen, Liselotte Jauffred; Taheri, S. M.

    2015-01-01

    Aerosol trapping has proven challenging and was only recently demonstrated.1 This was accomplished by utilizing an air chamber designed to have a minimum of turbulence and a laser beam with a minimum of aberration. Individual gold nano-particles with diameters between 80 nm and 200 nm were trapped...... in air using a 1064 nm laser. The positions visited by the trapped gold nano-particle were quantified using a quadrant photo diode placed in the back focal plane. The time traces were analyzed and the trapping stiffness characterizing gold aerosol trapping determined and compared to aerosol trapping...... of nanometer sized silica and polystyrene particles. Based on our analysis, we concluded that gold nano-particles trap more strongly in air than similarly sized polystyrene and silica particles. We found that, in a certain power range, the trapping strength of polystyrene particles is linearly decreasing...

  13. Gold, currencies and market efficiency

    Science.gov (United States)

    Kristoufek, Ladislav; Vosvrda, Miloslav

    2016-05-01

    Gold and currency markets form a unique pair with specific interactions and dynamics. We focus on the efficiency ranking of gold markets with respect to the currency of purchase. By utilizing the Efficiency Index (EI) based on fractal dimension, approximate entropy and long-term memory on a wide portfolio of 142 gold price series for different currencies, we construct the efficiency ranking based on the extended EI methodology we provide. Rather unexpected results are uncovered as the gold prices in major currencies lay among the least efficient ones whereas very minor currencies are among the most efficient ones. We argue that such counterintuitive results can be partly attributed to a unique period of examination (2011-2014) characteristic by quantitative easing and rather unorthodox monetary policies together with the investigated illegal collusion of major foreign exchange market participants, as well as some other factors discussed in some detail.

  14. Gold based bulk metallic glass

    Science.gov (United States)

    Schroers, Jan; Lohwongwatana, Boonrat; Johnson, William L.; Peker, Atakan

    2005-08-01

    Gold-based bulk metallic glass alloys based on Au-Cu-Si are introduced. The alloys exhibit a gold content comparable to 18-karat gold. They show very low liquidus temperature, large supercooled liquid region, and good processibility. The maximum casting thickness exceeds 5mm in the best glassformer. Au49Ag5.5Pd2.3Cu26.9Si16.3 has a liquidus temperature of 644K, a glass transition temperature of 401K, and a supercooled liquid region of 58K. The Vickers hardness of the alloys in this system is ˜350Hv, twice that of conventional 18-karat crystalline gold alloys. This combination of properties makes the alloys attractive for many applications including electronic, medical, dental, surface coating, and jewelry.

  15. Biomass processing over gold catalysts

    CERN Document Server

    Simakova, Olga A; Murzin, Dmitry Yu

    2014-01-01

    The book describes the valorization of biomass-derived compounds over gold catalysts. Since biomass is a rich renewable feedstock for diverse platform molecules, including those currently derived from petroleum, the interest in various transformation routes has become intense. Catalytic conversion of biomass is one of the main approaches to improving the economic viability of biorefineries.  In addition, Gold catalysts were found to have outstanding activity and selectivity in many key reactions. This book collects information about transformations of the most promising and important compounds derived from cellulose, hemicelluloses, and woody biomass extractives. Since gold catalysts possess high stability under oxidative conditions, selective oxidation reactions were discussed more thoroughly than other critical reactions such as partial hydrogenation, acetalization, and isomerization. The influence of reaction conditions, the role of the catalyst, and the advantages and disadvantages of using gold are pre...

  16. Birth Weight

    Science.gov (United States)

    ... may become sick in the first days of life or develop infections. Others may suffer from longer-term problems such as delayed motor and social development or learning disabilities. High birth weight babies are often big because ...

  17. Immunological properties of gold nanoparticles

    OpenAIRE

    Dykman, Lev A.; Khlebtsov, Nikolai G.

    2016-01-01

    In the past decade, gold nanoparticles have attracted strong interest from the nanobiotechnological community owing to the significant progress made in robust and easy-to-make synthesis technologies, in surface functionalization, and in promising biomedical applications. These include bioimaging, gene diagnostics, analytical sensing, photothermal treatment of tumors, and targeted delivery of various biomolecular and chemical cargos. For the last-named application, gold nanoparticles should be...

  18. Mercury hazards from gold mining to humans, plants, and animals

    Science.gov (United States)

    Eisler, R.

    2004-01-01

    Mercury contamination of the environment from historical and ongoing mining practices that rely on mercury amalgamation for gold extraction is widespread. Contamination was particularly severe in the immediate vicinity of gold extraction and refining operations; however, mercury--especially in the form of water-soluble methylmercury--may be transported to pristine areas by rainwater, water currents, deforestation, volatilization, and other vectors. Examples of gold mining-associated mercury pollution are shown for Canada, the United States, Africa, China, the Philippines, Siberia, and South America. In parts of Brazil, for example, mercury concentrations in all abiotic materials, plants, and animals--including endangered species of mammals and reptiles--collected near ongoing mercury-amalgamation gold mining sites were far in excess of allowable mercury levels promulgated by regulatory agencies for the protection of human health and natural resources. Although health authorities in Brazil are unable to detect conclusive evidence of human mercury intoxication, the potential exists in the absence of mitigation for epidemic mercury poisoning of the mining population and environs. In the United States, environmental mercury contamination is mostly from historical gold mining practices, and portions of Nevada remain sufficiently mercury-contaminated to pose a hazard to reproduction of carnivorous fishes and fish-eating birds. Concentrations of total mercury lethal to sensitive representative natural resources range from 0.1 to 2.0 ug/L of medium for aquatic organisms; from 2200 to 31,000 ug/kg body weight (acute oral) and 4000 to 40,000 ug/kg (dietary) for birds; and from 100 to 500 ug/kg body weight (daily dose) and 1000 to 5000 ug/kg diet for mammals. Significant adverse sublethal effects were observed among selected aquatic species at water concentrations of 0.03 to 0.1 ug Hg/L. For some birds, adverse effects--mainly on reproduction--have been associated with total

  19. Goldenphilicity: Luminescent gold compounds

    International Nuclear Information System (INIS)

    Sansores, L.E.

    2002-01-01

    In the solids and molecules different types of bonds are presented depending on the involved atoms, covalent bonds are common among elements of open shell, where more bond orbitals are filled than anti bond orbitals. It is expected that ionic bonds among closed shell atoms which have charges of opposite sign. Bonds type Van der Waals are presented among molecules which have a bipolar moment. It would not be expected bonds among zero charge species, or more generally with the same nominal charge and in any case the attractive forces would be very small. In fact it is expected that two metallic cations to be repelled each other. There recently is evidence that in organic or organometallic compounds could exist attractive interactions between two cations of the d 8 -d 10 -s 2 families. These bonds are weak but stronger than those of Van der Waals. They are compared with the hydrogen bonds. In this work it was reviewed some examples in which the goldenphilicity plays an important role in the luminescence that the gold complexes present. Examples of mono, bi and trinuclear and the structures that these organometallic compounds could take are examined. (Author)

  20. [Findings from Total Colonoscopy in Obstructive Colorectal Cancer Patients Who Underwent Stent Placement as a Bridge to Surgery(BTS)].

    Science.gov (United States)

    Maruo, Hirotoshi; Tsuyuki, Hajime; Kojima, Tadahiro; Koreyasu, Ryohei; Nakamura, Koichi; Higashi, Yukihiro; Shoji, Tsuyoshi; Yamazaki, Masanori; Nishiyama, Raisuke; Ito, Tatsuhiro; Koike, Kota; Ikeda, Takashi; Takayanagi, Yasuhiro; Kubota, Hiroyuki

    2017-11-01

    We clinically investigated 34 patients with obstructive colorectal cancer who underwent placement of a colonic stent as a bridge to surgery(BTS), focusing on endoscopic findings after stent placement.Twenty -nine patients(85.3%)underwent colonoscopy after stent placement, and the entire large intestine could be observed in 28(96.6%).Coexisting lesions were observed in 22(78.6%)of these 28 patients.The lesions comprised adenomatous polyps in 17 patients(60.7%), synchronous colon cancers in 5 patients(17.9%), and obstructive colitis in 3 patients(10.7%), with some overlapping cases.All patients with multiple cancers underwent one-stage surgery, and all lesions were excised at the same time.Colonoscopy after colonic stent placement is important for preoperative diagnosis of coexisting lesions and planning the extent of resection. These considerations support the utility of colonic stenting for BTS.

  1. Size fractional gold assaying of gold bearing rocks from the Amansie West District of Ghana by instrumental neutron activation: implication for gold extraction process by small-scale miners. Technical report for 2004/2005

    International Nuclear Information System (INIS)

    Ahmed, K.; Dampare, S.B.; Addo, M.A.; Osae, S.; Adotey, D. K.; Adomako, D.

    2005-01-01

    This paper examines the possibility of improving the extraction process of gold from gold bearing rocks by small-scale gold miners in Ghana. The investigation involved crushing of 25 hard rock gold ore samples with a total weight of 7,126.98g to fine particles to form a composite sample and screening at a range of grind sizes. This was followed by the determination of gold distribution as a function of 'particle size' in the composite sample using INAA. The following concentrations of gold for the corresponding particle sizes are reported: 63-125 μm, 161±0.75 mg/kg; Sub 63 μm, 16.4 ± 0.17 mg/kg; 250-355 μm, 4.66 ± 0. 07; 355-425μm, 1.55 ± 0.06 mg/kg; 1000-2000 μm, 1.27±005 mg/kg; 125-250 μm, 0.53 ± 0.03 mg/kg; 425-1000 μm, 0.180 ± 0.008 mg/kg. An estimate for gold in the composite sample based on particle size yielded an average value of 3.80 mg/kg. (au)

  2. Histopathologic Consideration of Fiducial Gold Markers Inserted for Real-Time Tumor-Tracking Radiotherapy Against Lung Cancer

    International Nuclear Information System (INIS)

    Imura, Mikado; Yamazaki, Koichi; Kubota, Kanako C.; Itoh, Tomoo; Onimaru, Rikiya; Cho, Yasushi; Hida, Yasuhiro; Kaga, Kichizo; Onodera, Yuya; Ogura, Shigeaki; Dosaka-Akita, Hirotoshi; Shirato, Hiroki; Nishimura, Masaharu

    2008-01-01

    Purpose: Internal fiducial gold markers, safely inserted with bronchoscopy, have been used in real-time tumor-tracking radiotherapy for lung cancer. We investigated the histopathologic findings at several points after the insertion of the gold markers. Methods and Materials: Sixteen gold markers were inserted for preoperative marking in 7 patients who subsequently underwent partial resection of tumors by video-assisted thoracoscopic surgery within 7 days. Results: Fibrotic changes and hyperplasia of type 2 pneumocytes around the markers were seen 5 or 7 days after insertion, and fibrin exudation without fibrosis was detected 1 or 2 days after insertion. Conclusions: Because fibroblastic changes start approximately 5 days after gold marker insertion, real-time tumor-tracking radiotherapy should be started >5 days after gold marker insertion

  3. Monoclonal antibody "gold rush".

    Science.gov (United States)

    Maggon, Krishan

    2007-01-01

    The market, sales and regulatory approval of new human medicines, during the past few years, indicates increasing number and share of new biologics and emergence of new multibillion dollar molecules. The global sale of monoclonal antibodies in 2006 were $20.6 billion. Remicade had annual sales gain of $1 billion during the past 3 years and five brands had similar increase in 2006. Rituxan with 2006 sales of $4.7 billion was the best selling monoclonal antibody and biological product and the 6th among the top selling medicinal brand. It may be the first biologic and monoclonal antibody to reach $10 billion annual sales in the near future. The strong demand from cancer and arthritis patients has surpassed almost all commercial market research reports and sales forecast. Seven monoclonal antibody brands in 2006 had sales exceeding $1 billion. Humanized or fully human monoclonal antibodies with low immunogenicity, enhanced antigen binding and reduced cellular toxicity provide better clinical efficacy. The higher technical and clinical success rate, overcoming of technical hurdles in large scale manufacturing, low cost of market entry and IND filing, use of fully human and humanized monoclonal antibodies has attracted funds and resources towards R&D. Review of industry research pipeline and sales data during the past 3 years indicate a real paradigm shift in industrial R&D from pharmaceutical to biologics and monoclonal antibodies. The antibody bandwagon has been joined by 200 companies with hundreds of new projects and targets and has attracted billions of dollars in R&D investment, acquisitions and licensing deals leading to the current Monoclonal Antibody Gold Rush.

  4. Structure and bonding in gold compounds

    International Nuclear Information System (INIS)

    Parish, R.V.

    1988-01-01

    Recent developments in chemical applications of 197 Au Moessbauer spectroscopy are reviewed. For gold(I) and gold(III), systematic variations in isomer shift and quadrupole splitting are seen as the ligands are changed; the effects of change in coordination number of the gold atoms are also systematic. Data for gold(II) systems involving gold-gold bonds lie between those for corresponding gold(I) and gold(III) materials, showing a small increase in isomer shift and a larger increase in quadrupole splitting as the oxidation state decreases; these trends are explained in terms of the structures. Data for mixed-metal cluster compounds are much more sensitive to structural effects than in homonuclear clusters. Both sets of data show systematic changes with increase in the number of metal atoms to which the gold atom is bound. The connectivity also influences the recoil-free fraction. (orig.)

  5. Gold nanoparticle (AuNPs) and gold nanopore (AuNPore) catalysts in organic synthesis.

    Science.gov (United States)

    Takale, Balaram S; Bao, Ming; Yamamoto, Yoshinori

    2014-04-07

    Organic synthesis using gold has gained tremendous attention in last few years, especially heterogeneous gold catalysis based on gold nanoparticles has made its place in almost all organic reactions, because of the robust and green nature of gold catalysts. In this context, gold nanopore (AuNPore) with a 3D metal framework is giving a new dimension to heterogeneous gold catalysts. Interestingly, AuNPore chemistry is proving better than gold nanoparticles based chemistry. In this review, along with recent advances, major discoveries in heterogeneous gold catalysis are discussed.

  6. Grafting of Gold Nanoparticles on Glass Using Sputtered Gold Interlayers

    Directory of Open Access Journals (Sweden)

    Ondřej Kvítek

    2014-01-01

    Full Text Available Three-step preparation of nanostructured Au layer on glass substrate is described. The procedure starts with sputtered gold interlayer, followed by grafting with dithiols and final coverage with gold nanoparticles (AuNPs. Successful binding of dithiols on the sputtered Au film was confirmed by X-ray photoelectron spectroscopy measurement. AuNPs bound to the surface were observed using atomic force microscopy. Both single nanoparticles and their aggregates were observed. UV-Vis spectra show broadening of surface plasmon resonance peak after AuNPs binding caused by aggregation of AuNPs on the sample surface. Zeta potential measurements suggest that a large part of the dithiol molecules are preferentially bound to the gold interlayer via both –SH groups.

  7. Surface Chemistry of Gold Nanorods.

    Science.gov (United States)

    Burrows, Nathan D; Lin, Wayne; Hinman, Joshua G; Dennison, Jordan M; Vartanian, Ariane M; Abadeer, Nardine S; Grzincic, Elissa M; Jacob, Lisa M; Li, Ji; Murphy, Catherine J

    2016-10-04

    Gold nanorods have garnered a great deal of scientific interest because of their unique optical properties, and they have the potential to greatly impact many areas of science and technology. Understanding the structure and chemical makeup of their surfaces as well as how to tailor them is of paramount importance in the development of their successful applications. This Feature Article reviews the current understanding of the surface chemistry of as-synthesized gold nanorods, methods of tailoring the surface chemistry of gold nanorods with various inorganic and organic coatings/ligands, and the techniques employed to characterize ligands on the surface of gold nanorods as well as the associated measurement challenges. Specifically, we address the challenges of determining how thick the ligand shell is, how many ligands per nanorod are present on the surface, and where the ligands are located in regiospecific and mixed-ligand systems. We conclude with an outlook on the development of the surface chemistry of gold nanorods leading to the development of a synthetic nanoparticle surface chemistry toolbox analogous to that of synthetic organic chemistry and natural product synthesis.

  8. Gold nanoparticles stabilized by chitosan

    International Nuclear Information System (INIS)

    Geraldes, Adriana N.; Oliveira, Maria Jose A.; Silva, Andressa A. da; Leal, Jessica; Batista, Jorge G.S.; Lugao, Ademar B.

    2015-01-01

    In our laboratory has been growing the interest in studying gold nanoparticles and for this reason, the aim of this work is report the first results of the effect of chitosan as stabilizer in gold nanoparticle formulation. AuNPs were synthesized by reducing hydrogen tetrachloroaurate (HAuCl 4 ) using NaBH 4 or gamma irradiation (25kGy) as reduction agent. The chitosan (3 mol L -1 ) was added at 0.5; 1.0 and 1.5 mL. The gold nanoparticles were characterized by UV-Vis absorption spectroscopy, X-ray diffraction (XRD) and Transmission electron microscopy (TEM). Their physical stability was determined using a UV-Vis spectrophotometer over one week during storage at room temperature. Absorption measurements indicated that the plasmon resonance wavelength appears at a wavelength around 530 nm. Has been observed that Chitosan in such quantities were not effective in stabilizing the AuNPs. (author)

  9. Geostatistical Approach to Estimating the Gold Ore Characteristics and Gold Reserves: A Case Study Daksa Area, Quang Nam Province, Viet Nam

    Science.gov (United States)

    Luan Truong, Xuan; Luong Le, Van; Quang Truong, Xuan

    2015-04-01

    Daksa gold deposit is the biggest gold deposits in Vietnam. The Daksa geological structure complicated, distributed mainly metamorphosed sedimentary NuiVu formation (PR3-?1nv2). The sulfide gold ore bodies distributed in quartz schist, quartz - biotite related to faut and distribution wing anticline. The gold ore bodies form circuits, network circuits, circuits lenses; fill the cup surface layer of the developing northeast - southwest; is the less than or west longitude north - SE. The results show that, Au and accompanying elements (Ag, Pb and Zn) have correlated pretty closely. All of its consistent with the logarithmic distribution standard, in accordance with the law of distribution of content mineral rare. The structure functions have nugget effect and spherical models with show that Au and accompanying elements special variation are changes. Au contents shown local anisotropy, no clearly anisotropy (K=1,17) and weakly anisotropy (K=1,4). Intensity mineralization of the ore bodies are quite high with demand spherical conversion coefficient ranging from 0.49 to 0.75 and from 0.66 to 0.97 (for other body). With nugget effects, ore bodies shown that it is consistent with mineralization in the ore bodies study, ore erasable, micro vein, infilling fractures in quartz vein. All of variogram presents local anisotropy, indicated gold mineralization at study area has least two-mineralization stages, consistent with the analysis of mineralography samples. By the results of the structure function study, the authors present the system optimization for exploration deposit and used to evaluate gold reserves by Ordinary Kriging. High accuracy of Kriging estimation results are expressed in the minimum Kriging variance, by compare the results calculated by some other methods (such as distance inverse weighting method, ..) and specially compare to the results of a some blocks have been exploited. Key words: Geostat and gold deposits VN. Daksa and gold mineralization. Geostat

  10. New Trends in Gold Catalysts

    Directory of Open Access Journals (Sweden)

    Leonarda F. Liotta

    2014-07-01

    Full Text Available Gold is an element that has fascinated mankind for millennia. The catalytic properties of gold have been a source of debate, due to its complete chemical inertness when in a bulk form, while it can oxidize CO at temperatures as low as ~200 K when in a nanocrystalline state, as discovered by Haruta in the late 1980s [1]. Since then, extensive activity in both applied and fundamental research on gold has been initiated. The importance of the catalysis by gold represents one of the fasted growing fields in science and is proven by the promising applications in several fields, such as green chemistry and environmental catalysis, in the synthesis of single-walled carbon nanotubes, as modifiers of Ni catalysts for methane steam and dry reforming reactions and in biological and electrochemistry applications. The range of reactions catalyzed by gold, as well as the suitability of different supports and the influence of the preparation conditions have been widely explored and optimized in applied research [2]. Gold catalysts appeared to be very different from the other noble metal-based catalysts, due to their marked dependence on the preparation method, which is crucial for the genesis of the catalytic activity. Several methods, including deposition-precipitation, chemical vapor deposition and cation adsorption, have been applied for the preparation of gold catalysts over reducible oxides, like TiO2. Among these methods, deposition-precipitation has been the most frequently employed method for Au loading, and it involves the use of tetrachloroauric (III acid as a precursor. On the other hand, the number of articles dealing with Au-loaded acidic supports is smaller than that on basic supports, possibly because the deposition of [AuCl4]− or [AuOHxCl4−x]− species on acidic supports is difficult, due to their very low point of zero charge. Despite this challenge, several groups have reported the use of acidic zeolites as supports for gold. Zeolites

  11. Nanobubble trouble on gold surfaces

    DEFF Research Database (Denmark)

    Holmberg, Maria; Kuhle, A.; Garnaes, J.

    2003-01-01

    When analyzing surfaces related to biosensors with in situ atomic force microscopy (AFM), the existence of nanobubbles called for our attention. The bubbles seem to form spontaneously when gold surfaces are immersed in clean water and are probably a general phenomenon at water-solid interfaces....... Besides from giving rise to undesired effects in, for example, biosensors, nanobubbles can also cause artifacts in AFM imaging. We have observed nanobubbles on unmodified gold surfaces, immersed in clean water, using standard silicon AFM probes. Nanobubbles can be made to disappear from contact mode AFM...

  12. APACHE II SCORING SYSTEM AND ITS MODIFICATION FOR THE ASSESSMENT OF DISEASE SEVERITY IN CHILDREN WHO UNDERWENT POLYCHEMOTHERAPY

    Directory of Open Access Journals (Sweden)

    А. V. Sotnikov

    2014-01-01

    Full Text Available Short-term disease prognosis should be considered for the appropriate treatment policy based on the assessment of disease severity in patients with acute disease. The adequate assessment of disease severity and prognosis allows the indications for transferring patients to the resuscitation and intensive care department to be defined more precisely. Disease severity of patients who underwent polychemotherapy was assessed using APACHE II scoring system.

  13. Atrioventricular septal defect (AVSD) : A study of 219 patients who underwent surgery for AVSD at Rikshospitalet from 1979 to 1999

    OpenAIRE

    Skraastad, Ingrid Birthe Bendixen; Skraastad, Berit Kristine

    2010-01-01

    Background: The present study evaluates 219 consecutive patients that underwent surgical repair for AVSD in a long term follow-up. Methods: The patients had a surgical correction for AVSD at Rikshospitalet from January 1979 to December 1999. The follow-up was closed in January 2009. AVSD with additional defects and syndromes were included. Results: Forty-two patients died during the observational period. Early mortality was 12.8% and late mortality was 6.4%. Early mortality declined f...

  14. Comparison of libido, Female Sexual Function Index, and Arizona scores in women who underwent laparoscopic or conventional abdominal hysterectomy

    Science.gov (United States)

    Kayataş, Semra; Özkaya, Enis; Api, Murat; Çıkman, Seyhan; Gürbüz, Ayşen; Eser, Ahmet

    2017-01-01

    Objective: The aim of the present study was to compare female sexual function between women who underwent conventional abdominal or laparoscopic hysterectomy. Materials and Methods: Seventy-seven women who were scheduled to undergo hysterectomy without oophorectomy for benign gynecologic conditions were included in the study. The women were assigned to laparoscopic or open abdominal hysterectomy according to the surgeons preference. Women with endometriosis and symptomatic prolapsus were excluded. Female sexual function scores were obtained before and six months after the operation from each participant by using validated questionnaires. Results: Pre- and postoperative scores of three different quationnaires were found as comparable in the group that underwent laparoscopic hysterectomy (p>0.05). Scores were also found as comparable in the group that underwent laparotomic hysterectomy (p>0.05). Pre- and postoperative values were compared between the two groups and revealed similar results with regard to all three scores (p>0.05). Conclusion: Our data showed comparable pre- and the postoperative scores for the two different hysterectomy techniques. The two groups were also found to have similar pre- and postoperative score values. PMID:28913149

  15. Vaginal and pelvic recurrence rates based on vaginal cuff length in patients with cervical cancer who underwent radical hysterectomies.

    Science.gov (United States)

    Kim, K; Cho, S Y; Park, S I; Kim, B J; Kim, M H; Choi, S C; Ryu, S Y; Lee, E D

    2011-09-01

    The objective of this study was to determine the association of vaginal cuff length (VCL) with vaginal and pelvic recurrence rates in patients with cervical cancer who underwent radical hysterectomies. The clinicopathologic characteristics were collected from the medical records of 280 patients with cervical cancer who underwent radical hysterectomies. The association of VCL with 3-year vaginal and pelvic recurrence rates was determined using a Z-test. The association of VCL with other clinicopathologic characteristics was also determined. The VCL was not associated with 3-year vaginal and pelvic recurrence rates. The 3-year vaginal recurrence rate was 0%-2% and the 3-year pelvic recurrence rate was 7%-8%, independent of VCL. The VCL and the age of patients had an inverse relationship. However, the VCL was not associated with histologic type, FIGO stage, clinical tumor size, tumor size in the surgical specimen, depth of invasion, lymphovascular space invasion, parametrial involvement, lymph node involvement, and adjuvant therapy. One-hundred ninety of 280 patients (68%) underwent adjuvant therapies following radical hysterectomies. Although it is limited by the high rate of adjuvant therapy, the current study suggested that the VCL following radical hysterectomy in patients with cervical cancer was not associated with vaginal and pelvic recurrence rates. Copyright © 2011 Elsevier Ltd. All rights reserved.

  16. A Novel Strategy for Synthesis of Gold Nanoparticle Self Assemblies

    NARCIS (Netherlands)

    Verma, Jyoti; Lal, Sumit; van Veen, Henk A.; van Noorden, Cornelis J. F.

    2014-01-01

    Gold nanoparticle self assemblies are one-dimensional structures of gold nanoparticles. Gold nanoparticle self assemblies exhibit unique physical properties and find applications in the development of biosensors. Methodologies currently available for lab-scale and commercial synthesis of gold

  17. The geology of the gold deposits of Prestea gold belt of Ghana ...

    African Journals Online (AJOL)

    This paper presents the geology of the gold deposits along the Prestea gold belt of Ghana to assist exploration work for new orebodies along the belt. Prestea district is the third largest gold producer in West Africa after Obuasi and Tarkwa districts (over 250 metric tonnes Au during the last century). The gold deposits are ...

  18. Gold Nanoparticle Mediated Phototherapy for Cancer

    International Nuclear Information System (INIS)

    Yao, C.; Zhang, L.; Wang, J.; He, Y.; Xin, J.; Wang, S.; Xu, H.; Zhang, Z.

    2016-01-01

    Gold nanoparticles exhibit very unique physiochemical and optical properties, which now are extensively studied in range of medical diagnostic and therapeutic applications. In particular, gold nanoparticles show promise in the advancement of cancer treatments. This review will provide insights into the four different cancer treatments such as photothermal therapy, gold nanoparticle-aided photodynamic therapy, gold nanoparticle-aided radiation therapy, and their use as drug carrier. We also discuss the mechanism of every method and the adverse effects and its limitations

  19. The mineralogical phase transformation of invisible gold-concentrate by microwave heating, and enhancement of their gold leaching rate

    Science.gov (United States)

    Bak, Geonyoung; Kim, Bongju; Choi, Nagchoul; Park*, Cheonyoung

    2015-04-01

    In this study, in order to obtain the maximum Au leaching rate, an invisible gold concentrate sample was microwave-treated and a thiourea leaching experiment was performed. It is found that gold exists as invisible as a result of observation with an optical microscope and an electron microscope. As the invisible gold concentrate sample was exposed to microwave longer, its temperature and weight loss were increased together and its S content was decreased. The conditions for the maximum Au leaching rate and the fast leaching effect were a particle size of -325×400 mesh, exposure to microwave for 70 minutes, 1.0 g of thiourea, 0.0504 g of sodium sulfite and 0.425 g of ferric sulfate. However, the condition under which Au was leached out to the maximum was applied to the control sample, but its Au leaching rate was just in a range of 78% to 88%. Such results suggest that the effect of sodium sulfite and ferric sulfate was more effective in the microwave-treated sample than in the control sample. Therefore, it was confirmed that the complete and very fast Au leaching can be achieved by means of the microwave pretreatment of invisible gold concentrate.

  20. Lamellar multilayer hexadecylaniline-modified gold nanoparticle ...

    Indian Academy of Sciences (India)

    Organization of hexadecylaniline (HDA)-modified colloidal gold particles at the air-water interface and the formation thereafter of lamellar, multilayer films of gold nanoparticles by the Langmuir-Blodgett technique is described in this paper. Formation of HDA-capped gold nanoparticles is accomplished by a simple biphasic ...

  1. Lamellar multilayer hexadecylaniline-modified gold nanoparticle

    Indian Academy of Sciences (India)

    Organization of hexadecylaniline (HDA)-modified colloidal gold particles at the air-water interface and the formation thereafter of lamellar, multilayer films of gold nanoparticles by the Langmuir-Blodgett technique is described in this paper. Formation of HDA-capped gold nanoparticles is accomplished by a simple biphasic ...

  2. Highly active thermally stable nanoporous gold catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Biener, Juergen; Wittstock, Arne; Biener, Monika M.; Bagge-Hansen, Michael; Baeumer, Marcus; Wichmann, Andre; Neuman, Bjoern

    2016-12-20

    In one embodiment, a system includes a nanoporous gold structure and a plurality of oxide particles deposited on the nanoporous gold structure; the oxide particles are characterized by a crystalline phase. In another embodiment, a method includes depositing oxide nanoparticles on a nanoporous gold support to form an active structure and functionalizing the deposited oxide nanoparticles.

  3. Gold and Silver Extraction from Leach Solutions

    OpenAIRE

    Bagdaulet K. Kenzhaliyev; Renata R. Iskhakova; Zamzagul D. Dosymbaeva; Esen N. Sulejmenov

    2014-01-01

    There has been carried out an investigation on the extraction of gold and silver from thiosulfate solutions: standard test and technological solutions of chemical and electrochemical leaching. The influence of related metals on the process of extracting gold from solution was studied. There has been conducted a comparative study of the IR spectra of solutions after the sorption of gold, silver and related metals.

  4. Ultrafast vibrations of gold nanorings

    DEFF Research Database (Denmark)

    Kelf, T; Tanaka, Y; Matsuda, O

    2011-01-01

    We investigate the vibrational modes of gold nanorings on a silica substrate with an ultrafast optical technique. By comparison with numerical simulations, we identify several resonances in the gigahertz range associated with axially symmetric deformations of the nanoring and substrate. We...

  5. Exploring the Stability of Gold Nanoparticles by Experimenting with Adsorption Interactions of Nanomaterials in an Undergraduate Lab

    Science.gov (United States)

    Lee, Chi-Feng; You, Pei-Yun; Lin, Ying-Chiao; Hsu, Tsai-Ling; Cheng, Pi-Yun; Wu, Yu-Xuan; Tseng, Chi-Shun; Chen, Sheng-Wen; Chang, Huey-Por; Lin, Yang-Wei

    2015-01-01

    The proposed experiment can help students to understand the factors involved in the stability of gold nanoparticles (Au NPs) by exploring the adsorption interaction between Au NPs and various substances. The students in this study found that the surface plasmon resonance band of Au NP solutions underwent a red shift (i.e., from 520 to 650 nm)…

  6. The prognostic significance of preoperatively assessed AST/ALT (De Ritis) ratio on survival in patients underwent radical cystectomy.

    Science.gov (United States)

    Gorgel, Sacit Nuri; Kose, Osman; Koc, Esra Meltem; Ates, Erhan; Akin, Yigit; Yilmaz, Yuksel

    2017-09-01

    We aimed to evaluate prognostic significance of preoperatively assessed aspartate aminotransaminase (AST)/alanine aminotransferase (ALT) (De Ritis) ratio on survival in bladder cancer (BC) patients underwent radical cystectomy (RC). We, respectively, analysed clinical and pathological data of 153 patients who underwent RC for BC between February 2006 and December 2016 at a tertiary level hospital. The potential prognostic value of De Ritis ratio was assessed by using ROC curve analysis. The effect of the De Ritis ratio was analysed by the Kaplan-Meier method and Cox regression hazard models for patients' disease-specific survival (DSS) and overall survival (OAS). We had 149 BC patients, in total. Mean age was 61.65 ± 9.13 years. One hundred and thirty-nine (93.3%) of the patients were men. According to ROC analysis, optimal threshold of De Ritis ratio for DSS was 1.30. In Kaplan-Meier analyses, the high De Ritis ratio group showed worse progression in DSS and OAS (all parameters, p < 0.001). On Cox regression models of clinical and pathological parameters to predict DSS, De Ritis ratio (HR 5.79, 95% CI 2.25-15.13), pathological T stage (HR 15.89, 95% CI 3.92-64.33, in all p < 0.001); and to predict OAS, De Ritis ratio (HR 2.61, 95% CI 1.49-4.56; p < 0.001), pathological T stage (HR 5.42, 95% CI 2.63-11.64; p < 0.001) and age (HR 1.05, 95% CI 1.02-1.08; p = 0.001) were determined as independent prognostic factors. Preoperative elevated De Ritis ratio could be an independent prognostic factor in BC patients underwent RC. Our results should be confirmed by large and properly designed prospective, randomized trials.

  7. Systematic review with network meta-analysis: comparative efficacy of different enteral immunonutrition formulas in patients underwent gastrectomy.

    Science.gov (United States)

    Song, Guo-Min; Liu, Xiao-Ling; Bian, Wei; Wu, Jing; Deng, Yong-Hong; Zhang, Hui; Tian, Xu

    2017-04-04

    Optimal enteral immunonutrition (EIN) regime for gastric cancer (GC) patients underwent gastrectomy remains uncertainty. To assess comparative efficacy of different EIN formulas in GC patients underwent gastrectomy, we performed network meta-analysis. We included 11 RCTs enrolling 840 patients. Pairwise meta-analysis indicated that EIN (RR 0.56, 95% CI 0.36-0.86; MD -0.42, 95% CI -0.74-0.10), Arg+RNA+ω-3-FAs (RR 0.37, 95% CI 0.22-0.63; MD -0.42, 95% CI -0.75-0.07), Arg+Gln+ω-3-FAs (RR 0.22, 95% CI 0.05-0.94; MD -0.69, 95% CI -1.22-1.07) reduced ICs and LOS. Network meta-analysis confirmed the potential of Arg+RNA+ω-3-FAs for ICs (OR 0.27, 95% Crl 0.12-0.49) and Arg+Gln+ω-3-FAs for CIs (OR 0.22, 95% Crl 0.02-0.84) and LOS (SMD -0.63, 95% Crl -1.07-0.13), and indicated that Arg+RNA+ω-3-FAs was superior to Arg+RNA and Arg+Gln for ICs as well. We performed direct and network meta-analyses for randomized controlled trials comparing EIN formulas with each other or standard enteral nutrition (SEN) in reducing infectious complications (ICs), noninfectious complications (NICs) and length of hospital stay (LOS), through January 2016. The surface under the cumulative ranking curve (SCURA) and Grading of Recommendations Assessment, Development and Evaluation (GRADE) were used to rank regimes and rate qualities of evidences respectively. As for GC patients underwent gastrectomy, Arg+RNA+ω-3-FAs and Arg+Gln+ω-3-FAs are the optimal regimes of reducing ICs and LOS.

  8. [Four patients with hepatitis A presenting with fulminant hepatitis and acute renal failure and who underwent liver transplantation].

    Science.gov (United States)

    Oh, Se Hoon; Lee, Joon Hyoek; Hwang, Ji Won; Kim, Hye Young; Lee, Chang Hoon; Gwak, Geum Youn; Choi, Moon Seok; Koh, Kwang Chul; Paik, Seung Woon; Yoo, Byung Chul

    2009-09-01

    Hepatitis A is generally known as a mild, self-limiting disease of the liver, but in rare instances it can progress to fulminant hepatitis, which may require liver transplantation for recovery. Such cases are known to be related to old age and underlying liver disease. We report four cases of hepatitis A in which patients presented with fulminant hepatitis and acute renal failure and underwent liver transplantation. The following common features were observed in our cases: (1) occurrence in relatively old age (>/=39 years old), (2) association with acute renal failure, (3) presence of hepatomegaly, and (4) microscopic features of submassive hepatic necrosis.

  9. Clinical Outcomes of patients with coronary artery disease who underwent FFR evaluation of intermediate coronary lesionS– COFFRS study

    Directory of Open Access Journals (Sweden)

    Srinivasa Prasad

    2017-07-01

    Conclusion: In our experience, MACE events were not higher in patients with FFR > 0.8 and kept under medical therapy and were similarly lower in patients with FFR ≤0.8 and underwent revascularisation (p = 0.73. Also MACE events were higher in patients with FFR ≤ 0.8 and did not undergo revascularisation compared to other two appropriately treated groups (p = 0.03. FFR based revascularization decision appears to be a safe strategy in Indian patients.

  10. [Biosynthesis of gold nanoparticles by Azospirillum brasilense].

    Science.gov (United States)

    Kupriashina, M A; Vetchinkina, E P; Burov, A M; Ponomareva, E G; Nikitina, V E

    2014-01-01

    Plant-associated nitrogen-fixing soil bacteria Azospirillum brasilense were shown to reduce the gold of chloroauric acid to elemental gold, resulting in formation of gold nanoparicles. Extracellular phenoloxidizing enzymes (laccases and Mn peroxidases) were shown to participate in reduction of Au+3 (HAuCl4) to Au(0). Transmission electron microscopy revealed accumulation of colloidal gold nanoparticles of diverse shape in the culture liquid of A. brasilense strains Sp245 and Sp7. The size of the electron-dense nanospheres was 5 to 50 nm, and the size of nanoprisms varied from 5 to 300 nm. The tentative mechanism responsible for formation of gold nanoparticles is discussed.

  11. Ultrasonic inspection of fake gold jewelry

    Science.gov (United States)

    Pauzi Ismail, Mohamad; Sani, Suhairy; Shofri, Faris Syazwan bin Mohd; Harun, Mohd.; Omar, Norlaili Binti

    2018-01-01

    Hollow jewelry made from combination of gold and other material was found in the market. At the outside it is made of gold and the inside layer is made of other material. X-ray fluorescent method cannot detect the inside material that was covered by gold. This paper explained the experimental result of ultrasonic inspection of fake gold used for jewelry. The ultrasonic pulse echo contact method was used to measure longitudinal wave velocity in the gold jewelry. The results of measurements are explained and discussed.

  12. Surface vertical deposition for gold nanoparticle film

    International Nuclear Information System (INIS)

    Diao, J J; Qiu, F S; Chen, G D; Reeves, M E

    2003-01-01

    In this rapid communication, we present the surface vertical deposition (SVD) method to synthesize the gold nanoparticle films. Under conditions where the surface of the gold nanoparticle suspension descends slowly by evaporation, the gold nanoparticles in the solid-liquid-gas junction of the suspension aggregate together on the substrate by the force of solid and liquid interface. When the surface properties of the substrate and colloidal nanoparticle suspension define for the SVD, the density of gold nanoparticles in the thin film made by SVD only depends on the descending velocity of the suspension surface and on the concentration of the gold nanoparticle suspension. (rapid communication)

  13. Gold and not so real gold in Medieval treatises

    Directory of Open Access Journals (Sweden)

    Srebrenka Bogovic-Zeskoski

    2015-01-01

    Full Text Available The aim of this study is to evidence diverse materials and processes used by artisans (and alchemists required to synthesize a visually viable replacement for gold. The emphasis of the research is upon the production of mosaic gold or porporina, a pigment that has survived into modern times, which was used as ink and as paint. Base metals, mostly tin, but also alloys were used both into foils coated with glazes and varnishes and as pigment. The research focuses upon recipes documented in treatises dating from Antiquity to the late Medieval period (ca. 1500 and an attempt is made to answer two questions. In the first place, why was there a need for a surrogate? Secondly, why are there so few tangible examples detected on surviving artifacts? In conclusion, an argument is offered pointing out that, although much can be learned by scientific examination of artifacts, textual analysis is equally important and necessary to unravel mysteries of ancient technologies

  14. Citrus aurantium Naringenin Prevents Osteosarcoma Progression and Recurrence in the Patients Who Underwent Osteosarcoma Surgery by Improving Antioxidant Capability

    Directory of Open Access Journals (Sweden)

    Lirong Zhang

    2018-01-01

    Full Text Available Citrus aurantium is rich in flavonoids, which may prevent osteosarcoma progression, but its related molecular mechanism remains unclear. Flavonoids were extracted from C. aurantium and purified by reparative HPLC. Each fraction was identified by using electrospray ionisation mass spectrometry (ESI-MS. Three main components (naringin, naringenin, and hesperetin were isolated from C. aurantium. Naringenin inhibited the growth of MG-63 cells, whereas naringin and hesperetin had no inhibitory function on cell growth. ROS production was increased in naringin- and hesperetin-treated groups after one day of culture while the level was always lowest in the naringenin-treated group after three days of culture. 95 osteosarcoma patients who underwent surgery were assigned into two groups: naringenin group (NG, received 20 mg naringenin daily, n=47 and control group (CG, received 20 mg placebo daily, n=48. After an average of two-year follow-up, osteosarcoma volumes were smaller in the NG group than in the CG group (P>0.01. The rate of osteosarcoma recurrence was also lower in the NG group than in CG group. ROS levels were lower in the NG group than in the CG group. Thus, naringenin from Citrus aurantium inhibits osteosarcoma progression and local recurrence in the patients who underwent osteosarcoma surgery by improving antioxidant capability.

  15. Prognostic Impact of the Geriatric Nutritional Risk Index on Long-Term Outcomes in Patients Who Underwent Percutaneous Coronary Intervention.

    Science.gov (United States)

    Wada, Hideki; Dohi, Tomotaka; Miyauchi, Katsumi; Doi, Shinichiro; Naito, Ryo; Konishi, Hirokazu; Tsuboi, Shuta; Ogita, Manabu; Kasai, Takatoshi; Hassan, Ahmed; Okazaki, Shinya; Isoda, Kikuo; Suwa, Satoru; Daida, Hiroyuki

    2017-06-01

    Malnutrition has been identified as an important predictor of poor clinical outcomes in patients with heart failure. The aim of this study is to examine the prognostic impact of nutritional status in patients with coronary artery disease (CAD) who underwent percutaneous coronary intervention (PCI). The impact of nutrition, assessed using the geriatric nutritional risk index (GNRI) calculated by serum albumin and body mass index, was evaluated in 2,853 patients with CAD who underwent their first PCI between 2000 and 2011. Patients were assigned to tertiles based on their GNRI levels. The incidences of all-cause death and cardiac death were assessed. The median GNRI values were 101 (interquartile range 95 to 106). Lower GNRI levels were associated with older age and higher prevalence of acute coronary syndrome and chronic kidney disease. During the median follow-up period of 7.4 years, Kaplan-Meier curves showed ongoing divergence in rates of mortality among tertiles (GNRI nutritional status was associated with long-term clinical outcomes in CAD patients after PCI. Evaluation of GNRI carries important prognostic information and may guide the therapeutic approach to such patients. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. The Mid-Term Results of Patients who Underwent Radiofrequency Atrial Fibrillation Ablation Together with Mitral Valve Surgery

    Directory of Open Access Journals (Sweden)

    Abdurrahim Çolak

    Full Text Available Abstract Objetive: Saline-irrigated radiofrequency ablation, which has been widely used for surgical treatment of atrial fibrillation in recent years, is 80-90% successful in achieving sinus rhythm. In our study, our surgical experience and mid-term results in patients who underwent mitral valve surgery and left atrial radiofrequency ablation were analyzed. Methods: Forty patients (15 males, 25 females; mean age 52.05±9.9 years; range 32-74 underwent surgery for atrial fibrillation associated with mitral valvular disease. All patients manifested atrial fibrillation, which started at least six months before the surgical intervention. The majority of patients (36 patients, 90% were in NYHA class III; 34 (85% patients had rheumatic heart disease. In addition to mitral valve surgery and radiofrequency ablation, coronary artery bypass, DeVega tricuspid annuloplasty, left ventricular aneurysm repair, and left atrial thrombus excision were performed. Following discharge from the hospital, patients' follow-up was performed as outpatient clinic examinations and the average follow-up period of patients was 18±3 months. Results: While the incidence of sinus rhythm was 85.3% on the first postoperative day, it was 80% during discharge and 71% in the 1st year follow-up examination. Conclusion: Radiofrequency ablation is an effective method when it is performed by appropriate surgical technique. Its rate for returning to sinus rhythm is as high as the rate of conventional surgical procedure.

  17. Light addressable gold electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Khalid, Waqas

    2011-07-01

    The main objective carried out in this dissertation was to fabricate Light Amplified Potentiometric sensors (LAPS) based upon the semiconductor nanoparticles (quantum dots) instead of its bulk form. Quantum dots (QDs) were opted for this device fabrication because of their superior fluorescent, electric and catalytic properties. Also in comparison to their bulk counterparts they will make device small, light weighted and power consumption is much lower. QDs were immobilized on a Au substrate via 1,4 benzene dithiol (BDT) molecule. Initially a self-assembled monolayer (SAM) of BDT was established on Au substrate. Because of SAM, the conductivity of Au substrate decreased dramatically. Furthermore QDs were anchored with the help of BDT molecule on Au substrate. When QDs immobilized on Au substrate (QD/Au) via BDT molecule were irradiated with UV-visible light, electron-hole pairs were generated in QDs. The surface defect states in QDs trapped the excited electrons and long lived electron-hole pairs were formed. By the application of an appropriate bias potential on Au substrate the electrons could be supplied or extracted from the QDs via tunneling through BDT. Thus a cathodic or anodic current could be observed depending upon bias potential under illumination. However without light illumination the QD/Au electrode remained an insulator. To improve the device different modifications were made, including different substrates (Au evaporated on glass, Au evaporated on mica sheets and Au sputtered on SiO{sub 2}/Si) and different dithiol molecules (capped and uncapped biphenyl 4,4' dithiol and capped and uncapped 4,4' dimercaptostilbenes) were tried. Also different QD immobilization techniques (normal incubation, spin coating, layer by layer assembly (LbL) of polyelectrolytes and heat immobilization) were employed. This device was able to detect electrochemically different analytes depending upon the QDs incorporated. For example CdS QDs were able to detect 4

  18. Prediction of low birth weight

    DEFF Research Database (Denmark)

    Sinding, Marianne; Peters, David A; Frøkjær, Jens B

    2017-01-01

    operating characteristic curves demonstrated a significantly higher performance of T2* (AUC of 0.92; 95% CI, 0.85-0.98) than UtA PI (AUC of 0.74; 95% CI, 0.60-0.89) in the prediction of low birth weight (p = 0.010). Placental pathological findings were closely related to the T2* values. CONCLUSIONS...... placental function. Therefore, we aimed to evaluate the performance of placental T2* in the prediction of low birth weight using the uterine artery (UtA) pulsatility index (PI) as gold standard. METHODS: This was a prospective observational study of 100 singleton pregnancies included at 20-40 weeks......' gestation. Placental T2* was obtained using a gradient recalled multi-echo MRI sequence and UtA PI was measured using Doppler ultrasound. Placental pathological examination was performed in 57 of the pregnancies. Low birth weight was defined by a Z-score ≤ -2.0. RESULTS: The incidence of low birth weight...

  19. Methods to reduce mercury pollution is small gold mining operations

    International Nuclear Information System (INIS)

    Pantoja-Timaran, F.; Alvarez-Rodriguez, R.; Rodriguez-Avello, A. S.

    2005-01-01

    The use of mercury for gold beneficiation is still a current practice in small mining operations, mainly in underdeveloped countries, due to the low investment required and necessity of easy to operate systems. But the lack of basic protections makes unavoidable the high pollution of water streams, soils, and in fact, human bodies. some improvements have been done at site like that related to the removal of the mercury from the amalgam, that usually was done in the open air, and now have been changed to the utilization of artisan iron retorts which considerable reduce the emissions of mercury vapors to the atmosphere, but there are still high losses of mercury into the waste solids or tailings coming from the amalgamation process (nearly most of the total weight of the ore treated). In order to reduce the mercury losses into the tailings from the process, this research work has been based in the use of cheap systems, available to the isolated miners, to proof that it is feasible to get an important reduction of the losses and the pollution. the procedure has been accomplished by means of washing the ores with alkaline or detergent agents, together with the use of activated mercury purified by electrowinning in a simple device, easily manufactured in site by the own workers. It is also proven herewith that controlling the time of amalgamation and the total amount of mercury used could reduce the total pollution, and in addition, the gold recovery would be improved. This investigation reports the possibility of a reduction of mercury losses down to 2.4 g per 100 of gold produced (case of rich ores like LaBruja), with gold recovery up to 94%; and 8,6 g per 100 g of gold produced (from ores with average grades like La Gruesa), and gold recoveries in the range of 92%. All that is about 20 to 100 times lower than data reported in current bibliography. The introduction of a previous step of the ore concentration in shaking tables, decreases the total amount of solids for

  20. Weight-loss medicines

    Science.gov (United States)

    Prescription weight loss drugs; Diabetes - weight loss drugs; Obesity - weight loss drugs; Overweight - weight loss drugs ... Several weight-loss medicines are available. About 5 to 10 pounds (2 to 4.5 kilograms) can be lost by ...

  1. CMS Industries awarded gold, crystal

    CERN Multimedia

    2006-01-01

    The CMS collaboration honoured 10 of its top suppliers in the seventh annual awards ceremony The representatives of the firms that recieved the CMS Gold and Crystal Awards stand with their awards after the ceremony. The seventh annual CMS Awards ceremony was held on Monday 13 March to recognize the industries that have made substantial contributions to the construction of the collaboration's detector. Nine international firms received Gold Awards, and General Tecnica of Italy received the prestigious Crystal Award. Representatives from the companies attended the ceremony during the plenary session of CMS week. 'The role of CERN, its machines and experiments, beyond particle physics is to push the development of equipment technologies related to high-energy physics,'said CMS Awards Coordinator Domenico Campi. 'All of these industries must go beyond the technologies that are currently available.' Without the involvement of good companies over the years, the construction of the CMS detector wouldn't be possible...

  2. Byzantine gold coins and jewellery

    International Nuclear Information System (INIS)

    Oddy, A.; La Niece, S.

    1986-01-01

    The article deals with the dating of Byzantine gold coinage. The results of such a study are of fundamental importance for the study of the economic history of the later Byzantine Empire and they are also of importance for the historian of technology when studying the composition of the contemporary Byzantine jewellery. Although Carbon-14 dating cannot be used as a method af dating, historians can still benefit from the analysis of the alloy of which the antiquity is made, as this is sometimes characteristic of the period in which it was used. A number of pieces of Byzantine jewellery has been analysed by x-ray fluorescence analysis, after first gently abrading a small area of the surface of the gold with the carborundum paper in an inconspicious position on the back or side of the object. A table is given on the results of this analysis

  3. Distribution and composition of gold in porphyry gold systems: example from the Biely Vrch deposit, Slovakia

    Science.gov (United States)

    Koděra, Peter; Kozák, Jaroslav; Brčeková, Jana; Chovan, Martin; Lexa, Jaroslav; Jánošík, Michal; Biroň, Adrián; Uhlík, Peter; Bakos, František

    2018-03-01

    The Biely Vrch deposit in the Western Carpathians is assigned to the shallow, sulfide-poor porphyry gold deposit type and has an exceptionally low Cu/Au ratio. According to 3-D geochemical models, there is a limited spatial correlation between Au and Cu due to the primary introduction of gold by a salt melt and Cu by low-density vapor. Despite a rough spatial correlation of gold grades with quartz stockwork intensity, gold is hosted mostly by altered rock, exclusively in native form. Three main gold mineral assemblages were recognized here. In the deepest parts of the system, the K- and Ca-Na silicate gold assemblage is associated with minerals of high-temperature alteration (plagioclase, K-feldspar, actinolite), with gold grades and fineness depending on depth and potassium content of the host rock: K-silicate alteration hosts the lowest fineness gold ( 914), whereas Ca-Na silicate alteration has the highest ( 983). The intermediate argillic gold assemblage is the most widespread, with gold hosted mainly by chlorite, illite, smectite, and interstratified illite-chlorite-smectite minerals. The gold fineness is mostly variable (875-990) and inherited from the former gold mineral assemblages. The latest advanced argillic gold assemblage has its gold mostly in kaolinite. The extremely high fineness ( 994) results from gold remobilization by late-stage aqueous magmatic-hydrothermal fluids. Uncommon bonanza-grade appears where the earlier gold mineral assemblages were further enriched by this remobilized gold. Primary precipitation of gold occurred during ascent and cooling of salt melts at 450 to 309 °C, mostly during retrograde quartz solubility.

  4. Improved image quality in abdominal CT in patients who underwent treatment for hepatocellular carcinoma with small metal implants using a raw data-based metal artifact reduction algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Sofue, Keitaro; Sugimura, Kazuro [Kobe University Graduate School of Medicine, Department of Radiology, Kobe, Hyogo (Japan); Yoshikawa, Takeshi; Ohno, Yoshiharu [Kobe University Graduate School of Medicine, Advanced Biomedical Imaging Research Center, Kobe, Hyogo (Japan); Kobe University Graduate School of Medicine, Division of Functional and Diagnostic Imaging Research, Department of Radiology, Kobe, Hyogo (Japan); Negi, Noriyuki [Kobe University Hospital, Division of Radiology, Kobe, Hyogo (Japan); Inokawa, Hiroyasu; Sugihara, Naoki [Toshiba Medical Systems Corporation, Otawara, Tochigi (Japan)

    2017-07-15

    To determine the value of a raw data-based metal artifact reduction (SEMAR) algorithm for image quality improvement in abdominal CT for patients with small metal implants. Fifty-eight patients with small metal implants (3-15 mm in size) who underwent treatment for hepatocellular carcinoma were imaged with CT. CT data were reconstructed by filtered back projection with and without SEMAR algorithm in axial and coronal planes. To evaluate metal artefact reduction, mean CT number (HU and SD) and artefact index (AI) values within the liver were calculated. Two readers independently evaluated image quality of the liver and pancreas and visualization of vasculature using a 5-point visual score. HU and AI values and image quality on images with and without SEMAR were compared using the paired Student's t-test and Wilcoxon signed rank test. Interobserver agreement was evaluated using linear-weighted κ test. Mean HU and AI on images with SEMAR was significantly lower than those without SEMAR (P < 0.0001). Liver and pancreas image qualities and visualizations of vasculature were significantly improved on CT with SEMAR (P < 0.0001) with substantial or almost perfect agreement (0.62 ≤ κ ≤ 0.83). SEMAR can improve image quality in abdominal CT in patients with small metal implants by reducing metallic artefacts. (orig.)

  5. Improved image quality in abdominal CT in patients who underwent treatment for hepatocellular carcinoma with small metal implants using a raw data-based metal artifact reduction algorithm.

    Science.gov (United States)

    Sofue, Keitaro; Yoshikawa, Takeshi; Ohno, Yoshiharu; Negi, Noriyuki; Inokawa, Hiroyasu; Sugihara, Naoki; Sugimura, Kazuro

    2017-07-01

    To determine the value of a raw data-based metal artifact reduction (SEMAR) algorithm for image quality improvement in abdominal CT for patients with small metal implants. Fifty-eight patients with small metal implants (3-15 mm in size) who underwent treatment for hepatocellular carcinoma were imaged with CT. CT data were reconstructed by filtered back projection with and without SEMAR algorithm in axial and coronal planes. To evaluate metal artefact reduction, mean CT number (HU and SD) and artefact index (AI) values within the liver were calculated. Two readers independently evaluated image quality of the liver and pancreas and visualization of vasculature using a 5-point visual score. HU and AI values and image quality on images with and without SEMAR were compared using the paired Student's t-test and Wilcoxon signed rank test. Interobserver agreement was evaluated using linear-weighted κ test. Mean HU and AI on images with SEMAR was significantly lower than those without SEMAR (P small metal implants by reducing metallic artefacts. • SEMAR algorithm significantly reduces metallic artefacts from small implants in abdominal CT. • SEMAR can improve image quality of the liver in dynamic CECT. • Confidence visualization of hepatic vascular anatomies can also be improved by SEMAR.

  6. Gold Nanocages for Biomedical Applications**

    OpenAIRE

    Skrabalak, Sara E.; Chen, Jingyi; Au, Leslie; Lu, Xianmao; Li, Xingde; Xia, Younan

    2007-01-01

    Nanostructured materials provide a promising platform for early cancer detection and treatment. Here we highlight recent advances in the synthesis and use of Au nanocages for such biomedical applications. Gold nanocages represent a novel class of nanostructures, which can be prepared via a remarkably simple route based on the galvanic replacement reaction between Ag nanocubes and HAuCl4. The Au nanocages have a tunable surface plasmon resonance peak that extends into the near-infrared, where ...

  7. Extinction Coefficient of Gold Nanostars

    OpenAIRE

    de Puig, Helena; Tam, Justina O.; Yen, Chun-Wan; Gehrke, Lee; Hamad-Schifferli, Kimberly

    2015-01-01

    Gold nanostars (NStars) are highly attractive for biological applications due to their surface chemistry, facile synthesis and optical properties. Here, we synthesize NStars in HEPES buffer at different HEPES/Au ratios, producing NStars of different sizes and shapes, and therefore varying optical properties. We measure the extinction coefficient of the synthesized NStars at their maximum surface plasmon resonances (SPR), which range from 5.7 × 108 to 26.8 × 108 M−1cm−1. Measured values correl...

  8. Gold, currencies and market efficiency

    Czech Academy of Sciences Publication Activity Database

    Krištoufek, Ladislav; Vošvrda, Miloslav

    2016-01-01

    Roč. 449, č. 1 (2016), s. 27-34 ISSN 0378-4371 R&D Projects: GA ČR(CZ) GBP402/12/G097 Institutional support: RVO:67985556 Keywords : Efficient market hypothesis, * Gold * Currencies, * Fractal dimension * Entropy * Long-Term memory Subject RIV: AH - Economics Impact factor: 2.243, year: 2016 http://library.utia.cas.cz/separaty/2016/E/kristoufek-0455876.pdf

  9. Ground Optical Lightning Detector (GOLD)

    Science.gov (United States)

    Jackson, John, Jr.; Simmons, David

    A photometer developed to characterize lightning from the ground is discussed. The detector and the electronic signal processing and data storage systems are presented along with field data measured by the system. The discussion will include improvements that will be incorporated to enhance the measurement of lightning and the data storage capability to record for many days without human involvement. Finally, the calibration of the GOLD system is presented.

  10. Biomolecular Assembly of Gold Nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Micheel, Christine Marya [Univ. of California, Berkeley, CA (United States)

    2005-05-20

    Over the past ten years, methods have been developed to construct discrete nanostructures using nanocrystals and biomolecules. While these frequently consist of gold nanocrystals and DNA, semiconductor nanocrystals as well as antibodies and enzymes have also been used. One example of discrete nanostructures is dimers of gold nanocrystals linked together with complementary DNA. This type of nanostructure is also known as a nanocrystal molecule. Discrete nanostructures of this kind have a number of potential applications, from highly parallel self-assembly of electronics components and rapid read-out of DNA computations to biological imaging and a variety of bioassays. My research focused in three main areas. The first area, the refinement of electrophoresis as a purification and characterization method, included application of agarose gel electrophoresis to the purification of discrete gold nanocrystal/DNA conjugates and nanocrystal molecules, as well as development of a more detailed understanding of the hydrodynamic behavior of these materials in gels. The second area, the development of methods for quantitative analysis of transmission electron microscope data, used computer programs written to find pair correlations as well as higher order correlations. With these programs, it is possible to reliably locate and measure nanocrystal molecules in TEM images. The final area of research explored the use of DNA ligase in the formation of nanocrystal molecules. Synthesis of dimers of gold particles linked with a single strand of DNA possible through the use of DNA ligase opens the possibility for amplification of nanostructures in a manner similar to polymerase chain reaction. These three areas are discussed in the context of the work in the Alivisatos group, as well as the field as a whole.

  11. A Case of Type 2 Amiodarone-Induced Thyrotoxicosis That Underwent Total Thyroidectomy under High-Dose Steroid Administration

    Directory of Open Access Journals (Sweden)

    Koshi Hashimoto

    2015-01-01

    Full Text Available Amiodarone is used commonly and effectively in the treatment of arrhythmia; however, it may cause thyrotoxicosis categorized into two types: iodine-induced hyperthyroidism (type 1 amiodarone-induced thyrotoxicosis (AIT and destructive thyroiditis (type 2 AIT. We experienced a case of type 2 AIT, in which high-dose steroid was administered intravenously, and we finally decided to perform total thyroidectomy, resulting in a complete cure of the AIT. Even though steroid had been administered to the patient (maximum 80 mg of prednisolone, the operation was performed safely and no acute adrenal crisis as steroid withdrawal syndrome was found after the operation. Few cases of type 2 AIT that underwent total thyroidectomy with high-dose steroid administration have been reported. The current case suggests that total thyroidectomy should be taken into consideration for patients with AIT who cannot be controlled by medical treatment and even in those under high-dose steroid administration.

  12. Jabiluka gold-uranium project

    International Nuclear Information System (INIS)

    1988-01-01

    The Jabiluka gold-uranium deposit, 230km east of Darwin in the Alligator Rivers Region of the Northern Territory, was discovered by Pancontinental Mining Limited in 1971. Jabiluka, with reserves in excess of 200,000 tonnes of contained U 3 O 8 in two deposits 500 metres apart, is the world's largest high grade uranium deposit and also contains nearly 12 tonnes of gold. It is proposed that only the larger deposit, Jabiluka II will be mined - by underground extraction methods, and that 275,000 tonnes of ore per year will be mined and processed to produce 1,500 tonnes of U 3 O 8 and up to 30,000 oz of gold. The revenue from the uranium sales is estimated to be of the order of A$100 million per year at A$30/lb. By the end of 1982 all necessary mining and environmental approvals had been obtained and significant marketing progress made. With the Australian Labor Party winning Commonwealth Government in the 1983 election, Pancontinental's permission to seek sales contracts was withdrawn and development of the Jabiluka deposit ceased. Jabiluka remains undeveloped - awaiting a change in Australian Government policy on uranium. figs., maps

  13. Infants with Atypical Presentations of Alveolar Capillary Dysplasia with Misalignment of the Pulmonary Veins Who Underwent Bilateral Lung Transplantation.

    Science.gov (United States)

    Towe, Christopher T; White, Frances V; Grady, R Mark; Sweet, Stuart C; Eghtesady, Pirooz; Wegner, Daniel J; Sen, Partha; Szafranski, Przemyslaw; Stankiewicz, Pawel; Hamvas, Aaron; Cole, F Sessions; Wambach, Jennifer A

    2018-03-01

    To describe disease course, histopathology, and outcomes for infants with atypical presentations of alveolar capillary dysplasia with misalignment of the pulmonary veins (ACDMPV) who underwent bilateral lung transplantation. We reviewed clinical history, diagnostic studies, explant histology, genetic sequence results, and post-transplant course for 6 infants with atypical ACDMPV who underwent bilateral lung transplantation at St. Louis Children's Hospital. We compared their histology with infants with classic ACDMPV and compared their outcomes with infants transplanted for other indications. In contrast with neonates with classic ACDPMV who present with severe hypoxemia and refractory pulmonary hypertension within hours of birth, none of the infants with atypical ACDMPV presented with progressive neonatal respiratory failure. Three infants had mild neonatal respiratory distress and received nasal cannula oxygen. Three other infants had no respiratory symptoms at birth and presented with hypoxemia and pulmonary hypertension at 2-3 months of age. Bilateral lung transplantation was performed at 4-20 months of age. Unlike in classic ACDMPV, histopathologic findings were not distributed uniformly and were not diffuse. Three subjects had apparent nonmosaic genetic defects involving FOXF1. Two infants had extrapulmonary anomalies (posterior urethral valves, inguinal hernia). Three transplanted children are alive at 5-16 years of age, similar to outcomes for infants transplanted for other indications. Lung explants from infants with atypical ACDMPV demonstrated diagnostic but nonuniform histopathologic findings. The 1- and 5-year survival rates for infants with atypical ACDMPV are similar to infants transplanted for other indications. Given the clinical and histopathologic spectra, ACDMPV should be considered in infants with hypoxemia and pulmonary hypertension, even beyond the newborn period. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. The association between orthostatic hypotension and cognitive state among adults 65 years and older who underwent a comprehensive geriatric assessment

    Science.gov (United States)

    Punchick, Boris; Freud, Tamar; Press, Yan

    2016-01-01

    Abstract The prevalence of cognitive impairment and orthostatic hypotension (OH) increases with age, but the results of studies that assessed possible associations between them are inconsistent. The aim of this study is to assess possible associations between cognitive impairment and OH in patients ≥65 years of age who underwent a comprehensive geriatric assessment. A retrospective analysis was conducted of the computerized medical records of the study population from 2005 to 2013. Data collected included blood pressure measurements that enabled the calculation of OH, results of the mini-mental state examination (MMSE), results of the Montreal cognitive assessment (MoCA) test, and cognitive diagnoses that were determined over the course of the assessment. The rate of OH in the study population of 571 adults was 32.1%. The mean MMSE score was 22.5 ± 5.2 among participants with OH and 21.6 ± 5.8 among those without OH (P = 0.09). The absence of a significant association between OH and MMSE remained after adjusting the MMSE score for age and education level. The mean MoCA score was 16.4 ± 5.0 among participants with OH and 16.4 ± 4.8 among those without (P = 0.33). The prevalence of OH was 39% among participants without cognitive impairment, 28.9% among those with mild cognitive impairment (MCI), and 30.6% among those with dementia (P = 0.13). There was no association between OH and cognitive impairment in adults who underwent a comprehensive geriatric assessment. PMID:27442658

  15. Long-term prognosis and clinical characteristics of young adults (≤40 years old) who underwent percutaneous coronary intervention.

    Science.gov (United States)

    Konishi, Hirokazu; Miyauchi, Katsumi; Kasai, Takatoshi; Tsuboi, Shuta; Ogita, Manabu; Naito, Ryo; Katoh, Yoshiteru; Okai, Iwao; Tamura, Hiroshi; Okazaki, Shinya; Daida, Hiroyuki

    2014-09-01

    Limited data exist regarding the long-term prognosis of percutaneous coronary intervention (PCI) in young adults. The aim of this study was to retrospectively assess the long-term clinical outcomes in young patients who underwent PCI. Between 1985 and 2011, 7649 consecutive patients underwent PCI, and data from 69 young adults (age ≤40 years) and 4255 old adults (age ≧65 years) were analyzed. A Cox proportional hazards regression analysis was used to determine the independent predictors of a composite endpoint that included all-cause death and acute coronary syndrome (ACS) during the follow-up period. The mean age of the 69 young patients was 36.1±4.9 years, and 96% of them were men. Approximately 30% were current smokers, and their body mass index (BMI) was 26.7±5.0kg/m(2). The prevalence of diabetes and hypertension was 33% and 48%, respectively. All patients had ≥1 conventional cardiovascular risk factor. At a median follow-up of 9.8 years, the overall death rate was 5.8%, and new-onset ACS occurred in 8.7%. Current smoking was an independent predictor of the composite endpoint (hazard ratio 4.46, confidence interval 1.08-19.1, p=0.04) for young adults. Current smoking and obesity (high BMI) are the important clinical characteristics in young Japanese coronary heart disease patients who undergo PCI. The long-term prognosis in young patients is acceptable, but current smoking is a significant independent predictor of death and the recurrence of ACS in young Japanese coronary heart disease patients who are obese. Copyright © 2014 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

  16. Analysis of Ulcer Recurrences After Metatarsal Head Resection in Patients Who Underwent Surgery to Treat Diabetic Foot Osteomyelitis.

    Science.gov (United States)

    Sanz-Corbalán, Irene; Lázaro-Martínez, José Luis; Aragón-Sánchez, Javier; García-Morales, Esther; Molines-Barroso, Raúl; Alvaro-Afonso, Francisco Javier

    2015-06-01

    Metatarsal head resection is a common and standardized treatment used as part of the surgical routine for metatarsal head osteomyelitis. The aim of this study was to define the influence of the amount of the metatarsal resection on the development of reulceration or ulcer recurrence in patients who suffered from plantar foot ulcer and underwent metatarsal surgery. We conducted a prospective study in 35 patients who underwent metatarsal head resection surgery to treat diabetic foot osteomyelitis with no prior history of foot surgeries, and these patients were included in a prospective follow-up over the course of at least 6 months in order to record reulceration or ulcer recurrences. Anteroposterior plain X-rays were taken before and after surgery. We also measured the portion of the metatarsal head that was removed and classified the patients according the resection rate of metatarsal (RRM) in first and second quartiles. We found statistical differences between the median RRM in patients who had an ulcer recurrence and patients without recurrences (21.48 ± 3.10% vs 28.12 ± 10.8%; P = .016). Seventeen (56.7%) patients were classified in the first quartile of RRM, which had an association with ulcer recurrence (P = .032; odds ratio = 1.41; 95% confidence interval = 1.04-1.92). RRM of less than 25% is associated with the development of a recurrence after surgery in the midterm follow-up, and therefore, planning before surgery is undertaken should be considered to avoid postsurgical complications. © The Author(s) 2015.

  17. [Evaluation of the antithrombotic strategy in low thrombotic risk patients who underwent aortic valve replacement with a bioprosthesis].

    Science.gov (United States)

    Aceves-Velázquez, Eduardo; Vieyra-Herrera, Gerardo; Rodríguez-Chávez, Laura; Herrera-Alarcón, Valentín

    2017-07-16

    According to current guidelines, in patients without additional risk factors who have undergone aortic valve replacement with a bioprosthesis, anticoagulation in the first 3 months after surgery is still a matter of debate. According to current evidence, aspirin in low doses is a reasonable alternative to vitamin K antagonists (VKA). A comparison is made between the incidence of thrombotic and haemorrhagic complications in patients with low thrombotic risk who underwent aortic valve replacement with a bioprosthesis in the National Institute of Cardiology of Ignacio Chávez of Mexico. The hypothesis: aspirin as monotherapy has a beneficial effect compared to VKA. The studied patients were the low thrombotic risk patients who underwent aortic valve replacement with a bioprosthesis in the National Institute of Cardiology of Ignacio Chávez of Mexico from 2011 to 2015. The groups studied were: aspirin only, VKA only, and the combination of VKA plus aspirin. The patients were retrospectively followed-up for 12 months, and the thrombotic and haemorrhagic complications were documented. Of the 231 patients included in the study, only one patient in the VKA only group presented with a haemorrhagic complication. No thrombotic complications were observed. In the present study no thrombotic complications were observed in patients who did not receive anticoagulation in the first 3 months after an aortic valve replacement with a bioprosthesis after a follow up period of 12 months. This suggests that the use of aspirin only is safe during this period. Copyright © 2017 Instituto Nacional de Cardiología Ignacio Chávez. Publicado por Masson Doyma México S.A. All rights reserved.

  18. Autotransplantation of spleen tissue in children with mansonic schistosomiasis who underwent splenectomy: Evaluation of splenic residual functions

    Directory of Open Access Journals (Sweden)

    Brandt Carlos Teixeira

    1998-01-01

    Full Text Available Autotransplantation of spleen tissue is an attempt for maintenance of splenic functions when splenectomy is indicated in children. It minimizes the risks of overwhelming postsplenectomy infection and it has been done in children with severe portal hypertension due to hepatosplenic mansonic schistosomiasis that underwent splenectomy. The purposes of this investigation were to study the morphology of the residual splenic tissue; to evaluate the residual filtration function of this splenosis; and to assess the immune response to polyvalent pneumococcal vaccine of these patients. Twenty-three children with portal hypertension from mansonic schistosomiasis who underwent splenectomy, ligature of the left gastric vein, autotransplantation of spleen tissue into an omental pouch were evaluated for residual splenic parenchyma and functions. Tc-99m sulfur colloid liver-spleen scans were used for detection of splenic nodules. The search for Howell Jolly bodies were used for assessing the filtration function and Enzyme-linked immunosorbent assay was used for measuring the relative rise in titter of specific pneumococcal antibodies. Splenosis was evident in all children; however, in two there were less than five splenic nodules in the greater omentum, which was considered insufficient. Howell-Jolly bodies were found in the peripheral blood only in these two patients with less evident splenosis. The immune response was adequate in 15 patients; it was intermediate in 4 patients and inadequate in 4 patients. Autotransplantation of spleen tissue into an omental pouch is efficient in maintaining the filtration splenic function in more than 90% of the cases and the immune response to pneumococcal vaccination in approximately 65% of the children.

  19. Effect of advanced blood pressure control with nifedipine delayedrelease tablets on the blood pressure in patients underwent nasal endoscope surgery

    Directory of Open Access Journals (Sweden)

    Qing-Hua Xia

    2016-08-01

    Full Text Available Objective: To explore the effect of advanced blood pressure control with nifedipine delayedrelease tablets on the blood pressure in patients underwent nasal endoscope surgery and its feasibility. Methods: A total of 80 patients who were admitted in ENT department from June, 2012 to June, 2015 for nasal endoscope surgery were included in the study and randomized into the observation group and the control group with 40 cases in each group. The patients in the observation group were given nifedipine delayed-release tablets for advanced blood pressure control before operation, and were given routine blood pressure control during operation; while the patients in the control group were only given blood pressure control during operation. The changes of blood pressure, mean central arterial pressure, and heart rate before anesthesia (T0, after intubation (T1, during operation (T2, extubation when waking (T3, 30 min after extubation (T4, and 3 h after back to wards (T5 in the two groups were compared. The intraoperative situation and the surgical field quality in the two groups were compared. Results: SBP, DBP, and MAP levels at T1-5 in the two groups were significantly lower than those at T0. SBP, DBP, and MAP levels at T2 were significantly lower than those at other timing points, and were gradually recovered after operation, but were significantly lower than those at T0. The effect taking time of blood pressure reducing, intraoperative nitroglycerin dosage, and postoperative wound surface exudation amount in the observation group were significantly less than those in the control group. The surgical field quality scores in the observation group were significantly superior to those in the control group. Conclusions: Advanced blood pressure control with nifedipine delayed-release tablets can stabilize the blood pressure during the perioperative period in patients underwent nasal endoscope surgery, and enhance the surgical field qualities.

  20. A correlation found between gold concentration in blood and patch test reactions in patients with coronary stents.

    Science.gov (United States)

    Ekqvist, Susanne; Svedman, Cecilia; Lundh, Thomas; Möller, Halvon; Björk, Jonas; Bruze, Magnus

    2008-09-01

    Patients with dental gold restorations are known to have a higher level of gold concentration in blood (B-Au). To further investigate, in a study on patients with intracoronary stents and contact allergy to metals, the gold and nickel release from stainless steel stent with (Au stent) and without (Ni stent) gold plating. A total of 460 patients treated with stenting underwent patch testing with metals, and information on gold and nickel exposure and blood samples were collected. About 200 blood samples were randomly selected and the analysis of B-Au and nickel concentration in blood (B-Ni) was made using inductively coupled plasma mass spectrometry. There was a correlation between the intensity of Au patch test reaction and B-Au (P stent gave a fivefold higher B-Au than a Ni stent. Gold is released from the Au stent and patients with a Au stent have a fivefold higher B-Au than patients with an Ni stent. The patch test reactions for gold were correlated with B-Au.

  1. Predicting a single HIV drug resistance measure from three international interpretation gold standards.

    Science.gov (United States)

    Yashik, Singh; Maurice, Mars

    2012-07-01

    To investigate the possibility of combining the interpretation of three gold standard interpretation algorithms using weighted heuristics in order to produce a single resistance measure. The outputs of HIVdb, Rega, ANRS were combined to obtain a single resistance profile using the equally weighted voting algorithm, accuracy based weighing voting algorithm and the Bayesian based weighted voting algorithm techniques. The Bayesian based voting combination increased the accuracy of the resistance profile prediction compared to phenotype, from 58% to 69%. The equal weighted voting algorithm and the accuracy based algorithm both increased the prediction accuracy to 60%. From the result obtained it is evident that combining the gold standard interpretation algorithms may increase the predictive ability of the individual interpretation algorithms. Copyright © 2012 Hainan Medical College. Published by Elsevier B.V. All rights reserved.

  2. The role of magnetic resonance cholangiopancreatography and diffusion-weighted imaging for the differential diagnosis of obstructive biliary disorders

    Directory of Open Access Journals (Sweden)

    Zeynep Cetiner-Alpay

    2017-06-01

    Full Text Available Background: Although endoscopic retrograde cholangiopancreatography (ERCP is accepted as the gold standard, there is a place for magnetic resonance cholangiopancreatography (MRCP and diffusion-weighted imaging (DWI in the diagnosis of obstructive biliary disorders. Aim: To compare the findings of MRCP with ERCP in patients with obstructive biliary disorders and to investigate the diagnostic efficacy of MRCP combined with DWI. Study design: Retrospective, analytic, cross-sectional study. Methods: The MRCP images of 126 patients who underwent both MRCP and ERCP owing to biliary obstruction were reviewed. Nine patients were excluded because of incomplete diagnostic workup or a long period (>3 months between MRCP and ERCP. Ninety-two patients underwent DWI, which was also evaluated. The sensitivity, specificity and accuracy of MRCP and DWI were analysed. Results: The sensitivity, specificity and accuracy of MRCP according to ERCP results as the gold standard was 97%, 71% and 93% for assessment of biliary dilatation; 100%, 94.7% and 97.5% for the diagnosis of choledocholithiasis; 93.7%, 100% and 99% for the identification of benign strictures; 100%, 100% and 100% for the diagnosis of malignant tumours; and 100%, 100% and 100% for the detection of complicated hydatid cysts; respectively. The sensitivity and specificity of DWI for the diagnosis of malignant tumour was 100%. In the detection of choledocholithiasis, the sensitivity and specificity of DWI was 70.8% and 100%. Conclusions: MRCP is an alternative, non-invasive, diagnostic modality, comparable with ERCP for the evaluation of pancreaticobiliary diseases. DWI can be helpful for diagnosis of choledocholithiasis and tumours.

  3. Thermoresponsive poly(N-vinyl caprolactam)-coated gold nanoparticles: sharp reversible response and easy tunability.

    Science.gov (United States)

    Beija, Mariana; Marty, Jean-Daniel; Destarac, Mathias

    2011-03-14

    Narrowly distributed poly(N-vinyl caprolactam) obtained by the MADIX/RAFT process was used for the preparation of novel thermoresponsive gold nanoparticles presenting a sharp reversible response to temperature, which can be easily modulated near the physiological temperature by simply changing the polymer molecular weight or concentration.

  4. Quantification and Prediction of Bulk Gold Fineness at Placer Gold Mines: A New Zealand Example

    Directory of Open Access Journals (Sweden)

    Dave Craw

    2017-11-01

    Full Text Available This study documents the bulk Au fineness (Au parts per thousand of the bullion from a placer gold mine in southern New Zealand. The compositions of doré bars produced approximately every 10 days over nearly three years is compared to the range of compositions of gold particles which have been extracted. Silver is the principal impurity in the gold, and the doré bars contained 2–3 wt % Ag over the period examined. At the scale of a typical individual 0.5 mm gold particle, there are three different types of gold: an Ag-bearing core (2–9 wt % Ag, a 10–50 µm wide Ag-poor rim (typically <1 wt % Ag, and micron scale overgrowth gold (0% Ag. The overgrowths are volumetrically negligible, and the average Ag content of a gold particle is controlled principally by the proportions of core and rim gold. The rims have been formed by recrystallisation of deformed core gold, with associated leaching of the Ag from the recrystallised gold. The volumetric proportion of cores has decreased with increasing flattening of gold particles, and highly flattened and folded flakes have little or no remnant cores. The bulk Au fineness of doré bars from the mine has decreased from ~980 to ~970 as the mine progressed upstream in a Pleistocene paleochannel because the upstream gold has been less flattened than the downstream gold.

  5. CO extrusion in homogeneous gold catalysis: reactivity of gold acyl species generated through water addition to gold vinylidenes.

    Science.gov (United States)

    Bucher, Janina; Stößer, Tim; Rudolph, Matthias; Rominger, Frank; Hashmi, A Stephen K

    2015-01-26

    Herein, we describe a new gold-catalyzed decarbonylative indene synthesis. Synergistic σ,π-activation of diyne substrates leads to gold vinylidene intermediates, which upon addition of water are transformed into gold acyl species, a type of organogold compound hitherto only scarcely reported. The latter are shown to undergo extrusion of CO, an elementary step completely unknown for homogeneous gold catalysis. By tuning the electronic and steric properties of the starting diyne systems, this new reactivity could be exploited for the synthesis of indene derivatives in high yields. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Gold markers for tumor localization and target volume delineation in radiotherapy for rectal cancer

    International Nuclear Information System (INIS)

    Vorwerk, Hilke; Christiansen, Hans; Hess, Clemens Friedrich; Hermann, Robert Michael; Liersch, Thorsten; Ghadimi, Michael; Rothe, Hilka

    2009-01-01

    In locally advanced rectal cancer, neoadjuvant radiochemotherapy is indicated. To improve target volume definition for radiotherapy planning, the potential of implanted gold markers in the tumor region was evaluated. In nine consecutive patients, two to three gold markers were implanted in the tumor region during rigid rectoscopy. Computed tomography scans were performed during treatment planning. All electronic portal imaging devices (EPIDs) recorded during treatment series were analyzed. All patients underwent complete tumor resection with meticulous histopathologic examination. The gold markers could easily be implanted into the mesorectal tissue at the caudal tumor border without any complications. They were helpful in identifying the inferior border of the planning target volume in order to spare normal tissue (in particular anal structures). No significant shift of the markers was found during the course of therapy. Marker matching of the EPIDs did not improve patient positioning in comparison to bone structure matching. The former position of at least one marker could be identified in all patients during histopathologic examination. The use of gold marker enables a more precise definition of the target volume for radiotherapy in patients with rectal cancer. This could eventually allow a better protection of anal structures of patients with a tumor localization = 5 cm cranial of the anal sphincter. The implantation of the gold markers improved communication between the surgeon, the radiooncologist and the pathologist resulting in intensified exchange of relevant informations. (orig.)

  7. Effect of heat treatments on machinability of gold alloy with age-hardenability at intraoral temperature.

    Science.gov (United States)

    Watanabe, I; Baba, N; Watanabe, E; Atsuta, M; Okabe, T

    2004-01-01

    This study investigated the effect of heat treatment on the machinability of heat-treated cast gold alloy with age-hardenability at intraoral temperature using a handpiece engine with SiC wheels and an air-turbine handpiece with carbide burs and diamond points. Cast gold alloy specimens underwent various heat treatments [As-cast (AC); Solution treatment (ST); High-temperature aging (HA), Intraoral aging (IA)] before machinability testing. The machinability test was conducted at a constant machining force of 0.784N. The three circumferential speeds used for the handpiece engine were 500, 1,000 and 1,500 m/min. The machinability index (M-index) was determined as the amount of metal removed by machining (volume loss, mm(3)). The results were analyzed by ANOVA and Scheffé's test. When an air-turbine handpiece was used, there was no difference in the M-index of the gold alloy among the heat treatments. The air-turbine carbide burs showed significantly (pmachinability of the gold alloy using the air-turbine handpiece. The heat treatments had a small effect on the M-index of the gold alloy machined with a SiC wheel for a handpiece engine.

  8. Application of Gold Nanoparticles to Paint Colorants

    Science.gov (United States)

    Ishibashi, Hideo

    Metal nanoparticles possess unique properties that they do not exhibit in their bulk states. One of these properties is the color due to surface plasmon resonance. Gold nanoparticles appear red. This color has been utilized in glass for a long long time. In recent years, highly concentrated pastes of gold and silver nanoparticles have been successfully produced by using a special type of protective polymer and a mild reductant. The paste of gold nanoparticles can be used for paint and other materials as red colorants. In this article,application examples of gold nanoparticles as colorant are introduced. Recently, methods for producing bimetal nanoparticles such as gold/silver and gold/copper have been developed. These nanoparticles allow colors from yellow to green to be created. These methods and colors they produce are also described in this article.

  9. Linear Optical Properties of Gold Colloid

    Directory of Open Access Journals (Sweden)

    Jingmin XIA

    2015-11-01

    Full Text Available Gold colloid was prepared by reducing HAuCl4·4H2O with Na3C6H5O7·2H2O. The morphology, size of gold nanoparticles and the optical property of colloid were characterized by transmission electron microscope and UV-Vis spectrophotometer, respectively. It shows that the gold nanoparticles are in the shape of spheres with diameters less than 8 nm, and the surface plasmon resonance absorption peak is located at about 438 nm. As the volume fraction of gold particles increases, the intensity of absorption peak strengthens. The optical property of gold colloid was analyzed by Maxwell-Garnett (MG effective medium theory in the company of Drude dispersion model. The results show that the matrix dielectric constant is a main factor, which influences the optical property of gold colloid.DOI: http://dx.doi.org/10.5755/j01.ms.21.4.9558

  10. Fabrication of Gold Nanoparticles Doped DVB Foams

    International Nuclear Information System (INIS)

    Fang Yu; Luo Xuan; Fan Yongheng; Zhang Qingjun; Ren Hongbo; Xiao Lei

    2009-01-01

    The fabrication of gold nanoparticles doped low density DVB foams was researched, which can be used as ICF target materials. By high internal phase emulsion (HIPE) method, gold nanoparticles doped low density DVB foams were prepared, with gold nanoparticles dissolved in inner phase. The results show that the content of Au in the gold nanoparticles doped DVB foam is 3. 19%, the axial direction density of the foam is uniform which indicates none evident settlement of gold nanoparticles. SEM tests show that the gold doped DVB polymer foams have open-celled structure and very uniform aperture, and the average pore size is about 1 μm, which is much smaller than that of pure DVB foams. EDX test shows that Au disperses uniformly in the foams. (authors)

  11. Recovery of carrier-free gold-195

    International Nuclear Information System (INIS)

    Iofa, B.Z.; Ivanova, N.A.

    1995-01-01

    It is known that gold(III) is readily extracted from nitric acid solutions with ethers. The authors have studied extraction of trace amounts of gold(III) from nitric acid solutions with diethyl and diisopropyl ethers in the presence of significant excess of Pt(IV). Distribution coefficients of gold(III) were measured radiometrically using carrier-free gold-195 or spectrophotometrically in the presence of platinum(IV). Very high coefficients of gold separation from platinum may be achieved. Preliminary experiments have shown that zinc-65 was not extracted with ethers from nitric acid solutions. As an extraction system, the authors have chosen the system 10 M HNO 3 -diisopropyl ether. After model experiments, the authors have performed recovery of carrier-free gold-195 from a real platinum target irradiated with protons in a cyclotron

  12. Metallic gold beads in hyaluronic acid

    DEFF Research Database (Denmark)

    Pedersen, Dan Sonne; Tran, Thao Phuong; Smidt, Kamille

    2013-01-01

    Multiple sclerosis (MS) is a neurodegenerative disease caused by recurring attacks of neuroinflammation leading to neuronal death. Immune-suppressing gold salts are used for treating connective tissue diseases; however, side effects occur from systemic spread of gold ions. This is limited...... by exploiting macrophage-induced liberation of gold ions (dissolucytosis) from gold surfaces. Injecting gold beads in hyaluronic acid (HA) as a vehicle into the cavities of the brain can delay clinical signs of disease progression in the MS model, experimental autoimmune encephalitis (EAE). This study...... investigates the anti-inflammatory properties of metallic gold/HA on the gene expression of tumor necrosis factor (Tnf-α), Interleukin (Il)-1β, Il-6, Il-10, Colony-stimulating factor (Csf)-v2, Metallothionein (Mt)-1/2, Bcl-2 associated X protein (Bax) and B cell lymphoma (Bcl)-2 in cultured J774 macrophages...

  13. Physiological investigation of gold nanorods toward watermelon.

    Science.gov (United States)

    Wan, Yujie; Li, Junli; Ren, Hongxuan; Huang, Jin; Yuan, Hong

    2014-08-01

    The objective of the present study was to evaluate the phytotoxicity and oxidant stress of the gold nanorods toward watermelon, and hence give a quantitative risk assessment of both seeds and plants phase. The seed germination, the activity of antioxidant enzymes, and the contents of soluble protein and malondialdehyde (MDA) have been measured while the plant roots were observed by transmission electron microscopy (TEM). It was found that the gold nanorods significantly promoted the root elongation. Furthermore, the results on the enzymes activities of plant indicated that oxidative stress happened in the plant treated with gold nanorods. However, the gold nanorods resulted in the phytotoxicity toward plant especially at high concentration. The TEM images of the plant roots with and without the treatment of gold nanorods showed the significant different size of starch granules. In conclusion, significant physiological changes of plant occurred after treatment with the gold nanorods.

  14. Overweight, Obesity, and Weight Loss

    Science.gov (United States)

    ... Back to section menu Healthy Weight Weight and obesity Underweight Weight, fertility, and pregnancy Weight loss and ... section Home Healthy Weight Healthy Weight Weight and obesity Underweight Weight, fertility, and pregnancy Weight loss and ...

  15. Impact of GOLD groups of chronic pulmonary obstructive disease on surgical complications

    Directory of Open Access Journals (Sweden)

    Kim HJ

    2016-02-01

    Full Text Available Hyung-Jun Kim,1,2 Jinwoo Lee,1,2 Young Sik Park,1,2 Chang-Hoon Lee,1,2 Sang-Min Lee,1,2 Jae-Joon Yim,1,2 Chul-Gyu Yoo,1,2 Young Whan Kim,1,2 Sung Koo Han,1,2 Sun Mi Choi1,2 1Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Seoul National University Hospital, Seoul, Republic of Korea; 2Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea Purpose: Chronic obstructive pulmonary disease (COPD is associated with increased postoperative complications. Recently, the Global Initiative for Chronic Obstructive Lung Disease (GOLD classified COPD patients into four groups based on spirometry results and the severity of symptoms. The objective of this study was to evaluate the impact of GOLD groups on postoperative complications. Patients and methods: We reviewed the medical records of COPD patients who underwent preoperative spirometry between April and August 2013 at a tertiary hospital in Korea. We divided the patients into GOLD groups according to the results of spirometry and self-administered questionnaires that assessed the symptom severity and exacerbation history. GOLD groups, demographic characteristics, and operative conditions were analyzed. Results: Among a total of 405 COPD patients, 70 (17.3% patients experienced various postoperative complications, including infection, wound, or pulmonary complications. Thoracic surgery, upper abdominal surgery, general anesthesia, large estimated blood loss during surgery, and longer anesthesia time were significant risk factors for postoperative complications. Patients in high-risk group (GOLD groups C or D had an increased risk of postoperative complications compared to those in low-risk group (GOLD groups A or B. Conclusion: COPD patients in GOLD groups representing a high exacerbation risk have an increased risk of postoperative complications compared to those with low risk. Keywords: chronic obstructive pulmonary

  16. Estimation of absorbed dose of radiosensitive organs and effective sose in patients underwent abdominopelvic spiral CT scan using impact CT patient dosimetry

    Directory of Open Access Journals (Sweden)

    Ayoub Amirnia

    2017-05-01

    Full Text Available Background: Due to the presence of radiosensitive organs in the abdominopelvic region and increasing the number of requests for CT scan examinations, concerns about increasing radiation doses in patients has been greatly elevated. Therefore, the goal of this study was to determine the absorbed dose of radiosensitive organs and the effective dose in patients underwent abdominopelvic CT scan using ImPACT CT patient dosimetry Calculator (version 1.0.4, Imaging Performance Assessment on Computed Tomography, www.impactscan.org. Methods: This prospective cross-sectional study was conducted in Imam Reza Hospital from November to February 2015 February 2015 in the Imam Reza Hospital, in Urmia, Iran. The demographic and dosimetric information of 100 patients who underwent abdominopelvic CT scan in a 6-slice CT scanner were obtained through the data collection forms. The demographic data of the patients included age, weight, gender, and BMI. The dosimetric parameters included pitch value, CT dose volume index (CTDIvol, dose-length product (DLP, tube voltage, tube current, exposure time, collimation size, scan length, and scan time. To determine the absorbed dose of radiosensitive organs and also the effective dose in patients, ImPACT CT patient dosimetry calculator was used. Results: The results of this study demonstrated that the mean and standard deviation (SD of patients' effective dose in abdominopelvic CT scan was 4.927±0.164 mSv. The bladder in both genders had the greatest mean organ dose, which was 64.71±17.15 mGy for men and 77.56±18.48 mGy for women (P<0.001. Conclusion: The effective dose values of this examination are in the same range as previous studies, as well as International Commission on Radiological Protection (ICRP recommendations. However, the radiation dose from CT scan has the largest contribution to the medical imaging. According to the ALARA principle, it is recommended that the scan parameters, especially mAs, should be

  17. [Analysis of prevalence and risk factors of pelvic organ prolapse of women underwent gynecologic health care in Peking Union Medical College Hospital].

    Science.gov (United States)

    Zhu, Lan; Wang, Jing-yi; Lang, Jing-he; Xu, Tao; Li, Lin

    2010-07-01

    To investigate prevalence and risk factors of pelvic organ prolapse in women underwent routine gynecologic health care in Peking Union Medical College Hospital (PUMCH). From Jan. 2008 to Aug. 2009, 972 women underwent gynecological health care in PUMCH were enrolled in this study. Questionnaires and pelvic examinations were given. The pelvic organ prolapse quantitive examination (POP-Q) system was used as the assessment tool. (1) Among all participants, the mean ages were (42 ± 10) years (range 22 to 78 years), the mean height were (162 ± 5) cm (range 142 to 180 cm), and the mean weight were (59 ± 8) kg (range 42 to 91 kg). 83.8% (815/972) of women were multipara. The mean total vaginal length (TVL) of 972 women was 8.20 cm. No women met the standard of pelvic organ prolapse, while 35.5% (345/972) of women presented mild posterior vaginal descent and 96.7% (940/972) presented mild anterior vaginal descent, all of them were asymptomatic. (2) The length of genital hiatus (gh), TVL and C, D proximal to the hymen in nullipara were (2.26 ± 0.32), (8.08 ± 0.30), (-7.08 ± 0.24) and (-8.08 ± 0.30) cm, which were significantly less than (2.33 ± 0.39), (8.22 ± 0.35), (-7.14 ± 0.28) and (-8.22 ± 0.35) cm in multipara (P 0.05). However, those in women at group of 22 - 34 years and 35 - 49 years showed statistical difference when compared with women at group of more than 50 years (P < 0.05). When compared with women at group of 22 - 34 years, the incidence of posterior and anterior vaginal wall protrusion were increased (OR = 1.713, 3.765). (4) Menopause status was associated with severities of all kinds of descent (P < 0.05) and presence of posterior vaginal protrusion (OR = 3.354). Mild anterior and posterior vaginal descent by POP-Q were common among women in China. The risk of anterior vaginal descent is relatively higher than posterior vaginal descent. However, most of the women with descent are asymptomatic and need no treatment. The most important factors

  18. 65. Impact of focused echocardiography in clinical decision of patients presented with STMI, underwent primary percutenouse angioplasty

    Directory of Open Access Journals (Sweden)

    M. Qasem

    2016-07-01

    Full Text Available Echocardiography in coronary artery diseases is an essential, routine echocardiography prior to primary percutaneous angioplasty is not clear. In our clinical practice in primary angioplasty we faced lots of complications either before or during or after the procedure. Moreover, lots of incidental findings that discovered after the procedure which if known will affect the plan of management. One-hundred-nineteen consecutive underwent primary angioplasty. All patients underwent FE prior to the procedure in catheterization lab while the patient was preparing for the procedure. FE with 2DE of LV at base, mid and apex, and apical stander views. Diastology grading, E/E′ and color doppler of mitral and aortic valve were performed. (N = 119 case of STMI were enrolled, mean age 51 ± 12 year. Eleven cases (9.2% had normal coronary and normal LV function. Twenty cases (17% of MI complication detected before the procedures: RV infarction 8.4% (5.1% asymptomatic and 3.3% symptomatic, ischemic MR (8.4%, LV apical aneurysm (0.8%, significant pericardial effusion (0.80%. Acute pulmonary edema in 17 cases (14.3%: six cases (5.1% developed acute pulmonary edema on the cath lab with grade 3 diastolic dysfunction and E/E ′  >20, 9 cases (7.6% develop acute pulmonary edema in CCU with grade 2–3 diastolic dysfunction and E/E′ 15–20. 2 cases (2.7% develop acute pulmonary in CCU with grade 1–2 diastolic dysfunction and E/E′ 9–14. One case (0.8% presented cardiac tamponade 2 h post PCI. Incidental finding not related to STMI were as follow: 2 cases (1.7% with severe fibro degenerative MR, 2 cases (1.7% with mild to moderate AR and 2 cases (1.7% with mild to moderate AS. Isoled CABG 5/4.2% and CABG and MVR 2/1.7%. FE play an important role in guiding the management, early detection the incidental findings and complication post PCI.

  19. Geological characteristics and ore-forming process of the gold deposits in the western Qinling region, China

    Science.gov (United States)

    Liu, Jiajun; Liu, Chonghao; Carranza, Emmanuel John M.; Li, Yujie; Mao, Zhihao; Wang, Jianping; Wang, Yinhong; Zhang, Jing; Zhai, Degao; Zhang, Huafeng; Shan, Liang; Zhu, Laimin; Lu, Rukui

    2015-05-01

    , changes of physico-chemical conditions resulted in fluid immiscibility that played a key role in gold and sulfide deposition. The geochemical and mineralogical characteristics of the Carlin-type deposits in the western Qinling region are similar to those in the Carlin trend, Nevada, USA. Gold deposits such as La'erma and Jinlongshan occur mostly in the southeastern margin of the western Qinling regionic region whereas some deposits occur in its eastern part. These deposits are hosted in slightly metamorphosed Cambrian to Triassic sedimentary rocks, showing structurally- and stratigraphically-controlled features. The deposits mainly contain submicroscopic and microscopic gold in arsenian pyrite and arsenopyrite, with characteristic ore-forming elements of Au-As-Sb-Ba. The ore-forming fluids are early-stocked formation water and later-recharged meteoric water. Meteoric water apparently evolved in ore-forming fluids by circulation, indicating the extensional setting, and led to the deposition of Au and other elements in cool reactive permeable rocks at shallow levels, forming the disseminated ores. Carlin-like gold deposits occur between the Shang-Dan suture and the Fengxian-Zhen'an fault. The host rocks are mainly sedimentary rocks that underwent reconstruction through reworking by structural metamorphism. These deposits are structurally controlled by brittle-ductile shear zone and occur adjacent to granitoid plutons. The most important characteristic that differ to the orogenic and Carlin-type gold deposits is the genetic relationship with the synchronous magmatism. Gold occurs mainly as microscopic gold. Pyrite and arsenian pyrite can be recognized as gold-bearing minerals. The ore-forming fluids are main magmatic water mixed with metamorphic and/or formation water. Similar to orogenic gold deposits, fluid immiscibility caused the deposition of gold Carlin-like gold deposits.

  20. Glyco-gold nanoparticles: synthesis and applications

    OpenAIRE

    Compostella, Federica; Pitirollo, Olimpia; Silvestri, Alessandro; Polito, Laura

    2017-01-01

    Glyco-gold nanoparticles combine in a single entity the peculiar properties of gold nanoparticles with the biological activity of carbohydrates. The result is an exciting nanosystem, able to mimic the natural multivalent presentation of saccharide moieties and to exploit the peculiar optical properties of the metallic core. In this review, we present recent advances on glyco-gold nanoparticle applications in different biological fields, highlighting the key parameters which inspire the glyco ...

  1. Glyco-gold nanoparticles: synthesis and applications

    Directory of Open Access Journals (Sweden)

    Federica Compostella

    2017-05-01

    Full Text Available Glyco-gold nanoparticles combine in a single entity the peculiar properties of gold nanoparticles with the biological activity of carbohydrates. The result is an exciting nanosystem, able to mimic the natural multivalent presentation of saccharide moieties and to exploit the peculiar optical properties of the metallic core. In this review, we present recent advances on glyco-gold nanoparticle applications in different biological fields, highlighting the key parameters which inspire the glyco nanoparticle design.

  2. Gold, fiat money and price stability

    OpenAIRE

    Michael D. Bordo; Robert Dittmar; William T. Gavin

    2006-01-01

    The classical gold standard has long been associated with long-run price stability. But short-run price variability led critics of the gold standard to propose reforms that look much like modern versions of price-path targeting. This paper uses a dynamic stochastic general equilibrium model to examine price dynamics under alternative policy regimes. In the model, an inflation target provides more short-run price stability than does the gold standard and, although it introduces a unit root int...

  3. Gold and Silver Extraction from Leach Solutions

    Directory of Open Access Journals (Sweden)

    Bagdaulet K. Kenzhaliyev

    2014-03-01

    Full Text Available There has been carried out an investigation on the extraction of gold and silver from thiosulfate solutions: standard test and technological solutions of chemical and electrochemical leaching. The influence of related metals on the process of extracting gold from solution was studied. There has been conducted a comparative study of the IR spectra of solutions after the sorption of gold, silver and related metals.

  4. Shape-Controlled Gold Nanoparticle Synthesis

    Science.gov (United States)

    2013-09-01

    Shankar, S. S.; Bhargava, S.; Sastry, M. Synthesis of Gold Nanospheres and Nanotriangles by the Turkevich Approach. Journal of Nanoscience and...Accounts of Chemical Research 2008, 41, 1587–1595. 22. Sun, Y.; Xia, Y. Shape-Controlled Synthesis of Gold And Silver Nanoparticles. Science...N.; Griep, M. H.; and Karna, S. P. Chemical vs. Sonochemical Synthesis and Characterization of Silver , Gold, and Hybrid Nanoparticles; ARL-TR-5764

  5. Russian and Belorussian firms receive CMS Gold Awards

    CERN Multimedia

    Maximilien Brice

    2003-01-01

    On 7 March, CMS handed out its three latest Gold Awards in recognition of outstanding supplier performance. Photos 01,02: Prof. Felicitas Pauss, Deputy Chair of the CMS Collaboration Board, presents a CMS Gold Award to Professor Valery Novikov, Director-General of Myasishchev Design Bureau, Zhukovsky, Moscow Region, Russia. The Myasishchev company was responsible for the carbon fibre structures in which the fragile lead tungstate crystals of the electromagnetic calorimeter end-caps are to be embedded. These lightweight structures must support a weight of 22.9 tonnes in each end-cap! The company produced a very thin-walled modular structure that ensured the calorimeter performance would not be harmed, while remaining stable and strong. Photos 03,04: Prof. Felicitas Pauss, Deputy Chair of the CMS Collaboration Board, presents a CMS Gold Award to Professor Boris Gabaraev, General director of N.A. Dollezhal Research and Development Institute of Power Engineering (NIKIET), Moscow, Russia (a.k.a. ENTEK) for the de...

  6. Spectroscopic ellipsometry study of gold nanostructures for LSPR bio-sensing applications

    Directory of Open Access Journals (Sweden)

    Ali Ghamin Al-Rubaye

    2017-02-01

    Full Text Available This main aim of this work is the development of optical biosensors based on the LSPR phenomenon in nano-structured gold films suitable for detection of low molecular weight analytes such as mycotoxins. A simple technology of annealing thin gold films was utilized for the formation of gold nano-islands exhibiting the LSPR effect. The morphology of gold nano-structures produced was studied with SEM and AFM, and their optical properties were analysed with UV-visible absorption spectroscopy and spectroscopic ellipsometry (SE. The position of LSPR band appeared to depend on the dimensions of gold nano-islands. The dependence of the LSPR band spectral shift on the refractive index of a medium was studied with both UV-vis absorption and SE, and the refractive index sensitivity (RIS was evaluated. The method of SE gave from two to three times higher values of RIS as compared to those obtained by absorption spectroscopy. LSPR bio-sensing tests were attempted using total internal reflection ellipsometry (TIRE; a noticeable spectral shift was recorded on course of immune binding of Aflatoxin B1 to specific antibodies immobilized on the surface of gold.

  7. Coal gold agglomeration: an innovative approach to the recovery of gold in environmentally sensitive areas

    Energy Technology Data Exchange (ETDEWEB)

    Wall, N.C.; Hughes-Narborough, C.; Willey, G. [Davy (Stockton) Ltd., Stockton-on-Tees (United Kingdom)

    1994-11-01

    Coal Gold Agglomeration (CGA) was developed by BP Minerals and involves the selective recovery of oleophilic gold particles from an aqueous slurry into coal-oil agglomerates. These agglomerates are allowed to build up to a high gold loading and are then separated from the slurry. The loaded agglomerates are burned and the gold is finally recovered from the ash residue by dissolution and precipitation or by direct smelting. 6 figs.

  8. Assessment of quality of life of patients who underwent anterior cruciate ligament reconstruction and a rehabilitation program

    Directory of Open Access Journals (Sweden)

    Moises Cohen

    2004-12-01

    Full Text Available Introduction: Quality of life can be defined as the expression of aconceptual model that tries to represent patient’s perspectivesand his/her level of satisfaction expressed by numbers. Theobjective of this study is to evaluate the parameters of quality oflife of 23 patients who underwent surgery for anterior cruciateligament reconstruction. Methods: We adopted SF-36, a generichealth-related evaluation questionnaire, to obtain informationregarding several aspects of patients’ health conditions, and theLysholm questionnaire, specific to evaluate the symptoms andfunction of the knee. The questionnaires were applied at two stagesof the treatment: pre- and postoperatively (after the rehabilitationprogram. Results: Before surgery, the Lysholm questionnairepresented the following results: excellent in 4% of the cases, goodin 22%, fair in 22%, and poor in 52%. After surgery (Lysholm e SF-36 the correlation level was approximately 44% (p = 0.041.Discussion: The correlation between the Lysholm and the SF-36questionnaires showed the following: the lower the level of pain,the higher the Lysholm score. The high scores presented by theLysholm questionnaire are directly proportional to physical andemotional aspects, and to functional capacity. Conclusion:Analysis of both questionnaires, as well as of their correlation,showed some improvement in patients´ quality of life. We werealso able to demonstrate the importance and usefulness of applyingthe two questionnaires at three different moments: before, duringand after physiotherapeutic intervention.

  9. The effect of anxiety and depression scores of couples who underwent assisted reproductive techniques on the pregnancy outcomes.

    Science.gov (United States)

    Terzioglu, Fusun; Turk, Rukiye; Yucel, Cigdem; Dilbaz, Serdar; Cinar, Ozgur; Karahalil, Bensu

    2016-06-01

    The aim of this study was to determine the effect of anxiety and depression scores of couples who underwent Assisted Reproductive Techniques (ART) on pregnancy outcomes. This study was conducted as a prospective and comparative study with 217 couples. The study data was collected by using a semi-structured questionnaire and the Turkish version of the State-Trait Anxiety Inventory (STAI), and Beck Depression Inventory (BDI). The questionnaire, STAI and BDI were applied to couples who initiated ART treatment. Couples' state anxiety scores were re-evaluated after embryo transfer (ET). A significant relationship was found between the depression score of women and pregnancy outcome (p 0.05) and lower depression scores (p positive pregnancy outcome. Study results indicated that the anxiety and depression scores of couples who had achieved a positive pregnancy result were lower than for couples with a negative result. The results of this study will contribute to the health professionals especially to the nurses who spend the most time with couples in providing consulting services and supporting psychological status of couples during ART process in Turkey.

  10. The Effects of Functional Knee Brace on Postural Control in Patients Who Underwent Anterior Cruciate Ligament Reconstruction

    Directory of Open Access Journals (Sweden)

    Salehi

    2016-09-01

    Full Text Available Background The current study aimed to evaluate the postural control in patients underwent anterior cruciate ligament reconstruction pre and post wearing functional knee brace. Methods Eighteen athletes undergone unilateral anterior cruciate ligament reconstruction included in the study. They had unilateral anterior cruciate ligament reconstruction at least six months before session test. Postural control was assessed pre and post wearing custom-fit functional knee brace using a posturographic platform prokin 254. The balance tests included: 1 standing on prokin platform with eyes open/closed on anterior cruciate ligament reconstruction limb, 2 standing on prokin platform with eyes open/closed on both limbs. The standard deviation (SD of body sway along the anteroposterior (AP and mediolateral (ML axis, mean velocity of center of pressure (COP along AP/ ML axis and the area ellipse (measured in 2 mm were calculated. Results Results of the paired T-test revealed a significant effect on selected postural control variables for the brace conditions especially in low challengeable conditions (double leg, eyes open test situations (P < 0.05. But in high challengeable conditions this effect was not significant. Conclusions Functional knee brace improved postural control in the simple balancing task in the subjects with anterior cruciate ligament reconstruction. But this improvement in more difficult balancing task was limited.

  11. The Effect of Prazosin and Oxybutynin on the Symptoms Due to Using Double J Catheter in Patients Underwent TUL

    Directory of Open Access Journals (Sweden)

    K. Tavakkoli Tabassi

    2014-01-01

    Full Text Available Background & Aims: Double J catheter has been used for years as an independent practice or a part of other urological practices. Although these catheters have solved many patients’ problems but those can cause symptoms and problems for patients. The aim of this study was the investigation the effect of prazosin and oxybutynin on the degree of symptoms due to using Double J catheter. Methods: In this interventional study, patients who underwent TUL from July 2008 to march 2008 in the lithotripsy ward of Imam Reza hospital were entered to the study and randomly divided in 3 groups randomly. In the first group, placebo, in the second group, oxybutynin, in the third group prazosin were prescribed. Three weeks later standard questionnaire Ureteric Stent Symptom Questionnaire (USSQ was completed. After collecting data, was analyzed using SPSS software. Results: A total of 113 patients (70 men 43 women were included to the study. The mean age was 39 years. There were no significance difference among urinary symptoms score pain of body and physical activity problems in three groups (P>0.05, but there was a significant difference in general health and work problems among them (P<0.05. Conclusion: Oxybutynin caused a low effect on improvement of general health and work problems in patients who were studied. It might Prazosin does not has a sufficient time to affect on urinary symptoms, because of shortness of usage.

  12. Factors associated with late specialized rehabilitation among veterans with lower extremity amputation who underwent immediate postoperative rehabilitation.

    Science.gov (United States)

    Kurichi, Jibby E; Xie, Dawei; Kwong, Pui L; Bates, Barbara E; Vogel, W Bruce; Stineman, Margaret G

    2011-05-01

    The aim of this study was to determine what patient- and facility-level characteristics drive late specialized rehabilitation among veterans who already received immediate postoperative services. Data were obtained from eight administrative databases for 2,453 patients who underwent lower limb amputation in Veterans Affairs Medical Centers in 2002-2004. A Cox proportional hazards model was used to determine the hazard ratios and 95% confidence intervals of the factors associated with days to readmission for late services after discharge from surgical hospitalization. There were 2304 patients who received only immediate postoperative services, whereas 152 also received late specialized rehabilitation. After adjustment, veterans who were less disabled physically, residing in the South Central compared with the Southeast region, and had their surgeries in facilities accredited by the Commission on Accreditation of Rehabilitation Facilities were all more likely to receive late services. The hazard ratios for type of immediate postoperative rehabilitation were not constant over time. At hospital discharge, there was no difference in receipt; however, after 3 mos, those who received early specialized rehabilitation were significantly less likely to receive late services. The factors associated with late specialized rehabilitation were due mainly to facility-level characteristics and care process variables. Knowledge of these factors may help with decision-making policies regarding units accredited by the Commission on Accreditation of Rehabilitation Facilities.

  13. Anatomical location of metastatic lymph nodes: an indispensable prognostic factor for gastric cancer patients who underwent curative resection.

    Science.gov (United States)

    Zhao, Bochao; Zhang, Jingting; Zhang, Jiale; Chen, Xiuxiu; Chen, Junqing; Wang, Zhenning; Xu, Huimian; Huang, Baojun

    2018-02-01

    Although the numeric-based lymph node (LN) staging was widely used in the worldwide, it did not represent the anatomical location of metastatic lymph nodes (MLNs) and not reflect extent of LN dissection. Therefore, in the present study, we investigated whether the anatomical location of MLNs was still necessary to evaluate the prognosis of node-positive gastric cancer (GC) patients. We reviewed 1451 GC patients who underwent radical gastrectomy in our institution between January 1986 and January 2008. All patients were reclassified into several groups according to the anatomical location of MLNs and the number of MLNs. The prognostic differences between different patient groups were compared and clinicopathologic features were analyzed. In the present study, both anatomical location of MLNs and the number of MLNs were identified as the independent prognostic factors (p location of MLNs was considered (p location of MLNs had no significant effect on the prognosis of these patients, the higher number of MLNs in the extraperigastric area was correlated with the unfavorable prognosis (p location of MLNs was an important factor influencing the prognostic outcome of GC patients. To provide more accurate prognostic information for GC patients, the anatomical location of MLNs should not be ignored.

  14. Chemistry of Oligonucleotibe-Gold Nanoparticle Conjugates

    National Research Council Canada - National Science Library

    Letsinger, Robert

    2003-01-01

    Conjugates prepared by immobilizing thiol-terminated oligonucleotides onto gold nanoparticles from stable colloidal solutions in aqueous media The oligo nucleotides can serve as linkers to organize...

  15. Gold nano-particles fixed on glass

    International Nuclear Information System (INIS)

    Worsch, Christian; Wisniewski, Wolfgang; Kracker, Michael; Rüssel, Christian

    2012-01-01

    Highlights: ► We produced wear resistant gold–ruby coatings on amorphous substrates. ► Thin sputtered gold layers were covered by or embedded in silica coatings. ► Annealing above T g of the substrate glass led to the formation of gold nano particles. ► A 1 1 1-texture of the gold particles is observed via XRD and EBSD. ► EBSD-patterns can be acquired from crystals covered by a thin layer of glass. - Abstract: A simple process for producing wear resistant gold nano-particle coatings on transparent substrates is proposed. Soda-lime-silica glasses were sputtered with gold and subsequently coated with SiO 2 using a combustion chemical vapor deposition technique. Some samples were first coated with silica, sputtered with gold and then coated with a second layer of silica. The samples were annealed for 20 min at either 550 or 600 °C. This resulted in the formation of round, well separated gold nano-particles with sizes from 15 to 200 nm. The color of the coated glass was equivalent to that of gold–ruby glasses. Silica/gold/silica coatings annealed at 600 °C for 20 min were strongly adherent and scratch resistant. X-ray diffraction and electron backscatter diffraction (EBSD) were used to describe the crystal orientations of the embedded particles. The gold particles are preferably oriented with their (1 1 1) planes perpendicular to the surface.

  16. CO oxidation on gold nanoparticles: Theoretical studies

    DEFF Research Database (Denmark)

    Remediakis, Ioannis; Lopez, Nuria; Nørskov, Jens Kehlet

    2005-01-01

    We present a summary of our theoretical results regarding CO oxidation on both oxide-supported and isolated gold nanoparticles. Using Density Functional Theory we have studied the adsorption of molecules and the oxidation reaction of CO on gold clusters. Low-coordinated sites on the gold...... nanoparticles can adsorb small inorganic molecules such as O2 and CO, and the presence of these sites is the key factor for the catalytic properties of supported gold nanoclusters. Other contributions, induced by the presence of the support, can provide parallel channels for the reaction and modulate the final...

  17. Gold Rushes and mineral property rights allocation

    DEFF Research Database (Denmark)

    Sinding, Knud

    , is to handle the other projects that are generated by the "gold rush" informational externalities created by the initial discovery. At the core of the problems of dealing with a gold rush situation is both the informational externality and an institutional framework which is not designed to deal with large...... influxes of prospectors competing for a very limited area. This paper charts significant gold rush events in the mineral industry in recent decades and uses preliminary data on the areas impacted by these gold rushes to argue that many mineral tenure systems should be modified in order to be better able...

  18. Gold Cleaning Methods for Electrochemical Detection Applications

    DEFF Research Database (Denmark)

    Fischer, Lee MacKenzie; Tenje, Maria; Heiskanen, Arto

    2009-01-01

    This work investigates methods for obtaining reliably clean gold film surfaces. Nine gold cleaning methods are investigated here: UV ozone photoreactor; potassium hydroxide-hydrogen peroxide; potassium hydroxide potential sweep; sulfuric acid hydrogen peroxide; sulfuric acid potential cycling......-ray photo-electron spectroscopy are used to characterize surface cleanliness. A low peak-current potential-difference and charge transfer resistance indicates a cleaner surface, as does a higher percentage of elemental gold on the electrode surface. The potassium hydroxide potential sweep method is found...... to leave the gold surface the cleanest overall....

  19. Nuclear excitation in muonic gold

    CERN Document Server

    Robert Tissot, B; Debrunner, P; Engfer, R; Link, R; Schellenberg, L; Schneuwly, H; Walter, H K

    1973-01-01

    Energies and intensities of muonic X-rays in gold were measured at the CERN muon channel with an experimental set-up as described by Backe et al. (1972). The 2p-1s and 3d-2p transitions could only be analysed taking into account beside the static quadrupole interaction a dynamical hyperfine interaction of the 2p states, which leads to an excitation of the first four nuclear levels. The dynamical hyperfine interaction was calculated using the core excitation model (de Shalit, (1961)). (0 refs).

  20. Clinical and echocardiographic findings of patients with suspected acute pulmonary thromboembolism who underwent computed tomography pulmonary angiography

    Science.gov (United States)

    Adibi, Atoosa; Nouri, Shadi; Moradi, Maryam; Shahabi, Javad

    2016-01-01

    Background: The aim of the study was to determine the correlation between clinical and echocardiographic findings and risk factors of patients with suspected acute pulmonary thromboembolism (PTE) who underwent computed tomography pulmonary angiography (CTPA). Materials and Methods: In this cross-sectional study, 310 hospitalized patients aged >18 years with high clinical suspicion of PTE referred to imaging center of our hospital from different wards for CTPA were enrolled. The frequency of different clinical presentations, risk factors, items of Wells’ criteria, and echocardiographic findings was compared in patients with and without PTE, which have been diagnosed according to the CTPA results. Results: PTE was diagnosed in 53 (17.1%) of patients with suspected PTE. From clinical manifestations, tachypnea, pleuritic chest pain, and edema of lower extremities were significantly more frequent among patients with PTE (P < 0.05). Major surgery was the risk factor which was significantly more prevalent among patients with PTE (P < 0.05). Frequency of all criteria of Wells’ criteria, except hemoptysis, was significantly higher in patients with PTE (P < 0.05). The frequency of all studied echocardiographic variables was significantly higher in patients with PTE (P < 0.05). Conclusion: It is suggested that we could use the results of this study for utilizing the diagnostic process of PTE in patients with highly clinical suspicion of PTE and providing more validated decision. Using the results of this study, we could identify high-risk patients and made appropriate risk assessment for better management of patients with suspected PTE as well as reduce the rate of unnecessary CTPA and its related adverse consequences. PMID:28255326

  1. The effects of transfusion of irradiated blood upon cellular immune response in patients underwent open heart surgery

    International Nuclear Information System (INIS)

    Togashi, Ken-ichi; Nakazawa, Satoshi; Moro, Hisanaga; Yazawa, Masatomo; Kanazawa, Hiroshi; Hayashi, Jun-ichi; Yamazaki, Yoshihiko; Eguchi, Shoji

    1989-01-01

    The purpose of this paper is to demonstrate the effect of the transfusion of blood received 1500 rad exposure upon the immune response in 14 patients underwent various type of cardiac surgery. 13 patients received known amounts banked blood and irradiated fresh blood, while one patient received a lot of amounts of banked and irradiated and non-irradiated fresh blood. The authors studied the numbers of lymphocytes as well as lymphocyte subsets such as pan-T cells, B cells, helper/inducer T cells (T H/I ), cytotoxic/supressor T cells (T C/S ), active T cells, natural killer (NK) cells and NK cell activity during two weeks after surgeries. In all 14 patients, pan-T lymphocytes decreased markedly in a few days after surgeries, but increased to higher levels on the eight postoperative day than the levels preoperatively. T H/I and T C/S lymphocytes changed on the similar pattern as pan-T lymphocytes. Active T and B cells did not change significantly in two weeks. The number and activity of NK cells gave the lowest levels on the second postoperative day and did not recovery to the preoperative levels in two weeks. One patient received non-irradiated fresh blood showed the similar immune response as other 13 patients, while he gave the lower levels than others did. This patient died of graft-versus-host disease (GVHD)-like syndrome on the 36th postoperative day. It may be thought that the transfusion of irradiated blood would prevent the host from GVHD and gave the better effects on the immune response than that of non-irradiated blood following open-heart surgeries. (author)

  2. Clinical and echocardiographic findings of patients with suspected acute pulmonary thromboembolism who underwent computed tomography pulmonary angiography

    Directory of Open Access Journals (Sweden)

    Atoosa Adibi

    2016-01-01

    Full Text Available Background: The aim of the study was to determine the correlation between clinical and echocardiographic findings and risk factors of patients with suspected acute pulmonary thromboembolism (PTE who underwent computed tomography pulmonary angiography (CTPA. Materials and Methods: In this cross-sectional study, 310 hospitalized patients aged >18 years with high clinical suspicion of PTE referred to imaging center of our hospital from different wards for CTPA were enrolled. The frequency of different clinical presentations, risk factors, items of Wells' criteria, and echocardiographic findings was compared in patients with and without PTE, which have been diagnosed according to the CTPA results. Results: PTE was diagnosed in 53 (17.1% of patients with suspected PTE. From clinical manifestations, tachypnea, pleuritic chest pain, and edema of lower extremities were significantly more frequent among patients with PTE (P < 0.05. Major surgery was the risk factor which was significantly more prevalent among patients with PTE (P < 0.05. Frequency of all criteria of Wells' criteria, except hemoptysis, was significantly higher in patients with PTE (P < 0.05. The frequency of all studied echocardiographic variables was significantly higher in patients with PTE (P < 0.05. Conclusion: It is suggested that we could use the results of this study for utilizing the diagnostic process of PTE in patients with highly clinical suspicion of PTE and providing more validated decision. Using the results of this study, we could identify high-risk patients and made appropriate risk assessment for better management of patients with suspected PTE as well as reduce the rate of unnecessary CTPA and its related adverse consequences.

  3. Early prediction of treatment response by serum CRP levels in patients with advanced esophageal cancer who underwent definitive chemoradiotherapy

    International Nuclear Information System (INIS)

    Yoneda, Masayuki; Fujiwara, Hitoshi; Okamura, Shinichi

    2010-01-01

    Serum C reactive protein (CRP) has been shown to be associated with the progression of esophageal cancer. The purpose of this study was to examine the relationship between treatment response and serum CRP levels in time course during definitive chemoradiotherapy (CRT) in terms of early prediction of CRT response by serum CRP. The subjects of this study were 36 patients with cT3/cT4 esophageal squamous cell carcinoma who underwent definitive CRT in our hospital. Serum CRP levels during definitive CRT (pretreatment, 1W, 2W and 3W after CRT initiation) were compared between CR and non-CR group. In addition, partition model was constructed to discriminate CR with non-CR and the prediction accuracy was evaluated. The patients were consisted of 28 males and 8 females. At pretreatment diagnosis, tumors were categorized as T3 (n=21) and T4 (n=15). Thirty four patients received FP-based chemotherapy and 2 patients received docetaxel-based chemotherapy. Treatment responses were categorized as CR (n=8), partial response (PR) (n=14), no change (NC) (n=2) and progressive disease (PD) (n=12). Serum CRP levels at the time of 2W after CRT initiation (CRT2W) in CR group were low compared to those in non-CR group (p=0.071). The partition model was constructed based on CRP levels at CRT2W. The prediction accuracies to discriminate CR from non-CR by CRP ≤0.1 were 50%, 82%, and 75% in sensitivity, specificity and accuracy, respectively. Serum CRP is a useful biomarker for an early prediction of CRT response. (author)

  4. Preoperative evaluation of myocardial viability by thallium-201 imaging in patients with old myocardial infarction who underwent coronary revascularization

    International Nuclear Information System (INIS)

    Naruse, Hitoshi; Ohyanagi, Mitsumasa; Iwasaki, Tadaaki; Miyamoto, Takashi; Fukuchi, Minoru

    1992-01-01

    The myocardial uptake and redistribution in thallium scintigraphy and the regional wall motion by echocardiography were evaluated by a semi-quantitative method in 42 patients who previously had myocardial infarction (50 target vessels) and underwent coronary revascularization. The aim of this study was to elucidate the significance of the initial image, delayed image and redistribution on thallium-201 scintigraphy for clinical diagnosis of the myocardial viability. As a semi-quantitative analysis, we used a bull's-eye display for thallium image and centerline method for echocardiographic wall motion, and compared the results before and after revascularization. As a result, the thallium grade improved postoperatively in all 17 areas which preoperatively had showed redistribution, and also in 11 of the 32 areas without preoperative redistribution. The sensitivity, specificity and accuracy of preoperative thallium redistribution for predicting myocardial viability were 61%, 100% and 78%, respectively, when the postoperative improvement in the thallium grade was used as the standard. The postoperative probability of improvement in the thallium grade increased in proportion to the preoperative grade (delayed image)(p<0.01). There was no correlation between the preoperative thallium delayed image and postoperative improvement in wall motion. Postoperative improvement in thallium image and wall motion could not be predicted from the preoperative wall motion. Thus, postoperative improvement in thallium images can be anticipated if redistribution is present on the preoperative thallium image, and the preoperative thallium delayed image is useful for predicting myocardial viability. Improvement in wall motion could not be predicted preoperatively by these methods. (author)

  5. Posttraumatic Stress Disorder, Orientation to Pain, and Pain Perception in Ex-Prisoners of War Who Underwent Torture.

    Science.gov (United States)

    Tsur, Noga; Defrin, Ruth; Ginzburg, Karni

    Studies suggest that torture survivors often experience long-term chronic pain and increased pain perception. However, it is unclear whether the actual experience of torture or rather the subsequent posttraumatic stress disorder (PTSD) explains these pain problems. Furthermore, although catastrophic and fearful orientations to pain have been suggested to play a significant role in the association between trauma and pain, the underlying mechanisms remain unclear. This study examined whether chronic pain and pain perception among torture survivors are associated with torture experience or PTSD and whether catastrophic and fearful orientations mediate or moderate these associations. Fifty-nine ex-prisoners of war who underwent torture and 44 matched veterans participated in this study. Pain perception was evaluated by assessing pain threshold and reactivity to experimental suprathreshold noxious stimuli. Participants completed self-administered questionnaires assessing PTSD, chronic pain, pain catastrophizing, and fear of pain. Although chronic pain was associated with PTSD (0.44 < β < 0.49, p < .002), increased pain perception was correlated with torture (0.33 < β < 0.65, p < .05). Pain catastrophizing was found to mediate the association between PTSD and chronic pain (β = 0.18 and 0.19, respectively; p < .05). Fear of pain moderated the association between torture and pain perception (β = 0.41 and 0.42, respectively; p < .017). The findings suggest that chronic pain is contingent upon the psychological toll of torture, that is, PTSD. This study also indicates that PTSD exacerbates catastrophic orientation, which in turn may amplify chronic pain. Reactivity to experimental noxious stimuli was related to previous experiences of torture, which enhances perceived pain intensity when interacting with a fearful pain orientation. These findings highlight the significance of orientation to bodily experiences after trauma.

  6. CA-125–indicated asymptomatic relapse confers survival benefit to ovarian cancer patients who underwent secondary cytoreduction surgery

    Directory of Open Access Journals (Sweden)

    Wang Fang

    2013-02-01

    Full Text Available Abstract Background There is no consensus regarding the management of ovarian cancer patients, who have shown complete clinical response (CCR to primary therapy and have rising cancer antigen CA-125 levels but have no symptoms of recurrent disease. The present study aims to determine whether follow-up CA-125 levels can be used to identify the need for imaging studies and secondary cytoreductive surgery (CRS. Methods We identified 410 ovarian cancer patients treated at The University of Texas MD Anderson Cancer Center between 1984 and 2011. These patients had shown CCR to primary therapy. Follow-up was conducted based on the surveillance protocol of the MD Anderson Cancer Center. We used the Cox proportional hazards model and log-rank test to assess the associations between the follow-up CA-125 levels and secondary CRS and survival duration. Results The CA-125 level of 1.68 × nadir was defined as the indicator of recurrent disease (p  1.68 × nadir at relapse (55.7 and 10.4 months; p = 0.04 and 0.01, respectively. The overall and progression free survival duration of patients with asymptomatic relapse and underwent a secondary CRS was longer than that of patients with symptomatic relapse (p = 0.02 and 0.04 respectively. Conclusions The increase of serum CA-125 levels is an early warning of clinical relapse in ovarian cancer. Using CA-125 levels in guiding the treatment of patients with asymptomatic recurrent ovarian cancer, who have shown CCR to primary therapy, can facilitate optimal secondary CRS and extend the survival duration of the patients.

  7. Periodical assessment of genitourinary and gastrointestinal toxicity in patients who underwent prostate low-dose-rate brachytherapy

    International Nuclear Information System (INIS)

    Tanaka, Nobumichi; Asakawa, Isao; Anai, Satoshi; Hirayama, Akihide; Hasegawa, Masatoshi; Konishi, Noboru; Fujimoto, Kiyohide

    2013-01-01

    To compare the periodical incidence rates of genitourinary (GU) and gastrointestinal (GI) toxicity in patients who underwent prostate low-dose-rate brachytherapy between the monotherapy group (seed implantation alone) and the boost group (in combination with external beam radiation therapy (EBRT)). A total of 218 patients with a median follow-up of 42.5 months were enrolled. The patients were divided into 2 groups by treatment modality, namely, the monotherapy group (155 patients) and the boost group (63 patients). The periodical incidence rates of GU and GI toxicity were separately evaluated and compared between the monotherapy group and the boost group using the National Cancer Institute - Common Terminology Criteria for Adverse Events, version 3.0. To elucidate an independent factor among clinical and postdosimetric parameters to predict grade 2 or higher GU and GI toxicity in the acute and late phases, univariate and multivariate logistic regression analyses were carried out. Of all patients, 78.0% showed acute GU toxicity, and 7.8% showed acute GI toxicity, while 63.8% showed late GU toxicity, and 21.1% showed late GI toxicity. The incidence rates of late GU and GI toxicity were significantly higher in the boost group. Multivariate analysis showed that the International Prostate Symptom Score (IPSS) before seed implantation was a significant parameter to predict acute GU toxicity, while there were no significant predictive parameters for acute GI toxicity. On the other hand, combination with EBRT was a significant predictive parameter for late GU toxicity, and rectal volume (mL) receiving 100% of the prescribed dose (R100) was a significant predictive parameter for late GI toxicity. The boost group showed higher incidence rates of both GU and GI toxicity. Higher IPSS before seed implantation, combination with EBRT and a higher R100 were significant predictors for acute GU, late GU and late GI toxicity

  8. Comparison of quality of life between men and women who underwent Transforaminal Percutaneous Endoscopic Discectomy for lumbar disc herniation.

    Science.gov (United States)

    Kapetanakis, Stylianos; Gkasdaris, Grigorios; Thomaidis, Tryfon; Charitoudis, Georgios; Kazakos, Konstantinos

    2017-01-01

    Studies describing the efficacy of TPED on shortness of recovery and improvement of postoperative quality of life are limited, especially regarding gender something that has never been reported before in the literature. The purpose of this study is to evaluate possible differences of the health-related quality of life in patients who underwent TPED for LDH in accordance with sex. Seventy-six patients diagnosed and treated with TPED for LDH with 1 year follow-up were selected and divided into two groups of equal number depending on sex. Their quality of life was evaluated by using the SF-36 before the operation, six weeks, three, six and twelve months postoperatively. A statistical analysis was conducted, in order to compare the 8 scaled scores of the SF-36 combining each time two chronological phases in the total of patients, in each group and between groups. Fifty-two (68.4%) patients were ≤63 years old, while the rest 24 (31,4%) were >63 years old (mean ±SD = 56,5 ±12,1 years). Apart from the PF domain, the scores were higher in every visit for the two groups, but the change between groups was not significant. Women had a significantly higher increase of PF score in 3 months after TPED and in the interval 6 weeks-3 months comparing with men. However, in the intervals 3 months-6 months and 3 months-12 months men presented significantly higher increase compared to women. Statistically significant improvement of the quality of life for both men and women was observed. Generally, there was no significant difference between the two groups. As regards to the physical functioning, it appears to be a significant difference which is counterpoised over time. 2. TPED for LDH does not present major differences in the improvement of quality of life regarding gender.

  9. Metallogeny of gold in the Fennoscandian Shield

    Science.gov (United States)

    Gaál, G.; Sundblad, K.

    1990-12-01

    Gold occurs in a number of different ore types in the Fennoscandian Shield ranging in age from Late Archean to Late Proterozoic. Until recently, the metal was exploited primarily as a byproduct in volcanogenic massive sulphide deposits but during the 1980s more gold mines have been opened than during any other episode in the mining history of northern Europe. The occurrence of gold in the Fennoscandian Shield is reviewed in the context of the major tectonostratigraphic units: 1. In the Karelian Province, gold is hosted by greenstone belts of the Archean basement complex e.g. at Ilomantsi, eastern Finland. Greenstone belts of the Nordkalott Province, which are interpreted as part of an Early Proterozoic cover sequence, contain gold deposits associated with copper (Bidjovagge, Saattopora and Pahtohavare). Gold is also associated with cobalt in the metasomatically altered Early Proterozoic cover in north-eastern Finland (Meurastuksenaho and Juomasuo). 2. In the Svecofennian Domain, the major gold deposits were generated during the emplacement of 1.92 1.87 Ga old accretional magmatism. These deposits occur in the northeastern part of the Svecofennian Domain, close to the Archean-Proterozoic boundary. They comprise two major types: (a) the porphyry-type and shear-zone gold hosted by tonalite at Tallberg, Laivakangas, Kopsa and Osikonmäki; (b) as a component of volcanogenic massive sulphide deposits (e.g. Holmtjärn, Boliden and Pyhäsalmi). Other types are: (c) gold-bearing quartz-alumina alteration zones formed during the 1.92 1.87 Ga magmatic period (Enåsen); (d) gold in massive sulphide and iron ore deposits in Bergslagen. 3. Gold associated with 1.84 1.54 Ga granites has been reported from several sites in the Shield, including quartz veins and contact-metasomatic deposits. In addition, shear-zone-related gold deposits post-dating these granites have been identified in southeastern Sweden (Ädelfors). 4. In the Sveconorwegian Domain, the gold deposits at Bleka

  10. [Assessment of the correlation between histological degeneration and radiological and clinical parameters in a series of patients who underwent lumbar disc herniation surgery].

    Science.gov (United States)

    Munarriz, Pablo M; Paredes, Igor; Alén, José F; Castaño-Leon, Ana M; Cepeda, Santiago; Hernandez-Lain, Aurelio; Lagares, Alfonso

    The use of histological degeneration scores in surgically-treated herniated lumbar discs is not common in clinical practice and its use has been primarily restricted to research. The objective of this study is to evaluate if there is an association between a higher grade of histological degeneration when compared with clinical or radiological parameters. Retrospective consecutive analysis of 122 patients who underwent single-segment lumbar disc herniation surgery. Clinical information was available on all patients, while the histological study and preoperative magnetic resonance imaging were also retrieved for 75 patients. Clinical variables included age, duration of symptoms, neurological deficits, or affected deep tendon reflex. The preoperative magnetic resonance imaging was evaluated using Modic and Pfirrmann scores for the affected segment by 2 independent observers. Histological degeneration was evaluated using Weiler's score; the presence of inflammatory infiltrates and neovascularization, not included in the score, were also studied. Correlation and chi-square tests were used to assess the association between histological variables and clinical or radiological variables. Interobserver agreement was also evaluated for the MRI variables using weighted kappa. No statistically significant correlation was found between histological variables (histological degeneration score, inflammatory infiltrates or neovascularization) and clinical or radiological variables. Interobserver agreement for radiological scores resulted in a kappa of 0.79 for the Pfirrmann scale and 0.65 for the Modic scale, both statistically significant. In our series of patients, we could not demonstrate any correlation between the degree of histological degeneration or the presence of inflammatory infiltrates when compared with radiological degeneration scales or clinical variables such as the patient's age or duration of symptoms. Copyright © 2017 Sociedad Española de Neurocirug

  11. Geochemical methodology for gold prospect ion in Uruguay

    International Nuclear Information System (INIS)

    Spangenber, J.

    1987-01-01

    This work is about the history of gold prospection in Uruguay. In this study there are considered the geochemical aspects, the gold performance, the applicability to mining prospection and the gold prospection aluvionar

  12. Gold emissivities for hydrocode applications

    International Nuclear Information System (INIS)

    Bowen, C.; Wagon, F.; Galmiche, D.; Loiseau, P.; Dattolo, E.; Babonneau, D.

    2004-01-01

    The Radiom model [M. Busquet, Phys Fluids B 5, 4191 (1993)] is designed to provide a radiative-hydrodynamic code with non-local thermodynamic equilibrium (non-LTE) data efficiently by using LTE tables. Comparison with benchmark data [M. Klapisch and A. Bar-Shalom, J. Quant. Spectrosc. Radiat. Transf. 58, 687 (1997)] has shown Radiom to be inaccurate far from LTE and for heavy ions. In particular, the emissivity was found to be strongly underestimated. A recent algorithm, Gondor [C. Bowen and P. Kaiser, J. Quant. Spectrosc. Radiat. Transf. 81, 85 (2003)], was introduced to improve the gold non-LTE ionization and corresponding opacity. It relies on fitting the collisional ionization rate to reproduce benchmark data given by the Averroes superconfiguration code [O. Peyrusse, J. Phys. B 33, 4303 (2000)]. Gondor is extended here to gold emissivity calculations, with two simple modifications of the two-level atom line source function used by Radiom: (a) a larger collisional excitation rate and (b) the addition of a Planckian source term, fitted to spectrally integrated Averroes emissivity data. This approach improves the agreement between experiments and hydrodynamic simulations

  13. Paper Money but a Gold Debt. Italy in the Gold Standard

    OpenAIRE

    Giuseppe Tattara; or consequences)

    2002-01-01

    During the 52 years between the Unification of the Kingdom of Italy and World War 1, the lira was legally convertible into metal for a limited period of time. Although not formally committed to gold, the lira exchange towards the gold standard countries proved remarkably stable, \\223shadowing\\224 gold. It is widely claimed that being one of the successful members of the gold standard circle entailed a number of advantages. If the lira was closely linked to gold, suggesting that there was only...

  14. Lamellar multilayer hexadecylaniline-modified gold nanoparticle ...

    Indian Academy of Sciences (India)

    Materials Chemistry Division, National Chemical Laboratory, Pune 411 008,. India e-mail: ... to the Brust method for the synthesis of hydrophobized gold nanoparticles.33 This process essentially consists of .... due to rearrangement of the gold nanoparticles within domains (and reorganization of the domains themselves) on ...

  15. Dress Images on Gold-foil Figures

    DEFF Research Database (Denmark)

    Mannering, Ulla; Andersson Strand, Eva Birgitta

    2009-01-01

    From the Late Iron Age settlement Sorte Muld on Bornholm both gold foil figures with depictions of costumes and textile tools can tell about textile production.......From the Late Iron Age settlement Sorte Muld on Bornholm both gold foil figures with depictions of costumes and textile tools can tell about textile production....

  16. Nonlinear optical studies of single gold nanoparticles

    NARCIS (Netherlands)

    Dijk, Meindert Alexander van

    2007-01-01

    Gold nanoparticles are spherical clusters of gold atoms, with diameters typically between 1 and 100 nanometers. The applications of these particles are rather diverse, from optical labels for biological experiments to data carrier for optical data storage. The goal of my project was to develop new

  17. Computational approaches to homogeneous gold catalysis.

    Science.gov (United States)

    Faza, Olalla Nieto; López, Carlos Silva

    2015-01-01

    Homogenous gold catalysis has been exploding for the last decade at an outstanding pace. The best described reactivity of Au(I) and Au(III) species is based on gold's properties as a soft Lewis acid, but new reactivity patterns have recently emerged which further expand the range of transformations achievable using gold catalysis, with examples of dual gold activation, hydrogenation reactions, or Au(I)/Au(III) catalytic cycles.In this scenario, to develop fully all these new possibilities, the use of computational tools to understand at an atomistic level of detail the complete role of gold as a catalyst is unavoidable. In this work we aim to provide a comprehensive review of the available benchmark works on methodological options to study homogenous gold catalysis in the hope that this effort can help guide the choice of method in future mechanistic studies involving gold complexes. This is relevant because a representative number of current mechanistic studies still use methods which have been reported as inappropriate and dangerously inaccurate for this chemistry.Together with this, we describe a number of recent mechanistic studies where computational chemistry has provided relevant insights into non-conventional reaction paths, unexpected selectivities or novel reactivity, which illustrate the complexity behind gold-mediated organic chemistry.

  18. Geochemistry of hydrothermal gold deposits: A review

    Directory of Open Access Journals (Sweden)

    Yongfeng Zhu

    2011-07-01

    Full Text Available Mineral assemblages formed during hydrothermal alteration reflect the geochemical composition of ore-forming fluids. Gold is mainly transported in solution as Au–Cl and Au–S complexes. The change of physicochemical conditions such as temperature, pressure, oxygen fugacity, and sulfur fugacity are effective mechanisms for gold precipitation. Gold tends to be concentrated in the vapor phase of fluids at high temperatures and pressures. Au–As and Au–Sb associations are common in gold deposit. Native antimony and/or arsenic – native gold assemblages may precipitate from hydrothermal fluids with low sulfur fugacity. Hydrothermal fluids forming epithermal gold deposits are Au-saturated in most cases, whereas fluids of Carlin-type are Au-undersaturated. Quasi-steady As-bearing pyrite extracts solid solution Au from hydrothermal fluids through absorption. The capability of As-bearing pyrite to absorb Au from under-saturated fluid is the key to the formation of large-scale Carlin-type deposits. With increasing new data, studies on the geochemistry of gold deposits can be used to trace the origin of ore-forming fluids, the source of gold, and the transporting form of Au and other ore-forming elements, such as Si, S, F, Cl, As and Ag.

  19. Gold - Old Drug with New Potentials.

    Science.gov (United States)

    Faa, Gavino; Gerosa, Clara; Fanni, Daniela; Lachowicz, Joanna I; Nurchi, Valeria M

    2018-01-01

    Research into gold-based drugs for a range of human diseases has seen a revival in recent years. This article reviews the most important applications of gold products in different fields of human pathology. Au(I) and Au(III) compounds have been re-introduced in clinical practice for targeting the cellular components involved in the onset and progression of viral and parasitic diseases, rheumatoid arthritis and cancer. After some brief historical notes, this article takes into account the applications of gold compounds against Mycobacterium tuberculosis, and also in tuberculosis and in rheumatoid arthritis treatment. The use of gold containing drugs in the cure of cancer are then considered, with special emphasis to the use of nanoparticles and to the photo-thermal cancer therapy. The use of colloidal gold in diagnostics, introduced in the last decade is widely discussed. As a last point a survey on the adverse effects and on the toxicity of the various gold derivatives in use in medicine is presented. In this review, we described the surprisingly broad spectrum of possible uses of gold in diagnostics and in therapeutic approaches to multiple human diseases, ranging from degenerative to infectious diseases, and to cancer. In particular, gold nanoparticles appear as attractive elements in modern clinical medicine, combining high therapeutic properties, high selectivity in targeting cancer cells and low toxicity. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  20. Goudafzettingen in Suriname (Gold deposits in Surinam)

    NARCIS (Netherlands)

    Brinck, J.W.

    1956-01-01

    THE GOLD DEPOSITS IN SURINAM AND THE DISTRIBUTION OF CONCESSIONS THROUGH THE COUNTRY The fieldwork on the occurrence of primary and secondary gold deposits in Surinam on which this thesis is based was carried out by order of the Welfare Fund Surinam (Welvaarts Fonds Suriname) during the periods

  1. Numerical simulations of nanostructured gold films

    DEFF Research Database (Denmark)

    Repän, Taavi; Frydendahl, Christian; Novikov, Sergey M.

    2017-01-01

    We present an approach to analyse near-field effects on nanostructured gold films by finite element simulations. The studied samples are formed by fabricating gold films near the percolation threshold and then applying laser damage. Resulting samples have complicated structures, which...

  2. Spherical aggregates composed of gold nanoparticles

    International Nuclear Information System (INIS)

    Chen, C-C; Kuo, P-L; Cheng, Y-C

    2009-01-01

    Alkylated triethylenetetramine (C12E3) was synthesized and used as both a reductant in the preparation of gold nanoparticles by the reduction of HAuCl 4 and a stabilizer in the subsequent self-assembly of the gold nanoparticles. In acidic aqueous solution, spherical aggregates (with a diameter of about 202 ± 22 nm) of gold nanoparticles (with the mean diameter of ∼18.7 nm) were formed. The anion-induced ammonium adsorption of the alkylated amines on the gold nanoparticles was considered to provide the electrostatic repulsion and steric hindrance between the gold nanoparticles, which constituted the barrier that prevented the individual particles from coagulating. However, as the amino groups became deprotonated with increasing pH, the ammonium adsorption was weakened, and the amino groups were desorbed from the gold surface, resulting in discrete gold particles. The results indicate that the morphology of the reduced gold nanoparticles is controllable through pH-'tunable' aggregation under the mediation of the amino groups of alkylated amine to create spherical microstructures.

  3. Comparison of Standard Catheters Versus Radial Artery-Specific Catheter in Patients Who Underwent Coronary Angiography Through Transradial Access.

    Science.gov (United States)

    Chen, On; Goel, Sunny; Acholonu, Michael; Kulbak, Guy; Verma, Shivani; Travlos, Efstratios; Casazza, Richard; Borgen, Elliot; Malik, Bilal; Friedman, Michael; Moskovits, Norbert; Frankel, Robert; Shani, Jacob; Ayzenberg, Sergey

    2016-08-01

    In this prospective, randomized controlled study, we aim to compare the performance outcomes of standard catheters with the radial artery-specific catheter. Over the past decade, transradial cardiac catheterization has gained widespread popularity because of its low complication rates compared with transfemoral access. Operators have the choice of using either standard catheters (used for both transfemoral and transradial approach, with need for separate catheter use for either right or left coronary artery engagement) or a dedicated radial artery catheter, which is specifically designed to engage both coronary arteries through radial artery access. A total of 110 consecutive patients who underwent coronary angiography at our institution from March 2015 to April 2015 were prospectively randomized to either radial artery-specific Tiger catheter (5Fr; Terumo Interventional Systems, Somerset, New Jersey) versus standard Judkins left and right catheters (5Fr R4, L4; Cordis Corporation, Miami, Florida). The end points of the study included fluoroscopy time, dose-area product, contrast volume used, and total procedure time for the coronary angiography. A total of 57 patients (52%) were randomized to radial artery-specific catheter and 53 (48%) to the standard catheter. Tiger catheter was associated with significantly lower fluoroscopy time (184 ± 91 vs 238 ± 131 seconds, p = 0.015), which was statistically significant. Other outcome measures such as dose-area product (2,882.4 ± 1,471.2 vs 3,524.6 ± 2,111.7 Gy·cm(2), p = 0.07), total contrast volume (48.1 ± 16.1 vs 53.4 ± 18.5 ml, p = 0.114), and total procedure time (337 ± 382 vs 434 ± 137 seconds, p = 0.085) were also lower in single-catheter group, but it did not reach statistical significance. A total of 8 patients (14%) were crossed over from radial-specific catheter arm to standard catheter arm because of substandard image quality and difficulty in coronary engagement. Six patients had to be

  4. CA-125–indicated asymptomatic relapse confers survival benefit to ovarian cancer patients who underwent secondary cytoreduction surgery

    Science.gov (United States)

    2013-01-01

    Background There is no consensus regarding the management of ovarian cancer patients, who have shown complete clinical response (CCR) to primary therapy and have rising cancer antigen CA-125 levels but have no symptoms of recurrent disease. The present study aims to determine whether follow-up CA-125 levels can be used to identify the need for imaging studies and secondary cytoreductive surgery (CRS). Methods We identified 410 ovarian cancer patients treated at The University of Texas MD Anderson Cancer Center between 1984 and 2011. These patients had shown CCR to primary therapy. Follow-up was conducted based on the surveillance protocol of the MD Anderson Cancer Center. We used the Cox proportional hazards model and log-rank test to assess the associations between the follow-up CA-125 levels and secondary CRS and survival duration. Results The CA-125 level of 1.68 × nadir was defined as the indicator of recurrent disease (p CA-125 biochemical progression prior to clinically-defined relapse was 31 days (ranging from 1 to 391 days). The median number of the negative imaging studies for the clinical relapse findings in patients with a CA-125 level of CA-125 level at relapse was an independent predictor of overall and progression free survival in patients who had shown CCR to primary therapy (p = 0.04 and 0.02 respectively). The overall and progression free survival durations in patients with a CA-125 level ≤ 1.68 × nadir at relapse (69.4 and 13.8 months) were longer than those with a CA-125 level > 1.68 × nadir at relapse (55.7 and 10.4 months; p = 0.04 and 0.01, respectively). The overall and progression free survival duration of patients with asymptomatic relapse and underwent a secondary CRS was longer than that of patients with symptomatic relapse (p = 0.02 and 0.04 respectively). Conclusions The increase of serum CA-125 levels is an early warning of clinical relapse in ovarian cancer. Using CA-125 levels in

  5. Gold 100: proceedings of the international conference on gold. V. 2

    International Nuclear Information System (INIS)

    Fivaz, C.E.; King, R.P.

    1986-01-01

    The proceedings of Gold 100 have been published in three separate volumes. The first deals with the mining of gold, the second with the extractive metallurgy of gold, and the third with industrial uses of gold. In this second volume, the papers on extractive metallurgy presented at the Conference reflect most of the problems that are currently of significant technical interest to the industry. This volume is divided in six main parts covering plant design, carbon-in-pulp technology, refractory gold, new technology, grinding and concentration, and leaching. The part on new technology includes papers on x-ray fluorescence analyzers, Moessbauer spectroscopy and leaching processes for uranium, while the part on grinding and concentration includes papers on nuclear and radiotracer techniques for the recovery of gold as well as various flotation parameters in the flotation behaviour of gold and uranium

  6. Synthesis of camptothecin-loaded gold nanomaterials

    International Nuclear Information System (INIS)

    Xing Zhimin; Liu Zhiguo; Zu Yuangang; Fu Yujie; Zhao Chunjian; Zhao Xiuhua; Meng Ronghua; Tan Shengnan

    2010-01-01

    Camptothecin-loaded gold nanomaterials have been synthesized by the sodium borohydride reduction method under a strong basic condition. The obtained gold nanomaterials have been characterized by transmission electron microscopy (TEM), atomic force microscopy (AFM) and UV-vis absorption spectroscopy. The camptothecin-loaded gold colloidal solution was very stable and can be stored for more than two months at room temperature without obvious changes. The color of the colloidal solution can change from wine red to purple and blue during the acidifying process. It was revealed that the release of camptothecin and the aggregation of gold nanoparticles can be controlled by tuning the solution pH. The present study implied that the gold nanomaterials can be used as the potential carrier for CPT delivery.

  7. Optical constant of thin gold films

    DEFF Research Database (Denmark)

    Yakubovsky, D. I.; Fedyanin, D. Yu; Arsenin, A. V.

    2017-01-01

    The performance of metal-based devices is limited by ohmic losses in the metal, which are determined by electron scattering. The structural properties of gold thin films also play an important role in the film quality, which may affect its' optical properties and the overall capability of the dev......The performance of metal-based devices is limited by ohmic losses in the metal, which are determined by electron scattering. The structural properties of gold thin films also play an important role in the film quality, which may affect its' optical properties and the overall capability...... and spectroscopic ellipsometry, the structural morphology and optical properties of polycrystalline gold thin films (fabricated by e-beam deposition at a low sputtering rate smooth gold) in the thickness range of 20 - 200 nm. By extracting the real and imaginary dielectric function and the Drude parameter...... predicts optical losses based on structure of the gold films....

  8. The interaction of gold with gallium arsenide

    Science.gov (United States)

    Weizer, Victor G.; Fatemi, Navid S.

    1988-01-01

    Gold and gold-based alloys, commonly used as solar-cell contact materials, are known to react readily with gallium arsenide. Experiments designed to identify the mechanisms involved in these GaAs-metal interactions have yielded several interesting results. It is shown that the reaction of GaAs with gold takes place via a dissociative diffusion process. It is shown further that the GaAs-metal reaction rate is controlled to a very great extent by the condition of the free surface of the contact metal, an interesting example of which is the previously unexplained increase in the reaction rate that has been observed for samples annealed in a vacuum environment as compared to those annealed in a gaseous ambient. A number of other hard-to-explain observations, such as the low-temperature formation of voids in the gold lattice and crystallite growth on the gold surface, are also explained by invoking this mechanism.

  9. Gold analysis by the gamma absorption technique

    International Nuclear Information System (INIS)

    Kurtoglu, Arzu; Tugrul, A.B.

    2003-01-01

    Gold (Au) analyses are generally performed using destructive techniques. In this study, the Gamma Absorption Technique has been employed for gold analysis. A series of different gold alloys of known gold content were analysed and a calibration curve was obtained. This curve was then used for the analysis of unknown samples. Gold analyses can be made non-destructively, easily and quickly by the gamma absorption technique. The mass attenuation coefficients of the alloys were measured around the K-shell absorption edge of Au. Theoretical mass attenuation coefficient values were obtained using the WinXCom program and comparison of the experimental results with the theoretical values showed generally good and acceptable agreement

  10. Gold Liquid Crystals in the XXI Century

    Directory of Open Access Journals (Sweden)

    Manuel Bardají

    2014-08-01

    Full Text Available Since the first gold liquid crystal was described in 1986, much effort has been done to prepare new compounds bearing this property. The review deals with the last results obtained in this new century. Gold(I has a strong affinity to give linear co-ordination and metal-metal interactions, which produce a rich supramolecular chemistry, and can promote the behavior as liquid crystal. Therefore, most liquid crystals are based on rod-like gold(I compounds, while gold(III liquid crystals are scarce. Calamitic and discotic mesogens have been reported, as well as chiral liquid crystals. Weak interactions such as H-bonds have also been used to obtain gold mesogens. Some of them exhibit additional properties, such as color, luminescence, and chirality. Luminescence has been reported, not only in the solid state or in solution, but also in the mesophase. This is relevant for applications in LEDs (Light Emitting Diodes, information storage, and sensors.

  11. Determinants of weight regain after bariatric surgery.

    Science.gov (United States)

    Bastos, Emanuelle Cristina Lins; Barbosa, Emília Maria Wanderley Gusmão; Soriano, Graziele Moreira Silva; dos Santos, Ewerton Amorim; Vasconcelos, Sandra Mary Lima

    2013-01-01

    Bariatric surgery leads to an average loss of 60-75% of excess body weight with maximum weight loss in the period between 18 and 24 months postoperatively. However, several studies show that weight is regained from two years of operation. To identify the determinants of weight regain in post-bariatric surgery users. Prospective cross-sectional study with 64 patients who underwent bariatric surgery with postoperative time > 2 years valued at significant weight regain. The variables analyzed were age, sex, education, socioeconomic status, work activity related to food, time after surgery, BMI, percentage of excess weight loss, weight gain, attendance monitoring nutrition, lifestyle, eating habits, self-perception of appetite, daily use of nutritional supplements and quality of life. There were 57 (89%) women and 7 (11%) men, aged 41.76 ± 7.93 years and mean postoperative period of 53.4 ± 18.4 months. The average weight and BMI were respectively 127.48 ± 24.2 kg and 49.56 ± 6.7 kg/m2 at surgery. The minimum weight and BMI were achieved 73.0 ± 18.6 kg and 28.3 ± 5.5 kg/m2, reached in 23.7 ± 12 months postoperatively. Regained significant weight occurred in 18 (28.1%) cases. The mean postoperative period of 66 ± 8.3 months and work activities related to food showed statistical significance (p=000 and p=0.003) for the regained weight. Bariatric surgery promotes adequate reduction of excess body weight, with significant weight regain observed after five years; post-operative time and work activity related to eating out as determining factors for the occurrence of weight regain.

  12. Carbonate hosted gold deposit in Tasmania, Australia

    International Nuclear Information System (INIS)

    Abadi, M.H.

    1999-01-01

    Full text: This study uses elemental and isotopic composition of carbonates associated with gold from Henty and Beaconsfield in Tasmania, Australia, to illustrate source of gold-bearing fluids, salinity, temperature and dissolution and reprecipitation of carbonate. The Beaconsfield and Henty gold mines are located in northern and western Tasmania respectively. Gold mineralisation in Beaconsfield occurs within the quartz-carbonate Tasmania Reef (Lower to Middle Palaeozoic sequence, Hills, 1998). The Henty gold mine is located at the base of the Cambrian Tyndall Group (volcano-sedimentary succession, White and McPhie, 1996) close to Henty Fault. Gold in carbonate samples from Henty ranges from 7.7 to 9360 ppm and in Beaconsfield ranges from 0.01 to 434 ppm. The amount of carbonate in samples from Henty and Beaconsfield gold mines varies from approximately 24 to 99.8%. Bivariate plot of Ca relative to total amounts of Mg, Fe and Mn illustrates that the major carbonate minerals at Beaconsfield and Henty gold mines are magnesian ankerite and calcite. The difference in carbonate mineralogy, at Henty and Beaconsfield gold mines, is attributed to the composition of fluids responsible for carbonate alteration. Gold and magnesium in Beaconsfield ankerite are derived from the leaching of Cambrian ultramafic rocks during the Devonian by the passage of meteoric fluids through tectonically affected Ordovician carbonates (Rao and Adabi, 1999). The total concentration of Fe and Mn are low (0.5 to 2%) in Henty and high (1 to 17.5%) in Beaconsfield ankerite, possibly due to oxidising conditions at Henty and reducing conditions at Beaconsfield gold mines during gold mineralisation. Variation of Sr values between Beaconsfield ankerite and Henty calcite is related to dissolution of limestone that increase Sr concentrations in gold mineralising fluids. Na values in both Beaconsfield (20 to 1100 ppm) and Henty carbonates (25 to 1650 ppm) suggest low salinity fluids responsible for gold

  13. [Retrospective analysis of 856 cases with stage 0 to III rectal cancer underwent curative surgery combined modality therapy].

    Science.gov (United States)

    Chen, Pengju; Yao, Yunfeng; Zhao, Jun; Li, Ming; Peng, Yifan; Zhan, Tiancheng; Du, Changzheng; Wang, Lin; Chen, Nan; Gu, Jin

    2015-07-01

    To investigate the survival and prognostic factors of stage 0 to III rectal cancer in 10 years. Clinical data and follow-up of 856 rectal cancer patients with stage 0-III underwent curative surgery from January 2000 to December 2010 were retrospective analyzed. There were 470 male and 386 female patients, with a mean age of (58 ± 12) years. Kaplan-Meier method was used to analyze the overall survival and disease free survival. Log-rank test was used to compare the survival between groups. Cox regression was used to analyze the independent prognostic factors of rectal cancer. The patients in each stage were stage 0 with 18 cases, stage I with 209 cases, stage II with 235 cases, and stage III with 394 cases. All patients received curative surgery. There were 296 patients evaluated as cT3, cT4 and any T with N+ received preoperative radiotherapy. 5.4% patients got pathological complete response (16/296), and the recurrence rate was 4.7% (14/296). After a median time of 41.7 months (range 4.1 to 144.0 months) follow-up, the 5-year overall survival rate in stage 0 to I of was 91.0%, stage II 86.2%, and stage III 60.0%, with a significant difference (P=0.000). The cumulative local recurrence rate was 4.8% (41/856), of which 70.7% (29/41) occurred within 3 years postoperatively, 97.6% (40/41) in 5 years. The cumulative distant metastasis rate was 16.4% (140/856), of which 82.9% (129/140) occurred within 3 years postoperatively, 96.4% (135/140) in 5 years. The incidence of abnormal imaging findings was significantly higher in pulmonary than liver and other sites metastases (75.0% vs. 21.7%, χ² =25.691, P=0.000). The incidence of CEA elevation was significantly higher in liver than lung and other sites metastases (56.8% vs. 37.8%, χ² =25.691, P=0.000). Multivariable analysis showed that age (P=0.015, HR=1.385, 95% CI: 1.066 to 1.801), surgical approach (P=0.029, HR=1.337, 95% CI: 1.030 to 1.733), differentiation (P=0.000, HR=1.535, 95% CI: 1.222 to 1.928), TNM stage (P

  14. Gold nanoparticles: generation and characterization

    International Nuclear Information System (INIS)

    Dey, G.R.

    2013-07-01

    In this presentation we report the reduction of Au 3+ through chemical and free radical (e solv - ) reactions both in non-aqueous and aqueous media. In chemical reduction, the spectral nature in ascorbic acid (AA) and citric acid (CA) systems was different. The band intensity of gold nanoparticles was lower in AA system. While in free radical reaction, the yield of nanoparticles was pure i.e. free from excess reactants. Under the study 60-200 nm size nanoparticles were generated, which are inert to oxygen. Using pulse radiolysis technique, the initial rate for e solv - reaction with Au 3+ was determined to be 7.6 x 10 9 M -1 s -1 . (author)

  15. Extinction Coefficient of Gold Nanostars.

    Science.gov (United States)

    de Puig, Helena; Tam, Justina O; Yen, Chun-Wan; Gehrke, Lee; Hamad-Schifferli, Kimberly

    2015-07-30

    Gold nanostars (NStars) are highly attractive for biological applications due to their surface chemistry, facile synthesis and optical properties. Here, we synthesize NStars in HEPES buffer at different HEPES/Au ratios, producing NStars of different sizes and shapes, and therefore varying optical properties. We measure the extinction coefficient of the synthesized NStars at their maximum surface plasmon resonances (SPR), which range from 5.7 × 10 8 to 26.8 × 10 8 M -1 cm -1 . Measured values correlate with those obtained from theoretical models of the NStars using the discrete dipole approximation (DDA), which we use to simulate the extinction spectra of the nanostars. Finally, because NStars are typically used in biological applications, we conjugate DNA and antibodies to the NStars and calculate the footprint of the bound biomolecules.

  16. Mindfulness Approaches and Weight Loss, Weight Maintenance, and Weight Regain.

    Science.gov (United States)

    Dunn, Carolyn; Haubenreiser, Megan; Johnson, Madison; Nordby, Kelly; Aggarwal, Surabhi; Myer, Sarah; Thomas, Cathy

    2018-03-01

    There is an urgent need for effective weight management techniques, as more than one third of US adults are overweight or obese. Recommendations for weight loss include a combination of reducing caloric intake, increasing physical activity, and behavior modification. Behavior modification includes mindful eating or eating with awareness. The purpose of this review was to summarize the literature and examine the impact of mindful eating on weight management. The practice of mindful eating has been applied to the reduction of food cravings, portion control, body mass index, and body weight. Past reviews evaluating the relationship between mindfulness and weight management did not focus on change in mindful eating as the primary outcome or mindful eating as a measured variable. This review demonstrates strong support for inclusion of mindful eating as a component of weight management programs and may provide substantial benefit to the treatment of overweight and obesity.

  17. Management of antithrombotic therapy in patients with coronary artery disease or atrial fibrillation who underwent abdominal surgical operations.

    Science.gov (United States)

    Schizas, Dimitrios; Kariori, Maria; Boudoulas, Konstantinos Dean; Siasos, Gerasimos; Patelis, Nikolaos; Kalantzis, Charalampos; Carmen-Maria, Moldovan; Vavuranakis, Manolis

    2018-04-02

    's thrombotic and bleeding risk. Management of antithrombotics therapy during the perioperative period in patients undergoing abdominal surgery should follow a patient-centered approach according to a patient's medical history and thrombotic risk weighted for bleeding risk. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  18. Intensification Behavior of Mercury Ions on Gold Cyanide Leaching

    Directory of Open Access Journals (Sweden)

    Qiang Zhong

    2018-01-01

    Full Text Available Cyanidation is the main method used to extract gold from gold raw materials; however, a serious problem with this method is the low leaching rate. In order to improve gold leaching, the intensification behavior of mercury ions on gold cyanide leaching, for two types of materials, sulphide gold concentrate and oxide gold ore, was investigated. The results showed that mercury ions, with only a 10−5 M dosage, could significantly intensify leaching and gold recovery. The dissolution behavior of gold plate was also intensified by 10−5 M mercury ions. Microstructure analysis showed that mercury ions intensified the cyanidation corrosion of the gold surface, resulting in a loose structure, where a large number of deep ravines and raised particles were evident across the whole gold surface. The loose structure added contact surface between the gold and cyanide, and accelerated gold dissolution. Moreover, mercury ions obstructed the formation of insoluble products, such as AuCN, Au(OHCN, and Au(OHx, that lead to a passivation membrane on the gold surface, reducing contact between the gold and cyanide. These effects, brought about by mercury ions, change the structure and product of the gold surface during gold cyanidation and promote gold leaching.

  19. Coal-gold agglomeration: an alternative separation process in gold recovery

    Energy Technology Data Exchange (ETDEWEB)

    Akcil, A.; Wu, X.Q.; Aksay, E.K. [Suleyman Demirel University, Isparta (Turkey). Dept. of Mining Engineering

    2009-07-01

    Considering the increasing environmental concerns and the potential for small gold deposits to be exploited in the future, the uses of environmentally friendly processes are essential. Recent developments point to the potential for greatly increased plant performance through a separation process that combines the cyanide and flotation processes. In addition, this kind of alternative treatment processes to the traditional gold recovery processes may reduce the environmental risks of present small-scale gold mining. Gold recovery processes that applied to different types of gold bearing ore deposits show that the type of deposits plays an important role for the selection of mineral processing technologies in the production of gold and other precious metals. In the last 25 years, different alternative processes have been investigated on gold deposits located in areas where environmental issues are a great concern. In 1988, gold particles were first recovered by successful pilot trial of coal-gold agglomeration (CGA) process in Australia. The current paper reviews the importance of CGA in the production of gold ore and identifies areas for further development work.

  20. Gold Leaching Characteristics and Intensification of a High S and As-Bearing Gold Concentrate

    Science.gov (United States)

    Yang, Yong-bin; Liu, Xiao-liang; Jiang, Tao; Li, Qian; Xu, Bin; Zhang, Yan

    Some high sulfur and arsenic-bearing gold concentrate has a gold leaching rate less than 80% by oxidation roasting-pickling-cyanidation process. The characteristics and intensification of gold leaching were studied systemically. By combining chemical composition and phase analysis, the low gold leaching rate was found to lie in the capsulation of gold by iron-containing phases including iron oxides, arsenopyrite and pyrite. 96.66% of gold in the industrial leaching residue was capsulated and 95.88% of the capsulated turned out to be in the iron-containing phases. The results of laboratory pickling-cyanidation experiments on the calcine and industrial leaching residue presented further demonstration for the fact that gold capsulated in the iron-containing phases was hard to be leached. However, the gold cyanide leaching rate of calcine could be raised over 95% by a reduction roasting-pickling pretreatment which played such a significant role in exposing the capsulated gold that gold leaching was intensified remarkably.

  1. The giant Jiaodong gold province: The key to a unified model for orogenic gold deposits?

    Directory of Open Access Journals (Sweden)

    David I. Groves

    2016-05-01

    Full Text Available Although the term orogenic gold deposit has been widely accepted for all gold-only lode-gold deposits, with the exception of Carlin-type deposits and rare intrusion-related gold systems, there has been continuing debate on their genesis. Early syngenetic models and hydrothermal models dominated by meteoric fluids are now clearly unacceptable. Magmatic-hydrothermal models fail to explain the genesis of orogenic gold deposits because of the lack of consistent spatially – associated granitic intrusions and inconsistent temporal relationships. The most plausible, and widely accepted, models involve metamorphic fluids, but the source of these fluids is hotly debated. Sources within deeper segments of the supracrustal successions hosting the deposits, the underlying continental crust, and subducted oceanic lithosphere and its overlying sediment wedge all have their proponents. The orogenic gold deposits of the giant Jiaodong gold province of China, in the delaminated North China Craton, contain ca. 120 Ma gold deposits in Precambrian crust that was metamorphosed over 2000 million years prior to gold mineralization. The only realistic source of fluid and gold is a subducted oceanic slab with its overlying sulfide-rich sedimentary package, or the associated mantle wedge. This could be viewed as an exception to a general metamorphic model where orogenic gold has been derived during greenschist- to amphibolite-facies metamorphism of supracrustal rocks: basaltic rocks in the Precambrian and sedimentary rocks in the Phanerozoic. Alternatively, if a holistic view is taken, Jiaodong can be considered the key orogenic gold province for a unified model in which gold is derived from late-orogenic metamorphic devolatilization of stalled subduction slabs and oceanic sediments throughout Earth history. The latter model satisfies all geological, geochronological, isotopic and geochemical constraints but the precise mechanisms of auriferous fluid release, like many

  2. Gold nanoparticles produced in a microalga

    International Nuclear Information System (INIS)

    Luangpipat, Tiyaporn; Beattie, Isabel R.; Chisti, Yusuf; Haverkamp, Richard G.

    2011-01-01

    An efficient biological route to production of gold nanoparticles which allows the nanoparticles to be easily recovered remains elusive. Live cells of the green microalga Chlorella vulgaris were incubated with a solution of gold chloride and harvested by centrifugation. Nanoparticles inside intact cells were identified by transmission electron microscopy and confirmed to be metallic gold by synchrotron based X-ray powder diffraction and X-ray absorption spectroscopy. These intracellular gold nanoparticles were 40–60 nm in diameter. At a concentration of 1.4% Au in the alga, a better than 97% recovery of the gold from solution was achieved. A maximum of 4.2% Au in the alga was obtained. Exposure of C. vulgaris to solutions containing dissolved salts of palladium, ruthenium, and rhodium also resulted in the production of the corresponding nanoparticles within the cells. These were surmised to be also metallic, but were produced at a much lower intracellular concentration than achieved with gold. Iridium was apparently toxic to the alga. No nanoparticles were observed using platinum solutions. C. vulgaris provides a possible route to large scale production of gold nanoparticles.

  3. Gel Electrophoresis of Gold-DNA Nanoconjugates

    Directory of Open Access Journals (Sweden)

    T. Pellegrino

    2007-01-01

    Full Text Available Gold-DNA conjugates were investigated in detail by a comprehensive gel electrophoresis study based on 1200 gels. A controlled number of single-stranded DNA of different length was attached specifically via thiol-Au bonds to phosphine-stabilized colloidal gold nanoparticles. Alternatively, the surface of the gold particles was saturated with single stranded DNA of different length either specifically via thiol-Au bonds or by nonspecific adsorption. From the experimentally determined electrophoretic mobilities, estimates for the effective diameters of the gold-DNA conjugates were derived by applying two different data treatment approaches. The first method is based on making a calibration curve for the relation between effective diameters and mobilities with gold nanoparticles of known diameter. The second method is based on Ferguson analysis which uses gold nanoparticles of known diameter as reference database. Our study shows that effective diameters derived from gel electrophoresis measurements are affected with a high error bar as the determined values strongly depend on the method of evaluation, though relative changes in size upon binding of molecules can be detected with high precision. Furthermore, in this study, the specific attachment of DNA via gold-thiol bonds to Au nanoparticles is compared to nonspecific adsorption of DNA. Also, the maximum number of DNA molecules that can be bound per particle was determined.

  4. Nature vs. nurture: gold perpetuates "stemness".

    Science.gov (United States)

    Paul, Willi; Sharma, Chandra P; Deb, Kaushik Dilip

    2011-01-01

    Adult tissues contain quiescent reservoirs of multipotent somatic stem cells and pluripotent embryonic-like stem cells (ELSCs). Credited with regenerative properties gold is used across both -contemporary and -ancient medicines. Here, we show that gold exerted these effects by enhancing the pool of pluripotent ELSC while improving their stemness. We used hESCs as an in-vitro model to understand if gold could enhance self-renewal and pluripotency. Swarna-bhasma (SB), an ancient Indian gold microparticulate (41.1 nm), preparation, reduced spontaneous-differentiation, improved self-renewal, pluripotency and proliferation of hESCs. Colloidal gold-nanoparticles (GNP) (15.59 nm) were tested to confirm that the observations were attributable to nanoparticulate-gold. SB and GNP exposure: maintained -stemness, -karyotypic stability, enhanced pluripotency till day-12, increased average colony-sizes, and reduced the number of autonomously-derived differentiated FGFR1 positive fibroblast-niche-cells/colony. Particulate-gold induced upregulation of FGFR1 and IGF2 expression, and decrease in IGF1 secretion indicates IGF1/2 mediated support for enhanced pluripotency and self-renewal in hESCs.

  5. Urban artisanal gold shops and mercury emissions

    International Nuclear Information System (INIS)

    Cordy, P.; Veiga, M.; Carrasco, V.H.G.

    2008-01-01

    Artisanal miners in developing countries use mercury amalgamation processes to extract gold. The amalgams are then refined before being sold on to urban gold shops. The amalgams can often contain between 2 to 40 per cent mercury. Unburned amalgams are also often sold directly to gold shops. There are serious health risks for shop employees and nearby populations when the gold is melted and further purified. Studies have shown that mercury concentrations in the ambient air of gold shops often exceeds World Health Organization (WHO) limits by an order of magnitude or more. This study examined the practices and technologies used to refine gold in Latin America and Indonesia. The study compared and contrasted various refining methods and their resulting mercury emissions. Methods of reducing mercury emissions were also investigated, including a filtration system designed to capture 80 per cent of mercury emissions. Barriers to implementing mercury emissions reduction plans were also investigated. It was concluded that the design of urban gold shops must include condensers, fume hoods, and efficient mercury capture systems. 15 refs

  6. NUCLEATION STUDIES OF GOLD ON CARBON ELECTRODES

    Directory of Open Access Journals (Sweden)

    S. SOBRI

    2008-04-01

    Full Text Available Interest has grown in developing non-toxic electrolytes for gold electrodeposition to replace the conventional cyanide-based bath for long term sustainability of gold electroplating. A solution containing thiosulphate and sulphite has been developed specially for microelectronics applications. However, at the end of the electrodeposition process, the spent electrolyte can contain a significant amount of gold in solution. This study has been initiated to investigate the feasibility of gold recovery from a spent thiosulphate-sulphite electrolyte. We have used flat-plate glassy carbon and graphite electrodes to study the mechanism of nucleation and crystal growth of gold deposition from the spent electrolyte. It was found that at the early stages of reduction process, the deposition of gold on glassy carbon exhibits an instantaneous nucleation of non-overlapping particles. At longer times, the particles begin to overlap and the deposition follows a classic progressive nucleation phenomenon. On the other hand, deposition of gold on graphite does not follow the classical nucleation phenomena.

  7. Urban artisanal gold shops and mercury emissions

    Energy Technology Data Exchange (ETDEWEB)

    Cordy, P.; Veiga, M.; Carrasco, V.H.G. [British Columbia Univ., Vancouver, BC (Canada). Dept. of Mining and Mineral Process Engineering

    2008-07-01

    Artisanal miners in developing countries use mercury amalgamation processes to extract gold. The amalgams are then refined before being sold on to urban gold shops. The amalgams can often contain between 2 to 40 per cent mercury. Unburned amalgams are also often sold directly to gold shops. There are serious health risks for shop employees and nearby populations when the gold is melted and further purified. Studies have shown that mercury concentrations in the ambient air of gold shops often exceeds World Health Organization (WHO) limits by an order of magnitude or more. This study examined the practices and technologies used to refine gold in Latin America and Indonesia. The study compared and contrasted various refining methods and their resulting mercury emissions. Methods of reducing mercury emissions were also investigated, including a filtration system designed to capture 80 per cent of mercury emissions. Barriers to implementing mercury emissions reduction plans were also investigated. It was concluded that the design of urban gold shops must include condensers, fume hoods, and efficient mercury capture systems. 15 refs.

  8. Comparison of CT and diffusion-weighted MRI in acute ischemic stroke

    International Nuclear Information System (INIS)

    Moriwaki, Hiroshi; Okazaki, Shuhei; Yamada, Naoaki; Naritomi, Hiroaki

    2006-01-01

    Non-contrast CT and diffusion-weighted MRI (DWI) are widely used for assessing patients with acute ischemic stroke including candidates for thrombolytic therapy. Early CT signs, still a gold standard as the diagnostic measure for thrombolysis, are quite subtle and strongly depend on image quality. We evaluated 76 patients (47 male, mean age 71.0 yrs) with ischemic stroke of the anterior cerebral circulation who underwent CT and DWI within 6 hours of onset. The scans were examined separately by two neurologists in a blinded fashion with knowledge of the affected hemisphere. Detection of acute ischemic changes were significantly higher on DWI (72/76, 95%) compared with that on CT (50/76, 66%) (P<0.0001), especially in cases with subcortical lesions (P<0.001). Detection of the lesion with more than 33% of MCA involvement, which should exclude from the thrombolitic therapy, was somewhat higher for DWI (26/26, 100%) compared with CT (22/26, 85%). DWI is more sensitive than CT in the identification of acute ischemic stroke and can visualize major ischemia more easily than CT. Additional studies are required to determine whether these advantages of DWI are clinically relevant in the management of patients with acute stroke. (author)

  9. Safety and efficacy of targeted hyperthermia treatment utilizing gold nanorod therapy in spontaneous canine neoplasia.

    Science.gov (United States)

    Schuh, Elizabeth M; Portela, Roberta; Gardner, Heather L; Schoen, Christian; London, Cheryl A

    2017-10-02

    Hyperthermia is an established anti-cancer treatment but is limited by tolerance of adjacent normal tissues. Parenteral administration of gold nanorods (NRs) as a photosensitizer amplifies the effects of hyperthermia treatment while sparing normal tissues. This therapy is well tolerated and has demonstrated anti-tumor effects in mouse models. The purpose of this phase 1 study was to establish the safety and observe the anti-tumor impact of gold NR enhanced (plasmonic) photothermal therapy (PPTT) in client owned canine patients diagnosed with spontaneous neoplasia. Seven dogs underwent gold NR administration and subsequent NIR PPTT. Side effects were mild and limited to local reactions to NIR laser. All of the dogs enrolled in the study experienced stable disease, partial remission or complete remission. The overall response rate (ORR) was 28.6% with partial or complete remission of tumors at study end. PPTT utilizing gold nanorod therapy can be safely administered to canine patients. Further studies are needed to determine the true efficacy in a larger population of canine cancer patients and to and identify those patients most likely to benefit from this therapy.

  10. Endometrial cancer with cervical stromal invasion: diagnostic accuracy of diffusion-weighted and dynamic contrast enhanced MR imaging at 3T

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Gigin; Lu, Hsin-Ying [Chang Gung Memorial Hospital at Linkou and Chang Gung University, Department of Medical Imaging and Intervention, Institute for Radiological Research, Guishan, Taoyuan (China); Chang Gung Memorial Hospital at Linkou, Clinical Phenome Center, Guishan, Taoyuan (China); Huang, Yu-Ting; Lin, Yu-Chun; Ng, Shu-Hang; Ng, Koon-Kwan [Chang Gung Memorial Hospital at Linkou and Chang Gung University, Department of Medical Imaging and Intervention, Institute for Radiological Research, Guishan, Taoyuan (China); Chao, Angel; Lai, Chyong-Huey [Chang Gung Memorial Hospital at Linkou and Chang Gung University, Department of Obstetrics and Gynecology and Gynecologic Cancer Research Center, Guishan, Taoyuan (China); Yang, Lan-Yan [Chang Gung Memorial Hospital at Linkou and Chang Gung University, Clinical Trial Center, Guishan, Taoyuan (China); Wu, Ren-Chin [Chang Gung Memorial Hospital at Linkou and Chang Gung University, Department of Pathology, Guishan, Taoyuan (China)

    2017-05-15

    To compare the diagnostic accuracy of diffusion-weighted (DW) and dynamic contrast-enhanced (DCE) magnetic resonance (MR) imaging for detecting cervical stromal invasion in endometrial cancer. Eighty-three consecutive women with endometrial cancer underwent preoperative evaluation in a 3-T unit, including T2-weighted, DW (b = 0 and 1000 s/mm{sup 2}), and DCE MR imaging. Two radiologists independently assessed presence of cervical stromal invasion, with histopathological reference as gold standard. For assessing cervical stromal invasion, the diagnostic accuracy, sensitivity, and specificity, respectively for Reader 1/Reader 2, were as follows: DW MR imaging - 95.2 %/91.6 %, 91.7 %/100 %, and 95.8 %/90.1 %; DCE MR imaging - 91.6 %/88 %, 58.3 %/50 %, and 97.2 %/94.4 %. The diagnostic performance of DW MR imaging (Reader 1: areas under the receiver operating characteristic curve (AUC) = 0.98; Reader 2: AUC = 0.97) was significantly higher than that of DCE MR imaging (p = 0.009 for Reader 2) or T2-weighted MR imaging (Reader 1: p = 0.006; Reader 2: p = 0.013). Patients with cervical stromal invasion showed a significantly greater canal width (p < 0.0001) and myometrial invasion extent (p = 0.006). DW MR imaging has superior diagnostic performance compared with DCE MR imaging in the detection of cervical stromal invasion. (orig.)

  11. The giant Kalgoorlie Gold Field revisited

    Directory of Open Access Journals (Sweden)

    Noreen Mary Vielreicher

    2016-05-01

    Direct timing constraints on gold mineralization indicate that Fimiston- and Mt Charlotte-style mineralization formed within a relative short period of time around 2.64 Ga, and, as such, support a model of progressive deformation of a rheologically heterogeneous rock package late in the structural history. Fluid characteristics, combined with the structural, metamorphic and absolute timing, support description of gold mineralization at the Golden Mile as orogenic and mesozonal, and this allows direct correlation with orogenic gold deposits worldwide, which classically formed during accretion along convergent margins throughout Earth history.

  12. Integer conductance quantization of gold atomic sheets

    Science.gov (United States)

    Kurui, Yoshihiko; Oshima, Yoshifumi; Okamoto, Masakuni; Takayanagi, Kunio

    2008-04-01

    Using a transmission electron microscope combined with a scanning tunneling microscope, we find that a gold (111) or (001) atomic sheet is formed between two gold electrodes. Simultaneous conductance measurements indicate a value in the vicinity of G0 ( =2e2/h : conductance quantum), 2G0 , 3G0 , and 4G0 . Each quantum number is equal to the number of atomic strands. First-principle calculations suggest that the atomic sheet should be deformed to explain this rule. It is likely that the gold atomic sheet is stabilized by an increment of the nonlocal bond because of the deformation.

  13. Synthesis of gold nanoparticles with graphene oxide.

    Science.gov (United States)

    Wang, Wenshuo; He, Dawei; Zhang, Xiqing; Duan, Jiahua; Wu, Hongpeng; Xu, Haiteng; Wang, Yongsheng

    2014-05-01

    Single sheets of functionalized graphene oxide are derived through chemical exfoliation of natural flake graphite. We present an effective synthetic method of graphene-gold nanoparticles hybrid nanocomposites. AFM (Atomic Force Microscope) was used to measure the thickness of the individual GO nanosheet. FTIR (Fourier transform infrared) spectroscopy was used to verify the attachment of oxygen functionalities on the surface of graphene oxide. TEM (Transmission Electron Microscope) data revealed the average diameters of the gold colloids and characterized the composite particles situation. Absorption spectroscopy showed that before and after synthesis the gold particle size did not change. Our studies indicate that the hybrid is potential substrates for catalysts and biosensors.

  14. Gold nanoparticles extraction from dielectric scattering background

    Science.gov (United States)

    Hong, Xin; Wang, Jingxin

    2014-11-01

    The unique advantages such as brightness, non-photobleaching, good bio-compatibility make gold nanoparticles desirable labels and play important roles in biotech and related research and applications. Distinguishing gold nanoparticles from other dielectric scattering particles is of more importance, especially in bio-tracing and imaging. The enhancement image results from the localized surface plasmon resonance associated with gold nanopartilces makes themselves distinguishable from other dielectric particles, based on which, we propose a dual-wavelength detection method by employing a high sensitive cross-polarization microscopy.

  15. Biosynthesis of Gold Nanoparticles Using Pseudomonas Aeruginosa

    International Nuclear Information System (INIS)

    Abd El-Aziz, M.; Badr, Y.; Mahmoud, M. A.

    2007-01-01

    Pseudomonas aeruginosa were used for extracellular biosynthesis of gold nanoparticles (Au NPs). Consequently, Au NPs were formed due to reduction of gold ion by bacterial cell supernatant of P. aeruginos ATCC 90271, P. aeruginos (2) and P. aeruginos (1). The UV-Vis. and fluorescence spectra of the bacterial as well as chemical prepared Au NPs were recorded. Transmission electron microscopy (TEM) micrograph showed the formation of well-dispersed gold nanoparticles in the range of 15-30 nm. The process of reduction being extracellular and may lead to the development of an easy bioprocess for synthesis of Au NPs

  16. Gold Photoluminescence: Wavelength and Polarization Engineering

    DEFF Research Database (Denmark)

    Andersen, Sebastian Kim Hjælm; Pors, Anders Lambertus; Bozhevolnyi, Sergey I.

    2015-01-01

    We demonstrate engineering of the spectral content and polarization of photoluminescence (PL) from arrayed gold nanoparticles atop a subwavelength-thin dielectric spacer and optically-thick gold film, a configuration that supports gap-surface plasmon resonances (GSPRs). Choice of shapes...... and dimensions of gold nanoparticles influences the GSPR wavelength and polarization characteristics, thereby allowing us to enhance and spectrally mold the plasmon-assisted PL while simultaneously controlling its polarization. In order to understand the underlying physics behind the plasmon-enhanced PL, we...

  17. Morphology of gold nanoparticles synthesized by filamentous cyanobacteria from gold(I)-thiosulfate and gold(III)--chloride complexes.

    Science.gov (United States)

    Lengke, Maggy F; Fleet, Michael E; Southam, Gordon

    2006-03-14

    Plectonema boryanum UTEX 485, a filamentous cyanobacterium, has been reacted with aqueous Au(S(2)O(3))(2)(3)(-) and AuCl(4)(-) solutions ( approximately 400-550 mg/L Au) at 25-100 degrees C for up to 1 month and at 200 degrees C for 1 day. The interaction of cyanobacteria with aqueous Au(S(2)O(3))(2)(3)(-) promoted the precipitation of cubic (100) gold nanoparticles (gold sulfide within cells and encrusted on the cyanobacteria, whereas reaction with AuCl(4)(-) resulted in the precipitation of octahedral (111) gold platelets ( approximately 1-10 microm) in solutions and nanoparticles of gold (SIMS on (111) faces of the octahedral platelets were predominantly Cl and CN, with smaller amounts of C(2)H and CNO.

  18. Weight Loss Surgery

    Science.gov (United States)

    Weight loss surgery helps people with extreme obesity to lose weight. It may be an option if you ... caused by obesity. There are different types of weight loss surgery. They often limit the amount of food ...

  19. Thyroid and Weight

    Science.gov (United States)

    ... Thyroid and Weight Thyroid and Weight FAQs THYROID, BMR & WEIGHT WHAT IS THE RELATIONSHIP BETWEEN THYROID AND ... it is known as the basal metabolic rate (BMR). Indeed, measurement of the BMR was one of ...

  20. Electroplating Gold-Silver Alloys for Spherical Capsules for NIF Double-Shell Targets

    Energy Technology Data Exchange (ETDEWEB)

    Bhandarkar, N. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Horwood, C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Bunn, T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Stadermann, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-08-17

    For Inertial Confinement Fusion (ICF) implosions, a design based on gradients of high and mid Z materials could potentially be more robust than single element capsule systems. To that end, gold and silver alloys were electroplated on 2.0 mm diameter surrogate brass spheres using a new flow–based pulsed plating method specifically designed to minimize surface roughness without reducing plating rates. The coatings were analyzed by scanning electron microscope (SEM) and white light interferometry for surface topography, and by energy dispersive x-ray spectroscopy (EDX) to determine near-surface gold and silver compositions. The alloy range attainable was 15 to 85 weight percent gold using 1:1 and 1:3 silver to gold ratio plating baths at applied potentials of -0.7 volts to -1.8 volts. This range was bounded by the open circuit potential of the system and hydrogen evolution, and in theory could be extended by using ionic liquids or aprotic solutions. Preliminary gradient trials proved constant composition alloy data could be translated to smooth gradient plating, albeit at higher gold compositions.

  1. Biological response of HeLa cells to gold nanoparticles coated with organic molecules.

    Science.gov (United States)

    Cardoso Avila, P E; Rangel Mendoza, A; Pichardo Molina, J L; Flores Villavicencio, L L; Castruita Dominguez, J P; Chilakapati, M K; Sabanero Lopez, M

    2017-08-01

    In this work, gold nanospheres functionalized with low weight organic molecules (4-aminothiphenol and cysteamine) were synthesized in a one-step method for their in vitro cytotoxic evaluation on HeLa cells. To enhance the biocompatibility of the cysteamine-capped GNPs, BSA was used due to its broad PH stability and high binding affinity to gold nanoparticles. Besides, the widely reported silica coated gold nanorods were tested here to contrast their toxic response against our nanoparticles coated with organic molecules. Our results shown, the viability measured at 1.9×10 -5 M did not show significant differences against negative controls for all the samples; however, the metabolic activity of HeLa cells dropped when they were exposed to silica gold nanorods in the range of concentrations from 2.9×10 -7 M to 3.0×10 -4 M, while in the cases of gold nanospheres, we found that only at concentrations below 1.9×10 -5 M metabolic activity was normal. Our preliminary results did not indicate any perceivable harmful toxicity to cell membrane, cytoskeleton or nucleus due to our nanospheres at 1.9×10 -5 M. Additional test should be conducted in order to ensure a safe use of them for biological applications, and to determine the extent of possible damage. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Gold deposit styles and placer gold characterisation in northern and east-central Madagascar

    Science.gov (United States)

    Pitfield, Peter E. J; Styles, Michael T.; Taylor, Cliff D.; Key, Roger M.; Bauer,; Ralison, A

    2009-01-01

    Microchemical characterisation of bedrock and placer gold grains from six gold districts within the Archaean domains and intervening Neoproterozoic Anaboriana-Manampotsy belt of northern and east-central Madagascar show few opaque inclusions (e.g pyrrhotite, Bi tellurides) but wide range of Ag contents (40wt%). Some districts exhibit multiple source populations of grains. The ‘greenstone belt’ terranes have an orogenic gold signature locally with an intrusion-related to epithermal overprint. Proterozoic metasediments with felsic to ultramafic bodies yield dominantly intrusion-related gold. A high proportion of secondary gold (<0.5wt% Ag) is related to recycling of paleoplacers and erosion of post-Gondwana planation surfaces and indicates that some mesothermal gold systems were already partially to wholly removed by erosion by the PermoTriassic.

  3. Coal-oil gold agglomeration assisted flotation to recover gold from refractory ore

    Science.gov (United States)

    Otsuki, A.; Yue, C.

    2017-07-01

    This study aimed to investigate the applicability of coal-oil gold agglomeration (CGA) assisted flotation to recover gold from a refractory ore. The ore with the grade of 2-5 g/t was tested with the CGA-flotation process in six different size fractions from 38 to 300 urn using different collector types and dosages. In addition, the flotation without CGA was performed under the same condition for comparison. The results showed that the higher gold grade and recovery were achieved by applying the CGA-flotation, compared with the flotation without CGA. More than 20-60 times grade increase from the head grade was obtained with CGA-flotation. The elemental analysis of gold and sulphur explained their relationship with gold recovery. The results well indicated the applicability of CGA to upgrade the refractory gold ore.

  4. Nanoporous gold: a new gold catalyst with tunable properties.

    Science.gov (United States)

    Wittstock, Arne; Wichmann, Andre; Biener, Jürgen; Bäumer, Marcus

    2011-01-01

    Nanoporous gold (np-Au) represents a novel nanostructured bulk material with very interesting perspectives in heterogeneous catalysis. Its monolithic porous structure and the absence of a support or other stabilizing agents opens up unprecedented possibilities to tune structure and surface chemistry in order to adapt the material to specific catalytic applications. We investigated three of these tuning options in more detail: change of the porosity by annealing, increase of activity by the deposition of oxides and change of activity and selectivity by bimetallic effects. As an example for the latter case, the effect of Ag impurities will be discussed. The presence and concentration of Ag can be correlated to the availability of active oxygen. While for the oxidation of CO the activity of the catalyst can be significantly enhanced when increasing the content of Ag, we show for the oxidation of methanol that the selectivity is shifted from partial to total oxidation. In a second set of experiments, two different metal-oxides were deposited on np-Au, praseodymia and titania. In both cases, the surface chemistry changed significantly. The activity of the catalyst for oxidation of CO was increased by up to one order of magnitude after modification. Finally, we used adsorbate controlled coarsening to tune the structure of np-Au. In this way, even gradients in the pore- and ligament size could be induced, taking advantage of mass transport phenomena.

  5. Uji Ketahanan Beberapa Varietas Dan Pengaruh Jarak Tanam Terhadap Penyakit Karat Daun (Puccinia Polysora Underw) Pada Tanaman Jagung (Zea Mays L.)

    OpenAIRE

    Aditya, Sukma

    2013-01-01

    Sukma Aditya, "Some Resistance Test Plant Varieties and Influence Distance Against Disease Leaf Rust (Puccinia polysora Underw) In the Corn Plantation (Zea mays l.) In the Lowlands". Supervised by Dr. Ir. Hasanuddin, MS, and Ir. Mukhtar Pinem Iskandar, M. Agr. This study aims to determine the resistance of some varieties of maize (Zea mays L.) and plant spacing influence on leaf rust disease (Puccinia polysora Underw.) In the lowlands. Research conducted in the village of Tanjung Selamat, Med...

  6. 33 CFR 13.01-10 - Gold and silver bars.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Gold and silver bars. 13.01-10... DECORATIONS, MEDALS, RIBBONS AND SIMILAR DEVICES Gold and Silver Lifesaving Medals, Bars, and Miniatures § 13.01-10 Gold and silver bars. No person shall receive more than one Gold Lifesaving Medal and one...

  7. A study on gold detection in Wenyu gold mine with XRF techniques

    International Nuclear Information System (INIS)

    Liu Liuchun

    1988-01-01

    A portable X ray fluorescence analyzer was used for detecting fluorcescent X rays from the elements associated with gold ores. Fe, As and Ni were chosen to be the indicator elements to analyse rock samples in Wenyu gold mine. Optimum indicators were determined, and it had proved to be successful to detect gold indirectly by measuring the yields of characteristic X rays of the elements. The method provided also valuable information on geology mapping and deposits forming environment

  8. Particle size effect on velocity of gold particle embedded laser driven plastic targets

    Directory of Open Access Journals (Sweden)

    Dhareshwar L.J.

    2013-11-01

    Full Text Available A scheme to enhance the target foil velocity has been investigated for a direct drive inertial fusion target. Polymer PVA (polyvinyl alcohol or (C2H4On target foils of thickness 15–20 μm were used in plain form and also embedded with gold in the nano-particle (Au-np or micro-particle (Au-mp form. Nano-particles were of 20–50 nm and micro-particles of 2–3 μm in size. 17% higher target velocity was measured for foils embedded with nano-particle gold (Au-np as compared to targets embedded with micro-particles gold (Au-mp. The weight of gold in both cases was in the range 40–55% of the full target weight (atomic percentage of about 22%. Experiments were performed with the single beam of the Prague Asterix Laser System (PALS at 0.43 μm wavelength (3ω of the fundamental wavelength, 120 Joule energy and 300 psec pulse duration. Laser intensity on the target was about 1015 W/cm2. A simple model has been proposed to explain the experimental results.

  9. Effective PEGylation of gold nanorods

    Science.gov (United States)

    Schulz, F.; Friedrich, W.; Hoppe, K.; Vossmeyer, T.; Weller, H.; Lange, H.

    2016-03-01

    Standard procedures to coat gold nanorods (AuNR) with poly(ethylene glycol) (PEG)-based ligands are not reliable and high PEG-grafting densities are not achieved. In this work, the ligand exchange of AuNR with PEGMUA, a tailored PEG-ligand bearing a C10 alkylene spacer, is studied. PEGMUA provides AuNR with very high stability against oxidative etching with cyanide. This etching reaction is utilized to study the ligand exchange in detail. Ligand exchange is faster, less ligand consuming and more reproducible with assisting chloroform extraction. Compared to PEG ligands commonly used, PEGMUA provides much higher colloidal and chemical stability. Further analyses based on NMR-, IR- and UV/Vis-spectroscopy reveal that significantly higher PEG-grafting densities, up to ~3 nm-2, are obtained with PEGMUA. This demonstrates how the molecular structure of the PEG ligand can be used to dramatically improve the ligand exchange and to synthesize PEGylated AuNR with high chemical and colloidal stability and high PEG grafting densities. Such AuNR are especially interesting for applications in nanomedicine.Standard procedures to coat gold nanorods (AuNR) with poly(ethylene glycol) (PEG)-based ligands are not reliable and high PEG-grafting densities are not achieved. In this work, the ligand exchange of AuNR with PEGMUA, a tailored PEG-ligand bearing a C10 alkylene spacer, is studied. PEGMUA provides AuNR with very high stability against oxidative etching with cyanide. This etching reaction is utilized to study the ligand exchange in detail. Ligand exchange is faster, less ligand consuming and more reproducible with assisting chloroform extraction. Compared to PEG ligands commonly used, PEGMUA provides much higher colloidal and chemical stability. Further analyses based on NMR-, IR- and UV/Vis-spectroscopy reveal that significantly higher PEG-grafting densities, up to ~3 nm-2, are obtained with PEGMUA. This demonstrates how the molecular structure of the PEG ligand can be used to

  10. Electrocatalytic glucose oxidation at gold and gold-carbon nanoparticulate film prepared from oppositely charged nanoparticles

    International Nuclear Information System (INIS)

    Karczmarczyk, Aleksandra; Celebanska, Anna; Nogala, Wojciech; Sashuk, Volodymyr; Chernyaeva, Olga; Opallo, Marcin

    2014-01-01

    Graphical abstract: - Highlights: • Gold nanoparticulate film electrodes were prepared by layer-by-layer method from oppositely charged nanoparticles. • Positively charged nanoparticles play dominant role in glucose oxidation in alkaline solution. • Gold and gold-carbon nanoparticulate film electrodes exhibit similar glucose oxidation current and onset potential. - Abstract: Electrocatalytic oxidation of glucose was studied at nanoparticulate gold and gold-carbon film electrodes. These electrodes were prepared by a layer-by-layer method without application of any linker molecules. Gold nanoparticles were stabilized by undecane thiols functionalized by trimethyl ammonium or carboxylate groups, whereas the carbon nanoparticles were covered by phenylsulfonate functionalities. The gold nanoparticulate electrodes were characterized by UV-vis and XPS spectroscopy, atomic force microscopy and voltammetry, before and after heat-treatment. Heat-treatment facilitates the aggregation of the nanoparticles and affects the structure of the film. The comparison of the results obtained with film electrodes prepared from gold nanoparticles with the same charge and with gold-carbon nanoparticulate electrodes, proved that positively charged nanoparticles are responsible for the high electrocatalytic activity, whereas negatively charged ones act rather as a linker of the film

  11. Novel Catalysis by Gold: A Modern Alchemy

    Science.gov (United States)

    Haruta, Masatake

    Gold has long been neglected as a catalyst because of its chemical inertness. However, when gold is deposited as nanoparticles on carbon and polymer materials as well as on base metal oxides and hydroxides, it exhibits unique catalytic properties for many reactions such as CO oxidation at a temperature as low as 200 K, gas phase direct epoxidation of propylene, and aerobic oxidation of glucose to gluconic acid. The structure-catalytic activity correlations are discussed with emphasis on the contact structure, support selection, and the size control of gold particles. Gold clusters with diameters smaller than 2 nm are expected to exhibit novel properties in catalysis, optics, and electronics depending on the size (number of atoms), shape, and the electronic and chemical interaction with the support materials. The above achievements and attempts can be regarded as a modern alchemy that creates valuables by means of the noblest element with little practical use.

  12. A new route to gold nanoflowers

    Science.gov (United States)

    Liebig, Ferenc; Henning, Ricky; Sarhan, Radwan M.; Prietzel, Claudia; Bargheer, Matias; Koetz, Joachim

    2018-05-01

    Catanionic vesicles spontaneously formed by mixing the anionic surfactant bis(2-ethylhexyl) sulfosuccinate sodium salt with the cationic surfactant cetyltrimethylammonium bromide were used as a reducing medium to produce gold clusters, which are embedded and well-ordered into the template phase. The gold clusters can be used as seeds in the growth process that follows by adding ascorbic acid as a mild reducing component. When the ascorbic acid was added very slowly in an ice bath round-edged gold nanoflowers were produced. When the same experiments were performed at room temperature in the presence of Ag+ ions, sharp-edged nanoflowers could be synthesized. The mechanism of nanoparticle formation can be understood to be a non-diffusion-limited Ostwald ripening process of preordered gold nanoparticles embedded in catanionic vesicle fragments. Surface-enhanced Raman scattering experiments show an excellent enhancement factor of 1.7 · 105 for the nanoflowers deposited on a silicon wafer.

  13. Alternative Plasmonic Materials: Beyond Gold and Silver

    DEFF Research Database (Denmark)

    Naik, Gururaj V.; Shalaev, Vladimir M.; Boltasseva, Alexandra

    2013-01-01

    such as gold and silver, that exhibit metallic properties and provide advantages in device performance, design flexibility, fabrication, integration, and tunability. This review explores different material classes for plasmonic and metamaterial applications, such as conventional semiconductors, transparent...

  14. Adsorption-induced restructuring of gold nanochains

    DEFF Research Database (Denmark)

    Bahn, Sune Rastad; Lopez, Nuria; Nørskov, Jens Kehlet

    2002-01-01

    The chemical properties of single-atomic chains of gold atoms are investigated using density functional calculations. The nanochains are shown to be unusually chemically active with strong chemisorption of oxygen atoms and carbon monoxide. The chemisorption energies vary significantly with the st......The chemical properties of single-atomic chains of gold atoms are investigated using density functional calculations. The nanochains are shown to be unusually chemically active with strong chemisorption of oxygen atoms and carbon monoxide. The chemisorption energies vary significantly...... with the strain/stress conditions for the chain. Oxygen atoms are found to energetically prefer to get incorporated into a chain forming a new type of gold-oxygen nanochain with a conductance of one quantum unit. We suggest that the long bond lengths observed in electron microscopy investigations of gold chains...

  15. Synthesis method of asymmetric gold particles.

    Science.gov (United States)

    Jun, Bong-Hyun; Murata, Michael; Hahm, Eunil; Lee, Luke P

    2017-06-07

    Asymmetric particles can exhibit unique properties. However, reported synthesis methods for asymmetric particles hinder their application because these methods have a limited scale and lack the ability to afford particles of varied shapes. Herein, we report a novel synthetic method which has the potential to produce large quantities of asymmetric particles. Asymmetric rose-shaped gold particles were fabricated as a proof of concept experiment. First, silica nanoparticles (NPs) were bound to a hydrophobic micro-sized polymer containing 2-chlorotritylchloride linkers (2-CTC resin). Then, half-planar gold particles with rose-shaped and polyhedral structures were prepared on the silica particles on the 2-CTC resin. Particle size was controlled by the concentration of the gold source. The asymmetric particles were easily cleaved from the resin without aggregation. We confirmed that gold was grown on the silica NPs. This facile method for synthesizing asymmetric particles has great potential for materials science.

  16. Gold in the past, today and future

    Directory of Open Access Journals (Sweden)

    R. Rudolf

    2012-04-01

    Full Text Available This paper deals with gold, which is described as a chemical element. Special attention is paid to its physical-chemical properties and, furthermore, where or in what form it can be found in nature. We discuss the role it has played through history and we inform how gold has been developed to the level it has reached today’s value. Still more, when gold is broken into nanoparticles, this form could be highly useful for a wide range of processes, including general nanotechnology, electronics manufacturing and the synthesizing of different functional materials. It is important that we know that gold is also used in industry in many engineering applications (contacts in micro-electronics and medicine (dental alloys, implants.

  17. EOP Gold Coral (Gerardia sp.) Growth Measurements

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Gold coral (Gerardia sp.) trees that were inspected years earlier on Pisces submersible dives were revisited and their change in size measured. The fishery for...

  18. Body weight relationships in early marriage. Weight relevance, weight comparisons, and weight talk.

    Science.gov (United States)

    Bove, Caron F; Sobal, Jeffery

    2011-12-01

    This investigation uncovered processes underlying the dynamics of body weight and body image among individuals involved in nascent heterosexual marital relationships in Upstate New York. In-depth, semi-structured qualitative interviews conducted with 34 informants, 20 women and 14 men, just prior to marriage and again one year later were used to explore continuity and change in cognitive, affective, and behavioral factors relating to body weight and body image at the time of marriage, an important transition in the life course. Three major conceptual themes operated in the process of developing and enacting informants' body weight relationships with their partner: weight relevance, weight comparisons, and weight talk. Weight relevance encompassed the changing significance of weight during early marriage and included attracting and capturing a mate, relaxing about weight, living healthily, and concentrating on weight. Weight comparisons between partners involved weight relativism, weight competition, weight envy, and weight role models. Weight talk employed pragmatic talk, active and passive reassurance, and complaining and critiquing criticism. Concepts emerging from this investigation may be useful in designing future studies of and approaches to managing body weight in adulthood. Copyright © 2011 Elsevier Ltd. All rights reserved.

  19. The gold standard as a rule

    OpenAIRE

    Michael D. Bordo; Finn E. Kydland

    1992-01-01

    In this paper, we show that the monetary rule followed by a number of key countries, especially England and to a lesser extent the U. S., before 1914 represented a commitment technology preventing the monetary authorities from changing planned future policy. The experiences of these major countries suggest that the gold standard was intended as a contingent rule. By that, we mean, that the authorities could temporarily abandon the fixed price of gold during a wartime emergency on the understa...

  20. Neutron microtomography of voids in gold

    Directory of Open Access Journals (Sweden)

    Pavel Trtik

    2017-01-01

    Full Text Available Pilot attempt of the neutron microtomography of voids in gold carried out using the Neutron Microscope instrument is presented in the paper. The paper demonstrates that neutron microtomography provides viable alternative to X-ray imaging for the assessment of porosity in high atomic number materials. The model sample based on gold with artificially induced void system reveals segmented porosity with 5.4 micrometres voxel size and the spatial resolution close to 10 micrometres.

  1. Uranium extraction from gold-uranium ores

    Energy Technology Data Exchange (ETDEWEB)

    Laskorin, B.N.; Golynko, Z.Sh.

    1981-01-01

    The process of uranium extraction from gold-uranium ores in the South Africa is considered. Flowsheets of reprocessing gold-uranium conglomerates, pile processing and uranium extraction from the ores are presented. Continuous counter flow ion-exchange process of uranium extraction using strong-active or weak-active resins is noted to be the most perspective and economical one. The ion-exchange uranium separation with the succeeding extraction is also the perspective one.

  2. Numerical simulations of nanostructured gold films

    DEFF Research Database (Denmark)

    Repan, Taavi; Frydendahl, Christian; Novikov, Sergey M.

    2017-01-01

    We present an approach to analyse near-field effects on nanostructured gold films by finite element simulations. The studied samples are formed by fabricating gold films near the percolation threshold and then applying laser damage. Resulting samples have complicated structures, which then was ca...... then was captured using scanning transmission electron microscopy (STEM) and the obtained dark field images are used to set up COMSOL simulations corresponding to actual structures....

  3. The Modern Monetary System and Gold

    Directory of Open Access Journals (Sweden)

    N N Rubtsov

    2013-12-01

    Full Text Available The article considers the nature of modern money, analyzes the mechanism of its creation, showing that it is basically generated by credit and the principle of partial bank reserve. The article draws comparative parallels between trade money based on gold and contemporary, credit money; the author quotes leading bankers and finance experts on the need for partial return to the principles of functioning of the gold standard as the most effective institute of regulating the monetary system in society.

  4. Synthesis of radioactive gold nanoparticle in surfactant medium

    International Nuclear Information System (INIS)

    Swadesh Mandal

    2014-01-01

    The present study describes the synthesis of radioactive gold nanoparticle in surfactant medium. Proton irradiated stable 197 Au and radioactive 198 Au were simultaneously used for production of radioactive gold nanoparticle. Face centered cubic gold nanoparticles with size of 4-50 nm were found in proton irradiated gold foil. However, the size of nanoparticle varies with pH using both stable and radioactive gold. (author)

  5. Gold Nanocages for Biomedical Applications**

    Science.gov (United States)

    Skrabalak, Sara E.; Chen, Jingyi; Au, Leslie; Lu, Xianmao; Li, Xingde; Xia, Younan

    2008-01-01

    Nanostructured materials provide a promising platform for early cancer detection and treatment. Here we highlight recent advances in the synthesis and use of Au nanocages for such biomedical applications. Gold nanocages represent a novel class of nanostructures, which can be prepared via a remarkably simple route based on the galvanic replacement reaction between Ag nanocubes and HAuCl4. The Au nanocages have a tunable surface plasmon resonance peak that extends into the near-infrared, where the optical attenuation caused by blood and soft tissue is essentially negligible. They are also biocompatible and present a well-established surface for easy functionalization. We have tailored the scattering and absorption cross-sections of Au nanocages for use in optical coherence tomography and photothermal treatment, respectively. Our preliminary studies show greatly improved spectroscopic image contrast for tissue phantoms containing Au nanocages. Our most recent results also demonstrate the photothermal destruction of breast cancer cells in vitro by using immuno-targeted Au nanocages as an effective photo-thermal transducer. These experiments suggest that Au nanocages may be a new class of nanometer-sized agents for cancer diagnosis and therapy. PMID:18648528

  6. Gold Nanocages for Biomedical Applications.

    Science.gov (United States)

    Skrabalak, Sara E; Chen, Jingyi; Au, Leslie; Lu, Xianmao; Li, Xingde; Xia, Younan

    2007-10-17

    Nanostructured materials provide a promising platform for early cancer detection and treatment. Here we highlight recent advances in the synthesis and use of Au nanocages for such biomedical applications. Gold nanocages represent a novel class of nanostructures, which can be prepared via a remarkably simple route based on the galvanic replacement reaction between Ag nanocubes and HAuCl(4). The Au nanocages have a tunable surface plasmon resonance peak that extends into the near-infrared, where the optical attenuation caused by blood and soft tissue is essentially negligible. They are also biocompatible and present a well-established surface for easy functionalization. We have tailored the scattering and absorption cross-sections of Au nanocages for use in optical coherence tomography and photothermal treatment, respectively. Our preliminary studies show greatly improved spectroscopic image contrast for tissue phantoms containing Au nanocages. Our most recent results also demonstrate the photothermal destruction of breast cancer cells in vitro by using immuno-targeted Au nanocages as an effective photo-thermal transducer. These experiments suggest that Au nanocages may be a new class of nanometer-sized agents for cancer diagnosis and therapy.

  7. Metal enhanced fluorescence with gold nanoparticles

    Science.gov (United States)

    Mattingly, Shaina LaRissa Strating

    A novel hybrid nanocomposite of Au nanoparticle-modified silicon nanowire was developed for surface enhanced fluorescence applications. The designed nanocomposite contained a silicon nanowire, gold nanoparticles and a silica layer doped with dye molecules. The hybrid nanomaterial was characterized using scanning electron microscopy (SEM), scanning transmission electron microscopy (STEM), fluorescence measurements, Fourier transform infrared (FT-IR) spectroscopy, and energy-dispersive X-ray spectroscopy (EDS). The results showed that the gold nanoparticles were uniformly adhered on the silicon nanowires and covered by a thin silica layer. The nanostructure exhibited strong capacity for surface enhanced fluorescence. Different enhancement factors were obtained by changing synthetic conditions. The second goal of the project was to determine if the shape of gold nanoparticles affects the extent of its fluorescence enhancement under constant external factors. Two shapes of gold nanoparticles were synthesized and characterized by SEM, STEM, zeta potential and absorbance measurements. Then they were coated with fluorescent dye-doped silica and the fluorescence intensity was measured and compared to the pure fluorescent dye. Gold nanorods enhanced fluorescence more than gold nanostars and that the fluorescent dye Alexafluor 700 showed a greater fluorescence intensity change in the presence of nanoparticles than methylene blue.

  8. Milan's 1879 and 1882 gold coins

    Directory of Open Access Journals (Sweden)

    Pantelić Svetlana

    2014-01-01

    Full Text Available Following the exhausting wars against Turkey, Prince Milan Obrenović decided to mint larger denominations of silver and gold coins. The decision on minting these coins was explained by the fact that for the purpose of foreign payments, the expensive foreign money will no longer have to be purchased, given that the Serbian money will be recognized at its nominal value outside Serbia as well. The Law on the Serbian National Money confirmed by Prince Milan on December 10th 1878 introduced new types of metal coins into the monetary system of Serbia: 10 and 20 dinars in gold, 5 dinars in silver, and 2 paras in copper. All these coins were minted in 1879, except for the 10-dinar gold coin, minted when Prince Milan became the King, bearing the inscription of 1882. There were only 50,000 pieces of the 20-dinar gold coins minted, and it was legal tender in the Principality and Kingdom of Serbia, as well as in the Kingdom of Serbs, Croats and Slovenes, and in the Kingdom of Yugoslavia, for full 52 years. In 1882 there were 500,000 pieces of 10-dinar gold coins and 200,000 pieces of 20-dinar gold coins minted. They were named Milandors, and were used as official legal tender until June 28th 1931.

  9. Photochemical synthesis of polygonal gold nanoparticles

    International Nuclear Information System (INIS)

    Huang, W.-C.; Chen, Y.-C.

    2008-01-01

    In this paper, we propose a method to generate gold nanoparticles capable of absorbing near infrared light (NIR) radiation through a photochemical reaction. This approach does not require the use of either surfactants or polymers, reducing the difficulties that may arise in further chemical modifications for the gold nanoparticles. The gold nanoparticles with either triangular or hexagonal shapes were generated using the photo-reduction method, mixing hydrogen tetrachloroaurate with sodium oxalate, a reducing agent, in aqueous solution under illumination of a mercury lamp (λ max = 306 nm) for more than 10 min. The size of the gold nanoparticles varies from 25 to 200 nm, which mainly depends on the duration of light illumination and the concentration of sodium oxalate. Furthermore, we demonstrate that the presence of the gold nanoparticles in aqueous solutions can effectively elevate the temperature of the solutions under irradiation of NIR light (808 nm) within a few minutes. The gold nanoparticles can be potentially used as suitable photothermal agents for hyperthermia

  10. Study on Sumbawa gold recovery using centrifuge

    Science.gov (United States)

    Ferdana, A. D.; Petrus, H. T. B. M.; Bendiyasa, I. M.; Prijambada, I. D.; Hamada, F.; Sachiko, T.

    2018-01-01

    The Artisanal Small Gold Mining in Sumbawa has been processing gold with mercury (Hg), which poses a serious threat to the mining and global environment. One method of gold processing that does not use mercury is by gravity method. Before processing the ore first performed an analysis of Mineragraphy and analysis of compound with XRD. Mineragraphy results show that gold is associated with chalcopyrite and covelite and is a single particle (native) on size 58.8 μm, 117 μm up to 294 μm. characterization with XRD shows that the Sumbawa Gold Ore is composed of quartz, pyrite, pyroxene, and sericite compounds. Sentrifugation is one of separation equipment of gravity method to increase concentrate based on difference of specific gravity. The optimum concentration result is influenced by several variables, such as water flow rate and particle size. In this present research, the range of flow rate is 5 lpm and 10 lpm, the particle size - 100 + 200 mesh and -200 +300 mesh. Gold concentration in concentrate is measured by EDX. The result shows that the optimum condition is obtained at a separation with flow rate 5 lpm and a particle size of -100 + 200 mesh.

  11. Analysis on the Impact of the Fluctuation of the International Gold Prices on the Chinese Gold Stocks

    Directory of Open Access Journals (Sweden)

    Jiankang Jin

    2014-01-01

    Full Text Available Five gold stocks in Chinese Shanghai and Shenzhen A-share and Comex gold futures are chosen to form the sample, for the purpose of analysing the impact of the fluctuation of the international gold prices on the gold stocks in Chinese Shanghai and Shenzhen A-share. Using the methods of unit root test, Granger causality test, VAR model, and impulse response function, this paper has analysed the relationship between the price change of the international gold futures and the price fluctuation of gold stocks in Chinese Shanghai and Shenzhen comprehensively. The results suggest the fluctuation of the international gold futures has a strong influence on the domestic futures.

  12. Gold grade distribution within an epithermal quartz vein system, Kestanelik, NW Turkey: implications for gold exploration

    Science.gov (United States)

    Gulyuz, Nilay; Shipton, Zoe; Gulyuz, Erhan; Lord, Richard; Kaymakci, Nuretdin; Kuscu, İlkay

    2017-04-01

    Vein-hosted gold deposits contribute a large part to the global gold production. Discovery of these deposits mainly include drilling of hundreds of holes, collecting thousands of soil and rock samples and some geophysical surveys which are expensive and time consuming. Understanding the structures hosting the veins and the variations in gold concentrations within the veins is crucial to constrain a more economic exploration program. The main aim of this study is to investigate the gold grade distribution in the mineralized quartz veins of a well exposed epithermal gold deposit hosted by Paleozoic schist and Eocene quartz-feldspar-hornblende porphyry in Lapseki, NW Turkey. We have constructed 3D architecture of the vein surfaces by mapping their outcrop geometries using a highly sensitive Trimble GPS, collecting detailed field data, well-logs and geochemistry data from 396 drill holes (255 diamond cut and 141 reverse circulation holes). Modelling was performed in MOVE Structural Modelling and Analysis software granted by Midland Valley's Academic Software Initiative, and GIS application softwares Global Mapper and Esri-ArcGIS. We envisaged that while fluid entering the conduit ascents, a sudden thickness increase in the conduit would lead to a drop in the fluid pressure causing boiling (the most dominant gold precipitation mechanism) and associated gold precipitation. Regression analysis was performed between the orthogonal thickness values and gold grades of each vein, and statistical analyses were performed to see if the gold is concentrated at specific structural positions along dip. Gold grades in the alteration zones were compared to those in the adjacent veins to understand the degree of mineralization in alteration zones. A possible correlation was also examined between the host rock type and the gold grades in the veins. These studies indicated that gold grades are elevated in the adjacent alteration zones where high gold grades exist in the veins. Schist

  13. Development of Noncytotoxic Chitosan–Gold Nanocomposites as Efficient Antibacterial Materials

    Science.gov (United States)

    2014-01-01

    This work describes the synthesis and characterization of noncytotoxic nanocomposites either colloidal or as films exhibiting high antibacterial activity. The biocompatible and biodegradable polymer chitosan was used as reducing and stabilizing agent for the synthesis of gold nanoparticles embedded in it. Herein, for the first time, three different chitosan grades varying in the average molecular weight and deacetylation degree (DD) were used with an optimized gold precursor concentration. Several factors were analyzed in order to obtain antimicrobial but not cytotoxic nanocomposite materials. Films based on chitosan with medium molecular weight and the highest DD exhibited the highest antibacterial activity against biofilm forming strains of Staphylococcus aureus and Pseudomonas aeruginosa. The resulting nanocomposites did not show any cytotoxicity against mammalian somatic and tumoral cells. They produced a disruptive effect on the bacteria wall while their internalization was hindered on the eukaryotic cells. This selectivity and safety make them potentially applicable as antimicrobial coatings in the biomedical field. PMID:25522372

  14. Development of noncytotoxic chitosan-gold nanocomposites as efficient antibacterial materials.

    Science.gov (United States)

    Regiel-Futyra, Anna; Kus-Liśkiewicz, Małgorzata; Sebastian, Victor; Irusta, Silvia; Arruebo, Manuel; Stochel, Grażyna; Kyzioł, Agnieszka

    2015-01-21

    This work describes the synthesis and characterization of noncytotoxic nanocomposites either colloidal or as films exhibiting high antibacterial activity. The biocompatible and biodegradable polymer chitosan was used as reducing and stabilizing agent for the synthesis of gold nanoparticles embedded in it. Herein, for the first time, three different chitosan grades varying in the average molecular weight and deacetylation degree (DD) were used with an optimized gold precursor concentration. Several factors were analyzed in order to obtain antimicrobial but not cytotoxic nanocomposite materials. Films based on chitosan with medium molecular weight and the highest DD exhibited the highest antibacterial activity against biofilm forming strains of Staphylococcus aureus and Pseudomonas aeruginosa. The resulting nanocomposites did not show any cytotoxicity against mammalian somatic and tumoral cells. They produced a disruptive effect on the bacteria wall while their internalization was hindered on the eukaryotic cells. This selectivity and safety make them potentially applicable as antimicrobial coatings in the biomedical field.

  15. Proven Weight Loss Methods

    Science.gov (United States)

    Fact Sheet Proven Weight Loss Methods What can weight loss do for you? Losing weight can improve your health in a number of ways. ... limiting calories) usually isn’t enough to cause weight loss. But exercise plays an important part in helping ...

  16. The utility of weight loss medications after bariatric surgery for weight regain or inadequate weight loss: A multi-center study.

    Science.gov (United States)

    Stanford, Fatima Cody; Alfaris, Nasreen; Gomez, Gricelda; Ricks, Elizabeth T; Shukla, Alpana P; Corey, Kathleen E; Pratt, Janey S; Pomp, Alfons; Rubino, Francesco; Aronne, Louis J

    2017-03-01

    Patients who undergo bariatric surgery often have inadequate weight loss or weight regain. We sought to discern the utility of weight loss pharmacotherapy as an adjunct to bariatric surgery in patients with inadequate weight loss or weight regain. Two academic medical centers. We completed a retrospective study to identify patients who had undergone bariatric surgery in the form of a Roux-en-Y gastric bypass (RYGB) or a sleeve gastrectomy from 2000-2014. From this cohort, we identified patients who were placed on weight loss pharmacotherapy postoperatively for inadequate weight loss or weight regain. We extracted key demographic data, medical history, and examined weight loss in response to surgery and after the initiation of weight loss pharmacotherapy. A total of 319 patients (RYGB = 258; sleeve gastrectomy = 61) met inclusion criteria for analysis. More than half (54%; n = 172) of all study patients lost≥5% (7.2 to 195.2 lbs) of their total weight with medications after surgery. There were several high responders with 30.3% of patients (n = 96) and 15% (n = 49) losing≥10% (16.7 to 195.2 lbs) and≥15% (25 to 195.2 lbs) of their total weight, respectively, Topiramate was the only medication that demonstrated a statistically significant response for weight loss with patients being twice as likely to lose at least 10% of their weight when placed on this medication (odds ratio = 1.9; P = .018). Regardless of the postoperative body mass index, patients who underwent RYGB were significantly more likely to lose≥5% of their total weight with the aid of weight loss medications. Weight loss pharmacotherapy serves as a useful adjunct to bariatric surgery in patients with inadequate weight loss or weight regain. Copyright © 2017 American Society for Bariatric Surgery. Published by Elsevier Inc. All rights reserved.

  17. Tectonic setting of Late Cenozoic gold mineralization in the gold belt of Costa Rica

    Energy Technology Data Exchange (ETDEWEB)

    Deruyter, V.D.

    1985-01-01

    The Gold Belt of Costa Rica is a northwest-elongated zone 15 km wide by 120 km long containing numerous auriferous quartz veins and pyritic silicified patterns upon which abundant small mines are developed. Gold veins are related principally to northeast-southwest and north-south striking, steeply dipping faults. Higher grade ore and thicker veins invariably occur at intersections of these fracture orientations, indicating simultaneous opening at the time of gold introduction. Restriction of gold veins to the northwest-trending arc of Miocene Aguacate Group andesite volcanic rocks, a product of Cocos Plate subduction, suggested approximately coeval formation, but recognition by the writer of the important role played by 2-5 m.y. old altered, gold mineralized rhyolite dikes intruded along north-south gold vein structures and intimately involved with high grade ores at the Esperanza Mine and Rio Chiquito prospect, for example, suggest a much younger period of fracturing and gold introduction. The rhyolite intrusions are more brittle and stockwork mineralized than andesite host rocks and form bulk tonnage gold targets. Initiation of right-lateral movement along the north-south Panama Fracture Zone at 5 m.y.a. within the pattern of northeastward Cocos Plate subduction may have tapped rhyolites from subvolcanic magma chambers into new faults.

  18. Gold and gold-copper nanoparticles in 2-propanol: A radiation chemical study

    International Nuclear Information System (INIS)

    Dey, G.R.

    2011-01-01

    The studies on the reduction of Au 3+ to gold nanoparticles in presence and absence of Cu 2+ under deoxygenated conditions in 2-propanol by radiolytic method have been carried out. On γ-radiolysis, preliminary yellow colored solution of Au 3+ changed to purple color owing to gold nanoparticles formation, which exhibits an absorption peak at around 540 nm. In the presence of Cu 2+ , absorption of gold-copper nanoparticles, which was also produced during γ-radiolysis, was red shifted in contrast to the system containing no Cu 2+ . Under DLS studies the sizes of gold nanoparticles in the absence and the presence of Cu 2+ were found to be larger (>400 nm). However, in presence of polyethylene glycol, a stabilizer the nanoparticle sizes became smaller, sizes measured for gold and gold-copper nanoparticles are 40 and 140 nm, respectively. Moreover, the change in UV-vis spectra in the Cu 2+ and Au 3+ mixed system highlights the formation of gold-copper nanoparticles in core-shell type arrangement. - Highlights: → Present radiation chemical study highlights high reactivity of Au ·2+ with Cu 2+ . → Absorption of gold-copper nanoparticles is blue shifted as compared to copper nanoparticles. → Change in UV-vis spectra with dose emphasizes core-shell type arrangement of Au-Cu nanoparticles.

  19. Gold Nanoparticles Obtained by Bio-precipitation from Gold(III) Solutions

    International Nuclear Information System (INIS)

    Gardea-Torresdey, J.L.; Tiemann, K.J.; Gamez, G.; Dokken, K.; Tehuacanero, S.; Jose-Yacaman, M.

    1999-01-01

    The use of metal nanoparticles has shown to be very important in recent industrial applications. Currently gold nanoparticles are being produced by physical methods such as evaporation. Biological processes may be an alternative to physical methods for the production of gold nanoparticles. Alfalfa biomass has shown to be effective at passively binding and reducing gold from solutions containing gold(III) ions and resulting in the formation of gold(0) nanoparticles. High resolution microscopy has shown that five different types of gold particles are present after reaction with gold(III) ions with alfalfa biomass. These particles include: fcc tetrahedral, hexagonal platelet, icosahedral multiple twinned, decahedral multiple twinned, and irregular shaped particles. Further analysis on the frequency of distribution has shown that icosahedral and irregular particles are more frequently formed. In addition, the larger particles observed may be formed through the coalescence of smaller particles. Through modification of the chemical parameters, more uniform particle size distribution may be obtained by the alfalfa bio-reduction of gold(III) from solution

  20. Genesis of uranium-gold pyritic conglomerates

    International Nuclear Information System (INIS)

    Myers, W.B.

    1981-01-01

    The ancient pyritic ore conglomerates have a common origin best exemplified by the Witwatersrand deposits. All contain detrital pyrite and uraninite, which are unstable in modern oxygenated environments and were deposited in a reducing atmosphere. The Rand reefs are not similar to modern gold placers. Placers result from the near incapacity of streams and currents to transport coarse gold. Placers as rich as Rand reef occur only in narrow paystreaks within 15 kilometers of a coarse-gold source. The board dispersion of gold in the reefs is due to solution transport of metal complexed as aurous sulfide, leached anoxygenically from crustal rocks, probably from sea-floor basalt, and precipitated by a slow reaction driven by the radioactive decay of detrital uraninite. Radiolysis of water on shallow marine unconformities resulted in diffusion of hydrogen to the atmosphere and a slight excess of hydroxyl free radical in the reef environment. The mild oxidizing tendency slowly dissolved uranium, precipitated gold, and oxygenated thucholite. These actions define a maturing process. A uraninite placer accumulating on an unconformity becomes progressively converted to a gold reef with little residual uraninite. The most mature reefs tend to grade toward the thucholite-seam type, very thin but exceedingly rich in gold. A combination of chemical attack and physical reworking accounts for the general thinness of mature reefs. Pyrite, like uraninite, decreases in abundance with increasing maturity; buffering by pyrite moderated the oxidative depletion of uranium. Where pyrite was scanty or absent, uraninite was completely dissolved by the effects of radiolysis and no ore formed

  1. Prediction of Pathological Complete Response Using Endoscopic Findings and Outcomes of Patients Who Underwent Watchful Waiting After Chemoradiotherapy for Rectal Cancer.

    Science.gov (United States)

    Kawai, Kazushige; Ishihara, Soichiro; Nozawa, Hiroaki; Hata, Keisuke; Kiyomatsu, Tomomichi; Morikawa, Teppei; Fukayama, Masashi; Watanabe, Toshiaki

    2017-04-01

    Nonoperative management for patients with rectal cancer who have achieved a clinical complete response after chemoradiotherapy is becoming increasingly important in recent years. However, the definition of and modality used for patients with clinical complete response differ greatly between institutions, and the role of endoscopic assessment as a nonoperative approach has not been fully investigated. This study aimed to investigate the ability of endoscopic assessments to predict pathological regression of rectal cancer after chemoradiotherapy and the applicability of these assessments for the watchful waiting approach. This was a retrospective comparative study. This study was conducted at a single referral hospital. A total of 198 patients with rectal cancer underwent preoperative endoscopic assessments after chemoradiotherapy. Of them, 186 patients underwent radical surgery with lymph node dissection. The histopathological findings of resected tissues were compared with the preoperative endoscopic findings. Twelve patients refused radical surgery and chose watchful waiting; their outcomes were compared with the outcomes of patients who underwent radical surgery. The endoscopic criteria correlated well with tumor regression grading. The sensitivity and specificity for a pathological complete response were 65.0% to 87.1% and 39.1% to 78.3%. However, endoscopic assessment could not fully discriminate pathological complete responses, and the outcomes of patients who underwent watchful waiting were considerably poorer than the patients who underwent radical surgery. Eventually, 41.7% of the patients who underwent watchful waiting experienced uncontrollable local failure, and many of these occurrences were observed more than 3 years after chemoradiotherapy. The number of the patients treated with the watchful waiting strategy was limited, and the selection was not randomized. Although endoscopic assessment after chemoradiotherapy correlated with pathological response

  2. Gold leaf counter electrodes for dye-sensitized solar cells

    Science.gov (United States)

    Shimada, Kazuhiro; Toyoda, Takeshi

    2018-03-01

    In this study, a gold leaf 100 nm thin film is used as the counter electrode in dye-sensitized solar cells. The traditional method of hammering gold foil to obtain a thin gold leaf, which requires only small amounts of gold, was employed. The gold leaf was then attached to the substrate using an adhesive to produce the gold electrode. The proposed approach for fabricating counter electrodes is demonstrated to be facile and cost-effective, as opposed to existing techniques. Compared with electrodes prepared with gold foil and sputtered gold, the gold leaf counter electrode demonstrates higher catalytic activity with a cobalt-complex electrolyte and higher cell efficiency. The origin of the improved performance was investigated by surface morphology examination (scanning electron microscopy), various electrochemical analyses (cyclic voltammetry, linear sweep voltammetry, and electrochemical impedance spectroscopy), and crystalline analysis (X-ray diffractometry).

  3. Molecular dynamics simulations on the melting of gold nanoparticles

    Science.gov (United States)

    Qiao, Zhiwei; Feng, Haijun; Zhou, Jian

    2014-01-01

    Molecular dynamics is employed to study the melting of bulk gold and gold nanoparticles. PCFF, Sutton-Chen and COMPASS force fields are adopted to study the melting point of bulk gold and we find out that the Sutton-Chen force field is the most accurate model in predicting the melting point of bulk gold. Consequently, the Sutton-Chen force field is applied to study the melting points of spherical gold nanoparticles with different diameters. Variations of diffusion coefficient, potential energy and translational order parameter with temperature are analyzed. The simulated melting points of gold nanoparticles are between 615∼1115 K, which are much lower than that of bulk gold (1336 K). As the diameter of gold nanoparticle drops, the melting point also descends. The melting mechanism is also analyzed for gold nanoparticles.

  4. Moessbauer study of the chemical state of gold in gold ores

    International Nuclear Information System (INIS)

    Wagner, F.E.; Marion, P.H.; Regnard, J.-R.

    1986-01-01

    Information on the chemical state of gold in gold ores has been obtained by 197 Au Moessbauer spectroscopy in cases where the state of this element cannot be determined by such standard methods as optical or electron microscopy. Ore concentrates consisting mainly of pyrite or arsenopyrite and roasted ore and matte samples were studied. The results yielded directly the respective amounts of metallic and chemically bound gold. Unless the gold is metallic, its chemical state in the ores turns out to be different from that in the minerals studied so far as reference materials. The chemical processes taking place during various treatments of the ores, such as roasting or leaching, can also be followed by Moessbauer spectroscopy. It is hoped that Moessbauer spectroscopy will eventually facilitate the development of more efficient methods of gold extraction

  5. Effect of clothing weight on body weight.

    Science.gov (United States)

    Whigham, L D; Schoeller, D A; Johnson, L K; Atkinson, R L

    2013-01-01

    In clinical settings, it is common to measure weight of clothed patients and estimate a correction for the weight of clothing, but we can find no papers in the medical literature regarding the variability in clothing weight of adults with weather, season and gender. Fifty adults (35 women) were weighed four times during a 12-month period with and without clothing. Clothing weights were determined and regressed against minimum, maximum and average daily outdoor temperature. The average clothing weight (±s.d.) throughout the year was significantly greater in men than in women (1.2±0.3 vs 0.8±0.3 kg, Pclothing weights across the year were 0.9±0.2 and 1.5±0.4 kg for men, and 0.5±0.2 and 1.1±0.4 kg for women, respectively. The within-person s.d. in clothing weight was 0.3 kg for both men and women. Over the 55 °C range in the lowest to the highest outdoor temperatures, the regressions predicted a maximal change in clothing weight of only 0.4 kg in women and 0.6 kg in men. The clothing weight of men is significantly greater than that of women, but there is little variability throughout the year. Therefore, a clothing adjustment of approximately 0.8 kg for women and 1.2 kg for men is appropriate regardless of outdoor temperature.

  6. Synthesis and characterization of thiolated pectin stabilized gold coated magnetic nanoparticles

    International Nuclear Information System (INIS)

    Arora, Varun; Sood, Ankur; Shah, Jyoti; Kotnala, R.K.; Jain, Tapan K.

    2016-01-01

    Core–shell nanoparticles, magnetic core and gold shell, were synthesized by reduction of gold chloride on the surface of magnetic nanoparticles; using tyrosine as a reducing agent. The formation of gold shell on magnetic nanoparticles was confirmed by X-ray diffraction (XRD) and UV-Visible spectroscopy. The core–shell nanoparticles (CSn) were conjugated with thiolated pectin to form a stable aqueous dispersion. The hydrodynamic size of thiolated pectin stabilized core–shell nanoparticles (TP-CSn) measured by Dynamic light scattering (DLS) was 160.5 nm with a poly dispersity index (PDI) of 0.302, whereas the mean particle size of TP-CSn calculated by high resolution transmission electron microscopy (HRTEM) was 10.8 ± 2.7 nm. The value of zeta potential for TP-CSn was −13.6 mV. There was a decrease in the value of saturation magnetization upon formation of the gold shell on magnetic nanoparticles. The amount of thiolated pectin bound to the surface of core–shell nanoparticles, calculated using Thermogravimetric analysis (TGA), was 6% of sample weight. - Highlights: • Use of side group of tyrosine (phenol) as a pH dependent reducing agent to synthesize gold coated magnetic nanoparticles. • Successful coating of gold shell on magnetic nanoparticles core. • Synthesis of thiolated pectin and stabilization of aqueous dispersion of core–shell nanoparticles with thiolated pectin. • The superparamagnetic behaviour of magnetic nanoparticles is retained after shell formation.

  7. Correlating self-assembly of block copolymers for their application in synthesis of gold nanoparticles.

    Science.gov (United States)

    Ray, Debes; Aswall, Vinod Kumar; Srivastava, Dinesh

    2011-03-01

    We report the role of self-assembly of polyethylene oxide-polypropylene oxide-polyethylene oxide (PEO-PPO-PEO) block copolymers for the synthesis of gold nanoparticles from hydrogen tetrachloroaureate (III) hydrate (HAuCl4 x 3H2O) in aqueous solution. The synthesis has been carried out using three different block copolymers P85 [EO26PO39EO26], F88 [EO103PO39EO103] and P105 [EO37PO56EO37], which not only have varying molecular weight but also differ in hydrophobicity to hydrophilicity ratio. The formation of gold nanoparticles is confirmed by the UV-Visible Spectroscopy. Transmission electron microscopy (TEM) provides the sizes of the nanoparticles formed in these systems. Small-Angle Neutron Scattering (SANS) and Dynamic Light Scattering (DLS) techniques are used to correlate the self-assembly of block copolymer to their propensity to form gold nanoparticles. The yield is found to be in the order P105 > P85 > F88 and is related to the higher tendency of block copolymer to self-assemble to give greater yield of gold nanoparticles. For all the block copolymers, SANS and DLS results suggests that the yield in the synthesis does not always increases with the salt concentration and is limited due to the fact that most of the block copolymers remain unassociated with the gold nanoparticles. By making use of these unassociated block copolymers, we propose two methods (i) step addition method and (ii) additional reductant method, where the synthesis yield of gold nanoparticles can be enhanced by manifold.

  8. Silver, gold, and alloyed silver–gold nanoparticles: characterization and comparative cell-biologic action

    International Nuclear Information System (INIS)

    Mahl, Dirk; Diendorf, Jörg; Ristig, Simon; Greulich, Christina; Li Zian; Farle, Michael; Köller, Manfred; Epple, Matthias

    2012-01-01

    Silver, gold, and silver–gold-alloy nanoparticles were prepared by citrate reduction modified by the addition of tannin during the synthesis, leading to a reduction in particle size by a factor of three. Nanoparticles can be prepared by this easy water-based synthesis and subsequently functionalized by the addition of either tris(3-sulfonatophenyl)phosphine or poly(N-vinylpyrrolidone). The resulting nanoparticles of silver (diameter 15–25 nm), gold (5–6 nm), and silver–gold (50:50; 10–12 nm) were easily dispersable in water and also in cell culture media (RPMI + 10 % fetal calf serum), as shown by nanoparticle tracking analysis and differential centrifugal sedimentation. High-resolution transmission electron microscopy showed a polycrystalline nature of all nanoparticles. EDX on single silver–gold nanoparticles indicated that the concentration of gold is higher inside a nanoparticle. The biologic action of the nanoparticles toward human mesenchymal stem cells (hMSC) was different: Silver nanoparticles showed a significant concentration-dependent influence on the viability of hMSC. Gold nanoparticles showed only a small effect on the viability of hMSC after 7 days. Surprisingly, silver–gold nanoparticles had no significant influence on the viability of hMSC despite the silver content. Silver nanoparticles and silver–gold nanoparticles in the concentration range of 5–20 μg mL −1 induced the activation of hMSC as indicated by the release of IL-8. In contrast, gold nanoparticles led to a reduction of the release of IL-6 and IL-8.

  9. Silver, gold, and alloyed silver-gold nanoparticles: characterization and comparative cell-biologic action

    Energy Technology Data Exchange (ETDEWEB)

    Mahl, Dirk; Diendorf, Joerg; Ristig, Simon [University of Duisburg-Essen, Department of Inorganic Chemistry, Center for Nanointegration Duisburg-Essen (CeNIDE) (Germany); Greulich, Christina [Ruhr-University of Bochum, Bergmannsheil University Hospital/Surgical Research (Germany); Li Zian; Farle, Michael [University of Duisburg-Essen, Faculty of Physics, Center for Nanointegration Duisburg-Essen (CeNIDE) (Germany); Koeller, Manfred [Ruhr-University of Bochum, Bergmannsheil University Hospital/Surgical Research (Germany); Epple, Matthias, E-mail: matthias.epple@uni-due.de [University of Duisburg-Essen, Department of Inorganic Chemistry, Center for Nanointegration Duisburg-Essen (CeNIDE) (Germany)

    2012-10-15

    Silver, gold, and silver-gold-alloy nanoparticles were prepared by citrate reduction modified by the addition of tannin during the synthesis, leading to a reduction in particle size by a factor of three. Nanoparticles can be prepared by this easy water-based synthesis and subsequently functionalized by the addition of either tris(3-sulfonatophenyl)phosphine or poly(N-vinylpyrrolidone). The resulting nanoparticles of silver (diameter 15-25 nm), gold (5-6 nm), and silver-gold (50:50; 10-12 nm) were easily dispersable in water and also in cell culture media (RPMI + 10 % fetal calf serum), as shown by nanoparticle tracking analysis and differential centrifugal sedimentation. High-resolution transmission electron microscopy showed a polycrystalline nature of all nanoparticles. EDX on single silver-gold nanoparticles indicated that the concentration of gold is higher inside a nanoparticle. The biologic action of the nanoparticles toward human mesenchymal stem cells (hMSC) was different: Silver nanoparticles showed a significant concentration-dependent influence on the viability of hMSC. Gold nanoparticles showed only a small effect on the viability of hMSC after 7 days. Surprisingly, silver-gold nanoparticles had no significant influence on the viability of hMSC despite the silver content. Silver nanoparticles and silver-gold nanoparticles in the concentration range of 5-20 {mu}g mL{sup -1} induced the activation of hMSC as indicated by the release of IL-8. In contrast, gold nanoparticles led to a reduction of the release of IL-6 and IL-8.

  10. Radiofrequency Heating Pathways for Gold Nanoparticles

    Science.gov (United States)

    Collins, C. B.; McCoy, R. S.; Ackerson, B. J.; Collins, G. J.

    2015-01-01

    This feature article reviews the thermal dissipation of nanoscopic gold under radiofrequency (RF) irradiation. It also presents previously unpublished data addressing obscure aspects of this phenomenon. While applications in biology motivated initial investigation of RF heating of gold nanoparticles, recent controversy concerning whether thermal effects can be attributed to nanoscopic gold highlight the need to understand the involved mechanism or mechanisms of heating. Both the nature of the particle and the nature of the RF field influence heating. Aspects of nanoparticle chemistry and physics, including the hydrodynamic diameter of the particle, the oxidation state and related magnetism of the core, and the chemical nature of the ligand shell may all strongly influence to what extent a nanoparticle heats in an RF field. Aspects of RF include: power, frequency and antenna designs that emphasize relative strength of magnetic or electric fields, and also influence the extent to which a gold nanoparticle heats in RF. These nanoparticle and RF properties are analysed in the context of three heating mechanisms proposed to explain gold nanoparticle heating in an RF field. This article also makes a critical analysis of the existing literature in the context of the nanoparticle preparations, RF structure, and suggested mechanisms in previously reported experiments. PMID:24962620

  11. The fcc structure isomerization in gold nanoclusters.

    Science.gov (United States)

    Zhuang, Shengli; Liao, Lingwen; Li, Man-Bo; Yao, Chuanhao; Zhao, Yan; Dong, Hongwei; Li, Jin; Deng, Haiteng; Li, Lingling; Wu, Zhikun

    2017-10-12

    Structural isomerization is an important concept in organic chemistry and it is recently found to be applicable to thiolated gold nanoparticles. However, to the best of our knowledge, the isomerization with the kernel structure of the cluster changed while maintaining fcc packing was not previously found. Here, we report such a structural isomerization by synthesizing a novel gold nanocluster and solving its atomic structure. The as-obtained novel gold nanocluster Au 52 (PET) 32 (PET = phenylethanethiolate) has completely the same Au/S molar ratio as a well-known gold nanocluster Au 52 (TBBT) 32 (TBBT = 4-tert-butyl-benzenethiolate) but an essentially different fcc structure. As a result of fcc structure isomerization, Au 52 (PET) 32 has remarkably different UV/vis/NIR absorption from Au 52 (TBBT) 32 . Another interesting finding in this work is that the kernel of Au 52 (PET) 32 has high-indexed (311)-like facets, which is not previously reported in the structures of gold nanoclusters to the best of our knowledge.

  12. Engineered Gold Nanoparticles and Plant Adaptation Potential

    Science.gov (United States)

    Siddiqi, Khwaja Salahuddin; Husen, Azamal

    2016-09-01

    Use of metal nanoparticles in biological system has recently been recognised although little is known about their possible effects on plant growth and development. Nanoparticles accumulation, translocation, growth response and stress modulation in plant system is not well understood. Plants exposed to gold and gold nanoparticles have been demonstrated to exhibit both positive and negative effects. Their growth and yield vary from species to species. Cytoxicity of engineered gold nanoparticles depends on the concentration, particle size and shape. They exhibit increase in vegetative growth and yield of fruit/seed at lower concentration and decrease them at higher concentration. Studies have shown that the gold nanoparticles exposure has improved free radical scavenging potential and antioxidant enzymatic activities and alter micro RNAs expression that regulate different morphological, physiological and metabolic processes in plants. These modulations lead to improved plant growth and yields. Prior to the use of gold nanoparticles, it has been suggested that its cost may be calculated to see if it is economically feasible.

  13. Gold nanoparticle-based electrochemical biosensors

    International Nuclear Information System (INIS)

    Pingarron, Jose M.; Yanez-Sedeno, Paloma; Gonzalez-Cortes, Araceli

    2008-01-01

    The unique properties of gold nanoparticles to provide a suitable microenvironment for biomolecules immobilization retaining their biological activity, and to facilitate electron transfer between the immobilized proteins and electrode surfaces, have led to an intensive use of this nanomaterial for the construction of electrochemical biosensors with enhanced analytical performance with respect to other biosensor designs. Recent advances in this field are reviewed in this article. The advantageous operational characteristics of the biosensing devices designed making use of gold nanoparticles are highlighted with respect to non-nanostructured biosensors and some illustrative examples are commented. Electrochemical enzyme biosensors including those using hybrid materials with carbon nanotubes and polymers, sol-gel matrices, and layer-by-layer architectures are considered. Moreover, electrochemical immunosensors in which gold nanoparticles play a crucial role in the electrode transduction enhancement of the affinity reaction as well as in the efficiency of immunoreagents immobilization in a stable mode are reviewed. Similarly, recent advances in the development of DNA biosensors using gold nanoparticles to improve DNA immobilization on electrode surfaces and as suitable labels to improve detection of hybridization events are considered. Finally, other biosensors designed with gold nanoparticles oriented to electrically contact redox enzymes to electrodes by a reconstitution process and to the study of direct electron transfer between redox proteins and electrode surfaces have also been treated

  14. Gold Nanoparticle Labels Amplify Ellipsometric Signals

    Science.gov (United States)

    Venkatasubbarao, Srivatsa

    2008-01-01

    The ellipsometric method reported in the immediately preceding article was developed in conjunction with a method of using gold nanoparticles as labels on biomolecules that one seeks to detect. The purpose of the labeling is to exploit the optical properties of the gold nanoparticles in order to amplify the measurable ellipsometric effects and thereby to enable ultrasensitive detection of the labeled biomolecules without need to develop more-complex ellipsometric instrumentation. The colorimetric, polarization, light-scattering, and other optical properties of nanoparticles depend on their sizes and shapes. In the present method, these size-and-shape-dependent properties are used to magnify the polarization of scattered light and the diattenuation and retardance of signals derived from ellipsometry. The size-and-shape-dependent optical properties of the nanoparticles make it possible to interrogate the nanoparticles by use of light of various wavelengths, as appropriate, to optimally detect particles of a specific type at high sensitivity. Hence, by incorporating gold nanoparticles bound to biomolecules as primary or secondary labels, the performance of ellipsometry as a means of detecting the biomolecules can be improved. The use of gold nanoparticles as labels in ellipsometry has been found to afford sensitivity that equals or exceeds the sensitivity achieved by use of fluorescence-based methods. Potential applications for ellipsometric detection of gold nanoparticle-labeled biomolecules include monitoring molecules of interest in biological samples, in-vitro diagnostics, process monitoring, general environmental monitoring, and detection of biohazards.

  15. Precipitation of lamellar gold nanocrystals in molten polymers

    Science.gov (United States)

    Palomba, M.; Carotenuto, G.

    2016-05-01

    Non-aggregated lamellar gold crystals with regular shape (triangles, squares, pentagons, etc.) have been produced by thermal decomposition of gold chloride (AuCl) molecules in molten amorphous polymers (polystyrene and poly(methyl methacrylate)). Such covalent inorganic gold salt is high soluble into non-polar polymers and it thermally decomposes at temperatures compatible with the polymer thermal stability, producing gold atoms and chlorine radicals. At the end of the gold precipitation process, the polymer matrix resulted chemically modified because of the partial cross-linking process due to the gold atom formation reaction.

  16. Protracted elimination of gold nanoparticles from mouse liver

    DEFF Research Database (Denmark)

    Sadauskas, Evaldas; Wallin, Håkan; Stoltenberg, Meredin

    2009-01-01

    The present study aims at revealing the fate of 40-nm gold nanoparticles after intravenous injections. The gold nanoparticles were traced histochemically with light and transmission electron microscopy using autometallographic (AMG) staining, and the gold content in the liver was determined......% fall in the gold content over the observed 6 months, the AMG finding of a significant reduction in the stained area of the liver sections and number of macrophages loaded with gold nanoparticles reveals that over time an increasing part of the total amount of gold nanoparticles in the liver...

  17. Geomicrobial Optical Logging Detectors (GOLD)

    Science.gov (United States)

    Bramall, N. E.; Stoker, C. R.; Price, P. B.; Coates, J. D.; Allamandola, L. J.; Mattioda, A. L.

    2008-12-01

    to in situ processes. 4) Temperature and Oxygen Sensors: The ambient temperature will be recorded as well as the presence of oxygen. Oxygen presence can be measured using a fluorescence quenching fiber optic probe to avoid interference from other gases. We forsee that this technology will enable experiments including studies of gene transfer, microbial habitat, in situ stratigraphy and hydrological processes. In addition, though designed to scan borehole walls, GOLD could be used to scan core samples as they are recovered for rapid quantification and analysis in order to discover samples of particular interest that could then be prioritized for more in-depth, traditional analysis.

  18. Long-term psychological distress, and styles of coping, in parents of children and adolescents who underwent invasive treatment for congenital cardiac disease

    NARCIS (Netherlands)

    Spijkerboer, Alinda W.; Helbing, Willem A.; Bogers, Ad J. J. C.; van Domburg, Ron T.; Verhulst, Frank C.; Utens, Elisabeth M. W. J.

    2007-01-01

    To assess the level of psychological distress and styles of coping in both mothers and fathers of children who underwent invasive treatment for congenital cardiac disease at least 7 years and 6 months ago. The General Health Questionnaire and the Utrecht Coping List were completed by parents of

  19. Weight Loss & Acute Porphyria

    Science.gov (United States)

    ... APF You are here Home Diet and Nutrition Weight loss & acute Porphyria Being overweight is a particular problem ... one of these diseases before they enter a weight-loss program. Also, they should not participate in a ...

  20. Antidepressants and Weight Gain

    Science.gov (United States)

    Antidepressants and weight gain: What causes it? Can antidepressants cause weight gain? Answers from Daniel K. Hall- ... is a possible side effect of nearly all antidepressants. However, each person responds to antidepressants differently. Some ...

  1. Bayesian integration of networks without gold standards.

    Science.gov (United States)

    Weile, Jochen; James, Katherine; Hallinan, Jennifer; Cockell, Simon J; Lord, Phillip; Wipat, Anil; Wilkinson, Darren J

    2012-06-01

    Biological experiments give insight into networks of processes inside a cell, but are subject to error and uncertainty. However, due to the overlap between the large number of experiments reported in public databases it is possible to assess the chances of individual observations being correct. In order to do so, existing methods rely on high-quality 'gold standard' reference networks, but such reference networks are not always available. We present a novel algorithm for computing the probability of network interactions that operates without gold standard reference data. We show that our algorithm outperforms existing gold standard-based methods. Finally, we apply the new algorithm to a large collection of genetic interaction and protein-protein interaction experiments. The integrated dataset and a reference implementation of the algorithm as a plug-in for the Ondex data integration framework are available for download at http://bio-nexus.ncl.ac.uk/projects/nogold/

  2. Gold nanocrystals with DNA-directed morphologies.

    Science.gov (United States)

    Ma, Xingyi; Huh, June; Park, Wounjhang; Lee, Luke P; Kwon, Young Jik; Sim, Sang Jun

    2016-09-16

    Precise control over the structure of metal nanomaterials is important for developing advanced nanobiotechnology. Assembly methods of nanoparticles into structured blocks have been widely demonstrated recently. However, synthesis of nanocrystals with controlled, three-dimensional structures remains challenging. Here we show a directed crystallization of gold by a single DNA molecular regulator in a sequence-independent manner and its applications in three-dimensional topological controls of crystalline nanostructures. We anchor DNA onto gold nanoseed with various alignments to form gold nanocrystals with defined topologies. Some topologies are asymmetric including pushpin-, star- and biconcave disk-like structures, as well as more complex jellyfish- and flower-like structures. The approach of employing DNA enables the solution-based synthesis of nanocrystals with controlled, three-dimensional structures in a desired direction, and expands the current tools available for designing and synthesizing feature-rich nanomaterials for future translational biotechnology.

  3. Optical properties of spherical gold mesoparticles

    DEFF Research Database (Denmark)

    Evlyukhin, A. B.; Kuznetsov, A. I.; Novikov, S. M.

    2012-01-01

    Optical properties of spherical gold particles with diameters of 150-650 nm (mesoparticles) are studied by reflectance spectroscopy. Particles are fabricated by laser-induced transfer of metallic droplets onto metal and dielectric substrates. Contributions of higher multipoles (beyond the quadrup......Optical properties of spherical gold particles with diameters of 150-650 nm (mesoparticles) are studied by reflectance spectroscopy. Particles are fabricated by laser-induced transfer of metallic droplets onto metal and dielectric substrates. Contributions of higher multipoles (beyond...... results obtained in homogeneous environment is demonstrated. Multipole resonance features in the experimental reflection spectra of particles located on a gold substrate, in the wavelength range of 500-1000 nm, are discussed and theoretically analyzed on the basis of finite-difference time...

  4. Cancer nanotechnology: emerging role of gold nanoconjugates.

    Science.gov (United States)

    Kudgus, Rachel A; Bhattacharya, Resham; Mukherjee, Priyabrata

    2011-12-01

    Over the last few decades, the study of nanotechnology has grown exponentially. Nanotechnology bridges science, engineering and technology; it continues to expand in definition as well as practice. One sub-set of nanotechnology is bionanotechnology, this will be the focus of this review. Currently, bionanotechnology is being studied and exploited for utility within medicinal imaging, diagnosis and therapy in regard to cancer. Cancer is a world-wide health problem and the implication rate as well as the death rate increase year to year. However promising work is being done with gold nanoparticles for detection, diagnosis and targeted drug delivery therapy. Gold nanoparticles can be synthesized in various shapes and sizes, which directly correlates to the color; they can also be manipulated to carry various antibody, protein, plasmid, DNA or small molecule drug. Herein we summarize some of the very influential research being done in the field of Cancer Nanotechnology with an emphasis on gold nanoparticles.

  5. Reversible multi polyelectrolyte layers on gold nanoparticles

    Science.gov (United States)

    Djoumessi Lekeufack, Diane; Brioude, Arnaud; Lalatonne, Yoann; Motte, Laurence; Coleman, Anthony W.; Miele, Philippe

    2012-06-01

    Gold nanoparticles surface can be easily modified by different molecules such as polyelectrolytes. In a typical multilayer system made of polyethyleneimine and poly(styrene sulfonate)sodium alternated layers around gold nanoparticles, we have evaluated the interactions between the different layers and the relative strength of interfacial properties. By means of UV-Visible and FTIR spectroscopies, we have shown that due to its amine functionalities, the bonding of polyethyleneimine to gold particles is stronger than the one implied with the sulfonate anion in the PSS inducing a clean removal of this latter after the last polyethyleneimine deposition. Considering that polyethyleneimine is cytotoxic and that only weak covalent bonds are concerned in polyelectrolyte multilayer, this last point is of main importance since external degradation thus exposing polyethyleneimine sub-layer of multilayer films to in vivo tissue cells can occur by many ways.

  6. Gold Veins near Great Falls, Maryland

    Science.gov (United States)

    Reed, John Calvin; Reed, John C.

    1969-01-01

    Small deposits of native gold are present along an anastomosing system of quartz veins and shear zones just east of Great Falls, Montgomery County, Md. The deposits were discovered in 1861 and were worked sporadically until 1951, yielding more than 5,000 ounces of gold. The vein system and the principal veins within it strike a few degrees west of north, at an appreciable angle to foliation and fold axial planes in enclosing rocks of the Wissahickon Formation of late Precambrian (?) age. The veins cut granitic rocks of Devonian or pre-Devonian age and may be as young as Triassic. Further development of the deposits is unlikely under present economic conditions because of their generally low gold content and because much of the vein system lies on park property, but study of the Great Falls vein system may be useful in the search for similar deposits elsewhere in the Appalachian Piedmont.

  7. Preparation of radioactive colloidal gold 198Au

    International Nuclear Information System (INIS)

    Cammarosano, S.A.

    1979-01-01

    The preparation with simple equipment of radioactive colloidal gold of particle size about approximately 300 A from seed colloid stabilized by gelatine is described. Some physico-chemical parameters which can affect the process of formation of these colloidal particles are analysed; particle size has been meassured with an electron microscope. The colloid stability has been studied as a function of dilution, age and pH. Nucleation and growth of radioactive colloidal gold have been studied using spectrophotometry. Absorption spectra of the two ones are presented and compared. Quality control of the production process is verified through measurement of parameters, such as radioactive and radiochemical purity and biological distribution in laboratorial animals. This distribution was evalusted for rats injected endovenously with the gold colloidal solution.(Author) [pt

  8. Adaptive Context Tree Weighting

    OpenAIRE

    O'Neill, Alexander; Hutter, Marcus; Shao, Wen; Sunehag, Peter

    2012-01-01

    We describe an adaptive context tree weighting (ACTW) algorithm, as an extension to the standard context tree weighting (CTW) algorithm. Unlike the standard CTW algorithm, which weights all observations equally regardless of the depth, ACTW gives increasing weight to more recent observations, aiming to improve performance in cases where the input sequence is from a non-stationary distribution. Data compression results show ACTW variants improving over CTW on merged files from standard compres...

  9. Weight management in pregnancy

    OpenAIRE

    Olander, E. K.

    2015-01-01

    Key learning points:\\ud - Women who start pregnancy in an overweight or obese weight category have increased health risks\\ud - Irrespective of pre-pregnancy weight category, there are health risks associated with gaining too much weight in pregnancy for both mother and baby\\ud - There are currently no official weight gain guidelines for pregnancy in the UK, thus focus needs to be on supporting pregnant women to eat healthily and keep active

  10. Free gold recovery by coal-oil agglomeration

    Energy Technology Data Exchange (ETDEWEB)

    Kotze, W.; Petersen, F.W. [Cape Technikon Cape Town (South Africa). Dept. of Chemical Engineering

    2000-02-01

    The gold mining industry has mainly relied upon the use of highly polluting chemicals, such as mercury and cyanide to recover gold from its ores. The Coal Gold Agglomeration (CGA) process was developed some years ago and has the advantage in that gold is recovered by a procedure which has little or no negative impact on the environment. A gold ore containing liberated gold particles is contacted with coal-oil agglomerates, whereby the gold is recovered into the coal/oil phase. Laboratory scale batch tests were performed on an artificial mixture gold slurry and gold recoveries of up to 85% were found under optimized conditions. By recycling the coal/oil phase, it was found that the gold loading onto the agglomerates was increased. Tests performed on an industrial ore yielded slightly lower gold recoveries, and X-ray Diffraction (XRD) analysis on the coal/oil phase showed that minerals other than gold were recovered into this phase. A comparative study was conducted whereby the CGA process was compared to mercury amalgamation. Gold recoveries obtained through amalgamation were 15% lower than by the agglomeration process, which indicates that this process can be considered favourably as an alternative to amalgamation. 16 refs., 2 figs., 6 tabs.

  11. Contact allergy to gold in patients with gold-plated intracoronary stents.

    Science.gov (United States)

    Svedman, C; Tillman, C; Gustavsson, C G; Möller, H; Frennby, B; Bruze, M

    2005-04-01

    An increasingly common and effective method for the treatment of atherosclerotic disease in the coronary arteries is percutaneous transluminal coronary angioplasty (PTCA) and stenting. The stents are made of different metals. An increased rate of restenosis when using gold-plated stents has been shown. Contact allergy to gold is common in many countries. Recently, a study has shown an increased rate of contact allergy to nickel among patients with restenosis and a nickel-containing stent. The aims of our study were to investigate whether there was an increased rate of contact allergy to gold among patients with gold-plated stents and if this increased the risk of restenosis. 22 patients who had received a gold-plated stent were patch tested. An age- and sex-matched population of 88 patients, previously patch tested because of a suspected contact dermatitis, served as controls. In the stent group, 10/22 (45.5%) had a contact allergy to gold, in the control group 18/88 (20.5%); the difference is statistically significant (P = 0.04). There was no significant difference regarding frequency of restenosis. Our study indicates that there is a risk of sensitizing the patient when implanting a gold-plated stent. Further studies are needed to confirm these results and to evaluate whether there is an increased risk of restenosis.

  12. Size fraction assaying of gold bearing rocks (for gold extraction) by instrumental neutron activation analysis

    International Nuclear Information System (INIS)

    Ahmed, K.; Dampare, S.B.; Addo, M.A.; Osae, S.; Adotey, D.K.; Adomako, D.

    2005-01-01

    A novel method has been developed for processing and extraction of gold from gold bearing rocks for use by small-scale gold miners in Ghana. The methodology involved crushing of gold bearing hard rocks to fine particles to form a composite sample and screening at a range of sizes. Gold distribution in the composite sample was determined as a function of particle size by using Instrumental Neutron Activation Analysis. The concentrations of gold for the corresponding particle sizes were 16.4 ± 0.17mg/kg for sizes <63μm; 161± 0.75 mg/kg for 63 - 125 μm, 0.53 + 0.03 mg/kg for 125 - 250 μm, 4.66± 0.07 mg/kg for 250 - 355 μm, 1.55 ± 0.06 for 355 - 425 μm, 0.80 ± 0.008 mg/kg for 425 -1000 μm, and 1.27 + 0.05 mg/kg for 1000-2000 μm. The average gold content in a 7.127 kg composite sample based on particle size found to be 3.08 mg/kg. (au)

  13. Nuclear shape transition in light gold isotopes

    International Nuclear Information System (INIS)

    Wallmeroth, K.; Bollen, G.; Dohn, A.; Egelhof, P.; Kroenert, U.; Heyde, K.; Coster, C. de; Wood, J.L.; Kluge, H.J.; European Organization for Nuclear Research, Geneva; European Organization for Nuclear Research, Geneva

    1989-01-01

    The hyperfine structure and isotope shifts of short-lived gold isotopes with 185≤A≤190 and the 11/2 - isomer of 189 Au have been investigated by application of on-line resonance ionization mass spectroscopy. A detection efficiency of ε=10 -8 for gold atoms was observed at a background of about one event per 1000 laser shots. The deduced charge radii show a drastic change between A=187 and A=186 which is interpreted as an onset of strong deformation (β 2 ≅ 0.25) in 186 Au and 185 Au due to the influence of the π1h 9/2 intruder orbital. (orig.)

  14. 'Methane oxidation on supported gold catalysts'

    DEFF Research Database (Denmark)

    Walther, Guido

    2008-01-01

    the energy stored in the molecule available, is a major research challenge. In this PhD thesis, CH4 oxidation on nanoparticular gold is studied both experimentally and theoretically. In the course of this PhD project, CH4 oxidation was experimentally found more likely to form CO2 and H2O than other low index...... steady-state activity measurements were performed to obtain the reaction rates for CO and H2 oxidation. These reactions were studied on three different gold particle sizes using either O2 or N2O as oxidation agents. Using particle size distributions obtained from TEM analysis, it was found that the CO...

  15. Wet chemical synthesis of soluble gold nanogaps

    DEFF Research Database (Denmark)

    Jain, Titoo; Tang, Qingxin; Bjørnholm, Thomas

    2014-01-01

    on top-down approaches and often rely on subsequent deposition of molecules into the nanogap. In such an approach, the molecule may bridge the gap differently with each experiment due to variations at the metal-molecule interface. Conversely, chemists can readily synthesize gold nanorods (Au...... of dimeric AuNR structures from an insulating molecule linked to AuNR precursors (gold seeds). Conjugated, electronically active molecules are typically not soluble under the conditions required for the bottom-up growth of AuNRs. Therefore, we present a strategy that utilizes host-guest chemistry in order...

  16. Nanoporous Gold: Fabrication, Characterization, and Applications

    Directory of Open Access Journals (Sweden)

    Michael L. Reed

    2009-12-01

    Full Text Available Nanoporous gold (np-Au has intriguing material properties that offer potential benefits for many applications due to its high specific surface area, well-characterized thiol-gold surface chemistry, high electrical conductivity, and reduced stiffness. The research on np-Au has taken place on various fronts, including advanced microfabrication and characterization techniques to probe unusual nanoscale properties and applications spanning from fuel cells to electrochemical sensors. Here, we provide a review of the recent advances in np-Au research, with special emphasis on microfabrication and characterization techniques. We conclude the paper with a brief outline of challenges to overcome in the study of nanoporous metals.

  17. Definition of intertwin birth weight discordance.

    Science.gov (United States)

    Breathnach, Fionnuala M; McAuliffe, Fionnuala M; Geary, Michael; Daly, Sean; Higgins, John R; Dornan, James; Morrison, John J; Burke, Gerard; Higgins, Shane; Dicker, Patrick; Manning, Fiona; Mahony, Rhona; Malone, Fergal D

    2011-07-01

    To establish the level of birth weight discordance at which perinatal morbidity increases in monochorionic and dichorionic twin pregnancy. This prospective multicenter cohort study included 1,028 unselected twin pairs recruited over a 2-year period. Participants underwent two weekly ultrasonographic surveillance from 24 weeks of gestation with surveillance of monochorionic twins two-weekly from 16 weeks. Analysis using Cox proportional hazards compared a composite measure of perinatal morbidity (including any of the following: mortality, respiratory distress syndrome, hypoxic-ischemic encephalopathy, periventricular leukomalacia, necrotizing enterocolitis, or sepsis) at different degrees of birth weight discordance with adjustment for chorionicity, gestational age, twin-twin transfusion syndrome, birth order, gender, and growth restriction. Perinatal outcome data were recorded for 977 patients (100%) who continued the study with both fetuses alive beyond 24 weeks, including 14 cases of twin-twin transfusion syndrome. Adjusting for gestation at delivery, twin order, gender, and growth restriction, perinatal mortality, individual morbidity, and composite perinatal morbidity were all seen to increase with birth weight discordance exceeding 18% for dichorionic pairs (hazard ratio 2.2, 95% confidence interval [CI] 1.6-2.9, Pbirth weights were appropriate for gestational age. : The threshold for birth weight discordance established by this prospective study is 18% both for dichorionic twin pairs and for monochorionic twins without twin-twin transfusion syndrome. This threshold is considerably lower than that defined by many retrospective series as pathologic. We suggest that an anticipated difference of 18% in birth weight should prompt more intensive fetal monitoring.

  18. Comparative study of gum arabic and PVP as stabilizing agents for synthesis of gold nanoparticles

    International Nuclear Information System (INIS)

    Silva, Andressa A.; Leal, Jessica; Geraldes, Adriana N.; Lugao, Ademar B.

    2015-01-01

    Use Colloidal metallic nanoparticles such as gold nanoparticles have received a great attention, due in part to their specific properties and potential applications. Control of size and uniformity of nanoparticles is important to prevent aggregation. High-molecular-weight polymers were used as stabilizer agents. Natural polymers, such as gum Arabic, are used as stabilizer because of capping nanoparticles behavior and present advantages such as solubility, non- toxicity and its compatibility for pharmaceutical and biomedical applications. Previous studies showed that the hydrophilic group of Poly(vinyl pyrrolidone) (PVP) caused repulsion on gold nanoparticles surface because steric interactions with polymer, for this reason this kind of polymers could be used as stabilizer agent. The aim of this work is to study the synthesis and stabilization of gold nanoparticles with PVP and gum Arabic using gamma radiation. The results obtained by samples analysis using UV-Visible showed that the gamma irradiation doses influenced the nanoparticles formation by PVP but that is not the case with the GA, because for smaller quantity of Arabic gum in different doses produced and stabilized nanoparticles. The samples were observed for 20 days and showed stability. We have obtained preliminary results showed that the use of radiation is applicable to the formation of gold nanoparticles. (author)

  19. Comparative study of gum arabic and PVP as stabilizing agents for synthesis of gold nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Andressa A.; Leal, Jessica; Geraldes, Adriana N.; Lugao, Ademar B., E-mail: andressa_alvess@yahoo.com.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    Use Colloidal metallic nanoparticles such as gold nanoparticles have received a great attention, due in part to their specific properties and potential applications. Control of size and uniformity of nanoparticles is important to prevent aggregation. High-molecular-weight polymers were used as stabilizer agents. Natural polymers, such as gum Arabic, are used as stabilizer because of capping nanoparticles behavior and present advantages such as solubility, non- toxicity and its compatibility for pharmaceutical and biomedical applications. Previous studies showed that the hydrophilic group of Poly(vinyl pyrrolidone) (PVP) caused repulsion on gold nanoparticles surface because steric interactions with polymer, for this reason this kind of polymers could be used as stabilizer agent. The aim of this work is to study the synthesis and stabilization of gold nanoparticles with PVP and gum Arabic using gamma radiation. The results obtained by samples analysis using UV-Visible showed that the gamma irradiation doses influenced the nanoparticles formation by PVP but that is not the case with the GA, because for smaller quantity of Arabic gum in different doses produced and stabilized nanoparticles. The samples were observed for 20 days and showed stability. We have obtained preliminary results showed that the use of radiation is applicable to the formation of gold nanoparticles. (author)

  20. The Time to Weight-Loss Steady State After Gastric Bypass Predicts Weight-Loss Success.

    Science.gov (United States)

    Kindel, Tammy; Lomelin, Daniel; McBride, Corrigan; Kothari, Vishal; Thompson, Jon

    2016-02-01

    There is marked variability in weight loss achieved after laparoscopic Roux-en-Y gastric bypass (LRYGB) with little ability to predict pre-operatively poor weight-loss outcomes. In this study, we categorize the patterns of post-operative weight loss after LRYGB by using a novel method of measurement based on the time to weight-loss steady state (SS). A bariatric database was retrospectively reviewed for patients who underwent a LRYGB from 01/2001-12/2010. SS was defined as the month when the patient had ≤3% excess weight loss (%EWL) or weight gain from the prior visit. Percent total weight loss (%TWL) and %EWL were compared based on time to SS. The average time to SS was 15.5 months (n = 178). A percentage of 7.3 of patients lost >5%EWL after achieving their SS weight. Patients with SS surgery is more common with increasing age and may represent rapid physiologic adaptation with significantly lower %TWL and %EWL.

  1. Micro-nano Structurized Gold Chip for SPR Imaging Sensor

    International Nuclear Information System (INIS)

    Zhang, Bing; Pang, Kai; Shi, Chunfei; Sun, Yi; Wang, Xiaoping; Dong, Wei

    2016-01-01

    A micro-nano structurized gold chip was developed and applied to a surface plasmon resonance imaging (SPRi) sensor with polarization contrast method. Compared with the planar gold film, a total sensitivity enhancement (SEF=287%) was obtained. (paper)

  2. Gold nanoparticle assemblies through Hydrogen-bonded supramolecular mediators

    NARCIS (Netherlands)

    Kinge, S.S.; Crego Calama, Mercedes; Reinhoudt, David

    2007-01-01

    The synthesis of spherical gold nanoparticle assemblies with multicomponent double rosette molecular boxes as mediators is presented. These nine-component hydrogen-bonded supramolecular structures held together by 36 hydrogen bonds induce gold nanoparticle assembly. The morphologies of the

  3. Albumin-gold-glutathione is a probable auranofin metabolite

    International Nuclear Information System (INIS)

    Shaw, C.F. III; Coffer, M.; Isab, A.A.

    1989-01-01

    The newly licensed gold drug, auranofin ((2,3,4,6-tetra-O-acetyl-β-1-D-gluco-pyranosato-S-)triethylphoshine-gold(I)) crosses cell membranes and enters cells which are inaccessible to parenteral gold drugs. In vivo, the triethylphosphine ligand and gold of auranofin, but not the thio-sugar moiety, accumulate in and subsequently efflux from red blood cells (RBCs). Extracellular albumin increases in the extent of gold efflux and acts as a gold binding site. The rate of efflux is first-order in RBC gold concentration. Studies using RBCs in which labelled [ 14 C]-glutathione is generated in situ incorporation of [ 14 C]- glycine demonstrate that glutathione also effluxes from the RBCs and forms a gold-glutathione-albumin complex. This may be the immunopharmacologically active complex

  4. Determination of gold coating thickness measurement by using EDXRF

    International Nuclear Information System (INIS)

    Meor Yusoff Meor Sulaian; Masliana Muslimin; Fadlullah Jili Fursani

    2005-01-01

    The paper relates a study on the development of an analysis procedure for measuring the gold coating thickness using EDXRF technique. Gold coating thickness was measured by relating the counts under the Au L? peak its thickness value. In order to get a reasonably accurate result, a calibration graph was plotted using five gold-coated reference standards of different thickness. The calibration graph shows a straight line for thin coating measurement until 0.9 μm. Beyond this the relationship was not linear and this may be resulted from the self-absorption effect. Quantitative analysis was also performed on two different samples of gold coated jewelry and a phone connector. Result from the phone connector analysis seems to agree with the manufacturer gold coating value. From the analysis of gold-coated jewelry it had been able to differentiate the two articles as gold wash and gold electroplated. (Author)

  5. A Preliminary Study on Detecting Fake Gold Bars Using Prompt Gamma Activation Analysis: Simulation of Neutron Transmission in Gold Bar

    International Nuclear Information System (INIS)

    Lee, K. M.; Sun, G. M.

    2016-01-01

    The purpose of this study is to develop fake gold bar detecting method by using Prompt-gamma activation analysis (PGAA) facility at the Korea Atomic Energy Research Institute (KAERI). PGAA is an established nuclear analytical technique for non-destructive determination of elemental and isotopic compositions. For a preliminary study on detecting fake gold bar, Monte Carlo simulation of neutron transmission in gold bar was conducted and the possibility for detecting fake gold bar was confirmed. Under the gold bullion standard, it guaranteed the government would redeem any amount of currency for its value in gold. After the gold bullion standard ended, gold bars have been the target for investment as ever. But it is well known that fake gold bar exist in the gold market. This cannot be identified easily without performing a testing as it has the same appearance as the pure gold bar. In order to avoid the trading of fake gold bar in the market, they should be monitored thoroughly. Although the transmissivity of cold neutrons are low comparing that of thermal neutrons, the slower neutrons are more apt to be absorbed in a target, and can increase the prompt gamma emission rate. Also the flux of both thermal and cold neutron beam is high enough to activate thick target. If the neutron beam is irradiated on the front and the reverse side of gold bar, all insides of it can be detected

  6. Added value of diffusion-weighted magnetic resonance imaging for the detection of pancreatic fluid collection infection

    Energy Technology Data Exchange (ETDEWEB)

    Borens, Bruno [Polyclinique Santa Maria, Nice (France); Arvanitakis, Marianna; Eisendrath, Pierre; Toussaint, Emmanuel; Deviere, Jacques [Erasme Hospital, Department of Gastroenterology, Brussels (Belgium); Absil, Julie; Matos, Celso; Bali, Maria Antonietta [Erasme Hospital, Department of Radiology, Brussels (Belgium); El Bouchaibi, Said [Epicura, Ath (Belgium)

    2017-03-15

    To investigate the added value of diffusion-weighted (DW) magnetic resonance (MR) imaging in the detection of infection in pancreatic fluid collections (PFC). Forty-patients with PFC requiring endoscopic-transmural drainage underwent conventional-MR and DW-MR imaging (b = 1000 s/mm{sup 2}) before endoscopy. MR images were divided into two sets (set1, conventional-MR; set2, conventional-MR, DW-MR and ADC maps) and randomized. Two independent readers performed qualitative and quantitative (apparent diffusion coefficient, ADC) image analysis. Bacteriological analysis of PFC content was the gold standard. Non-parametric tests were used for comparisons. Sensitivity, specificity, negative predictive value (NPV), positive predictive value (PPV) and accuracy were calculated for the two sets for both readers. Receiver operating characteristic curves (ROC) were drawn to assess quantitative DW-MR imaging diagnostic performance. For both readers, sensitivity, specificity, NPV, PPV and accuracy for infected PFCs were higher for set2 (P >.05). ADC were lower in infected versus non-infected PFCs (P ≤.031). Minimum ADC cut-off: 1,090 x 10{sup -3} mm{sup 2}/s for reader 1 and 1,012 x 10{sup -3} mm{sup 2}/s for reader 2 (sensitivity and specificity 67 % and 96 % for both readers). Qualitative information provided by DW-MR may help to assess PFCs infection. Infected PFCs show significantly lower ADCs compared to non-infected ones. (orig.)

  7. Yogurt and weight management.

    Science.gov (United States)

    Jacques, Paul F; Wang, Huifen

    2014-05-01

    A large body of observational studies and randomized controlled trials (RCTs) has examined the role of dairy products in weight loss and maintenance of healthy weight. Yogurt is a dairy product that is generally very similar to milk, but it also has some unique properties that may enhance its possible role in weight maintenance. This review summarizes the human RCT and prospective observational evidence on the relation of yogurt consumption to the management and maintenance of body weight and composition. The RCT evidence is limited to 2 small, short-term, energy-restricted trials. They both showed greater weight losses with yogurt interventions, but the difference between the yogurt intervention and the control diet was only significant in one of these trials. There are 5 prospective observational studies that have examined the association between yogurt and weight gain. The results of these studies are equivocal. Two of these studies reported that individuals with higher yogurt consumption gained less weight over time. One of these same studies also considered changes in waist circumference (WC) and showed that higher yogurt consumption was associated with smaller increases in WC. A third study was inconclusive because of low statistical power. A fourth study observed no association between changes in yogurt intake and weight gain, but the results suggested that those with the largest increases in yogurt intake during the study also had the highest increase in WC. The final study examined weight and WC change separately by sex and baseline weight status and showed benefits for both weight and WC changes for higher yogurt consumption in overweight men, but it also found that higher yogurt consumption in normal-weight women was associated with a greater increase in weight over follow-up. Potential underlying mechanisms for the action of yogurt on weight are briefly discussed.

  8. Formation of gold nanoparticles by glycolipids of Lactobacillus casei

    OpenAIRE

    Kikuchi, Fumiya; Kato, Yugo; Furihata, Kazuo; Kogure, Toshihiro; Imura, Yuki; Yoshimura, Etsuro; Suzuki, Michio

    2016-01-01

    Gold nanoparticles have particular properties distinct from those of bulk gold crystals, and such nanoparticles are used in various applications in optics, catalysis, and drug delivery. Many reports on microbial synthesis of gold nanoparticles have appeared. However, the molecular details (reduction and dispersion) of such synthesis remain unclear. In the present study, we studied gold nanoparticle synthesis by Lactobacillus casei. A comparison of L. casei components before and after addition...

  9. Natural gold composition studied by proton activation analysis (PAA)

    International Nuclear Information System (INIS)

    Cojocaru, V.; Badica, T.; Popescu, I.V.

    2003-01-01

    The minor and trace element concentration of natural gold is essential for provenance studies of gold archaeological artifacts. In this work proton activation analysis is used in order to find what elements can be put into evidence in natural gold. For that purpose some gold nuggets from Romania were used. It was found that PAA is a good supplemental method to neutron activation analysis. (authors)

  10. Modelling spatial anisotropy of gold concentration data using GIS ...

    Indian Academy of Sciences (India)

    Linear trends of anomalously high gold values in the Florida Canyon gold deposit, Nevada have been identified using a combination of contour maps of gold (Au) concentration developed with a geographic information system (GIS) and variogram maps created using a geostatistical analysis package. These linear trends ...

  11. Benchmarking Density Functionals for Chemical Bonds of Gold

    DEFF Research Database (Denmark)

    Kepp, Kasper Planeta

    2017-01-01

    data set probes all types of bonding to gold from very electronegative halides that force Au+ electronic structure, via covalently bonded systems, hard and soft Lewis acids and bases that either work against or complement the softness of gold, the Au2 molecule probing gold's bond with itself, and weak...

  12. Gold nanoparticles: preparation, functionalisation and applications in biochemistry and immunochemistry

    International Nuclear Information System (INIS)

    Dykman, Lev A; Bogatyrev, Vladimir A

    2007-01-01

    The review summarises data on the synthesis and functionalisation of gold nanoparticles and their applications in biological investigations. Particular attention is given to applications of colloidal gold in solid-phase assays, immunoassay and studies of biologically active compounds by vibrational spectroscopy. A special section deals with the use of gold nanoparticles as antigen carriers in immunisation.

  13. Controlled synthesis and optical properties of pure gold nanoparticles

    NARCIS (Netherlands)

    Singh, A.K.; Rai, A.K.; Bicanic, D.D.

    2009-01-01

    Gold nanoparticles were synthesized by laser ablation of a gold metallic disc at wavelengths of 532 nm and 355 nm with 7 ns pulse duration in the pure water. The colloidal gold nanoparticles were characterized by ultraviolet-visible absorption spectroscopy, transmission electron microscopy, and

  14. Crystal growth, structure and phase studies on gold halides

    NARCIS (Netherlands)

    Janssen, Eugenius Maria Wilhelmus Janssen

    1977-01-01

    Only very corrosive substances attack gold, the most noble metal. In this study the reactivity and the phase diagrams of gold with the halogens chlorine, bromine and iodine have been investigated. owing to the noble behaviour of gold, its halides are sensitive to heat; on heating they decompose into

  15. Preg-robbing of Gold by Carbonaceous Materials Encountered in ...

    African Journals Online (AJOL)

    Processing of gold from refractory ores containing carbonaceous materials (CM) poses challenges due to the ability of the CM to preg-rob dissolved gold. Depending on the type and maturity of CM encountered, preg-robbing of aurocyanide ion can lead to reduction in gold recovery ranging from a few percentages to more ...

  16. 76 FR 60355 - Gold Star Mother's and Family's Day, 2011

    Science.gov (United States)

    2011-09-28

    ... Gold Star Mother's and Family's Day, 2011 By the President of the United States of America A... grief their families carry we can never fully know. Gold Star mothers and families know the immeasurable... inspired by their strength and determination. Through heartbreaking loss, our Gold Star families continue...

  17. 75 FR 60283 - Gold Star Mother's and Families' Day, 2010

    Science.gov (United States)

    2010-09-29

    ... Gold Star Mother's and Families' Day, 2010 By the President of the United States of America A... recognize the deep loss and great strength of those who share in that ultimate sacrifice: America's Gold... on in the people they loved. Their exceptional spirit of service dwells in the pride of Gold Star...

  18. Effects of Quebracho Tannin on Recovery of Colloidal Gold from ...

    African Journals Online (AJOL)

    Gold occurs in some concessions as submicron particles in pyrite and arsenopyrite, which is processed in a flotation concentration to obtain gold enriched sulphide concentrate. The concentrate is then treated in a biological oxidation step to oxidize the sulphides, liberate the occluded gold and make them amenable for ...

  19. Effects of Quebracho Tannin on Recovery of Colloidal Gold from ...

    African Journals Online (AJOL)

    Michael

    2015-06-01

    Jun 1, 2015 ... Gold occurs in some concessions as submicron particles in pyrite and arsenopyrite, which is processed in a flotation concentration to obtain gold enriched sulphide concentrate. The concentrate is then treated in a biological oxidation step to oxidize the sulphides, liberate the occluded gold and make them ...

  20. An experimental study on gold precipitation from leach solutions of ...

    African Journals Online (AJOL)

    This paper presents the results of the study dedicated to the determination of the optimum parameters for the electrolytic gold precipitation from thiourea leach solutions. The leaching was carried out using technogenic gold-bearing raw materials (gold-bearing sands) of the Far East of the Russian Federation. The study ...

  1. Gold-coated nanoparticles for use in biotechnology applications

    Science.gov (United States)

    Berning, Douglas E [Los Alamos, NM; Kraus, Jr., Robert H.; Atcher, Robert W [Los Alamos, NM; Schmidt, Jurgen G [Los Alamos, NM

    2009-07-07

    A process of preparing gold-coated magnetic nanoparticles is disclosed and includes forming a suspension of magnetic nanoparticles within a suitable liquid, adding an amount of a reducible gold compound and a reducing agent to the suspension, and, maintaining the suspension for time sufficient to form gold-coated magnetic nanoparticles.

  2. Increased cellular uptake of peptide-modified PEGylated gold nanoparticles.

    Science.gov (United States)

    He, Bo; Yang, Dan; Qin, Mengmeng; Zhang, Yuan; He, Bing; Dai, Wenbing; Wang, Xueqing; Zhang, Qiang; Zhang, Hua; Yin, Changcheng

    2017-12-09

    Gold nanoparticles are promising drug delivery vehicles for nucleic acids, small molecules, and proteins, allowing various modifications on the particle surface. However, the instability and low bioavailability of gold nanoparticles compromise their clinical application. Here, we functionalized gold nanoparticles with CPP fragments (CALNNPFVYLI, CALRRRRRRRR) through sulfhydryl PEG to increase their stability and bioavailability. The resulting gold nanoparticles were characterized with transmission electron microscopy (TEM), dynamic light scattering (DLS), UV-visible spectrometry and X-ray photoelectron spectroscopy (XPS), and the stability in biological solutions was evaluated. Comparing to PEGylated gold nanoparticles, CPP (CALNNPFVYLI, CALRRRRRRRR)-modified gold nanoparticles showed 46 folds increase in cellular uptake in A549 and B16 cell lines, as evidenced by the inductively coupled plasma atomic emission spectroscopy (ICP-AES). The interactions between gold nanoparticles and liposomes indicated CPP-modified gold nanoparticles bind to cell membrane more effectively than PEGylated gold nanoparticles. Surface plasmon resonance (SPR) was used to measure interactions between nanoparticles and the membrane. TEM and uptake inhibitor experiments indicated that the cellular entry of gold nanoparticles was mediated by clathrin and macropinocytosis. Other energy independent endocytosis pathways were also identified. Our work revealed a new strategy to modify gold nanoparticles with CPP and illustrated the cellular uptake pathway of CPP-modified gold nanoparticles. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. 16 CFR 23.4 - Misrepresentation as to gold content.

    Science.gov (United States)

    2010-01-01

    ... unfair or deceptive to misrepresent the presence of gold or gold alloy in an industry product, or the... abbreviation to describe all or part of an industry product composed throughout of an alloy of gold, unless a... designation of the karat fineness of the alloy that is of at least equal conspicuousness as the term used. (6...

  4. Plasmonic and Magnetically Responsive Gold ShellMagnetic Nanorod Hybrids

    Science.gov (United States)

    2017-10-10

    ARL-TR-8182 ● OCT 2017 US Army Research Laboratory Plasmonic and Magnetically Responsive Gold Shell– Magnetic Nanorod Hybrids...Army Research Laboratory Plasmonic and Magnetically Responsive Gold Shell– Magnetic Nanorod Hybrids by Mackenzie G Williams, Devon A Boyne, and...TITLE AND SUBTITLE Plasmonic and Magnetically Responsive Gold Shell– Magnetic Nanorod Hybrids 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c

  5. 21 CFR 872.3350 - Gold or stainless steel cusp.

    Science.gov (United States)

    2010-04-01

    ...) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3350 Gold or stainless steel cusp. (a) Identification. A gold or stainless steel cusp is a prefabricated device made of austenitic alloys or alloys containing 75 percent or greater gold and metals of the platinum group or stainless steel intended to provide...

  6. Impact of baseline renal function on all-cause mortality in patients who underwent cardiac resynchronization therapy: A systematic review and meta-analysis.

    Science.gov (United States)

    Bazoukis, G; Letsas, K P; Korantzopoulos, P; Thomopoulos, C; Vlachos, K; Georgopoulos, S; Karamichalakis, N; Saplaouras, A; Efremidis, M; Sideris, A

    2017-10-01

    Cardiac resynchronization therapy (CRT) improves both morbidity and mortality in selected patients with heart failure and increased QRS duration. However, chronic kidney disease (CKD) may have an adverse effect on patient outcome. The aim of this systematic review was to analyze the existing data regarding the impact of baseline renal function on all-cause mortality in patients who underwent CRT. Medline database was searched systematically, and studies evaluating the effect of baseline renal function on all-cause mortality in patients who underwent CRT were retrieved. We performed three separate analyses according to the comparison groups included in each study. Data were analyzed using Review Manager software (RevMan version 5.3; Oxford, UK). We included 16 relevant studies in our analysis. Specifically, 13 studies showed a statistically significant higher risk of all-cause mortality in patients with impaired baseline renal function who underwent CRT. The remaining three studies did not show a statistically significant result. The quantitative synthesis of five studies showed a 19% decrease in all-cause mortality per 10-unit increment in estimated glomerular filtration rate (eGFR) [HR: 0.81, 95% CI (0.73-0.90), p <0.01, 86% I 2 ]. Additionally, we demonstrated that patients with an eGFR<60 mL/min/1.73 m 2 had an all-cause mortality rate of 66% [HR: 1.66, 95% CI (1.37-2.02), p <0.01, 0% I 2 ], which was higher than in those with an eGFR≥60 mL/min/1.73 m 2 . Baseline renal dysfunction has an adverse effect on-all cause mortality in patients who underwent CRT.

  7. Invisible gold and arsenic in pyrite from the high-grade Hishikari gold deposit, Japan

    International Nuclear Information System (INIS)

    Morishita, Y.; Shimada, N.; Shimada, K.

    2008-01-01

    Gold occurs as both electrum (a natural alloy of gold and silver) and invisible gold in arsenian pyrite in the Hishikari epithermal gold deposit in Japan. Microanalyses of arsenian pyrite from the deposit using secondary ion mass spectrometry (SIMS) and electron probe microanalysis (EPMA) revealed that Au concentrations (0.1-2600 ppm) are positively correlated with As concentrations (0.0-6.1%). A small (3 μm) area of pyrite was analyzed because the sample textures were fine and complicated. The Au/As ratio is high in the Sanjin ore zone, which has very high-grade veins, while the ratio is low in the Yamada ore zone, which has average-grade veins

  8. Infrared light-absorbing gold/gold sulfide nanoparticles induce cell death in esophageal adenocarcinoma

    Science.gov (United States)

    Li, Yan; Gobin, Andre M; Dryden, Gerald W; Kang, Xinqin; Xiao, Deyi; Li, Su Ping; Zhang, Guandong; Martin, Robert CG

    2013-01-01

    Gold nanoparticles and near infrared-absorbing light are each innocuous to tissue but when combined can destroy malignant tissue while leaving healthy tissue unharmed. This study investigated the feasibility of photothermal ablation therapy for esophageal adenocarcinoma using chitosan-coated gold/gold sulfide (CS-GGS) nanoparticles. A rat esophagoduodenal anastomosis model was used for the in vivo ablation study, and three human esophageal cell lines were used to study the response of cancer cells and benign cells to near infrared light after treatment with CS-GGS. The results indicate that both cancerous tissue and cancer cells took up more gold nanoparticles and were completely ablated after exposure to near infrared light. The benign tissue and noncancerous cells showed less uptake of these nanoparticles, and remained viable after exposure to near infrared light. CS-GGS nanoparticles could provide an optimal endoluminal therapeutic option for near infrared light ablation of esophageal cancer. PMID:23818775

  9. The use of gold and gold alloys in prosthetic dentistry – a literature review

    Directory of Open Access Journals (Sweden)

    Oleszek-Listopad Justyna

    2015-09-01

    Full Text Available Gold is a noble metal with very good chemical resistance. It also does not become oxidized in water or air. Pure gold has a bright yellow color and shine, and it is a heavy, but soft metal with huge plasticity and ductility. For many years, gold and its alloys have been recognized as being great prosthetic material in dental practice. In current dentistry, the progress in materials science and galvanoforming techniques have made it possible to create precise restorations utilizing this metal. This pertains both to fixed and removable dentures. Galvanized gold has a range of advantages, among these being biocompatibility, proper marginal tightness, endurance, its esthetic design and the fact that it boasts bacteriostatic features.

  10. Photosynthetic light reactions at the gold interface

    NARCIS (Netherlands)

    Kamran, Muhammad

    2014-01-01

    In the project described in this thesis we studied a simple bio-electronic device for solar energy conversion by surface-assembly of photosynthetic pigment-protein complexes on a bare gold-electrode. Optical excitation of the photosynthetic pigments gives rise to charge separation in the so-called

  11. Functionalization of Biosynthesized Gold Nanoparticle from ...

    African Journals Online (AJOL)

    Dr Olaleye

    nanoparticles and formulated nanodrug were characterized using UV-Vis spectrophotometry, Zetasizer, Scanning and transmission Electron Microscopy .... UV–Vis Spectrophotometer (UV-1800 Shimadzu) was used to measure the wavelength .... plasma resonance at 545.5nm for biosynthesized gold nanoparticle using ...

  12. Electric field assisted nanocolloidal gold deposition

    NARCIS (Netherlands)

    Kooij, Ernst S.; Brouwer, E.A.M.; Poelsema, Bene

    2007-01-01

    The deposition of nanocolloidal gold particles under the influence of an externally applied electric field is studied in situ by means of spectroscopic ellipsometry. The variation of the relative coverage with time, as a function of applied potential, is determined using a principal component

  13. Synthesis and characterization of gold nanoparticles incorporated ...

    Indian Academy of Sciences (India)

    Synthesis and characterization of gold nanoparticles incorporated bentonite clay for electrocatalytic sensing of arsenic(III). Pankaj Kumar Rastogi Dharmendra Kumar Yadav Shruti Pandey Vellaichamy Ganesan Piyush Kumar Sonkar Rupali Gupta. Regular Articles Volume 128 Issue 3 March 2016 pp 349-356 ...

  14. A nanoporous gold membrane for sensing applications

    Directory of Open Access Journals (Sweden)

    Swe Zin Oo

    2016-03-01

    Full Text Available Design and fabrication of three-dimensionally structured, gold membranes containing hexagonally close-packed microcavities with nanopores in the base, are described. Our aim is to create a nanoporous structure with localized enhancement of the fluorescence or Raman scattering at, and in the nanopore when excited with light of approximately 600 nm, with a view to provide sensitive detection of biomolecules. A range of geometries of the nanopore integrated into hexagonally close-packed assemblies of gold micro-cavities was first evaluated theoretically. The optimal size and shape of the nanopore in a single microcavity were then considered to provide the highest localized plasmon enhancement (of fluorescence or Raman scattering at the very center of the nanopore for a bioanalyte traversing through. The optimized design was established to be a 1200 nm diameter cavity of 600 nm depth with a 50 nm square nanopore with rounded corners in the base. A gold 3D-structured membrane containing these sized microcavities with the integrated nanopore was successfully fabricated and ‘proof of concept’ Raman scattering experiments are described. Keywords: Nanopore, Polymer sphere, Gold membrane, Plasmons, Sensing, SERS

  15. Surface interactions between gold nanoparticles and biochar

    Science.gov (United States)

    Engineered nanomaterials are directly applied to agricultural soils as a part of pesticide/fertilize formulations and sludge/manure amendments. Yet, no prior reports are available on the extent and reversibility of gold nanoparticles (nAu) retention by soil components including charcoal black carbo...

  16. Biological synthesis and characterization of intracellular gold ...

    Indian Academy of Sciences (India)

    ... nontoxic, safe, biocompatible and environmentally acceptable. In the present study, Aspergillus fumigatus was used for the intracellular synthesis of gold nanoparticles. Stable nanoparticles were produced when an aqueous solution of chloroauric acid (HAuCl4) was reduced by A. fumigatus biomass as the reducing agent ...

  17. Uranium and gold in Serra da Jacobina

    International Nuclear Information System (INIS)

    Lemos, J.C.

    1974-01-01

    The study in details of the conglomerates of Serra do Corrego Formation is presented. In the Canavieira Gold Mine we made the radiometric research of the work front, sistematic sampling and gamma-ray of drilled holes. Many ore products from the jig of Canavieira Mine were analysed to determine a representative uranium content

  18. Gold ratio and a trigonometric identity

    OpenAIRE

    Shevelev, Vladimir

    2009-01-01

    We give two proofs of the identity $$\\sqrt{\\frac{\\cos\\frac{2\\pi}{5}} {\\cos\\frac{\\pi}{5}}}+\\sqrt{\\frac{\\cos\\frac{\\pi}{5}} {\\cos\\frac{2\\pi}{5}} }=\\sqrt{5},$$ using and not using the gold ratio.

  19. Absorption Spectra of Gold Nanoparticle Suspensions

    Science.gov (United States)

    Anan'eva, M. V.; Nurmukhametov, D. R.; Zverev, A. S.; Nelyubina, N. V.; Zvekov, A. A.; Russakov, D. M.; Kalenskii, A. V.; Eremenko, A. N.

    2018-02-01

    Three gold nanoparticle suspensions are obtained, and mean radii in distributions - (6.1 ± 0.2), (11.9 ± 0.3), and (17.3 ± 0.7) nm - are determined by the transmission electron microscopy method. The optical absorption spectra of suspensions are obtained and studied. Calculation of spectral dependences of the absorption index of suspensions at values of the gold complex refractive index taken from the literature showed a significant deviation of experimental and calculated data in the region of 450-800 nm. Spectral dependences of the absorption of suspensions are simulated within the framework of the Mie-Drude theory taking into account the interband absorption in the form of an additional term in the imaginary part of the dielectric permittivity of the Gaussian type. It is shown that to quantify the spectral dependences in the region of the plasmon absorption band of nanoparticles, correction of the parameters of the interband absorption is necessary in addition to the increase of the relaxation parameter of the Drude theory. Spectral dependences of the dielectric permittivity of gold in nanodimensional state are refined from the solution of the inverse problem. The results of the present work are important for predicting the special features of operation of photonic devices and optical detonators based on gold nanoparticles.

  20. Opposition to gold mining at Bergama, Turkey

    NARCIS (Netherlands)

    M. Arsel (Murat)

    2012-01-01

    textabstractIntroduction For much of the 1990s, the tourist town of Bergama was the epicentre of Turkey's most effective and visible environmental social movement against a multinational mining corporation aiming to establish the first modern gold mine in the country. Bringing

  1. Optical and morphological characteristics of gold nanostructures

    OpenAIRE

    Pereira, Francisco Claudece; Zanoni, Maria Valnice Boldrin; Moretto, Ligia Maria; Ugo, Paolo

    2007-01-01

    The present study describes a new procedure to obtain gold nanoparticles, directly in the pores of polycarbonate membranes commonly used in ultrafiltration. The dimensions of the particles may be controlled through the reduction time of the ions in the channels of the harbor matrix. The dissolution of the metallized polymer enables an investigation of the optical and morphologic properties of these elements.

  2. Bacterial leaching of pyritic gold ores

    International Nuclear Information System (INIS)

    Gagliardi, F.M.; Cashion, J.D.; Brown, J.; Jay, W.H.

    1998-01-01

    Full text: Pyritic ores (pyrite and arsenopyrite) containing gold concentrations in excess of 50g Au/t can be processed to recover the gold by the removal of the sulphur from the ore. This may be achieved by roasting (producing sulphur dioxide emissions), pressure oxidation (expensive and suitable for large high grade deposits), pressure leaching (still currently being developed) or bacterial oxidation. The bacterial oxidation process is a well known process in nature but has only recently come under investigation as a economically viable and relatively clean method of gold recovery from deep low grade sulphidic ores. Samples were obtained from the Wiluna Gold Mine in Western Australia consisting of the original ore, six successive bacterial reactors and the final products. Moessbauer experiments have been performed at room temperature, liquid nitrogen and liquid helium temperatures, and in applied magnetic fields. The main components of the iron phases which were present during the bacterial treatment were pyrite and arsenopyrite which were readily oxidised by the bacteria. Ferric sulfates and ferric arsenates were identified as by-products of the process with a small amount of the oxyhydroxide goethite. These results are in contrast to the similar study of the Fairview Mine in South Africa where principally Fe(II) species were observed

  3. Dynamic breaking of a single gold bond

    DEFF Research Database (Denmark)

    Pobelov, Ilya V.; Lauritzen, Kasper Primdal; Yoshida, Koji

    2017-01-01

    . Conversely, if the force is loaded rapidly it is more likely that the maximum breaking force is measured. Paradoxically, no clear differences in breaking force were observed in experiments on gold nanowires, despite being conducted under very different conditions. Here we explore the breaking behaviour...

  4. Poly-thiosemicarbazide membrane for gold recovery

    KAUST Repository

    Villalobos, Luis Francisco

    2014-11-01

    A novel polymeric membrane adsorber with a high density of adsorption sites that can selectively capture Au(III) ions, is proposed as an efficient alternative to recover gold from dilute solutions. Poly-thiosemicarbazide (PTSC), a polymer that contains one chelate site per monomeric unit, was used to fabricate the membranes. This polymer can be easily processed into membranes by a phase inversion technique, resulting in an open and interconnected porous structure suitable for high flux liquid phase applications. This method overcomes the usual low capacities of membrane adsorbents by selecting a starting material that contains the adsorption sites within it, therefore avoiding the necessity to add an external agent into the membrane matrix. The resulting mechanically stable PTSC membranes can operate in a pressure driven permeation process, which eliminates the diffusion limitations commonly present in packed column adsorption processes. This process can selectively recover 97% of the gold present in a solution containing a 9-fold higher copper concentration, while operating at a flux as high as 1868 L/m2 h. The maximum gold uptake measured without sacrificing the mechanical stability of the membrane was 5.4 mmol Au/g. Furthermore the gold can be easily eluted from the membrane with a 0.1 M thiourea solution and the membrane can be reused for at least three cycles without any decrease in its performance. Finally, the ability of this membrane for recovering metals from real-life samples, like seawater and tap water, was tested with promising results.

  5. The golden age: gold nanoparticles for biomedicine†

    Science.gov (United States)

    Dreaden, Erik C.; Alkilany, Alaaldin M.; Huang, Xiaohua; Murphy, Catherine J.; El-Sayed, Mostafa A.

    2018-01-01

    Gold nanoparticles have been used in biomedical applications since their first colloidal syntheses more than three centuries ago. However, over the past two decades, their beautiful colors and unique electronic properties have also attracted tremendous attention due to their historical applications in art and ancient medicine and current applications in enhanced optoelectronics and photovoltaics. In spite of their modest alchemical beginnings, gold nanoparticles exhibit physical properties that are truly different from both small molecules and bulk materials, as well as from other nanoscale particles. Their unique combination of properties is just beginning to be fully realized in range of medical diagnostic and therapeutic applications. This critical review will provide insights into the design, synthesis, functionalization, and applications of these artificial molecules in biomedicine and discuss their tailored interactions with biological systems to achieve improved patient health. Further, we provide a survey of the rapidly expanding body of literature on this topic and argue that gold nanotechnology-enabled biomedicine is not simply an act of ‘gilding the (nanomedicinal) lily’, but that a new ‘Golden Age’ of biomedical nanotechnology is truly upon us. Moving forward, the most challenging nanoscience ahead of us will be to find new chemical and physical methods of functionalizing gold nanoparticles with compounds that can promote efficient binding, clearance, and biocompatibility and to assess their safety to other biological systems and their long-term term effects on human health and reproduction (472 references). PMID:22109657

  6. Gold(III)-Catalyzed Hydration of Phenylacetylene

    Science.gov (United States)

    Leslie, J. Michelle; Tzeel, Benjamin A.

    2016-01-01

    A guided inquiry-based experiment exploring the regioselectivity of the hydration of phenylacetylene is described. The experiment uses an acidic gold(III) catalyst in a benign methanol/water solvent system to introduce students to alkyne chemistry and key principles of green chemistry. The experiment can be easily completed in approximately 2 h,…

  7. High-energy band structure of gold

    DEFF Research Database (Denmark)

    Christensen, N. Egede

    1976-01-01

    The band structure of gold for energies far above the Fermi level has been calculated using the relativistic augmented-plane-wave method. The calculated f-band edge (Γ6-) lies 15.6 eV above the Fermi level is agreement with recent photoemission work. The band model is applied to interpret...

  8. Plasmonic biocompatible silver-gold alloyed nanoparticles.

    Science.gov (United States)

    Sotiriou, Georgios A; Etterlin, Gion Diego; Spyrogianni, Anastasia; Krumeich, Frank; Leroux, Jean-Christophe; Pratsinis, Sotiris E

    2014-11-14

    The addition of Au during scalable synthesis of nanosilver drastically minimizes its surface oxidation and leaching of toxic Ag(+) ions. These biocompatible and inexpensive silver-gold nanoalloyed particles exhibit superior plasmonic performance than commonly used pure Au nanoparticles, and as such these nanoalloys have great potential in theranostic applications.

  9. Hydroquinone Based Synthesis of Gold Nanorods.

    Science.gov (United States)

    Picciolini, Silvia; Mehn, Dora; Ojea-Jiménez, Isaac; Gramatica, Furio; Morasso, Carlo

    2016-08-10

    Gold nanorods are an important kind of nanoparticles characterized by peculiar plasmonic properties. Despite their widespread use in nanotechnology, the synthetic methods for the preparation of gold nanorods are still not fully optimized. In this paper we describe a new, highly efficient, two-step protocol based on the use of hydroquinone as a mild reducing agent. Our approach allows the preparation of nanorods with a good control of size and aspect ratio (AR) simply by varying the amount of hexadecyl trimethylammonium bromide (CTAB) and silver ions (Ag(+)) present in the "growth solution". By using this method, it is possible to markedly reduce the amount of CTAB, an expensive and cytotoxic reagent, necessary to obtain the elongated shape. Gold nanorods with an aspect ratio of about 3 can be obtained in the presence of just 50 mM of CTAB (versus 100 mM used in the standard protocol based on the use of ascorbic acid), while shorter gold nanorods are obtained using a concentration as low as 10 mM.

  10. Substoichiometric neutron activation determination of gold

    International Nuclear Information System (INIS)

    Mitchell, J.W.; Riley, J.E. Jr.; Payne, V.

    1978-01-01

    A highly precise and selective method is described for the determination of traces of gold by substoichiometric extraction from hydrochloric acid with tri-n-octylphosphine sulfide in cyclohexane following thermal neutron activation. Fundamental aspects of the extraction system are discussed and results are reported for the determination of gold in an effluent from a recovery process containing a complexed species of gold and unknown amounts of cyanide, citrate, phosphate, potassium and sodium. Other constituents of the effluent stream include traces of the transition elements Co, Ni, Fe, Cu, Zn, Pb and Sn at concentrations less than 50 ppm. One hour was allowed for the Au 3+ carrier and the 198 Au complexed species in samples and standards to oxidize, exchange, and reach chemical equilibrium. Samples were then equilibrated by shaking with the organic phase for thirty min. The percentage extractions (%E) for the substoichiometric separation of gold from the effluent and from the corresponding comparison standards were monitored. The mean percentage extractions for the substoichiometric separations of carrier from the effluent, and its corresponding standard were 75.3 and 59.3, respectively. These data are estimated to be accurate within +-2.0%. (T.G.)

  11. Executive functions predict weight loss in a medically supervised weight loss programme.

    Science.gov (United States)

    Galioto, R; Bond, D; Gunstad, J; Pera, V; Rathier, L; Tremont, G

    2016-12-01

    Deficits in executive functions are related to poorer weight loss after bariatric surgery; however, less is known about the role that these deficits may play during participation in nonsurgical weight loss programmes. This study examined associations between objectively measured executive functions and weight loss during participation in a medically supervised weight loss programme. Twenty-three adult patients (age 50.4 ± 15.1, BMI 44.2 ± 8.8, 68% female, 92% White) enrolled in a medically supervised weight loss programme, involving prescription of a very low calorie diet and strategies to change eating and activity behaviours, underwent comprehensive computerized testing of executive functions at baseline. Weight was obtained at baseline and 8 weeks. Demographic and clinical information were obtained through medical chart review. Participants lost an average of 9.8 ± 3.4% of their initial body weight at 8 weeks. Fewer correct responses on a set-shifting task and faster reaction time on a response inhibition task were associated with lower weight loss percentage at 8 weeks after adjusting for age, education and depressive symptoms. There were no associations between performance on tests of working memory or planning and weight loss. This study shows that worse performance on a set-shifting task (indicative of poorer cognitive flexibility) and faster reaction times on a response inhibition test (indicative of higher impulsivity) are associated with lower weight loss among participants in a medically supervised weight loss programme. Pre-treatment assessment of executive functions may be useful in identifying individuals who may be at risk for suboptimal treatment outcomes. Future research is needed to replicate these findings in larger samples and identify underlying mechanisms.

  12. A dual energy gamma-ray transmission technique for gold alloy identification

    International Nuclear Information System (INIS)

    Sumi, Tetsuo; Shingu, Hiroyasu; Iwase, Hirotoshi

    1991-01-01

    An application of the dual energy gamma-ray transmission techniques to gold alloy identification is presented. The measurement by dual energy gamma-ray transmission is independent of thickness and density of a sample. Due to this advantage, golden accessories such as necklaces, earrings and rings can be assayed in spite of their various thicknesses and irregular sectional shapes. Choice of a gamma-ray energy pair suitable for the object is important. The authors chose 511 keV and 1275 keV gamma-rays from 22 Na. With this energy pair, R value (a ratio of mass attenuation coefficients for low and high energy gamma-rays) is predominantly related to the weight fraction of gold of the sample. Using a 370 kBq 22 Na small source and a 50 mm dia.x 50 mm thick NaI(Tl) scintillator for 1200 seconds, a resolution of 2% for the R value was obtained. This corresponds to approximately 5% of the weight fraction of gold. A better resolution can be obtained by increasing the source activity or measurement time. (author)

  13. Gold Nanoparticles Assembly on Silicon and Gold Surfaces: Mechanism, Stability and Efficiency in Diclofenac Biosensing

    OpenAIRE

    Ben Haddada , Maroua; Hübner , Maria; Casale , Sandra; Knopp , Dietmar; Niessner , Reinhard; Salmain , Michele; Boujday , Souhir

    2016-01-01

    International audience; We investigated the assembly of Gold nanoparticles (AuNPs) on Gold and Silicon sensors with two final objectives: (i) understanding the factors governing the interaction and (ii) building up a nanostructured piezoelectric immunosensor for diclofenac, a small-sized pharmaceutical pollutant. Different surface chemistries were devised to achieve AuNPs assembly on planar substrates. These surface chemistries included amines to immobilize AuNPs via electrostatic interaction...

  14. Applications of gold nanoparticles in cancer nanotechnology

    Directory of Open Access Journals (Sweden)

    Weibo Cai

    2008-09-01

    Full Text Available Weibo Cai1,2, Ting Gao3, Hao Hong1, Jiangtao Sun11Departments of Radiology and Medical Physics, School of Medicine and Public Health, University of Wisconsin – Madison, Madison, Wisconsin, USA; 2University of Wisconsin Paul P. Carbone Comprehensive Cancer Center, Madison, Wisconsin, USA; 3Tyco Electronics Corporation, 306 Constitution Drive, Menlo Park, California, USAAbstract: It has been almost 4 decades since the “war on cancer” was declared. It is now generally believed that personalized medicine is the future for cancer patient management. Possessing unprecedented potential for early detection, accurate diagnosis, and personalized treatment of cancer, nanoparticles have been extensively studied over the last decade. In this review, we will summarize the current state-of-the-art of gold nanoparticles in biomedical applications targeting cancer. Gold nanospheres, nanorods, nanoshells, nanocages, and surface enhanced Raman scattering nanoparticles will be discussed in detail regarding their uses in in vitro assays, ex vivo and in vivo imaging, cancer therapy, and drug delivery. Multifunctionality is the key feature of nanoparticle-based agents. Targeting ligands, imaging labels, therapeutic drugs, and other functionalities can all be integrated to allow for targeted molecular imaging and molecular therapy of cancer. Big strides have been made and many proof-of-principle studies have been successfully performed. The future looks brighter than ever yet many hurdles remain to be conquered. A multifunctional platform based on gold nanoparticles, with multiple receptor targeting, multimodality imaging, and multiple therapeutic entities, holds the promise for a “magic gold bullet” against cancer.Keywords: gold nanoparticles, cancer, nanotechnology, optical imaging, nanomedicine, molecular therapy

  15. Molecular biomarkers for weight control in obese individuals subjected to a multi-phase dietary intervention

    DEFF Research Database (Denmark)

    Bolton, Jennifer L; Montastier, Emilie; Carayol, Jérôme

    2017-01-01

    Context: While calorie restriction has proven beneficial for weight loss, long-term weight control is variable between individuals. Objective: To identify biomarkers of successful weight control during a dietary intervention (DI). Design, Setting, and Participants: Adipose tissue (AT) transcripto......-controllers. Interestingly, ASPN is a TGFβ1 inhibitor. Conclusions: We found circulating biomarkers associated with weight control, which could influence weight management strategies, and genes that may be prognostic for successful weight control.......Context: While calorie restriction has proven beneficial for weight loss, long-term weight control is variable between individuals. Objective: To identify biomarkers of successful weight control during a dietary intervention (DI). Design, Setting, and Participants: Adipose tissue (AT......) transcriptomes were compared between 21 obese individuals that either maintained weight loss or regained weight during the DI. Results were validated on 310 individuals from the same study using RT-qPCR, and protein levels of potential circulating biomarkers measured by ELISA. Intervention: Individuals underwent...

  16. Reactivity of Cys4 Zinc Finger Domains with Gold(III) Complexes : Insights into the Formation of "Gold Fingers"

    NARCIS (Netherlands)

    Jacques, Aurélie; Lebrun, Colette; Casini, Angela; Kieffer, Isabelle; Proux, Olivier; Latour, Jean-Marc; Sénèque, Olivier

    2015-01-01

    Gold(I) complexes such as auranofin or aurothiomalate have been used as therapeutic agents for the treatment of rheumatoid arthritis for several decades. Several gold(I) and gold(III) complexes have also shown in vitro anticancer properties against human cancer cell lines, including cell lines

  17. Internal crystallography and thermal history of natural gold alloys

    Science.gov (United States)

    Hough, R.; Cleverley, J. S.

    2011-12-01

    New studies of gold are revealing how metallography is a key component of our understanding of the deposition of precious alloys in primary ore systems. Alluvial gold nuggets once thought to be secondary in origin have now been shown to be the erosional residue of hypogene systems, i.e. primary. This has been achieved through analysis of the internal crystallography using electron back scattered diffraction of large area ion beam polished gold samples. Comparisons of the microstructure are also being made with experiments on gold alloys with the same Ag contents where real time heating and in-situ microstructure mapping reveal the structures are of high temperature origin. A new frontier in gold analysis in both hypogene and supergene systems is the nano domain. In hypogene settings gold at all scales can be metallic and particulate as has been directly observed in refractory ores, or the so called "invisible gold" in pyrite and arsenopyrite. Such nanoparticulate and colloidal transport of gold is a viable mechanism of dispersing the gold during weathering of ore deposits. These gold nanoparticles, long known about in materials sciences and manufacturing have now been seen in these natural environments. Such colloids are also likely to play an important role in gold transport in hydrothermal deposits. The regularly heterogeneous distribution, trace concentration and nanoparticulate grain size of metallic gold in all ore systems has made it difficult for direct observation. Yet, it is critical to be able to establish a broad view of the microstructural/microchemical residence of the actual gold in a given sample. New generation element mapping tools now allow us to 'see' this invisible gold component for the first time and to probe its chemistry and controls on deposition. These studies have the potential to provide a new approach and view of the formation, deposition and provenance history of the metal in all gold deposits.

  18. Robustness of weighted networks

    Science.gov (United States)

    Bellingeri, Michele; Cassi, Davide

    2018-01-01

    Complex network response to node loss is a central question in different fields of network science because node failure can cause the fragmentation of the network, thus compromising the system functioning. Previous studies considered binary networks where the intensity (weight) of the links is not accounted for, i.e. a link is either present or absent. However, in real-world networks the weights of connections, and thus their importance for network functioning, can be widely different. Here, we analyzed the response of real-world and model networks to node loss accounting for link intensity and the weighted structure of the network. We used both classic binary node properties and network functioning measure, introduced a weighted rank for node importance (node strength), and used a measure for network functioning that accounts for the weight of the links (weighted efficiency). We find that: (i) the efficiency of the attack strategies changed using binary or weighted network functioning measures, both for real-world or model networks; (ii) in some cases, removing nodes according to weighted rank produced the highest damage when functioning was measured by the weighted efficiency; (iii) adopting weighted measure for the network damage changed the efficacy of the attack strategy with respect the binary analyses. Our results show that if the weighted structure of complex networks is not taken into account, this may produce misleading models to forecast the system response to node failure, i.e. consider binary links may not unveil the real damage induced in the system. Last, once weighted measures are introduced, in order to discover the best attack strategy, it is important to analyze the network response to node loss using nodes rank accounting the intensity of the links to the node.

  19. Lung function decline rates according to GOLD group in patients with chronic obstructive pulmonary disease.

    Science.gov (United States)

    Kim, Joohae; Yoon, Ho Il; Oh, Yeon-Mok; Lim, Seong Yong; Lee, Ji-Hyun; Kim, Tae-Hyung; Lee, Sang Yeub; Lee, Jin Hwa; Lee, Sang-Do; Lee, Chang-Hoon

    2015-01-01

    Since the Global Initiative for Chronic Obstructive Lung Disease (GOLD) groups A-D were introduced, the lung function changes according to group have been evaluated rarely. We investigated the rate of decline in annual lung function in patients categorized according to the 2014 GOLD guidelines. Patients with COPD included in the Korean Obstructive Lung Disease (KOLD) prospective study, who underwent yearly postbronchodilator spirometry at least three times, were included. The main outcome was the annual decline in postbronchodilator forced expiratory volume in 1 second (FEV1), which was analyzed by random-slope and random-intercept mixed linear regression. A total 175 participants were included. No significant postbronchodilator FEV1 decline was observed between the groups (-34.4±7.9 [group A]; -26.2±9.4 [group B]; -22.7±16.0 [group C]; and -24.0±8.7 mL/year [group D]) (P=0.79). The group with less symptoms (-32.3±7.2 vs -25.0±6.5 mL/year) (P=0.44) and the low risk group (-31.0±6.1 vs -23.6±7.7 mL/year) (P=0.44) at baseline showed a more rapid decline in the postbronchodilator FEV1, but the trends were not statistically significant. However, GOLD stages classified by FEV1 were significantly related to the annual lung function decline. There was no significant difference in lung function decline rates according to the GOLD groups. Prior classification using postbronchodilator FEV1 predicts decline in lung function better than does the new classification.

  20. Modeling pore corrosion in normally open gold- plated copper connectors.

    Energy Technology Data Exchange (ETDEWEB)

    Battaile, Corbett Chandler; Moffat, Harry K.; Sun, Amy Cha-Tien; Enos, David George; Serna, Lysle M.; Sorensen, Neil Robert

    2008-09-01

    The goal of this study is to model the electrical response of gold plated copper electrical contacts exposed to a mixed flowing gas stream consisting of air containing 10 ppb H{sub 2}S at 30 C and a relative humidity of 70%. This environment accelerates the attack normally observed in a light industrial environment (essentially a simplified version of the Battelle Class 2 environment). Corrosion rates were quantified by measuring the corrosion site density, size distribution, and the macroscopic electrical resistance of the aged surface as a function of exposure time. A pore corrosion numerical model was used to predict both the growth of copper sulfide corrosion product which blooms through defects in the gold layer and the resulting electrical contact resistance of the aged surface. Assumptions about the distribution of defects in the noble metal plating and the mechanism for how corrosion blooms affect electrical contact resistance were needed to complete the numerical model. Comparisons are made to the experimentally observed number density of corrosion sites, the size distribution of corrosion product blooms, and the cumulative probability distribution of the electrical contact resistance. Experimentally, the bloom site density increases as a function of time, whereas the bloom size distribution remains relatively independent of time. These two effects are included in the numerical model by adding a corrosion initiation probability proportional to the surface area along with a probability for bloom-growth extinction proportional to the corrosion product bloom volume. The cumulative probability distribution of electrical resistance becomes skewed as exposure time increases. While the electrical contact resistance increases as a function of time for a fraction of the bloom population, the median value remains relatively unchanged. In order to model this behavior, the resistance calculated for large blooms has been weighted more heavily.

  1. Assessment of the In Vivo Toxicity of Gold Nanoparticles

    Directory of Open Access Journals (Sweden)

    Liau Ian

    2009-01-01

    Full Text Available Abstract The environmental impact of nanoparticles is evident; however, their toxicity due to their nanosize is rarely discussed. Gold nanoparticles (GNPs may serve as a promising model to address the size-dependent biological response to nanoparticles because they show good biocompatibility and their size can be controlled with great precision during their chemical synthesis. Naked GNPs ranging from 3 to 100 nm were injected intraperitoneally into BALB/C mice at a dose of 8 mg/kg/week. GNPs of 3, 5, 50, and 100 nm did not show harmful effects; however, GNPs ranging from 8 to 37 nm induced severe sickness in mice. Mice injected with GNPs in this range showed fatigue, loss of appetite, change of fur color, and weight loss. Starting from day 14, mice in this group exhibited a camel-like back and crooked spine. The majority of mice in these groups died within 21 days. Injection of 5 and 3 nm GNPs, however, did not induce sickness or lethality in mice. Pathological examination of the major organs of the mice in the diseased groups indicated an increase of Kupffer cells in the liver, loss of structural integrity in the lungs, and diffusion of white pulp in the spleen. The pathological abnormality was associated with the presence of gold particles at the diseased sites, which were verified by ex vivo Coherent anti-Stoke Raman scattering microscopy. Modifying the surface of the GNPs by incorporating immunogenic peptides ameliorated their toxicity. This reduction in the toxicity is associated with an increase in the ability to induce antibody response. The toxicity of GNPs may be a fundamental determinant of the environmental toxicity of nanoparticles.

  2. Metal weight table

    International Nuclear Information System (INIS)

    1995-03-01

    This book is comprised of two parts about metallic material weight table. the first part deals with steel on weight table of section steel and bar steel, hexagonal steel, equal angle steel, unequal angle steel, channel steel, T steel, H steel, CT steel, light gauge steel, light rail, stainless steel weight calculation, carbon steel pipe for general rescue a circular nail, zinc galvanizing and wire lope. The second part is about nonferrous metal on weight calculation for nonferrous metal nonferrous metal plates, steel pipe, brass copper bar and aluminum.

  3. Benchmarking Density Functionals for Chemical Bonds of Gold

    DEFF Research Database (Denmark)

    Kepp, Kasper Planeta

    2017-01-01

    Gold plays a major role in nanochemistry, catalysis, and electrochemistry. Accordingly, hundreds of studies apply density functionals to study chemical bonding with gold, yet there is no systematic attempt to assess the accuracy of these methods applied to gold. This paper reports a benchmark...... considering the diverse bonds to gold and the complication of relativistic effects. Thus, studies that use DFT with effective core potentials for gold chemistry, with no alternative due to computational cost, are on solid ground using TPSS-D3 or PBE-D3....

  4. The activation analysis of gold in small refractory pebbles

    International Nuclear Information System (INIS)

    Bibby, D.M.; Chaix, R.P.

    1975-08-01

    The gold content of a suite of small pebbles, residual to the milling and leach of a gold bearing ore, has been investigated by means of neutron activation analysis (NAA). An NAA technique presenting a sensitivity of 0.02μgm gold, was used as being appropriate to the samples under investigation. An alternative NAA technique developed with the same sample suite showed a sensitivity of the order of 10 -4 to 10 -5 μgm gold. The NAA techniques developed, are appropriate to the determination of gold in small samples of ore not normally amenable to milling and/or dissolution

  5. Periodically arranged colloidal gold nanoparticles for enhanced light harvesting in organic solar cells

    DEFF Research Database (Denmark)

    Mirsafaei, Mina; Fernandes Cauduro, André Luis; Kunstmann-Olsen, Casper

    2016-01-01

    Although organic solar cells show intriguing features such as low-cost, mechanical flexibility and light weight, their efficiency is still low compared to their inorganic counterparts. One way of improving their efficiency is by the use of light-trapping mechanisms from nano- or microstructures......, which makes it possible to improve the light absorption and charge extraction in the device’s active layer. Here, periodically arranged colloidal gold nanoparticles are demonstrated experimentally and theoretically to improve light absorption and thus enhance the efficiency of organic solar cells....... Surface-ordered gold nanoparticle arrangements are integrated at the bottom electrode of organic solar cells. The resulting optical interference and absorption effects are numerically investigated in bulk hetero-junction solar cells based on the Finite-Difference Time-Domain (FDTD) and Transfer Matrix...

  6. Cellular Uptake and Tissue Biodistribution of Functionalized Gold Nanoparticles and Nanoclusters.

    Science.gov (United States)

    Escudero-Francos, María A; Cepas, Vanesa; González-Menédez, Pedro; Badía-Laíño, Rosana; Díaz-García, Marta E; Sainz, Rosa M; Mayo, Juan C; Hevia, David

    2017-02-01

    In this study, the in vitro uptake by fibroblasts and in vivo biodistribution of 15 nm 11-mercaptoundecanoicacid-protected gold nanoparticles (AuNPs-MUA) and 3 nm glutathione- and 3 nm bovine serum albumin-protected gold nanoclusters (AuNCs@GSH and AuNCs@BSA, respectively) were evaluated. In vitro cell viability was examined after gold nanoparticle treatment for 48 h, based on MTT assays and analyses of morphological structure, the cycle cell, cellular doubling time, and the gold concentration in cells. No potential toxicity was observed at any studied concentration (up to 10 ppm) for AuNCs@GSH and AuNCs@BSA, whereas lower cell viability was observed for AuNPs-MUA at 10 ppm than for other treatments. Neither morphological damage nor modifications to the cell cycle and doubling time were detected after contact with nanoparticles. Associations between cells and AuNPs and AuNCs were demonstrated by inductively coupled plasma mass spectrometry (ICP-MS). AuNCs@GSH exhibited fluorescence emission at 611 nm, whereas AuNCs@BSA showed a band at 640 nm. These properties were employed to confirm their associations with cells by fluorescence confocal microscopy; both clusters were observed in cells and maintained their original fluorescence. In vivo assays were performed using 9 male mice treated with 1.70 μg Au/g body weight gold nanoparticles for 24 h. ICP-MS measurements showed a different biodistribution for each type of nanoparticle; AuNPs-MUA mainly accumulated in the brain, AuNCs@GSH in the kidney, and AuNCs@BSA in the liver and spleen. Spleen indexes were not affected by nanoparticle treatment; however, AuNCs@BSA increased the thymus index significantly from 1.28 to 1.79, indicating an immune response. These nanoparticles have great potential as organ-specific drug carriers and for diagnosis, photothermal therapy, and imaging.

  7. Trends in Weight Regain Following Roux-en-Y Gastric Bypass (RYGB) Bariatric Surgery.

    Science.gov (United States)

    Cooper, Timothy C; Simmons, Elizabeth B; Webb, Kirsten; Burns, James L; Kushner, Robert F

    2015-08-01

    The primary purpose of this study was to assess weight loss and occurrence of weight regain among patients who underwent Roux-en-Y gastric bypass (RYGB) using categorical analysis. Study participants were selected from patients who underwent RYGB from a single institution. Participants (n = 300, mean procedure age = 45.6 ± 9.9) completed surveys for self-reported preoperative weight, current weight, and subsequent weights over postoperative years. Measured weights and confirmed procedure dates were acquired from patient medical records. Mean preoperative weight and BMI were 140.8 kg ± 32.1 and 49.7 ± 9.9, respectively, and mean years since surgery was 6.9 ± 4.9. Study subjects were mostly Caucasian (56.7 %) and female (80.3 %). Participants were stratified a priori into four cohorts based on percent of weight loss at 1 year, 35 % (n = 113). General linear model analyses were conducted to assess the effect of year one weight loss on percent weight regain. The mean weight regain for all patients was 23.4 % of maximum weight loss. Using categorical analysis, mean weight regain in the 35 % weight loss cohorts was 29.1, 21.9, 20.9, and 23.8 %, respectively. Excessive weight regain, defined as ≥25 % of total lost weight, occurred in 37 % of patients. Weight gain is a common complication following RYGB surgery. Despite the percentage of weight loss over the first year, all cohort patient groups regained on average between 21 and 29 % of lost weight. Excessive weight gain was experienced by over one third of patients. Greater initial absolute weight loss leads to more successful long-term weight outcomes.

  8. Outcomes from a medical weight loss program: primary care clinics versus weight loss clinics.

    Science.gov (United States)

    Haas, William C; Moore, Justin B; Kaplan, Michael; Lazorick, Suzanne

    2012-06-01

    Few studies have focused on weight loss programs implemented in community-based primary care settings. The objective of this analysis was to evaluate the effectiveness of a weight loss program and determine whether physicians in primary care practices could achieve reductions in body weight and body fat similar to those obtained in weight loss clinics. Analyses were performed on chart review data from 413 obese participants who underwent weight loss at a primary care (n=234) or weight loss (n=179) clinic. Participants received physician-guided behavioral modification sessions and self-selected a diet plan partially or fully supplemented by meal replacements. A repeated-measures analysis of covariance was conducted with age and sex serving as covariates; significance was set at P≤.05. In 178 subjects (43%) completing 12 weeks of the program, primary care clinics were as effective as weight loss clinics at achieving reductions in body weight (12.4 vs 12.1 kg) but better with regard to reduction in body fat percentage (3.8% vs 2.7%; P≤.05). Regardless of location, participants completing 12 weeks lost an average of 11.1% of their body weight. Participants selecting full meal replacement had greater reductions in weight and body fat percentage (12.7 kg, 3.5%) compared with participants selecting a partial meal replacement plan (8.3 kg, 2.3%). Primary care physicians can successfully manage and treat obese patients using behavioral modification techniques coupled with meal replacement diets. Copyright © 2012 Elsevier Inc. All rights reserved.

  9. Synthesis of PEGylated gold nanostars and bipyramids for intracellular uptake

    International Nuclear Information System (INIS)

    Navarro, Julien R G; Lerouge, Frédéric; Chaput, Frédéric; Micouin, Guillaume; Gabudean, Ana-Maria; Baldeck, Patrice L; Kamada, Kenji; Parola, Stephane; Manchon, Delphine; Mosset, Alexis; Cottancin, Emmanuel; Blanchard, Nicholas P; Marotte, Sophie; Leverrier, Yann; Marvel, Jacqueline

    2012-01-01

    A great number of works have focused their research on the synthesis, design and optical properties of gold nanoparticles for potential biological applications (bioimaging, biosensing). For this kind of application, sharp gold nanostructures appear to exhibit the more interesting features since their surface plasmon bands are very sensitive to the surrounding medium. In this paper, a complete study of PEGylated gold nanostars and PEGylated bipyramidal-like nanostructures is presented. The nanoparticles are prepared in high yield and their surfaces are covered with a biocompatible polymer. The photophysical properties of gold bipyramids and nanostars, in suspension, are correlated with the optical response of single and isolated objects. The resulting spectra of isolated gold nanoparticles are subsequently correlated to their geometrical structure by transmission electron microscopy. Finally, the PEGylated gold nanoparticles were incubated with melanoma B16-F10 cells. Dark-field microscopy showed that the biocompatible gold nanoparticles were easily internalized and most of them localized within the cells. (paper)

  10. Preparation of gold nanoparticles by arc discharge in water

    International Nuclear Information System (INIS)

    Lung, Jen-Kuang; Huang, Jen-Chuen; Tien, Der-Chi; Liao, Chih-Yu; Tseng, Kuo-Hsiung; Tsung, Tsing-Tshin; Kao, Wen-Shiow; Tsai, Teh-Hua; Jwo, Ching-Song; Lin, Hong-Ming; Stobinski, Leszek

    2007-01-01

    Gold nanoparticles have been attracting attention due to their extensive application in chemistry, physics, material science, electronics, catalysis and bionanotechnology. Synthesis of gold nanoparticles often involves toxic and expensive physical-chemistry methods. Preparation of gold nanoparticles by arc discharge in water is proposed for the first time. Fabrication of gold nanostructures in deionized water has been successfully established. The evidence of gold particles' light absorbance reveals a unique surface plasmon resonance for Au nanoparticles suspended in deionized water. Gold nanostructures uniformly dispersed in water, their UV-Vis absorption and crystalline size are shown. Our experimental results demonstrate that fabrication of gold nanoparticles by arc discharge in water is an alternative, cheap, effective and environmentally friendly method

  11. Use of coal-oil agglomerates for particulate gold recovery

    Energy Technology Data Exchange (ETDEWEB)

    Calvez, J.P.S.; Kim, M.J.; Wong, P.L.M.; Tran, T. [University of New South Wales, Sydney, NSW (Australia). School of Chemical Engineering and Industrial Chemistry

    1998-09-01

    The underlying principles by which gold is recovered by coal-oil agglomerates was investigated. The effects of various parameters such as oil:coal ratios, agglomerate:ore ratios, pH and coal particle size on gold recovery were evaluated using synthetic gold bearing samples, bituminous coal, and diesel oil and kerosene. The effects of sulfides on gold recovery and the depth of gold particle penetration within the agglomerates were also investigated. Results showed that gold recovery was increased by increasing agglomerate:ore ratio, decreasing oil:coal ratio and decreasing coal particle size. There was no significant difference in gold recoveries at pH range of 4-12 and at up to 5% sulfides in the feed.

  12. Fabrication of Gold Nanochains with Octreotide Acetate Template

    Directory of Open Access Journals (Sweden)

    Jing Zhou

    2013-01-01

    Full Text Available We described a facile method for assembly gold nanochains by using octreotide acetate as template in aqueous environment. In acidic solution, octreotide acetate was conferred positive charges and its structure changed to chain-like. The monodisperse negative gold nanoparticles were bound to the surface of octreotide acetate template by electrostatic attraction and the interaction of gold nanoparticles with amino acid residues (tryptophan and lysine. The fabricated gold nanostructure presented chain-like observed by transmission electron microscopy. The cytotoxicity of gold nanochains was examined by tetrazolium dye-based microtitration (MTT assay, which demonstrated significantly less toxicity than that of octreotide acetate alone. The MTT assay also reflected the combinative action between the gold nanoparticles with octreotide acetate. Our work lays the groundwork for developing octreotide acetate-templated nanomaterials that can be used as a building block for the creation of nanomaterials. Meanwhile, the harmfulless gold nanochains have great application prospects in the biomedical filed.

  13. Physicochemical Properties of Gold Nanostructures Deposited on Glass

    Directory of Open Access Journals (Sweden)

    Zdenka Novotna

    2014-01-01

    Full Text Available Properties of gold films sputtered onto borosilicate glass substrate were studied. UV-Vis absorption spectra were used to investigate optical parameters. XRD analysis provided information about the gold crystalline nanostructure, the texture, and lattice parameter and biaxial tension was also determined by the XRD method. The surface morphology was examined by atomic force microscopy (AFM; chemical structure of sputtered gold nanostructures was examined by X-ray photoelectron spectroscopy (ARXPS. The gold crystallites are preferentially [111] oriented on the sputtered samples. Gold deposition leads to dramatic changes in the surface morphology in comparison to pristine glass substrate. Oxygen is not incorporated into the gold layer during gold deposition. Experimental data on lattice parameter were also confirmed by theoretical investigations of nanoclusters using tight-binding potentials.

  14. Measurement of the isotope effect of the diffusion of silver and gold in gold and of silver in silver-gold alloys

    International Nuclear Information System (INIS)

    Wolter, D.

    1974-01-01

    The silver isotopes Ag 105 and Agsup(110m) and the gold isotopes Au 195 and Au 199 were used for isotope effect measurements. The isotope effect of the gold self-diffusion was measured on four monocrystals samples at about 850 0 C, that of silver in gold monocrystals at five different temperatures between 731 0 C and 1050 0 C. Furthermore, the isotope effect for silver at 904 0 C was measured on seven silver-gold alloys of varying silver concentration. The correlation factor was determined from the measurements. (HPOE/LH) [de

  15. Weighted Bergman Kernels for Logarithmic Weights

    Czech Academy of Sciences Publication Activity Database

    Engliš, Miroslav

    2010-01-01

    Roč. 6, č. 3 (2010), s. 781-813 ISSN 1558-8599 R&D Projects: GA AV ČR IAA100190802 Keywords : Bergman kernel * Toeplitz operator * logarithmic weight * pseudodifferential operator Subject RIV: BA - General Mathematics Impact factor: 0.462, year: 2010 http://www.intlpress.com/site/pub/pages/journals/items/pamq/content/vols/0006/0003/a008/

  16. Impact of high-density lipoprotein 3 cholesterol subfraction on periprocedural myocardial injury in patients who underwent elective percutaneous coronary intervention.

    Science.gov (United States)

    Harada, Kazuhiro; Kikuchi, Ryosuke; Suzuki, Susumu; Tanaka, Akihito; Aoki, Toshijiro; Iwakawa, Naoki; Kojima, Hiroki; Hirayama, Kenshi; Mitsuda, Takayuki; Sumi, Takuya; Negishi, Yosuke; Ishii, Hideki; Murohara, Toyoaki

    2018-02-02

    Periprocedural myocardial injury (PMI) is a major complication of percutaneous coronary intervention (PCI) and is associated with atherosclerotic coronary plaque and worse clinical outcomes. High-density lipoprotein cholesterol (HDL-C) is a protective factor for cardiovascular disease. However, the role of HDL-C subfractions, such as HDL2 cholesterol (HDL2-C) or HDL3 cholesterol (HDL3-C), in cardiovascular disease remains unclear. The purpose of the study was to investigate the relationship between HDL2-C and HDL3-C subfractions and the incidence of PMI in patients who underwent elective PCI. We enrolled 129 patients who underwent elective PCI for stable angina pectoris. PMI was defined as an increase in high-sensitivity troponin T levels > 5 times the upper normal limit (> 0.070 ng/mL) at 24 h after PCI. Serum HDL-C subfractions (HDL2-C and HDL3-C) were assessed using ultracentrifugation in patients with and those without PMI. HDL3-C levels were significantly lower in patients with PMI than in those without (15.1 ± 3.0 mg/dL vs. 16.4 ± 2.9 mg/dL, p = 0.016) and had an independent and inverse association with PMI (odds ratio, 0.86; 95% confidence interval, 0.74-0.99; p = 0.038). When divided by the cut-off value of HDL3-C for PMI (14.3 mg/dL), the incidence of PMI was significantly higher in low HDL3-C patients than in high HDL3-C patients (51.2% vs. 30.2%, p = 0.020). HDL3-C was an independent inverse predictor of PMI in patients who underwent elective PCI.

  17. Patterns and Timing of Failure for Diffuse Large B-Cell Lymphoma After Initial Therapy in a Cohort Who Underwent Autologous Bone Marrow Transplantation for Relapse

    Energy Technology Data Exchange (ETDEWEB)

    Dhakal, Sughosh; Bates, James E. [Department of Radiation Oncology, Wilmot Cancer Institute, University of Rochester Medical Center, Rochester, New York (United States); Casulo, Carla; Friedberg, Jonathan W.; Becker, Michael W.; Liesveld, Jane L. [Department of Medicine, Wilmot Cancer Institute, University of Rochester Medical Center, Rochester, New York (United States); Constine, Louis S., E-mail: louis_constine@urmc.rochester.edu [Department of Radiation Oncology, Wilmot Cancer Institute, University of Rochester Medical Center, Rochester, New York (United States)

    2016-10-01

    Purpose: To evaluate the location and timing of initial recurrence in patients with diffuse large B-cell lymphoma (DLBCL) who subsequently underwent high-dose chemotherapy with autologous stem cell transplant (HDC/ASCT), to direct approaches for disease surveillance, elucidate the patterns of failure of contemporary treatment strategies, and guide adjuvant treatment decisions. Methods and Materials: We analyzed consecutive patients with DLBCL who underwent HDC/ASCT between May 1992 and March 2014 at our institution. Of the 187 evaluable patients, 8 had incomplete data, and 79 underwent HDC/ASCT as a component of initial treatment for de novo or refractory DLBCL and were excluded from further analysis. Results: The median age was 50.8 years; the median time to relapse was 1.3 years. Patients were segregated according to the initial stage at diagnosis, with early stage (ES) defined as stage I/II and advanced stage (AS) defined as stage III/IV. In total, 40.4% of the ES and 75.5% of the AS patients relapsed in sites of initial disease; 68.4% of those with ES disease and 75.0% of those with AS disease relapsed in sites of initial disease only. Extranodal relapses were common (44.7% in ES and 35.9% in AS) and occurred in a variety of organs, although gastrointestinal tract/liver (n=12) was most frequent. Conclusions: Most patients with DLBCL who relapse and subsequently undergo HDC/ASCT initially recur in the previously involved disease site(s). Time to recurrence is brief, suggesting that frequency of screening is most justifiably greatest in the early posttherapy years. © 2016 Elsevier Inc.

  18. Body Weight - Multiple Languages

    Science.gov (United States)

    ... V W XYZ List of All Topics All Body Weight - Multiple Languages To use the sharing features on this page, ... PDF Health Information Translations Spanish (español) Expand Section Body Weight: MedlinePlus Health Topic - English ... Health Information Translations Characters not displaying correctly on this page? See language display issues . Return to the MedlinePlus Health Information ...

  19. Weight and psychiatry

    African Journals Online (AJOL)

    Adele

    weight loss in morbidly obeses patients undergoing bariatric surgery. Obes Surg. 2002; 12: 835-40. 11. World Health Organisation. The ICD-10 Classification of Mental and. Behavioural Disorders. Clinical descriptions and diagnostic guidelines. The clinical relevance of weight in psychiatry varies. It may be:- I. an associated ...

  20. birth-weight infants

    African Journals Online (AJOL)

    hours of life was more strongly associated with death than four traditional risk factors (birth weight, short gestation, male sex and the diagnosis of respiratory distress syndrome). Furthermore, mean pH in the first 12 hours was as strongly associated with death as was birth weight. Previous research in our neonatal population ...

  1. Direct determination of thermodynamic activities of gold in the systems gold-palladium and gold-silver-palladium

    International Nuclear Information System (INIS)

    Hoehn, R.; Herzig, C.

    1986-01-01

    The thermodynamic activity of the gold component was directly measured in Au-Pd alloys in the concentration range between X Au =0.048 and 0.850 and in the temperature range 1070 and 1300 K. The ratio of the vapour pressures of pure gold and of the gold component of the alloys was determined - after effusion from a Knudsen twin cell and condensation on a collecting plate - by analysing the decay rate of the radioisotopes 195 Au and 198 Au in an intrinsic germanium well-type detector. The partial mixing enthalpy and the partial mixing entropy of Au were directly obtained from these results. By Gibbs-Duhem integration the integral mixing functions were deduced. Similar measurements were performed in several ternary Au-Ag-Pd alloys of fixed mole fraction X Ag /X Pd =1/9. A comparison of the directly measured partial free excess enthalpy of Au in these ternary alloys with data obtained by the approximate models of Kohler, Toop and Bonnier using data of the corresponding three binary systems yields satisfactory agreement. (orig.) [de

  2. Antifungal activity of gold nanoparticles prepared by solvothermal method

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, Tokeer, E-mail: tahmad3@jmi.ac.in [Nanochemistry Laboratory, Department of Chemistry, Jamia Millia Islamia, New Delhi 110025 (India); Wani, Irshad A.; Lone, Irfan H.; Ganguly, Aparna [Nanochemistry Laboratory, Department of Chemistry, Jamia Millia Islamia, New Delhi 110025 (India); Manzoor, Nikhat; Ahmad, Aijaz [Department of Biosciences, Jamia Millia Islamia, New Delhi 110025 (India); Ahmed, Jahangeer [Department of Chemistry, Michigan State University, East Lansing, MI 48824 (United States); Al-Shihri, Ayed S. [Department of Chemistry, Faculty of Science, King Khalid University, Abha 61413, P.O. Box 9004 (Saudi Arabia)

    2013-01-15

    Graphical abstract: Gold nanoparticles (7 and 15 nm) of very high surface area (329 and 269 m{sup 2}/g) have been successfully synthesized through solvothermal method by using tin chloride and sodium borohydride as reducing agents. As-prepared gold nanoparticles shows very excellent antifungal activity against Candida isolates and activity increases with decrease in the particle size. Display Omitted Highlights: ► Effect of reducing agents on the morphology of gold nanoparticles. ► Highly uniform and monodisperse gold nanoparticles (7 nm). ► Highest surface area of gold nanoparticles (329 m{sup 2/}g). ► Excellent antifungal activity of gold nanoparticles against Candida strains. -- Abstract: Gold nanoparticles have been successfully synthesized by solvothermal method using SnCl{sub 2} and NaBH{sub 4} as reducing agents. X-ray diffraction studies show highly crystalline and monophasic nature of the gold nanoparticles with face centred cubic structure. The transmission electron microscopic studies show the formation of nearly spherical gold nanoparticles of average size of 15 nm using SnCl{sub 2}, however, NaBH{sub 4} produced highly uniform, monodispersed and spherical gold nanoparticles of average grain size of 7 nm. A high surface area of 329 m{sup 2}/g for 7 nm and 269 m{sup 2}/g for 15 nm gold nanoparticles was observed. UV–vis studies assert the excitations over the visible region due to transverse and longitudinal surface plasmon modes. The gold nanoparticles exhibit excellent size dependant antifungal activity and greater biocidal action against Candida isolates for 7 nm sized gold nanoparticles restricting the transmembrane H{sup +} efflux of the Candida species than 15 nm sized gold nanoparticles.

  3. Coal-oil assisted flotation for the gold recovery

    Energy Technology Data Exchange (ETDEWEB)

    Sen, S.; Seyrankaya, A.; Cilingir, Y. [Dokuz Eylul University, Izmir (Turkey). Mining Engineering Department

    2005-09-01

    Using coal-oil agglomeration method for free or native gold recovery has been a research subject for many researchers over the years. In this study, a new approach 'coal-oil assisted gold flotation' was used to recover gold particles. The coal-oil-gold agglomeration process considers the preferential wetting of coal and gold particles. The method takes advantage of the greater hydrophobicity and oleophilicity of coal and gold compared to that the most gangue materials. Unlike the previous studies about coal-oil-gold agglomeration, this method uses a very small amount of coal and agglomerating agents. Some experiments were conducted on synthetic gold ore samples to reveal the reaction of the coal-oil assisted gold flotation process against the size and the number of gold particles in the feed. It was observed that there is no significant difference in process gold recoveries for feeds assaying different Au. Although there was a slight decrease for coarse gold particles, the process seems to be effective for the recovery of gold grains as coarse as 300 {mu} m. The decrease in the finest size ({lt} 53 {mu} m) is considered to be the decrease in the collision efficiency between the agglomerates and the finest gold particles. The effect of changing coal quantity for constant ore and oil amounts was also investigated. The experiments showed that the process gives very similar results for both artificial and natural ore samples; the best results have been obtained by using 30/1 coal-oil ratio.

  4. Red gold analysis by using gamma absorption tchnique

    International Nuclear Information System (INIS)

    Kurtoglu, A.; Tugrul, A.B.

    2001-01-01

    Gold is a valuable metal and also preferable materials for antique artefacts and some advanced technology products. It can be offered for the analysis of the gold as namely; neutron activation analysis, X-ray florescence technique, Auger spectroscopy, atomic absorption and wet chemistry. Some limitations exist in practice for these techniques, especially in the points of financial and applicability concepts. An advanced a practical technique is gamma absorption technique for the gold alloys. This technique is based on discontinuities in the absorption coefficient for gamma rays at corresponding to the electronic binding energies of the absorber. If irradiation is occurred at gamma absorption energy for gold, absorption rates of the red gold changes via the gold amounts in the alloy. Red gold is a basic and generally preferable alloy that has copper and silver additional of the gold in it. The gold amount defines as carat of the gold. Experimental studies were observed for four different carats of red gold; these are 8, 14, 18 and 22 carats. K-edge energy level of the gold is on 80 keV energy. So, Ba-133 radioisotope is preferred as the gamma source because of it has gamma energy peak in that energy. Experiments observed in the same geometry for all samples. NaI(Tl) detector and multichannel analyser were used for measurements. As a result of the experiments, the calibration curves could be drawn for red gold. For examine this curve, unknown samples are measured in experimental set and it can be determined the carat of it with the acceptability. So the red gold analysis can be observed non-destructively, easily and quickly by using the gamma absorption technique

  5. Antifungal activity of gold nanoparticles prepared by solvothermal method

    International Nuclear Information System (INIS)

    Ahmad, Tokeer; Wani, Irshad A.; Lone, Irfan H.; Ganguly, Aparna; Manzoor, Nikhat; Ahmad, Aijaz; Ahmed, Jahangeer; Al-Shihri, Ayed S.

    2013-01-01

    Graphical abstract: Gold nanoparticles (7 and 15 nm) of very high surface area (329 and 269 m 2 /g) have been successfully synthesized through solvothermal method by using tin chloride and sodium borohydride as reducing agents. As-prepared gold nanoparticles shows very excellent antifungal activity against Candida isolates and activity increases with decrease in the particle size. Display Omitted Highlights: ► Effect of reducing agents on the morphology of gold nanoparticles. ► Highly uniform and monodisperse gold nanoparticles (7 nm). ► Highest surface area of gold nanoparticles (329 m 2/ g). ► Excellent antifungal activity of gold nanoparticles against Candida strains. -- Abstract: Gold nanoparticles have been successfully synthesized by solvothermal method using SnCl 2 and NaBH 4 as reducing agents. X-ray diffraction studies show highly crystalline and monophasic nature of the gold nanoparticles with face centred cubic structure. The transmission electron microscopic studies show the formation of nearly spherical gold nanoparticles of average size of 15 nm using SnCl 2 , however, NaBH 4 produced highly uniform, monodispersed and spherical gold nanoparticles of average grain size of 7 nm. A high surface area of 329 m 2 /g for 7 nm and 269 m 2 /g for 15 nm gold nanoparticles was observed. UV–vis studies assert the excitations over the visible region due to transverse and longitudinal surface plasmon modes. The gold nanoparticles exhibit excellent size dependant antifungal activity and greater biocidal action against Candida isolates for 7 nm sized gold nanoparticles restricting the transmembrane H + efflux of the Candida species than 15 nm sized gold nanoparticles.

  6. Gold in the hills: patterns of placer gold accumulation under dynamic tectonic and climatic conditions

    Science.gov (United States)

    Roy, Sam; Upton, Phaedra; Craw, Dave

    2018-01-01

    Formation of placer accumulations in fluvial environments requires 103-106 or even greater times concentration of heavy minerals. For this to occur, regular sediment supply from erosion of adjacent topography is required, the river should remain within a single course for an extended period of time and the material must be reworked such that a high proportion of the sediment is removed while a high proportion of the heavy minerals remains. We use numerical modeling, constrained by observations of circum-Pacific placer gold deposits, to explore processes occurring in evolving river systems in dynamic tectonic environments. A fluvial erosion/transport model is used to determine the mobility of placer gold under variable uplift rate, storm intensity, and rock mass strength conditions. Gold concentration is calculated from hydraulic and bedload grain size conditions. Model results suggest that optimal gold concentration occurs in river channels that frequently approach a threshold between detachment-limited and transport-limited hydraulic conditions. Such a condition enables the accumulation of gold particles within the framework of a residual gravel lag. An increase in transport capacity, which can be triggered by faster uplift rates, more resistant bedrock, or higher intensity storm events, will strip all bedload from the channel. Conversely, a reduction in transport capacity, triggered by a reduction in uplift rate, bedrock resistance, or storm intensity, will lead to a greater accumulation of a majority of sediments and a net decrease in gold concentration. For our model parameter range, the optimal conditions for placer gold concentration are met by 103 times difference in strength between bedrock and fault, uplift rates between 1 and 5 mm a-1, and moderate storm intensities. Fault damage networks are shown to be a critical factor for high Au concentrations and should be a target for exploration.

  7. Spinopelvic balance evaluation of patients with degenerative spondylolisthesis L4L5 and L4L5 herniated disc who underwent surgery ?

    OpenAIRE

    Nunes, Viviane Regina Hernandez; Jacob, Charbel; Cardoso, Igor Machado; Batista, Jos? Lucas; Brazolino, Marcus Alexandre Novo; Maia, Thiago Cardoso

    2016-01-01

    ABSTRACT OBJECTIVE: To correlate spinopelvic balance with the development of degenerative spondylolisthesis and disk herniation. METHODS: This was a descriptive retrospective study that evaluated 60 patients in this hospital, 30 patients with degenerative spondylolisthesis at the L4-L5 level and 30 with herniated disk at the L4-L5 level, all of whom underwent Surgical treatment. RESULTS: Patients with lumbar disk herniation at L4-L5 level had a mean tilt of 8.06, mean slope of 36.93, an...

  8. Prevalence, risk factors, and consequences of overweight in children and adolescents who underwent renal transplantation--short- and medium-term analysis.

    Science.gov (United States)

    Boschetti, Sofia Bonna; Nogueira, Paulo Cesar Koch; Pereira, Aline Maria Luiz; Fisberg, Mauro; Pestana, José Osmar Medina

    2013-02-01

    To determine the prevalence and risk factors for (i) overweight/obesity and (ii) weight gain six months after transplantation and to study the effect of weight excess on graft function and survival. We performed a retrospective study of kidney transplanted children. (i) prevalence of overweight/obesity at sixth month, (ii) gaining 1.0 BMI SDS from one to six months. To study the effects of weight excess, graft function and survival at 36 months were the endpoints. The study included 197 individuals. At sixth month, 57/197 (29%) presented overweight/obesity, and the factors associated to this outcome were: (i) age at transplantation (OR = 3.04) and (ii) overweight/obesity in the first month (OR = 22.16). Groups presented no difference on graft function and survival at 36 months. From one to six months, 90/197 (46%) patients gained >1.0 BMI SDS. This outcome was associated with (i) female sex (OR = 2.50), (ii) steroids' pulses (OR = 2.98), (iii) steroids exposure (OR = 1.04), and (iv) living donor (OR = 2.69). The group that gained BMI presented a lower 36 months graft survival (86% vs. 98%, p < 0.001). Weight excess and gain after transplantation are frequent, particularly in younger female recipients and in those receiving high steroids exposure. The lower graft survival in patients with rapid weight gain deserves investigation. © 2012 John Wiley & Sons A/S.

  9. Weight discrimination and bullying.

    Science.gov (United States)

    Puhl, Rebecca M; King, Kelly M

    2013-04-01

    Despite significant attention to the medical impacts of obesity, often ignored are the negative outcomes that obese children and adults experience as a result of stigma, bias, and discrimination. Obese individuals are frequently stigmatized because of their weight in many domains of daily life. Research spanning several decades has documented consistent weight bias and stigmatization in employment, health care, schools, the media, and interpersonal relationships. For overweight and obese youth, weight stigmatization translates into pervasive victimization, teasing, and bullying. Multiple adverse outcomes are associated with exposure to weight stigmatization, including depression, anxiety, low self-esteem, body dissatisfaction, suicidal ideation, poor academic performance, lower physical activity, maladaptive eating behaviors, and avoidance of health care. This review summarizes the nature and extent of weight stigmatization against overweight and obese individuals, as well as the resulting consequences that these experiences create for social, psychological, and physical health for children and adults who are targeted. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. Gold-catalyzed formation of pyrrolo- and indolo-oxazin-1-one derivatives: The key structure of some marine natural products

    Directory of Open Access Journals (Sweden)

    Sultan Taskaya

    2015-05-01

    Full Text Available Various N-propargylpyrrole and indolecarboxylic acids were efficiently converted into 3,4-dihydropyrrolo- and indolo-oxazin-1-one derivatives by a gold(III-catalyzed cyclization reaction. Some of the products underwent TFA-catalyzed double bond isomerization and some did not. Cyclization reactions in the presence of alcohol catalyzed by Au(I resulted in the formation of hemiacetals after cascade reactions.

  11. Targeting of Gold Deposits in Amazonian Exploration Frontiers using Knowledge- and Data-Driven Spatial Modeling of Geophysical, Geochemical, and Geological Data

    Science.gov (United States)

    Magalhães, Lucíola Alves; Souza Filho, Carlos Roberto

    2012-03-01

    This paper reports the application of weights-of-evidence, artificial neural networks, and fuzzy logic spatial modeling techniques to generate prospectivity maps for gold mineralization in the neighborhood of the Amapari Au mine, Brazil. The study area comprises one of the last Brazilian mineral exploration frontiers. The Amapari mine is located in the Maroni-Itaicaiúnas Province, which regionally hosts important gold, iron, manganese, chromite, diamond, bauxite, kaolinite, and cassiterite deposits. The Amapari Au mine is characterized as of the orogenic gold deposit type. The highest gold grades are associated with highly deformed rocks and are concentrated in sulfide-rich veins mainly composed of pyrrhotite. The data used for the generation of gold prospectivity models include aerogeophysical and geological maps as well as the gold content of stream sediment samples. The prospectivity maps provided by these three methods showed that the Amapari mine stands out as an area of high potential for gold mineralization. The prospectivity maps also highlight new targets for gold exploration. These new targets were validated by means of detailed maps of gold geochemical anomalies in soil and by fieldwork. The identified target areas exhibit good spatial coincidence with the main soil geochemical anomalies and prospects, thus demonstrating that the delineation of exploration targets by analysis and integration of indirect datasets in a geographic information system (GIS) is consistent with direct prospecting. Considering that work of this nature has never been developed in the Amazonian region, this is an important example of the applicability and functionality of geophysical data and prospectivity analysis in regions where geologic and metallogenetic information is scarce.

  12. Determination of gold of No. 501 uranium deposits and soil samples by cold leaching gold in dilute aqua regia and collection on activated charcoal

    International Nuclear Information System (INIS)

    Shen Maogen; Yao Liying.

    1989-01-01

    The gold determination method is described by cold leaching gold in dilute aqua regia and collection on activated charcoal and presents the results obtained in determining gold of uranium deposits and soil samples

  13. Gold resource modeling using pod indicator kriging

    Science.gov (United States)

    Bargawa, Waterman Sulistyana; Rauf, Abdul; Amri, Nur Ali

    2016-02-01

    This paper describes an implementation of the pod indicator kriging method used to gold resource modeling. Method such as ordinary kriging estimate the mean grade of a block that is fairly large. The usual outcome is that large blocks rarely turn out to be all ore or all waste, thus making reserve estimates an incorrect estimate of what will be mined. Pod indicator kriging offers a solution to this problem by estimating the distribution of grade values within a large block, rather than just estimating the mean grade of the block. Knowing the distribution of grade value within the block, it is then easy to calculate the proportion of the block that is above cutoff grade and the grade of the ore above cutoff grade. This research shows that the pod indicator kriging model is quite applicable and reliable in gold resourcemodeling.

  14. Gold nanoparticles grafting on glass surface

    Science.gov (United States)

    Kvítek, Ondřej; Bot, Marek; Švorčík, Václav

    2012-09-01

    New method of grafting of gold nanoparticles (AuNPs) to glass surface was developed and investigated. The method based on glass activation by plasma discharge use dithiols for AuNP binding as an alternative to silane chemistry currently used for binding AuNPs onto glass surface. XPS measurements confirmed the presence of sulfur and gold on the modified glass surface. The presence of AuNPs on modified glass surface was then directly proven with AFM method. UV-vis spectra of samples with grafted AuNPs show a peak of SPR absorbance. With increasing modification time, more AuNPs are bound to the glass surface, which can aggregate.

  15. Ballistic transport in gold [110] nanowire

    Science.gov (United States)

    Kurui, Yoshihiko; Oshima, Yoshifumi; Okamoto, Masakuni; Takayanagi, Kunio

    2009-03-01

    Conductance of gold nanowire elongated along the [110] direction (gold [110] nanowire) was measured during many breaking procedures, while simultaneously acquiring transmission electron microscope images. The conductance histogram exhibits a series of peaks whose conductance values increased nearly in steps of the conductance quantum, G0 =2e^2/h. However thick nanowires above 10G0 showed dequantization, where the increment was only 0.9G0. The structure for each peak was determined to be either an atomic sheet or a hexagonal prism. The number of conductance channels calculated for each atomic structure by first principles theory, coincided well with the peak index in the conductance histogram. The present study shows that the [110] nanowire behave as ballistic conductors, and a conductance peak appears whenever a conductance channel is opened.

  16. Tamper indicating gold nanocup plasmonic films

    Energy Technology Data Exchange (ETDEWEB)

    DeVetter, Brent M.; Bernacki, Bruce E.; Bennett, Wendy D.; Schemer-Kohrn, Alan; Alvine, Kyle J.

    2017-02-13

    The spectral signature of nanoplasmonic films are both robust and tailorable with optical responses ranging from the visible to the near-infrared. We present the development of flexible, elastomeric nanoplasmonic films consisting of periodic arrays of gold nanocups as tamper indicating films. Gold nanocups have polarization-sensitive optical properties that may be manufactured into films that offer unique advantages for tamper indication. These flexible films can be made quickly and at low-cost using commercially available monodisperse polystyrene nanospheres through self-assembly followed by plasma etching, metal deposition, and lift-off from a sacrificial substrate. Polarization- and angle-dependent optical spectroscopic measurements were performed to characterize the fabricated films. Using polarization-sensitive hyperspectral imaging, we demonstrate how these films can be applied to tamper indication and counterfeit resistance applications.

  17. Reversible peptide oligomerization over nanoscale gold surfaces

    Directory of Open Access Journals (Sweden)

    Kazushige Yokoyama

    2015-11-01

    Full Text Available A selective oligomeric formation of amyloid beta 1-40 (Ab1-40 monomers over a nanogold colloidal surface was investigated. An unfolded Ab1-40 monomer is considered to construct a dimer or trimer based oligomeric form with its hydrophobic segment placing outward under an acidic condition. Under a basic condition, a conformation of Ab is expected to take a folded monomeric form with its hydrophilic segment folded inward, avoiding the networking with residual colloidal particles. The most probable oligomeric form constructed over a 20 nm gold colloidal surface within a 25 ℃ to 65 ℃ temperature range is a dimer based unit and that over 30 or 40 nm gold colloidal surface below 15 ℃ is concluded to be a trimer based unit. However, selective oligomerization was not successfully reproduced under the rest of the conditions. A dipole-induced dipole interaction must cause a flexible structural change between folded and unfolded forms.

  18. Formation of Silver and Gold Dendrimer Nanocomposites

    International Nuclear Information System (INIS)

    Balogh, Lajos; Valluzzi, Regina; Laverdure, Kenneth S.; Gido, Samuel P.; Hagnauer, Gary L.; Tomalia, Donald A.

    1999-01-01

    Structural types of dendrimer nanocomposites have been studied and the respective formation mechanisms have been described, with illustration of nanocomposites formed from poly(amidoamine) PAMAM dendrimers and zerovalent metals, such as gold and silver. Structure of {(Au(0)) n- PAMAM} and {(Ag(0)) n- PAMAM} gold and silver dendrimer nanocomposites was found to be the function of the dendrimer structure and surface groups as well as the formation mechanism and the chemistry involved. Three different types of single nanocomposite architectures have been identified, such as internal ('I'), external ('E') and mixed ('M') type nanocomposites. Both the organic and inorganic phase could form nanosized pseudo-continuous phases while the other components are dispersed at the molecular or atomic level either in the interior or on the surface of the template/container. Single units of these nanocomposites may be used as building blocks in the synthesis of nanostructured materials

  19. Synoviorthesis with radioactive gold in hemophiliacs

    International Nuclear Information System (INIS)

    Ahlberg, Aa.; Petterson, H.

    1979-01-01

    Twenty-seven patients with hemophilia treated with intra-articular injection of radioactive gold were followed up clinically and radiologically for 3 to 9 years after treatment. To assess the radiological changes, a new classification was designed, with a score describing the severity of the changes in a more accurate manner than the methods previously used. The treatment decreased the bleeding frequency and stopped the progress of the arthropathy if applied at an early stage when the arthropathy was still reversible. If the treatment was begun at a later stage, the arthropathy seemed to progress independently of the effect on the bleeding frequency. No negative effect of the radioactive gold was observed on the joint or the growing zone. (author)

  20. Topological states on the gold surface.

    Science.gov (United States)

    Yan, Binghai; Stadtmüller, Benjamin; Haag, Norman; Jakobs, Sebastian; Seidel, Johannes; Jungkenn, Dominik; Mathias, Stefan; Cinchetti, Mirko; Aeschlimann, Martin; Felser, Claudia

    2015-12-14

    Gold surfaces host special electronic states that have been understood as a prototype of Shockley surface states. These surface states are commonly employed to benchmark the capability of angle-resolved photoemission spectroscopy (ARPES) and scanning tunnelling spectroscopy. Here we show that these Shockley surface states can be reinterpreted as topologically derived surface states (TDSSs) of a topological insulator (TI), a recently discovered quantum state. Based on band structure calculations, the Z2-type invariants of gold can be well-defined to characterize a TI. Further, our ARPES measurement validates TDSSs by detecting the dispersion of unoccupied surface states. The same TDSSs are also recognized on surfaces of other well-known noble metals (for example, silver, copper, platinum and palladium), which shines a new light on these long-known surface states.

  1. Poly-thiosemicarbazide Membrane for Gold Adsorption and In-situ Growth of Gold Nanoparticles

    KAUST Repository

    Parra, Luis F.

    2012-12-01

    In this work the synergy between a polymer containing chelate sites and gold ions was explored by the fabrication of a polymeric membrane with embedded gold nanoparticles inside its matrix and by developing a process to recover gold from acidic solutions. After realizing that the thiosemicarbazide groups present in the monomeric unit of poly-thiosemicarbazide (PTSC) formed strong complexes with Au ions, membrane technology was used to exploit this property to its maximum. The incorporation of metal nanoparticles into polymeric matrices with current technologies involves either expensive and complicated procedures or leads to poor results in terms of agglomeration, loading, dispersion, stability or efficient use of raw materials. The fabrication procedure described in this thesis solves these problems by fabricating a PTSC membrane containing 33.5 wt% in the form of 2.9 nm gold nanoparticles (AuNPs) by a three step simple and scalable procedure. It showed outstanding results in all of the areas mentioned above and demonstrated catalytic activity for the reduction of 4-Nitrophenol (4−NP) to 4-Aminophenol (4−AP). The current exponential demand of gold for electronics has encouraged the development of efficient processes to recycle it. Several adsorbents used to recover gold from acidic solutions can be found in the literature with outstanding maximum uptakes,yet, poor kinetics leading to an overall inefficient process. The method developed in this dissertation consisted in permeating the gold-containing solution through a PTSC membrane that will capture all the Au ions by forming a metal complex with them. Forcing the ions through the pores of the membrane eliminates the diffusion limitations and the adsorption will only depended on the fast complexation kinetics, resulting in a very efficient process. A flux as high as 1868 L/h m2 was enough to capture >90% of the precious metal present in a solution of 100 ppm Au. The maximum uptake achieved without sacrificing

  2. Microbial biosynthesis of nontoxic gold nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Roy, Swarup, E-mail: swaruproy@klyuniv.ac.in [Department of Biochemistry and Biophysics, University of Kalyani, Kalyani 741235, West Bengal (India); Das, Tapan Kumar [Department of Biochemistry and Biophysics, University of Kalyani, Kalyani 741235, West Bengal (India); Maiti, Guru Prasad [Department of Molecular Biology and Biotechnology, University of Kalyani, Kalyani 741235, West Bengal (India); Department of Anesthesiology, Texas Tech University Health science Center, 3601 4th Street, Lubbock, TX 79430 (United States); Basu, Utpal [Department of Molecular Biology and Biotechnology, University of Kalyani, Kalyani 741235, West Bengal (India)

    2016-01-15

    Graphical abstract: The manuscript deals with the fungus mediated optimized biologically synthesized GNPs using Aspergillus foetidus and characterization of biosynthesized GNPs using various physico-chemical methods. The fairly stable synthesized nanoparticles have size in the range of 10–40 nm. Cytotoxicity study of biosynthesized GNPs on Human lung cancer cell line A549 showed no significant toxicity of GNPs. - Highlights: • A novel biosynthesis process of GNPs using Aspergillus foetidus. • Biosynthesized GNPs are in the range of 10–40 nm as observed from TEM. • This process of synthesis is an optimized biosynthesis process of GNPs. • Biosynthesized GNPs are noncytotoxic against A549 cell line. - Abstract: We study the extracellular biosynthesis of gold nanoparticles (GNPs) using the fungal species Aspergillus foetidus. The formation of GNPs were initially monitored by visual observation and then characterized with the help of various characterization techniques. X-ray diffraction (XRD) results revealed distinctive formation of face centered cubic crystalline GNPs. From field emission scanning electron microscopy (FESEM) the morphology of the nanoparticles were found to be roughly spherical and within the size range of 30–50 nm. The spherical and polydispersed GNPs in the range of 10–40 nm were observed by transmission electron microscopy (TEM) analysis. It was established that alkaline pH, 1 mM gold salt concentration and 75 °C temperature were the respective optimum parameter for biosynthesis of GNPs. Cell cytotoxicity of GNP was compared with that of normal gold salt solution on A549 cell. The A549 cell growth in presence of GNPs was found to be comparatively less toxic than the gold ion.

  3. Broadband Spectroscopy of Nanoporous-Gold Promoter

    Directory of Open Access Journals (Sweden)

    S. K. Nakatani

    2014-02-01

    Full Text Available The efficiency of UV photocatalysis on TiO2 particles was increased by mixing TiO2 particles with nanoporous gold (NPG with pore diameters of 10–40 nm. This means that NPG acts as a promoter in the photocatalytic reaction of TiO2. Broadband spectroscopic results from millimeter wave to ultra violet of NPG membrane are discussed to estimate plasmonic effect on the catalysis.

  4. NA35: sulphur-gold collision

    CERN Multimedia

    1991-01-01

    In this image the real particles produced by the collision of a 6400 GeV sulphur ion with a gold target can be seen as they pass through a streamer chamber. Streamer chambers consist of a gas chamber through which a strong pulsed electric field is passed, creating sparks as a charged particle passes through it. The NA35 experiment, which was in operation in the 1980s, was part of CERN's ongoing heavy ion project.

  5. Application of gold nanoparticles in separation sciences

    Czech Academy of Sciences Publication Activity Database

    Sýkora, D.; Kašička, Václav; Mikšík, Ivan; Řezanka, P.; Záruba, K.; Matějka, P.; Král, V.

    2010-01-01

    Roč. 33, č. 3 (2010), s. 372-387 ISSN 1615-9306 R&D Projects: GA ČR(CZ) GA203/09/0675; GA ČR(CZ) GA203/08/1428; GA MŠk(CZ) 1M0510 Institutional research plan: CEZ:AV0Z40550506; CEZ:AV0Z50110509 Keywords : gold nanoparticles * electrophoresis * chromatography Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 2.631, year: 2010

  6. Radiotracer investigation in gold leaching tanks

    International Nuclear Information System (INIS)

    Dagadu, C.P.K.; Akaho, E.H.K.; Danso, K.A.; Stegowski, Z.; Furman, L.

    2012-01-01

    Measurement and analysis of residence time distribution (RTD) is a classical method to investigate performance of chemical reactors. In the present investigation, the radioactive tracer technique was used to measure the RTD of aqueous phase in a series of gold leaching tanks at the Damang gold processing plant in Ghana. The objective of the investigation was to measure the effective volume of each tank and validate the design data after recent process intensification or revamping of the plant. I-131 was used as a radioactive tracer and was instantaneously injected into the feed stream of the first tank and monitored at the outlet of different tanks. Both sampling and online measurement methods were used to monitor the tracer concentration. The results of measurements indicated that both the methods provided identical RTD curves. The mean residence time (MRT) and effective volume of each tank was estimated. The tanks-in-series model with exchange between active and stagnant volume was used and found suitable to describe the flow structure of aqueous phase in the tanks. The estimated effective volume of the tanks and high degree of mixing in tanks could validate the design data and confirmed the expectation of the plant engineer after intensification of the process. - Highlights: ► I-131 radioactive tracer is suitable for tracing the aqueous phase in gold ore slurry. ► Online data collection is more convenient method for tracer monitoring in industrial process systems. ► The tanks-in-series model with exchange between active and stagnant zones is suitable to describe the flow behavior of leaching tanks. ► The radiotracer RTD technique could be used to validate design data after process intensification in gold leaching tanks.

  7. Radiotracer investigation in gold leaching tanks

    Energy Technology Data Exchange (ETDEWEB)

    Dagadu, C.P.K., E-mail: dagadukofi@yahoo.co.uk [Ghana Atomic Energy Commission, P.O. Box LG 80, Legon, Accra (Ghana); Akaho, E.H.K.; Danso, K.A. [Ghana Atomic Energy Commission, P.O. Box LG 80, Legon, Accra (Ghana); Stegowski, Z.; Furman, L. [Faculty of Physics and Applied Computer Science, AGH-UST, 30-059 Krakow (Poland)

    2012-01-15

    Measurement and analysis of residence time distribution (RTD) is a classical method to investigate performance of chemical reactors. In the present investigation, the radioactive tracer technique was used to measure the RTD of aqueous phase in a series of gold leaching tanks at the Damang gold processing plant in Ghana. The objective of the investigation was to measure the effective volume of each tank and validate the design data after recent process intensification or revamping of the plant. I-131 was used as a radioactive tracer and was instantaneously injected into the feed stream of the first tank and monitored at the outlet of different tanks. Both sampling and online measurement methods were used to monitor the tracer concentration. The results of measurements indicated that both the methods provided identical RTD curves. The mean residence time (MRT) and effective volume of each tank was estimated. The tanks-in-series model with exchange between active and stagnant volume was used and found suitable to describe the flow structure of aqueous phase in the tanks. The estimated effective volume of the tanks and high degree of mixing in tanks could validate the design data and confirmed the expectation of the plant engineer after intensification of the process. - Highlights: Black-Right-Pointing-Pointer I-131 radioactive tracer is suitable for tracing the aqueous phase in gold ore slurry. Black-Right-Pointing-Pointer Online data collection is more convenient method for tracer monitoring in industrial process systems. Black-Right-Pointing-Pointer The tanks-in-series model with exchange between active and stagnant zones is suitable to describe the flow behavior of leaching tanks. Black-Right-Pointing-Pointer The radiotracer RTD technique could be used to validate design data after process intensification in gold leaching tanks.

  8. Nanotoxicity of gold and iron nanoparticles.

    Science.gov (United States)

    Maiti, Souvik

    2011-02-01

    The extensive use of potentially hazardous nanoparticles in industrial applications suggest that their biological effects need to be evaluated following clinical testing practices as applicable for any new pharmaceutical. It was rationalized that a non hypothesis-driven approach is best suited for discovering the biological effects of nanoparticles. Gold nanoparticles (approximately 18 nm), showed no drastic effect on gene expression in cells but iron nanoparticles showed perturbations in the expression of a set of functional genes.

  9. A perspective on gold mine capex

    International Nuclear Information System (INIS)

    Brown, M.F.

    1982-01-01

    Capital expenditure by South Africa's gold and uranium mines is expected to total R5 248 million over the period 1982/1987 - well in excess of the R4 076 million spent in the six years preceding 1982. However, once inflation is taken into account the conclusion is one of declining real capex. This is the view of M F Brown, Chief Economist of the Chamber of Mines of South Africa

  10. DNA stretching on functionalized gold surfaces.

    OpenAIRE

    Zimmermann, R M; Cox, E C

    1994-01-01

    We describe a method for anchoring bacteriophage lambda DNA by one end to gold by Au-biotin-streptavidin-biotin-DNA bonds. DNA anchored to a microfabricated Au line could be aligned and stretched in flow and electric fields. The anchor was shown to resist a force of at least 11 pN, a linkage strong enough to allow DNA molecules of chromosome size to be stretched and aligned.

  11. COMMISSIONING OF RHIC DEUTERON - GOLD COLLISIONS.

    Energy Technology Data Exchange (ETDEWEB)

    SATOGATA,T.AHRENS,L.BAI,M.BEEBE-WANG,J.

    2003-05-12

    Deuteron and gold beams have been accelerated to a collision energy of {radical}s = 200 GeV/u in the Relativistic Heavy Ion Collider (RHIC), providing the first asymmetric-species collisions of this complex. Necessary changes for this mode of operation include new ramping software and asymmetric crossing angle geometries. This paper reviews machine performance, problem encountered and their solutions, and accomplishments during the 16 weeks of ramp-up and operations.

  12. Microbial biosynthesis of nontoxic gold nanoparticles

    International Nuclear Information System (INIS)

    Roy, Swarup; Das, Tapan Kumar; Maiti, Guru Prasad; Basu, Utpal

    2016-01-01

    Graphical abstract: The manuscript deals with the fungus mediated optimized biologically synthesized GNPs using Aspergillus foetidus and characterization of biosynthesized GNPs using various physico-chemical methods. The fairly stable synthesized nanoparticles have size in the range of 10–40 nm. Cytotoxicity study of biosynthesized GNPs on Human lung cancer cell line A549 showed no significant toxicity of GNPs. - Highlights: • A novel biosynthesis process of GNPs using Aspergillus foetidus. • Biosynthesized GNPs are in the range of 10–40 nm as observed from TEM. • This process of synthesis is an optimized biosynthesis process of GNPs. • Biosynthesized GNPs are noncytotoxic against A549 cell line. - Abstract: We study the extracellular biosynthesis of gold nanoparticles (GNPs) using the fungal species Aspergillus foetidus. The formation of GNPs were initially monitored by visual observation and then characterized with the help of various characterization techniques. X-ray diffraction (XRD) results revealed distinctive formation of face centered cubic crystalline GNPs. From field emission scanning electron microscopy (FESEM) the morphology of the nanoparticles were found to be roughly spherical and within the size range of 30–50 nm. The spherical and polydispersed GNPs in the range of 10–40 nm were observed by transmission electron microscopy (TEM) analysis. It was established that alkaline pH, 1 mM gold salt concentration and 75 °C temperature were the respective optimum parameter for biosynthesis of GNPs. Cell cytotoxicity of GNP was compared with that of normal gold salt solution on A549 cell. The A549 cell growth in presence of GNPs was found to be comparatively less toxic than the gold ion.

  13. Sensing Applications of Silver and Gold Nanoparticles

    OpenAIRE

    Jao, Chih-Yu

    2012-01-01

    Nanoscale materials have great applications in many areas. One of these applications is for manufacturing ultra-compact and efficient sensors for chemical and biological molecule detection. Noble metals, such as gold (Au) and silver (Ag), because of their distinguished optical property"localized surface plasmon resonances (LSPRs) that exhibit low loss, are ideal materials to fabricate these nanoscale plasmonic particles or structures. This work addresses the synthesis, characterization, and s...

  14. Association of Blood Fatty Acid Composition and Dietary Pattern with the Risk of Non-Alcoholic Fatty Liver Disease in Patients Who Underwent Cholecystectomy.

    Science.gov (United States)

    Shim, Poyoung; Choi, Dongho; Park, Yongsoon

    2017-01-01

    The relationship between diet and non-alcoholic fatty liver disease (NAFLD) in patients with gallstone disease and in those who have a high risk for NAFLD has not been investigated. This study was conducted to investigate the association between the risk of NAFLD and dietary pattern in patients who underwent cholecystectomy. Additionally, we assessed the association between erythrocyte fatty acid composition, a marker for diet, and the risk of NAFLD. Patients (n = 139) underwent liver ultrasonography to determine the presence of NAFLD before laparoscopic cholecystectomy, reported dietary intake using food frequency questionnaire, and were assessed for blood fatty acid composition. Fifty-eight patients were diagnosed with NAFLD. The risk of NAFLD was negatively associated with 2 dietary patterns: consuming whole grain and legumes and consuming fish, vegetables, and fruit. NAFLD was positively associated with the consumption of refined grain, meat, processed meat, and fried foods. Additionally, the risk of NAFLD was positively associated with erythrocyte levels of 16:0 and 18:2t, while it was negatively associated with 20:5n3, 22:5n3, and Omega-3 Index. The risk of NAFLD was negatively associated with a healthy dietary pattern of consuming whole grains, legumes, vegetables, fish, and fruit and with an erythrocyte level of n-3 polyunsaturated fatty acids rich in fish. © 2017 S. Karger AG, Basel.

  15. Prediction of vascular involvement and resectability by multidetector-row CT versus MR imaging with MR angiography in patients who underwent surgery for resection of pancreatic ductal adenocarcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jeong Kyong [Department of Radiology, School of Medicine, Ewha Womans University, 911-1 Mok-dong, YangCheon-ku, Seoul 158-710 (Korea, Republic of); Kim, Ah Young [Department of Radiology, Asan Medical Center, University of Ulsan College of Medicine, 388-1 Poongnab-dong, Songpa-ku, Seoul 138-736 (Korea, Republic of)], E-mail: aykim@amc.seoul.kr; Kim, Pyo Nyun; Lee, Moon-Gyu; Ha, Hyun Kwon [Department of Radiology, Asan Medical Center, University of Ulsan College of Medicine, 388-1 Poongnab-dong, Songpa-ku, Seoul 138-736 (Korea, Republic of)

    2010-02-15

    Purpose: To compare the diagnostic value of dual-phase multidetector-row CT (MDCT) and MR imaging with dual-phase three-dimensional MR angiography (MRA) in the prediction of vascular involvement and resectability of pancreatic ductal adenocarcinoma. Methods and materials: 116 patients with proven pancreatic adenocarcinoma underwent both MDCT and combined MR imaging prior to surgery. Of 116 patients, 56 who underwent surgery were included. Two radiologists independently attempt to assess detectability, vascular involvement and resectability of pancreatic adenocarcinoma on both images. Results were compared with surgical findings and statistical analysis was performed. Results: MDCT detected pancreatic mass in 45 of 56 patients (80.3%) and MR imaging in 44 patients (78.6%). In assessment of vascular involvement, sensitivities and specificities of MDCT were 61% and 96% on a vessel-by-vessel basis, respectively. Those of MR imaging were 57% and 98%, respectively. In determining resectability, sensitivities and specificities of MDCT were 90% and 65%, respectively. Those of MR imaging were 90% and 41%, respectively. There was no statistical difference in detecting tumor, assessing vascular involvement and determining resectability between MDCT and MR imaging (p = 0.5). Conclusion: MDCT and MR imaging with MRA demonstrated an equal ability in detection, predicting vascular involvement, and determining resectability for a pancreatic ductal adenocarcinoma.

  16. A New Risk Factor Profile for Contrast-Induced Acute Kidney Injury in Patients Who Underwent an Emergency Percutaneous Coronary Intervention.

    Science.gov (United States)

    Yuan, Ying; Qiu, Hong; Song, Lei; Hu, Xiaoying; Luo, Tong; Zhao, Xueyan; Zhang, Jun; Wu, Yuan; Qiao, Shubin; Yang, Yuejin; Gao, Runlin

    2017-01-01

    We developed a new risk factor profile for contrast-induced acute kidney injury (CI-AKI) under a new definition in patients who underwent an emergency percutaneous coronary intervention (PCI). Consecutive patients (n = 1061) who underwent an emergency PCI were divided into a derivation group (n = 761) and a validation group (n = 300). The rates of CI-AKI were 23.5% (definition 1: serum creatinine [SCr] increase ≥25% in 72 hours), 4.3% (definition 2: SCr increase ≥44.2 μmol/L in 72 hours), and 7.0% (definition 3: SCr increase ≥44.2 μmol/L in 7 days). Due to the high sensitivity of definition 1 and the high rate of missed cases for late diagnosis of CI-AKI under definition 2, definition 3 was used in the study. The risk factor profile included body surface area 15.00 × 10 9 /L ( P = .047), estimated glomerular filtration rate 133 μmol/L ( P = .007), intra-aortic balloon pump application ( P = .006), and diuretics administration ( P < .001), showing a significant predictive power in the derivation group and validation group. The new risk factor profile of CI-AKI under a new CI-AKI definition in emergency PCI patients is easily applicable with a useful predictive value.

  17. An evaluation of quality of life in women with endometriosis who underwent primary surgery: a 6-month follow up in Sabah Women & Children Hospital, Sabah, Malaysia.

    Science.gov (United States)

    M F, Ahmad; Narwani, Hussin; Shuhaila, Ahmad

    2017-10-01

    Endometriosis is a complex disease primarily affecting women of reproductive age worldwide. The management goals are to improve the quality of life (QoL), alleviate the symptoms and prevent severe disease. This prospective cohort study was to assess the QoL in women with endometriosis that underwent primary surgery. A pre- and post-operative questionnaire via ED-5Q and general VAS score used for the evaluation for endometrial-like pain such as dysmenorrhoea and dyspareunia. A total of 280 patients underwent intervention; 224 laparoscopically and 56 via laparotomy mostly with stage II disease with ovarian endometriomas. Improvements in dysmenorrhoea pain scores from 5.7 to 4.15 and dyspareunia from 4.05 to 2.17 (p <.001) were observed. The Self Rate Assessment was improved; 6.66-4.68 post-operatively (p < .05). In EQ-5 D Index, the anxiety and activities outcomes showed a significant worsening post-intervention. There was no correlation between the stage of disease and endometrial pain; (p = .289), method of intervention (p = .290) and usage of post-operative hormonal therapy (p = .632). This study concluded that surgical treatment improved the QoL with added hormonal therapy post-intervention, despite not reaching statistical significance, showed a promising result. Impact statement Surgical intervention does improve the QoL for women with endometriosis however post interventional hormonal therapy is remain inconclusive.

  18. The importance of superficial basal cell carcinoma in a retrospective study of 139 patients who underwent Mohs micrographic surgery in a Brazilian university hospital

    Directory of Open Access Journals (Sweden)

    Luciana Takata Pontes

    2015-11-01

    Full Text Available OBJECTIVE: Mohs micrographic surgery is a specialized surgical procedure used to treat skin cancer. The purpose of this study was to better understand the profile of the patients who underwent the procedure and to determine how histology might be related to complications and the number of stages required for complete removal. METHODS: The records of patients who underwent Mohs micrographic surgery from October 2008 to November 2013 at the Dermatology Division of the Hospital of the Campinas University were assessed. The variables included were gender, age, anatomical location, histology, number of stages required and complications. RESULTS: Contingency tables were used to compare the number of stages with the histological diagnosis. The analysis showed that patients with superficial basal cell carcinoma were 9.03 times more likely to require more than one stage. A comparison between complications and histological diagnosis showed that patients with superficial basal cell carcinoma were 6.5 times more likely to experience complications. CONCLUSION: Although superficial basal cell carcinoma is typically thought to represent a less-aggressive variant of these tumors, its propensity for demonstrating “skip areas” and clinically indistinct borders make it a challenge to treat. Its particular nature may result in the higher number of surgery stages required, which may, as a consequence, result in more complications, including recurrence. Recurrence likely occurs due to the inadequate excision of the tumors despite their clear margins. Further research on this subtype of basal cell carcinoma is needed to optimize treatments and decrease morbidity.

  19. The importance of superficial basal cell carcinoma in a retrospective study of 139 patients who underwent Mohs micrographic surgery in a Brazilian university hospital.

    Science.gov (United States)

    Takata Pontes, Luciana; Fantelli Stelini, Rafael; Cintra, Maria Leticia; Magalhães, Renata Ferreira; Velho, Paulo Eduardo N F; Moraes, Aparecida Machado

    2015-11-01

    Mohs micrographic surgery is a specialized surgical procedure used to treat skin cancer. The purpose of this study was to better understand the profile of the patients who underwent the procedure and to determine how histology might be related to complications and the number of stages required for complete removal. The records of patients who underwent Mohs micrographic surgery from October 2008 to November 2013 at the Dermatology Division of the Hospital of the Campinas University were assessed. The variables included were gender, age, anatomical location, histology, number of stages required and complications. Contingency tables were used to compare the number of stages with the histological diagnosis. The analysis showed that patients with superficial basal cell carcinoma were 9.03 times more likely to require more than one stage. A comparison between complications and histological diagnosis showed that patients with superficial basal cell carcinoma were 6.5 times more likely to experience complications. Although superficial basal cell carcinoma is typically thought to represent a less-aggressive variant of these tumors, its propensity for demonstrating "skip areas" and clinically indistinct borders make it a challenge to treat. Its particular nature may result in the higher number of surgery stages required, which may, as a consequence, result in more complications, including recurrence. Recurrence likely occurs due to the inadequate excision of the tumors despite their clear margins. Further research on this subtype of basal cell carcinoma is needed to optimize treatments and decrease morbidity.

  20. A halogen-free synthesis of gold nanoparticles using gold(III) oxide

    Energy Technology Data Exchange (ETDEWEB)

    Sashuk, Volodymyr, E-mail: vsashuk@ichf.edu.pl; Rogaczewski, Konrad [Polish Academy of Sciences, Institute of Physical Chemistry (Poland)

    2016-09-15

    Gold nanoparticles are one of the most used nanomaterials. They are usually synthesized by the reduction of gold(III) chloride. However, the presence of halide ions in the reaction mixture is not always welcome. In some cases, these ions have detrimental influence on the morphology and structure of resulting nanoparticles. Here, we present a simple and halogen-free procedure to prepare gold nanoparticles by reduction of gold(III) oxide in neat oleylamine. The method provides the particles with an average size below 10 nm and dispersity of tens of percent. The process of nanoparticle formation was monitored using UV–Vis spectroscopy. The structure and chemical composition of the nanoparticles was determined by SEM, XPS and EDX. We also proposed the mechanism of reduction of gold(III) oxide based on MS, IR and NMR data. Importantly, the synthetic protocol is general and applicable for the preparation of other coinage metal nanoparticles from the corresponding metal oxides. For instance, we demonstrated that the absence of halogen enables efficient alloying of metals when preparing gold–silver bimetallic nanoparticles.