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Sample records for stone formation methods

  1. Mechanisms of human kidney stone formation.

    PubMed

    Evan, Andrew P; Worcester, Elaine M; Coe, Fredric L; Williams, James; Lingeman, James E

    2015-01-01

    The precise mechanisms of kidney stone formation and growth are not completely known, even though human stone disease appears to be one of the oldest diseases known to medicine. With the advent of the new digital endoscope and detailed renal physiological studies performed on well phenotyped stone formers, substantial advances have been made in our knowledge of the pathogenesis of the most common type of stone former, the idiopathic calcium oxalate stone former as well as nine other stone forming groups. The observations from our group on human stone formers and those of others on model systems have suggested four entirely different pathways for kidney stone formation. Calcium oxalate stone growth over sites of Randall's plaque appear to be the primary mode of stone formation for those patients with hypercalciuria. Overgrowths off the ends of Bellini duct plugs have been noted in most stone phenotypes, do they result in a clinical stone? Micro-lith formation does occur within the lumens of dilated inner medullary collecting ducts of cystinuric stone formers and appear to be confined to this space. Lastly, cystinuric stone formers also have numerous small, oval, smooth yellow appearing calyceal stones suggestive of formation in free solution. The scientific basis for each of these four modes of stone formation are reviewed and used to explore novel research opportunities. PMID:25108546

  2. Histopathology Predicts the Mechanism of Stone Formation

    NASA Astrophysics Data System (ADS)

    Evan, Andrew P.

    2007-04-01

    About 5% of American women and 12% of men will develop a kidney stone at some time in their life and these numbers appear to be on the rise. Despite years of scientific research into the mechanisms of stone formation and growth, limited advances have been made until recently. Randall's original observations and thoughts on the mechanisms for kidney stone formation have been validated for idiopathic calcium oxalate stone formers (ICSF) but not for most other stone forming groups. Our current studies on selected groups of human stone formers using intraoperative papillary biopsies has shown overwhelming evidence for the presence of Randall's plaque in ICSF and that stone formation and growth are exclusively linked to its availability to urinary ions and proteins. Intense investigation of the plaque-stone junction is needed if we are to understand the factors leading to the overgrowth process on exposed regions of plaque. Such information should allow the development of treatment strategies to block stone formation in ICSF patients. Patients who form brushite stones, or who form apatite stones because of distal renal tubular acidosis (dRTA), or patients with calcium oxalate stones due to obesity bypass procedures, or patients with cystinuria, get plugged inner medullary collecting ducts (IMCD) which leads to total destruction of the lining cells and focal sites of interstitial fibrosis. These stone formers have plaque but at levels equal to or below non-stone formers, which would suggest that they form stones by a different mechanism than do ICSF patients.

  3. Diet and renal stone formation.

    PubMed

    Trinchieri, A

    2013-02-01

    The relationship between diet and the formation of renal stones is demonstrated, but restrictive diets do not take into account the complexity of metabolism and the complex mechanisms that regulate the saturation and crystallization processes in the urine. The restriction of dietary calcium can reduce the urinary excretion of calcium but severe dietary restriction of calcium causes hyperoxaluria and a progressive loss of bone mineral component. Furthermore urinary calcium excretion is influenced by other nutrients than calcium as sodium, potassium, protein and refined carbohydrates. Up to 40% of the daily excretion of oxalate in the urine is from dietary source, but oxalate absorption in the intestine depends linearly on the concomitant dietary intake of calcium and is influenced by the bacterial degradation by several bacterial species of intestinal flora. A more rational approach should be based on the cumulative effects of foods and different dietary patterns on urinary saturation rather than on the effect of single nutrients. A diet based on a adequate intake of calcium (1000-1200 mg per day) and containment of animal protein and salt can decrease significantly urinary supersaturation for calcium oxalate and reduce the relative risk of stone recurrence in hypercalciuric renal stone formers. The DASH-style diet that is high in fruits and vegetables, moderate in low-fat dairy products and low in animal proteins and salt is associated with a lower relative supersaturation for calcium oxalate and a marked decrease in risk of incident stone formation. All the diets above mentioned have as a common characteristic the reduction of the potential acid load of the diet that can be correlated with a higher risk of recurrent nephrolithiasis, because the acid load of diet is inversely related to urinary citrate excretion. The restriction of protein and salt with an adequate calcium intake seem to be advisable but should be implemented with the advice to increase the intake of vegetables that can carry a plentiful supply of alkali that counteract the acid load coming from animal protein. New prospective studies to evaluate the effectiveness of the diet for the prevention of renal stones should be oriented to simple dietary advices that should be focused on a few specific goals easily controlled by means of self-evaluation tools, such as the LAKE food screener. PMID:23392537

  4. Stone formation and management after bariatric surgery.

    PubMed

    Tarplin, Sarah; Ganesan, Vishnu; Monga, Manoj

    2015-05-01

    Obesity is a significant health concern and is associated with an increased risk of nephrolithiasis, particularly in women. The underlying pathophysiology of stone formation in obese patients is thought to be related to insulin resistance, dietary factors, and a lithogenic urinary profile. Uric acid stones and calcium oxalate stones are common in these patients. Use of surgical procedures for obesity (bariatric surgery) has risen over the past two decades. Although such procedures effectively manage obesity-dependent comorbidities, several large, controlled studies have revealed that modern bariatric surgeries increase the risk of nephrolithiasis by approximately twofold. In patients who have undergone bariatric surgery, fat malabsorption leads to hyperabsorption of oxalate, which is exacerbated by an increased permeability of the gut to oxalate. Patients who have undergone bariatric surgery show characteristic 24 h urine parameters including low urine volume, low urinary pH, hypocitraturia, hyperoxaluria and hyperuricosuria. Prevention of stones with dietary limitation of oxalate and sodium and a high intake of fluids is critical, and calcium supplementation with calcium citrate is typically required. Potassium citrate is valuable for treating the common metabolic derangements as it raises urinary pH, enhances the activity of stone inhibitors, reduces the supersaturation of calcium oxalate, and corrects hypokalaemia. Both pyridoxine and probiotics have been shown in small studies to reduce hyperoxaluria, but further study is necessary to clarify their effects on stone morbidity in the bariatric surgery population. PMID:25850790

  5. Bile duct stone formation around a Prolene suture after cholangioenterostomy

    PubMed Central

    Li, Qiang; Tao, Liang; Wu, Xingyu; Mou, Lingjun; Sun, Xitai; Zhou, Jianxin

    2016-01-01

    The iatrogenic cause of bile duct stone formation is mainly due to suture materials, especially silk sutures. In recent years, Prolene and Vicryl sutures have been widely used in biliary surgery, and bile duct stone formation related to sutures are seemingly becoming rare, as there has only been one report of bile duct stone formation caused by Prolene sutures in the literature. In the last few years we have had two cases of Prolene suture-related bile duct stone formation within our unit. We therefore suggest that Vicryl sutures should be used as the first choice in biliary surgery, in order to prevent the formation of iatrogenic bile duct stones. PMID:27022388

  6. Bile duct stone formation around a Prolene suture after cholangioenterostomy.

    PubMed

    Li, Qiang; Tao, Liang; Wu, Xingyu; Mou, Lingjun; Sun, Xitai; Zhou, Jianxin

    2016-01-01

    The iatrogenic cause of bile duct stone formation is mainly due to suture materials, especially silk sutures. In recent years, Prolene and Vicryl sutures have been widely used in biliary surgery, and bile duct stone formation related to sutures are seemingly becoming rare, as there has only been one report of bile duct stone formation caused by Prolene sutures in the literature. In the last few years we have had two cases of Prolene suture-related bile duct stone formation within our unit. We therefore suggest that Vicryl sutures should be used as the first choice in biliary surgery, in order to prevent the formation of iatrogenic bile duct stones. PMID:27022388

  7. Computational stoning method for surface defect detection

    NASA Astrophysics Data System (ADS)

    Ma, Ninshu; Zhu, Xinhai

    2013-12-01

    Surface defects on outer panels of automotive bodies must be controlled in order to improve the surface quality. The detection and quantitative evaluation of surface defects are quite difficult because the deflection of surface defects is very small. One of detecting methods for surface defects used in factories is a stoning method in which a stone block is moved on the surface of a stamped panel. The computational stoning method was developed to detect surface low defect by authors based on a geometry contact algorithm between a stone block and a stamped panel. If the surface is convex, the stone block always contacts with the convex surface of a stamped panel and the contact gap between them is zero. If there is a surface low, the stone block does not contact to the surface and the contact gap can be computed based on contact algorithm. The convex surface defect can also be detected by applying computational stoning method to the back surface of a stamped panel. By performing two way stoning computations from both the normal surface and the back surface, not only the depth of surface low defect but also the height of convex surface defect can be detected. The surface low defect and convex surface defect can also be detected through multi-directions. Surface defects on the handle emboss of outer panels were accurately detected using the computational stoning method and compared with the real shape. A very good accuracy was obtained.

  8. Androgens Involvement in the Pathogenesis of Renal Stones Formation

    PubMed Central

    Naghii, Mohammad Reza; Babaei, Mnasour; Hedayati, Mehdi

    2014-01-01

    Objective The potential role for the gonadal steroids in the pathogenesis of urolithiasis, higher mean of plasma oxalate concentration and kidney calcium oxalate deposition influenced by androgens in men has been proposed. In this study, the serum levels of steroid hormones as a pathogenesis of this condition in male patients with active renal stone disease compared with controls was investigated. Methods Forty patients diagnosed with renal stones and hospitalized for further clinical treatments or referred to our office after ultrasonographic evaluations participated in the study. Forty six healthy subjects served as controls. Steroid sex hormones in the plasma samples including testosterone, free testosterone, dihydrotestosterone, estradiol, and sex hormone binding globulin were analyzed. Results A significant difference was observed between patients and the control subjects regarding serum testosterone, free testosterone, dihydrotestosterone, estradiol, and sex hormone binding globulin. Conclusions Based on the results, a higher androgens level was diagnosed in renal stone patients, indicating a possibility of a substantial pathogenic role of testosterone, free testosterone, and dihydrotestosterone involvement in the pathogenesis of renal stones formation. Therefore, data presentation and further investigation on the relation between male steroids and urolithiasis is of importance and should be considered in evaluation of the etiology of the disease. PMID:24695421

  9. Measurement of kidney stone formation in the rat model using micro-computed tomography

    NASA Astrophysics Data System (ADS)

    Umoh, Joseph U.; Pitelka, Vasek; Goldberg, Harvey A.; Holdsworth, David W.

    2012-03-01

    Kidney stones were induced in 5 rats by treating them with 1% ethylene glycol and 1% ammonium chloride through free drinking water for six weeks. The animals were anesthetized and imaged in vivo before the treatment at week 0, to obtain baseline data, then at weeks 2 and 6 to monitor the kidney stone formation. Micro-CT imaging was performed with x-ray tube voltage of 90 kV and a current of 40 mA. At week 2, kidney stone formation was observed. A micro-computed tomography methodology of estimating the volume and hydroxyapatite-equivalent mineral content of the kidney stone is presented. It determines the threshold CT number (390 HU) that separates the kidney stone from the tissue. The mean volume of the stones in the 10 kidneys significantly increased from 3.81+/-0.72 mm3 at week 2 to 23.96+/-9.12 mm3 at week 6 (p<0.05, r2=0.34). Measurement precision error was about 4%. This method allows analysis of the kidney stone formation to be carried out in vivo, with fewer experimental animals compared with other ex vivo methods, in which animals are sacrificed. It is precise, accurate, non-destructive, and could be used in pre-clinical research to study the formation of kidney stones in live small animals.

  10. Probabilistic Modeling of the Renal Stone Formation Module

    NASA Technical Reports Server (NTRS)

    Best, Lauren M.; Myers, Jerry G.; Goodenow, Debra A.; McRae, Michael P.; Jackson, Travis C.

    2013-01-01

    The Integrated Medical Model (IMM) is a probabilistic tool, used in mission planning decision making and medical systems risk assessments. The IMM project maintains a database of over 80 medical conditions that could occur during a spaceflight, documenting an incidence rate and end case scenarios for each. In some cases, where observational data are insufficient to adequately define the inflight medical risk, the IMM utilizes external probabilistic modules to model and estimate the event likelihoods. One such medical event of interest is an unpassed renal stone. Due to a high salt diet and high concentrations of calcium in the blood (due to bone depletion caused by unloading in the microgravity environment) astronauts are at a considerable elevated risk for developing renal calculi (nephrolithiasis) while in space. Lack of observed incidences of nephrolithiasis has led HRP to initiate the development of the Renal Stone Formation Module (RSFM) to create a probabilistic simulator capable of estimating the likelihood of symptomatic renal stone presentation in astronauts on exploration missions. The model consists of two major parts. The first is the probabilistic component, which utilizes probability distributions to assess the range of urine electrolyte parameters and a multivariate regression to transform estimated crystal density and size distributions to the likelihood of the presentation of nephrolithiasis symptoms. The second is a deterministic physical and chemical model of renal stone growth in the kidney developed by Kassemi et al. The probabilistic component of the renal stone model couples the input probability distributions describing the urine chemistry, astronaut physiology, and system parameters with the physical and chemical outputs and inputs to the deterministic stone growth model. These two parts of the model are necessary to capture the uncertainty in the likelihood estimate. The model will be driven by Monte Carlo simulations, continuously randomly sampling the probability distributions of the electrolyte concentrations and system parameters that are inputs into the deterministic model. The total urine chemistry concentrations are used to determine the urine chemistry activity using the Joint Expert Speciation System (JESS), a biochemistry model. Information used from JESS is then fed into the deterministic growth model. Outputs from JESS and the deterministic model are passed back to the probabilistic model where a multivariate regression is used to assess the likelihood of a stone forming and the likelihood of a stone requiring clinical intervention. The parameters used to determine to quantify these risks include: relative supersaturation (RS) of calcium oxalate, citrate/calcium ratio, crystal number density, total urine volume, pH, magnesium excretion, maximum stone width, and ureteral location. Methods and Validation: The RSFM is designed to perform a Monte Carlo simulation to generate probability distributions of clinically significant renal stones, as well as provide an associated uncertainty in the estimate. Initially, early versions will be used to test integration of the components and assess component validation and verification (V&V), with later versions used to address questions regarding design reference mission scenarios. Once integrated with the deterministic component, the credibility assessment of the integrated model will follow NASA STD 7009 requirements.

  11. Stone formation and calcification by nanobacteria in the human body

    NASA Astrophysics Data System (ADS)

    Ciftcioglu, Neva; Bjorklund, Michael; Kajander, E. Olavi

    1998-07-01

    The formation of discrete and organized inorganic crystalline structures within macromolecular extracellular matrices is a widespread biological phenomenon generally referred to as biomineralization. Recently, bacteria have been implicated as factors in biogeochemical cycles for formation of many minerals in aqueous sediments. We have found nanobacterial culture systems that allow for reproducible production of apatite calcification in vitro. Depending on the culture conditions, tiny nanocolloid-sized particles covered with apatite, forming various size of aggregates and stones were observed. In this study, we detected the presence of nanobacteria in demineralized trilobit fossil, geode, apatite, and calcite stones by immunofluorescence staining. Amethyst and other quartz stones, and chalk gave negative results. Microorganisms are capable of depositing apatite outside the thermodynamic equilibrium in sea water. We bring now evidence that this occurs in the human body as well. Previously, only struvite kidney stones composed of magnesium ammonium phosphate and small amounts of apatite have been regarded as bacteria related. 90 percent of demineralized human kidney stones now screened, contained nanobacteria. At least three different distribution patterns of nanobacteria were conditions, and human kidney stones that are formed from small apatite units. Prerequisites for the formation of kidney stones are the supersaturation of urine and presence of nidi for crystallization. Nanobacteria are important nidi and their presence might be of special interest in space flights where supersaturation of urine is present due to the loss of bone. Furthermore, we bring evidence that nanobacteria may act as crystallization nidi for the formation of biogenic apatite structures in tissue calcification found in e.g., atherosclerotic plaques, extensive metastatic and tumoral calcification, acute periarthritis, malacoplakia, and malignant diseases. In nanaobacteria-infected fibroblasts, electron microscopy revealed intra- and extra-cellular needle-like crystal deposits, which were stainable with von Kossa stain and resemble calcospherules found in pathological calcification. Thus bacteria-mediated apatite formation takes place in aqueous environments, in humans and in geological sediments.

  12. Use of Potassium Citrate to Reduce the Risk of Renal Stone Formation During Spaceflight

    NASA Technical Reports Server (NTRS)

    Whitson, P. A.; Pietrzyk, R. A.; Sams, C. F.; Jones, J. A.; Nelman-Gonzalez, M.; Hudson, E. K.

    2008-01-01

    Introduction: NASA s Vision for Space Exploration centers on exploration class missions including the goals of returning to the moon and landing on Mars. One of NASA s objectives is to focus research on astronaut health and the development of countermeasures that will protect crewmembers during long duration voyages. Exposure to microgravity affects human physiology and results in changes in the urinary chemical composition favoring urinary supersaturation and an increased risk of stone formation. Nephrolithiasis is a multifactorial disease and development of a renal stone is significantly influenced by both dietary and environmental factors. Previous results from long duration Mir and short duration Shuttle missions have shown decreased urine volume, pH, and citrate levels and increased calcium. Citrate, an important inhibitor of calcium-containing stones, binds with urinary calcium reducing the amount of calcium available to form stones. Citrate inhibits renal stone recurrence by preventing crystal growth, aggregation, and nucleation and is one of the most common therapeutic agents used to prevent stone formation. Methods: Thirty long duration crewmembers (29 male, 1 female) participated in this study. 24-hour urines were collected and dietary monitoring was performed pre, in, and postflight. Crewmembers in the treatment group received two potassium citrate (KCIT) pills, 10 mEq/pill, ingested daily beginning 3 days before launch, all inflight days and through 14 days postflight. Urinary biochemical and dietary analyses were completed. Results: KCIT treated subjects exhibited decreased urinary calcium excretion and maintained the levels of calcium oxalate supersaturation risk at their preflight levels. The increased urinary pH levels in these subjects reduced the risk of uric acid stones. Discussion: The current study investigated the use of potassium citrate as a countermeasure to minimize the risk of stone formation during ISS missions. Results suggest that supplementation with potassium citrate decreases the risk of stone formation during and immediately after spaceflight.

  13. Aggregation of Calcium Phosphate and Oxalate Phases in the Formation of Renal Stones

    PubMed Central

    2015-01-01

    The majority of human kidney stones are comprised of multiple calcium oxalate monohydrate (COM) crystals encasing a calcium phosphate nucleus. The physiochemical mechanism of nephrolithiasis has not been well determined on the molecular level; this is crucial to the control and prevention of renal stone formation. This work investigates the role of phosphate ions on the formation of calcium oxalate stones; recent work has identified amorphous calcium phosphate (ACP) as a rapidly forming initial precursor to the formation of calcium phosphate minerals in vivo. The effect of phosphate on the nucleation of COM has been investigated using the constant composition (CC) method in combination with scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Our findings indicate COM nucleation is strongly promoted by the presence of phosphate; this occurs at relatively low phosphate concentrations, undersaturated with respect to brushite (dicalcium phosphate dehydrate, DCPD) formation. The results show that ACP plays a crucial role in the nucleation of calcium oxalate stones by promoting the aggregation of amorphous calcium oxalate (ACO) precursors at early induction times. The coaggregations of ACP and ACO precursors induce the multiple-point nucleation of COM. These novel findings expand our knowledge of urinary stone development, providing potential targets for treating the condition at the molecular level. PMID:25598742

  14. Fad diets and their effect on urinary stone formation.

    PubMed

    Nouvenne, Antonio; Ticinesi, Andrea; Morelli, Ilaria; Guida, Loredana; Borghi, Loris; Meschi, Tiziana

    2014-09-01

    The influence of unhealthy dietary habits on urinary stone formation has been widely recognized in literature. Dietary advice is indeed the cornerstone prescription for prevention of nephrolithiasis as well. However, only a small amount of medical literature has addressed the influence of popular or fad diets, often self-prescribed for the management of obesity and overweight or for cultural beliefs, on the risk of kidney stones. Thereby in this paper we analyze the current knowledge on the effects of some popular diets on overall lithogenic risk. High-protein diets, like Dukan diet, raise some concerns, since animal proteins are able to increase urinary calcium and to decrease urinary citrate excretion, thus leading to a high overall lithogenic risk. Low-carbohydrate diets, like Atkins diet or zone diet, may have a protective role against kidney stone formation, but there are also evidences stating that this dietary approach may rise calciuria and decrease citraturia, since it is generally associated to a relatively high intake of animal proteins. Vegan diet can be harmful for urinary stone disease, especially for the risk of hyperuricemia and micronutrient deficiencies, even if only few studies have addressed this specific matter. On the other side, the benefits of a lacto-ovo-vegetarian diet on kidney stone prevention have been largely emphasized, provided that the intake of calcium and oxalate is balanced. Traditional Mediterranean diet should exert a protective effect on nephrolithiasis as well, even if specific studies have not been carried out yet. High phytate and antioxidant content of this diet have however demonstrated to be beneficial in preventing the formation of new or recurrent calculi. Anyway, at the current state of knowledge, the most effective dietary approach to prevent kidney stone disease is a mild animal protein restriction, a balanced intake of carbohydrates and fats and a high intake of fruit and vegetables. Other fundamental aspects, which are often neglected in fad diets, are a normal intake of milk and dairy products and salt restriction. All these nutritional aspects should be greatly taken into account when patients who are willing to undergo fad or commercial diets ask for dietary advice. PMID:26816783

  15. Fad diets and their effect on urinary stone formation

    PubMed Central

    Nouvenne, Antonio; Ticinesi, Andrea; Morelli, Ilaria; Guida, Loredana; Meschi, Tiziana

    2014-01-01

    The influence of unhealthy dietary habits on urinary stone formation has been widely recognized in literature. Dietary advice is indeed the cornerstone prescription for prevention of nephrolithiasis as well. However, only a small amount of medical literature has addressed the influence of popular or fad diets, often self-prescribed for the management of obesity and overweight or for cultural beliefs, on the risk of kidney stones. Thereby in this paper we analyze the current knowledge on the effects of some popular diets on overall lithogenic risk. High-protein diets, like Dukan diet, raise some concerns, since animal proteins are able to increase urinary calcium and to decrease urinary citrate excretion, thus leading to a high overall lithogenic risk. Low-carbohydrate diets, like Atkins diet or zone diet, may have a protective role against kidney stone formation, but there are also evidences stating that this dietary approach may rise calciuria and decrease citraturia, since it is generally associated to a relatively high intake of animal proteins. Vegan diet can be harmful for urinary stone disease, especially for the risk of hyperuricemia and micronutrient deficiencies, even if only few studies have addressed this specific matter. On the other side, the benefits of a lacto-ovo-vegetarian diet on kidney stone prevention have been largely emphasized, provided that the intake of calcium and oxalate is balanced. Traditional Mediterranean diet should exert a protective effect on nephrolithiasis as well, even if specific studies have not been carried out yet. High phytate and antioxidant content of this diet have however demonstrated to be beneficial in preventing the formation of new or recurrent calculi. Anyway, at the current state of knowledge, the most effective dietary approach to prevent kidney stone disease is a mild animal protein restriction, a balanced intake of carbohydrates and fats and a high intake of fruit and vegetables. Other fundamental aspects, which are often neglected in fad diets, are a normal intake of milk and dairy products and salt restriction. All these nutritional aspects should be greatly taken into account when patients who are willing to undergo fad or commercial diets ask for dietary advice. PMID:26816783

  16. Nephrolithiasis: Molecular Mechanism of Renal Stone Formation and the Critical Role Played by Modulators

    PubMed Central

    Aggarwal, Kanu Priya; Narula, Shifa; Kakkar, Monica

    2013-01-01

    Urinary stone disease is an ailment that has afflicted human kind for many centuries. Nephrolithiasis is a significant clinical problem in everyday practice with a subsequent burden for the health system. Nephrolithiasis remains a chronic disease and our fundamental understanding of the pathogenesis of stones as well as their prevention and cure still remains rudimentary. Regardless of the fact that supersaturation of stone-forming salts in urine is essential, abundance of these salts by itself will not always result in stone formation. The pathogenesis of calcium oxalate stone formation is a multistep process and essentially includes nucleation, crystal growth, crystal aggregation, and crystal retention. Various substances in the body have an effect on one or more of the above stone-forming processes, thereby influencing a person's ability to promote or prevent stone formation. Promoters facilitate the stone formation while inhibitors prevent it. Besides low urine volume and low urine pH, high calcium, sodium, oxalate and urate are also known to promote calcium oxalate stone formation. Many inorganic (citrate, magnesium) and organic substances (nephrocalcin, urinary prothrombin fragment-1, osteopontin) are known to inhibit stone formation. This review presents a comprehensive account of the mechanism of renal stone formation and the role of inhibitors/promoters in calcium oxalate crystallisation. PMID:24151593

  17. [Kidney stone formation during space flight and long-term bed rest].

    PubMed

    Okada, Atsushi; Ichikawa, Jun; Tozawa, Keiichi

    2011-10-01

    Microgravity environment like space flight or a condition requiring long-term bed-rest increase bone resorption and decrease bone formation, inducing the rapid decrease of bone minerals to osteoporosis. Bone mineral loss increases urinary calcium excretion and the risk of urinary stone formation. To clarify the influence of the conditions on renal stone formation, a 90-day bed rest test was performed to analyze the mechanism of microgravity or bed rest-induced stone formation and prevention by bisphosphonate medication and bed-rest exercise. As the results, renal stone formation was observed in control and exercise groups and no stone was seen in the medication group. In the medication group, urinary calcium excretion and relative supersaturation of calcium oxalate were lower than in the control group throughout the bed-rest and recovery period. Bisphosphonate is useful for the prevention of renal stone formation during space flight and long-term bed-rest. PMID:21960236

  18. The risk of renal stone formation during and after long duration space flight

    NASA Technical Reports Server (NTRS)

    Whitson, P. A.; Pietrzyk, R. A.; Morukov, B. V.; Sams, C. F.

    2001-01-01

    BACKGROUND: The formation of a renal stone during space flight may have serious negative effects on the health of the crewmember and the success of the mission. Urinary biochemical factors and the influence of dietary factors associated with renal stone development were assessed during long duration Mir Space Station missions. METHODS: Twenty-four-hour urine samples were collected prior to, during and following long duration space flight. The relative urinary supersaturation of calcium oxalate, calcium phosphate (brushite), sodium urate, struvite and uric acid were determined. RESULTS: Changes in the urinary biochemistry of crewmembers during long duration spaceflight demonstrated increases in the supersaturation of the stone-forming salts. In-flight hypercalciuria was evident in a number of individual crewmembers and 24-hour dietary fluid intake and urine volume were significantly lower. During flight, there was a significant increase in brushite supersaturation. CONCLUSIONS: These data suggest acute effects of space flight and postflight changes in the urinary biochemistry favoring increased crystallization in the urine. The effects of dietary intake, especially fluid intake, may have a significant impact on the potential for renal stone formation. Efforts are now underway to assess the efficacy of a countermeasure to mitigate the increased risk. Copyright 2001 S. Karger AG, Basel.

  19. Impact of Nutritional Factors on Incident Kidney Stone Formation: A Report From the WHI OS

    PubMed Central

    Sorensen, Mathew D.; Kahn, Arnold J.; Reiner, Alex P.; Tseng, Timothy Y.; Shikany, James M.; Wallace, Robert B.; Chi, Thomas; Wactawski-Wende, Jean; Jackson, Rebecca D.; O’Sullivan, Mary Jo; Sadetsky, Natalia; Stoller, Marshall L.

    2014-01-01

    Purpose Increased fluid intake, and decreased dietary sodium and animal protein intake are thought to reduce the risk of kidney stones but the role of calcium intake is controversial. We evaluated the relationship between dietary factors and incident kidney stone formation. Materials and Methods Secondary analysis was done of 78,293 women from the prospective WHI OS (Women’s Health Initiative Observational Study) with no history of nephrolithiasis who completed the validated food frequency questionnaire. Multivariate logistic regression was used to determine demographic and dietary factors, and supplement use independently associated with incident kidney stones. Results Overall 1,952 women (2.5%) reported an incident kidney stone in 573,575 person-years of followup. The risk of incident kidney stones was decreased by 5% to 28% (p = 0.01) with higher dietary calcium intake and by 13% to 31% (p = 0.002) with higher water intake after adjusting for nephrolithiasis risk factors. Conversely higher dietary sodium intake increased the risk of nephrolithiasis by 11% to 61% (p <0.001) after adjustment with the most pronounced effect in women with the highest intake. Higher body mass index independently increased the risk of incident nephrolithiasis (adjusted OR 1.19–2.01, p <0.001). Animal protein intake was not associated with nephrolithiasis on multivariate analysis. Conclusions This study adds to the growing evidence underscoring the importance of maintaining adequate fluid and dietary calcium intake. Greater dietary calcium intake significantly decreased the risk of incident kidney stones. In contrast, excess sodium intake increased the risk of incident nephrolithiasis, especially in women with the highest intake. Animal protein intake was not independently associated with nephrolithiasis. PMID:22425103

  20. Progression of crack formation in artificial kidney stones subject to shock waves

    NASA Astrophysics Data System (ADS)

    Van Cauwelaert, Javier; Cleveland, Robin

    2002-11-01

    We used micro computed tomography (CT) imaging to follow the progressive development of cracks in artificial kidney stones. The artificial stones were made from U30 cement with a cylindrical shape (6.5 mm diameter and 7.5 mm long). The stones were held within a polypropylene vial in one of three different orientations: vertical, horizontal, and angled at 45 deg. The stones were treated with an electromagnetic lithotripter using between 50 and 150 shock waves. The initiation and growth of cracks was observed using microCT. We found that crack formation in the U30 stones was influenced by the orientation of the stone with respect to the shock wave (SW) propagation direction. Vertical stones developed a spall-like crack near the distal surface; horizontal stones had little internal damage for the number of shock waves applied; and angled stones were damaged primarily in the vicinity of the leading corner. The position of the cracks were in qualitative agreement with the numerical solutions of the pressure field inside the stones. The elastic properties of the U30 stones are being measured which will alow a quantitative analysis of crack growth to be performed and compared to the experimental data. [Work supported by the Whitaker Foundation.

  1. Assessment of the role of general, biochemical and family history characteristics in kidney stone formation

    PubMed Central

    Jabbar, Faiza; Asif, Muhammad; Dutani, Hajirah; Hussain, Abrar; Malik, Arif; Kamal, Mohammad Amjad; Rasool, Mahmood

    2014-01-01

    Aim The main objective of the study was to determine the urinary risk factors involved in kidney stone formation. Method In this study a total number of 101 patients (64 males and 37 females) between the age group 2 and 70 years were selected. Personal characteristics like age, family history, clinical sign and symptoms, education, monthly income, living style, smoking or tobacco chewing habit, dietary intake and daily amount of drinking water were recorded. Results The study showed that the risk of kidney stone formation was high in the median age group (16–25 years) both in male and female population. The most important factors associated with this were lack of drinking clean water, over weight and obesity as well as family history (37.5% and 27.02% in men and women, respectively). Conclusion Our study has confirmed that lack of drinking sufficient amount of water, increasing weight and obesity and family history are some major factors contributing to the increased risk of kidney stone formation. Therefore it is very important to live a healthy life, drink clean water and control weight to prevent such diseases. PMID:25561886

  2. AB152. Analysis of altered microRNA expression profile in calcium oxalate stone formation

    PubMed Central

    Liu, Zhuo; Jiang, Hongyang; Wang, Tao; Yang, Jun; Wang, Shaogang; Liu, Jihong; Yang, Weimin; Ye, Zhangqun

    2015-01-01

    Objective Calcium oxalate stones account for over 80% of urinary stones, while the molecular mechanism of its formation has been unclear. Hyperoxaluria plays an important role in the pathophysiological process of stone formation. The difference of miRNA expression profiles between experimental hyperoxaluric rats and normal rats is analyzed in our study, in order to find out the target genes and signaling pathways in the pathogenesis procedure of hyperoxaluria. Methods Feeding ethylene glycol and ammonium chloride to culture male experimental hyperoxaluric rats as the experimental group, and age-matched male rats were selected as the control group. The oxalate concentration of 24 hour urine of each experimental rat was measured, of which the three highest were selected for microarray test. MicroRNA microarray was applied to evaluate the expression difference between the two groups and screen miRNA whose fold change were above 2.0 or below 0.5. Quantitative real-time PCR (qRT-PCR) technology was used to validate the microarray results. Target prediction, Gene Ontology (GO) analysis and pathway analysis were applied to predict the potential roles of microRNAs in biological processes. Results There are 28 miRNAs differentially expressed with a more than 2.0-fold change. Among these miRNAs, 20 were up-regulated while 8 were down-regulated. After GO analysis and pathway analysis, the insulin resistance pathway and PI3K-Akt signaling pathway were associated with miRNA regulation. Conclusions This study identified differentially expressed miRNAs in hyperoxaluric rats, providing new insights into the role of miRNA in the formation of calcium oxalate stones.

  3. Ceftriaxone crystallization and its potential role in kidney stone formation.

    PubMed

    Chutipongtanate, Somchai; Thongboonkerd, Visith

    2011-03-18

    Drug-induced nephrolithiasis contributes to 1-2% of the incidence of renal calculi. We examined whether ceftriaxone at therapeutic doses could be crystallized in the urine and also explored its role in kidney stone formation. Crystallization was induced by mixing ceftriaxone sodium at therapeutic urinary excretion levels (0.5-4.0 mg/ml) to calcium chloride at physiologic urinary concentration (5mM) in deionized (dI) water or artificial urine (AU). The results showed that ceftriaxone was crystallized with free calcium in dose- and time-dependent manner. These ceftriaxone/calcium crystals showed birefringence property under polarized microscope. Individual crystals had needle-shape (5-100 μm in length), whereas the aggregated form had star-burst and irregular-plate shape (40-200 μm in diameter) (note that the crystal sizes were much larger than renal tubular lumens). Calcium-depletion assay revealed that crystallization required free calcium as a substrate. In AU, crystallization remained although it was partially inhibited when compared to that in dI water. Finally, these crystals could tightly adhere onto renal tubular cell surface. Our data demonstrated that ceftriaxone at therapeutic levels could be crystallized with free calcium in the urine under physiologic condition. We hypothesize that tubular occlusion and crystal-cell adhesion may play important role in pathogenic mechanisms of ceftriaxone-induced nephrolithiasis. PMID:21329669

  4. Hyperspectral imaging based method for fast characterization of kidney stone types

    NASA Astrophysics Data System (ADS)

    Blanco, Francisco; López-Mesas, Montserrat; Serranti, Silvia; Bonifazi, Giuseppe; Havel, Josef; Valiente, Manuel

    2012-07-01

    The formation of kidney stones is a common and highly studied disease, which causes intense pain and presents a high recidivism. In order to find the causes of this problem, the characterization of the main compounds is of great importance. In this sense, the analysis of the composition and structure of the stone can give key information about the urine parameters during the crystal growth. But the usual methods employed are slow, analyst dependent and the information obtained is poor. In the present work, the near infrared (NIR)-hyperspectral imaging technique was used for the analysis of 215 samples of kidney stones, including the main types usually found and their mixtures. The NIR reflectance spectra of the analyzed stones showed significant differences that were used for their classification. To do so, a method was created by the use of artificial neural networks, which showed a probability higher than 90% for right classification of the stones. The promising results, robust methodology, and the fast analytical process, without the need of an expert assistance, lead to an easy implementation at the clinical laboratories, offering the urologist a rapid diagnosis that shall contribute to minimize urolithiasis recidivism.

  5. Association of serum electrolytes and smoking with salivary gland stone formation.

    PubMed

    Yiu, A J; Kalejaiye, A; Amdur, R L; Todd Hesham, H N; Bandyopadhyay, B C

    2016-06-01

    To further define potential factors that may contribute to stone formation in salivary glands (sialolithiasis), a retrospective chart review was performed of patients diagnosed with sialolithiasis between March 1, 1998 and February 29, 2012. Information on salivary gland stone number, location and size, medical history, medications, and serum electrolyte levels were collected. Associations between electrolyte levels and stone characteristics (such as stone number and size) were examined. Fifty-nine patients were identified; their median age was 58 years (range 25-89 years) and most were male (95%). Salivary stones were most commonly located in the submandibular glands (83%). Thirty-five patients (59%) had a smoking history, with 16 (27%) reported as current smokers. There was a significant association between current smoker status and stone size (mean largest stone size 12.4±8.8mm vs. 7.5±4.8mm in current smokers vs. non-smokers; P=0.03). Serum sodium levels (r=0.32, P=0.014) and serum potassium levels (r=0.31, P=0.017) showed significant positive correlations with stone size. While the aetiology of sialolithiasis remains unclear, smoking (which can contribute to reduced saliva flow) and higher serum sodium levels (which can reflect volume depletion) are associated with larger salivary stones. PMID:26969301

  6. A potential cause for kidney stone formation during space flights: enhanced growth of nanobacteria in microgravity

    NASA Technical Reports Server (NTRS)

    Ciftcioglu, Neva; Haddad, Ruwaida S.; Golden, D. C.; Morrison, Dennis R.; McKay, David S.

    2005-01-01

    BACKGROUND: Although some information is available regarding the cellular/molecular changes in immune system exposed to microgravity, little is known about the reasons of the increase in the kidney stone formation in astronauts during and/or after long duration missions at zero gravity (0 g). In our earlier studies, we have assessed a unique agent, nanobacteria (NB), in kidney stones and hypothesized that NB have an active role in calcium phosphate-carbonate deposition in kidney. In this research we studied effect of microgravity on multiplication and calcification of NB in vitro. METHODS: We examined NB cultures in High Aspect Rotating Vessels (HARVs) designed at the NASA's Johnson Space Center, which are designed to stimulate some aspects of microgravity. Multiplication rate and calcium phosphate composition of those NB were compared with NB cultured on stationary and shaker flasks. Collected aliquots of the cultures from different incubation periods were analyzed using spectrophotometer, SEM, TEM, EDX, and x-ray diffraction techniques. RESULTS: The results showed that NB multiplied 4.6x faster in HARVs compared to stationary cultures, and 3.2x faster than shaker flask conditions. X-ray diffraction and EDX analysis showed that the degree of apatite crystal formation and the properties of the apatite depend on the specific culture conditions used. CONCLUSION: We now report an increased multiplication rate of NB in microgravity-simulated conditions. Thus, NB infection may have a potential role in kidney stone formation in crew members during space flights. For further proof to this hypothesis, screening of the NB antigen and antibody level in flight crew before and after flight would be necessary.

  7. Laser-induced breakdown spectroscopy is a reliable method for urinary stone analysis

    PubMed Central

    Mutlu, Nazım; Çiftçi, Seyfettin; Gülecen, Turgay; Öztoprak, Belgin Genç; Demir, Arif

    2016-01-01

    Objective We compared laser-induced breakdown spectroscopy (LIBS) with the traditionally used and recommended X-ray diffraction technique (XRD) for urinary stone analysis. Material and methods In total, 65 patients with urinary calculi were enrolled in this prospective study. Stones were obtained after surgical or extracorporeal shockwave lithotripsy procedures. All stones were divided into two equal pieces. One sample was analyzed by XRD and the other by LIBS. The results were compared by the kappa (κ) and Spearman’s correlation coefficient (rho) tests. Results Using LIBS, 95 components were identified from 65 stones, while XRD identified 88 components. LIBS identified 40 stones with a single pure component, 20 stones with two different components, and 5 stones with three components. XRD demonstrated 42 stones with a single component, 22 stones with two different components, and only 1 stone with three different components. There was a strong relationship in the detection of stone types between LIBS and XRD for stones components (Spearman rho, 0.866; p<0.001). There was excellent agreement between the two techniques among 38 patients with pure stones (κ index, 0.910; Spearman rho, 0.916; p<0.001). Conclusion Our study indicates that LIBS is a valid and reliable technique for determining urinary stone composition. Moreover, it is a simple, low-cost, and nondestructive technique. LIBS can be safely used in routine daily practice if our results are supported by studies with larger numbers of patients. PMID:27011877

  8. Ultrasound Based Method and Apparatus for Stone Detection and to Facilitate Clearance Thereof

    NASA Technical Reports Server (NTRS)

    Bailey, Michael (Inventor); Kucewicz, John (Inventor); Lu, Wei (Inventor); Sapozhnikov, Oleg (Inventor); Illian, Paul (Inventor); Shah, Anup (Inventor); Dunmire, Barbrina (Inventor); Owen, Neil (Inventor); Cunitz, Bryan (Inventor); Kaczkowski, Peter (Inventor)

    2015-01-01

    Described herein are methods and apparatus for detecting stones by ultrasound, in which the ultrasound reflections from a stone are preferentially selected and accentuated relative to the ultrasound reflections from blood or tissue. Also described herein are methods and apparatus for applying pushing ultrasound to in vivo stones or other objects, to facilitate the removal of such in vivo objects.

  9. Evaluation of effects of novel urease inhibitor, N-(pivaloyl)glycinohydroxamic acid on the formation of an infection bladder stone using a newly designed urolithiasis model in rats.

    PubMed

    Satoh, M; Munakata, K; Takeuchi, H; Yoshida, O; Takebe, S; Kobashi, K

    1991-04-01

    By using our new infection stone model of a rat, we evaluated the effect of a novel urease inhibitor, N-(pivaloyl)glycinohydroxamic acid (P-GHA), on the formation of an infection bladder stone. The oral dosing of P-GHA significantly inhibited the elevation of the urinary ammonia level of rats having the urinary tract infection with Proteus mirabilis. A short term regimen (7 d, 730 +/- 38 mg/kg) with P-GHA significantly inhibited the development of the infection bladder stone. Furthermore, a long term combination regimen (11 d) of P-GHA and aminobenzylpenicillin markedly inhibited the development of the infection bladder stone, and also caused a very slight renal impairment to the rats tested in contrast with the method of Vermeulen et al. Our infection stone model in rats, therefore, seems to be useful for the evaluation of therapeutic agents in long term examinations. PMID:1893494

  10. Nutritional Management of Kidney Stones (Nephrolithiasis)

    PubMed Central

    Segal, Adam M.; Seifter, Julian L.; Dwyer, Johanna T.

    2015-01-01

    The incidence of kidney stones is common in the United States and treatments for them are very costly. This review article provides information about epidemiology, mechanism, diagnosis, and pathophysiology of kidney stone formation, and methods for the evaluation of stone risks for new and follow-up patients. Adequate evaluation and management can prevent recurrence of stones. Kidney stone prevention should be individualized in both its medical and dietary management, keeping in mind the specific risks involved for each type of stones. Recognition of these risk factors and development of long-term management strategies for dealing with them are the most effective ways to prevent recurrence of kidney stones. PMID:26251832

  11. Urinary phosphorus rather than urinary calcium possibly increases renal stone formation in a sample of Asian Indian, male stone-formers.

    PubMed

    Berkemeyer, Shoma; Bhargava, Anupam; Bhargava, Usha

    2007-12-01

    The contribution of dietary Ca and P in renal stone formation is debated. Thus, the main objective was to investigate if there were any differences in the dietary, serum and urine values of Ca and P in stone formers (SF) compared with healthy controls (HC). The secondary aim was to analyse if dietary, serum and urine Ca and P correlated. The study enrolled ten patients with renal stones admitted for stone removal and ten healthy controls. Their dietary macronutrients, Ca and P intakes were calculated from 2-d dietary records. On the second day of dietary record 24-h urine was collected and on the third day morning a 5 ml blood sample was collected. Biochemical analyses were conducted for serum and urine Ca, P and uric acid with qualitative renal stone analysis. All the dietary intakes and urine P were significantly higher (P < 0.05) in SF than in HC. Correlation results showed that in SF dietary Ca correlated to serum and urine Ca. No such correlations were seen for P. Additionally, in SF urine Ca correlated to dietary proteins and fats but not to carbohydrates. None of the biochemical values lay outside the normal range of values. The study suggests urine P rather than urine Ca to be probably at work in the formation of renal stones. Limitation of protein intake with normal Ca intakes could provide a suitable measure to avoid renal stone formation. PMID:17617937

  12. Pathophysiological and physicochemical basis of ammonium urate stone formation in dolphins

    PubMed Central

    Smith, Cynthia R.; Poindexter, John R.; Meegan, Jennifer M.; Bobulescu, I. Alexandru; Jensen, Eric D.; Venn-Watson, Stephanie; Sakhaee, Khashayar

    2014-01-01

    Purpose Nephrolithiasis has been increasingly reported in bottlenose dolphins, with all cases to date being ammonium urate nephrolithiasis. Materials and Methods A case-control study was conducted in dolphins with and without evidence of nephrolithiasis, aiming to identify biomarkers and risk factors associated with stone formation in a managed population. Dolphins were sampled in both fasting and postprandial states in order to study the effect of dietary factors on serum and urinary biochemistry. Urine was continuously collected over a 6-hr period via catheter and divided into three 2-hour collections, with a bolus fish meal given after completion of the first collection. Blood was sampled at the beginning of the fasting period and end of the postprandial period. Results There were no significant differences in serum and urine chemistries and acid base profiles between dolphins with and without stones, at baseline or postprandially, suggesting that case and control animals in this study represent a continuum of stone risk. In analyses combining the case and control dolphins in a single cohort, we noted significant postprandial increases in urinary uric acid, sulfate and net acid excretion, accompanied by increased urinary ammonium excretion and a commensurate rise in urine pH. The supersaturation index of ammonium urate increased postprandially by more than twofold. Conclusion These findings suggest that dolphins are susceptible to ammonium urate nephrolithiasis at least in part because a high dietary load of acid and purines results in a transient but marked increase in the urinary supersaturation of the sparingly soluble ammonium urate salt. PMID:24518786

  13. Role of overweight and obesity on the urinary excretion of promoters and inhibitors of stone formation in stone formers.

    PubMed

    Negri, Armando Luis; Spivacow, Francisco Rodolfo; Del Valle, Elisa Elena; Forrester, Mariano; Rosende, Gabriela; Pinduli, Irene

    2008-12-01

    In recent decades there has been an increasing prevalence of urolitithiasis in many western countries and at the same time there has been an increasing progression of obesity that has reached epidemic proportions. The aim of the present study was to assess the influence of overweight/obesity on the metabolic risk factors for renal stone formation. We studied 799 renal stone formers (462 men and 337 women) who came to the clinic for metabolic risk factors evaluation. They were all studied with a standard protocol (two 24-h urine collections and serum parameters). They were divided according to their BMI in normal (BMI < 25) overweight (BMI 25-29.9) and obese (BMI > 30). Low-weight individuals were excluded. Overall, 487 of 799 (60.9%) patients had a BMI > 25, including 40.6% overweight and 20.3% obese. Among women 55.2% had normal weight, 25.5 were overweight, and 19.3% were Obese; among men 27.3% had normal weight, 51.7 were overweight, and 21% were obese. Age increased significantly with increasing BMI both in men and women. In women there was a significant increase in the excretion of oxalate, uric acid, phosphorus, creatinine, and sodium with increasing BMI, but no change was observed in calcium, magnesium, citrate, and urine pH. In men there was a significant increase in the excretion of oxalate, uric acid, creatinine, phosphorus, sodium, magnesium, and citrate with increasing BMI, no change in urinary calcium and significant progressive decrease in urinary pH. In this population of stone formers there was a high prevalence of overweight/obesity (60.9%). Both in men and women we found a significant increase in the urinary excretion of two promoters of stone formation, oxalate, and uric acid but no change in urinary calcium. There was either no change or increase in magnesium and citrate, inhibitors of crystallization, and a significant decrease in urine pH only in men. PMID:18985334

  14. Studying inhibition of calcium oxalate stone formation: an in vitro approach for screening hydrogen sulfide and its metabolites

    PubMed Central

    Vaitheeswari, S.; Sriram, R.; Brindha, P.; Kurian, Gino A.

    2015-01-01

    ABSTRACT Purpose: Calcium oxalate urolithiasis is one of the most common urinary tract diseases and is of high prevalence. The present study proposes to evaluate the antilithiatic property of hydrogen sulfide and its metabolites like thiosulfate & sulfate in an in vitro model. Materials and Methods: The antilithiatic activity of sodium hydrogen sulfide (NaSH), sodium thiosulfate (Na2S2O3) and sodium sulfate (Na2SO4) on the kinetics of calcium oxalate crystal formation was investigated both in physiological buffer and in urine from normal and recurrent stone forming volunteers. The stones were characterized by optical and spectroscopic techniques. Results: The stones were characterized to be monoclinic, prismatic and bipyramidal habit which is of calcium monohydrate and dihydrate nature. The FTIR displayed fingerprint corresponding to calcium oxalate in the control while in NaSH treated, S=O vibrations were visible in the spectrum. The order of percentage inhibition was NaSH>Na2S2O3>Na2SO4. Conclusion: Our study indicates that sodium hydrogen sulfide and its metabolite thiosulfate are inhibitors of calcium oxalate stone agglomeration which makes them unstable both in physiological buffer and in urine. This effect is attributed to pH changes and complexing of calcium by S2O3 2-and SO4 2- moiety produced by the test compounds. PMID:26200543

  15. [Advance in detection methods of microbes on historic stones--a review].

    PubMed

    Yu, Miao; Zhu, Xudong; Pan, Jiao

    2011-11-01

    We reviewed the methods for identification of microorganisms on the surface of historic stones, including nucleic acid analysis, cell membrane analysis, secondary metabolites analysis and the traditional culture analysis. After comprehensive comparison of the advantages and disadvantages of each method, we addressed the biological protection of stone artifacts. The establishment of rapid detection of microorganisms on the historic stones is important to prevent corrosion caused by microorganisms and to protect our valuable cultural heritage. PMID:22260041

  16. Nanouric acid or nanocalcium phosphate as central nidus to induce calcium oxalate stone formation: a high-resolution transmission electron microscopy study on urinary nanocrystallites

    PubMed Central

    Gao, Jie; Xue, Jun-Fa; Xu, Meng; Gui, Bao-Song; Wang, Feng-Xin; Ouyang, Jian-Ming

    2014-01-01

    Purpose This study aimed to accurately analyze the relationship between calcium oxalate (CaOx) stone formation and the components of urinary nanocrystallites. Method High-resolution transmission electron microscopy (HRTEM), selected area electron diffraction, fast Fourier transformation of HRTEM, and energy dispersive X-ray spectroscopy were performed to analyze the components of these nanocrystallites. Results The main components of CaOx stones are calcium oxalate monohydrate and a small amount of dehydrate, while those of urinary nanocrystallites are calcium oxalate monohydrate, uric acid, and calcium phosphate. The mechanism of formation of CaOx stones was discussed based on the components of urinary nanocrystallites. Conclusion The formation of CaOx stones is closely related both to the properties of urinary nanocrystallites and to the urinary components. The combination of HRTEM, fast Fourier transformation, selected area electron diffraction, and energy dispersive X-ray spectroscopy could be accurately performed to analyze the components of single urinary nanocrystallites. This result provides evidence for nanouric acid and/or nanocalcium phosphate crystallites as the central nidus to induce CaOx stone formation. PMID:25258530

  17. Stellar halos: a rosetta stone for galaxy formation and cosmology

    NASA Astrophysics Data System (ADS)

    Inglis Read, Justin

    2015-08-01

    Stellar halos make up about a percent of the total stellar mass in galaxies. Yet their old age and long phase mixing times make them living fossil records of galactic history. In this talk, I review the latest simulations of structure formation in our standard Lambda Cold Dark Matter cosmology. I discuss the latest predictions for stellar halos and the relationship between the stellar halo light and the underlying dark matter. Finally, I discuss how these simulations compare to observations of the Milky Way and Andromeda and, ultimately, what this means for our cosmological model and the formation history of the Galaxy.

  18. The influence of bacteria on struvite crystal habit and its importance in urinary stone formation

    NASA Astrophysics Data System (ADS)

    Clapham, L.; McLean, R. J. C.; Nickel, J. C.; Downey, J.; Costerton, J. W.

    1990-07-01

    Infection-induced urinary stones form as a result of a urinary tract infection by urease-producing bacteria. These stones are not totally crystalline in nature but rather consist of an agglomeration of bacteria, organic matrix, and crystal of struvite (MgNH 4PO 4· 6H 2O). Crystal formation is related to the ability of the bacteria to effect an increase in the urine pH. Another equally important bacterial role lies in their formation of a 'biofilm' which later becomes the organic matrix constituent of the stone. Results of the present in vitro study indicate that crystals are formed more readily if produced within the bacterial biofilm than in the surrounding urine. It is proposed that supersaturation, due in part to a bacterial-induced pH increase and in part to the metal binding tendency of the biofilm, leads to crystal formation via a gel growth mechanism within the biofilm itself. In time further bacterial cell division, microcolony.

  19. Effect of hydrogen adsorption on the formation and annealing of Stone-Wales defects in graphene

    NASA Astrophysics Data System (ADS)

    Podlivaev, A. I.; Openov, L. A.

    2015-12-01

    The heights of energy barriers preventing the formation and annealing of Stone-Wales defects in graphene with a hydrogen atom adsorbed on the defect or in its immediate vicinity have been calculated using the atomistic computer simulation. It has been shown that, in the presence of hydrogen, both barriers are significantly lower than those in the absence of hydrogen. Based on the analysis of the potential energy surface, the frequency factors have been calculated for two different paths of the Stone-Wales transformation, and the temperature dependences of the corresponding annealing times of the defects have been found. The results obtained have been compared with the first-principles calculations and molecular dynamics data.

  20. Stone Morphology: Implication for Pathogenesis

    NASA Astrophysics Data System (ADS)

    Daudon, Michel; Jungers, Paul; Bazin, Dominique

    2008-09-01

    Urinary stones of similar crystalline composition as identified by X-ray diffraction or Fourier transform infrared spectroscopy (FT-IR) may exhibit distinct structures, which are reflected in distinctive stone morphology. Among factors involved in stone morphology—some reflecting lithogenic activity, others depending on the crystal shape, or on the propensity of crystalline phases to form large aggregates, finally the environment where the stone is growing—all of these factors influence the inner structure of the stone and its superficial characteristics. We present here examples of the clinical interest of refined morphologic examination of stones, in addition to X-ray diffraction or FT-IR identification of its components. Such combination of methods allows the identification of specific etiologies among calcium oxalate stones, especially a morphological type pathognomonic of primary hyperoxaluria and other types related to distinct conditions of stone formation. Among phosphatic stones—in addition to stone composition, which must be considered not only on the basis of the main component, but also taking into account the minor crystalline phases, which often are clinically relevant—morphological types also contribute to diagnosis of the underlying etiology, especially for stones related to distal tubular acidosis. Finally, common purine stones also exhibit different morphologies related to stone composition and etiology: two main structures for uric acid and two for ammonium urate help to distinguish risk factors and lithogenic conditions involved in the formation of these calculi. Morphologic examination is a simple, rapid and cheap method that points to specific diseases or lithogenic factors. Better awareness of its clinical relevance should lead to wider utilization.

  1. Proteus mirabilis fimbriae- and urease-dependent clusters assemble in an extracellular niche to initiate bladder stone formation.

    PubMed

    Schaffer, Jessica N; Norsworthy, Allison N; Sun, Tung-Tien; Pearson, Melanie M

    2016-04-19

    The catheter-associated uropathogenProteus mirabilisfrequently causes urinary stones, but little has been known about the initial stages of bladder colonization and stone formation. We found thatP. mirabilisrapidly invades the bladder urothelium, but generally fails to establish an intracellular niche. Instead, it forms extracellular clusters in the bladder lumen, which form foci of mineral deposition consistent with development of urinary stones. These clusters elicit a robust neutrophil response, and we present evidence of neutrophil extracellular trap generation during experimental urinary tract infection. We identified two virulence factors required for cluster development: urease, which is required for urolithiasis, and mannose-resistantProteus-like fimbriae. The extracellular cluster formation byP. mirabilisstands in direct contrast to uropathogenicEscherichia coli, which readily formed intracellular bacterial communities but not luminal clusters or urinary stones. We propose that extracellular clusters are a key mechanism ofP. mirabilissurvival and virulence in the bladder. PMID:27044107

  2. SPECTRAL REFLECTANCE METHOD TO MEASURE ACID DEPOSITION EFFECTS ON BUILDING STONE.

    USGS Publications Warehouse

    Kingston, Marguerite J.; Ager, Cathy M.

    1985-01-01

    As part of the National Acid Precipitation Assessment Program (NAPAP), the U. S. Geological Survey is cooperating with other agencies to test the effects of acid deposition on building stone. A 10-year test-site study has been organized for the purpose of correlating possible stone deterioration with environmental factors. In Summer 1984, slabs of building stone, 3 by 2 by 2 inches, were exposed to the atmosphere at four test sites where the pH of precipitation and other meteorological variables are continuously monitored. This paper examines the development of one experimental technique used in this study - the application of diffuse spectral reflectance methods for laboratory and in situ measurement of those properties of stone which may be affected by acid deposition.

  3. Natural Abundance 43Ca NMR as a Tool for Exploring Calcium Biomineralization: Renal Stone Formation and Growth

    SciTech Connect

    Bowers, Geoffrey M.; Kirkpatrick, Robert J.

    2011-12-07

    Renal stone diseases are a global health issue with little effective therapeutic recourse aside from surgery and shock-wave lithotripsy, primarily because the fundamental chemical mechanisms behind calcium biomineralization are poorly understood. In this work, we show that natural abundance 43Ca NMR at 21.1 T is an effective means to probe the molecular-level Ca2+ structure in oxalate-based kidney stones. We find that the 43Ca NMR resonance of an authentic oxalate-based kidney stone cannot be explained by a single pure phase of any common Ca2+-bearing stone mineral. Combined with XRD results, our findings suggest an altered calcium oxalate monohydrate-like Ca2+ coordination environment for some fraction of Ca2+ in our sample. The evidence is consistent with existing literature hypothesizing that nonoxalate organic material interacts directly with Ca2+ at stone surfaces and is the primary driver of renal stone aggregation and growth. Our findings show that 43Ca NMR spectroscopy may provide unique and crucial insight into the fundamental chemistry of kidney stone formation, growth, and the role organic molecules play in these processes.

  4. Effect of Cystone on Urinary Composition and Stone Formation Over a One Year Period

    PubMed Central

    Erickson, S. B.; Vrtiska, T. J.; Lieske, J. C.

    2014-01-01

    Kidney stones are a common problem for which inadequate prevention exists. We recruited ten recurrent kidney stone formers with documented calcium oxalate stones into a two phased study to assess safety and effectiveness of Cystone, an herbal treatment for prevention of kidney stones. The first phase was a randomized double-blinded 12 week cross over study assessing the effect of Cystone vs. placebo on urinary supersaturation. The second phase was an open label one year study of Cystone to determine if renal stone burden decreased, as assessed by quantitative and subjective assessment of CT. Results revealed no statistically significant effect of Cystone on urinary composition short (6 weeks) or long (52 weeks) term. Average renal stone burden increased rather than decreased on Cystone. Therefore, this study does not support the efficacy of Cystone to treat calcium oxalate stone formers. Future studies will be needed to assess effects on stone passage, or on other stone types. PMID:21419609

  5. Therapy for urolithiasis with hydroxamic acids. IV. Prevention of infected urinary stone formation with N-(pivaloyl)glycinohydroxamic acid.

    PubMed

    Satoh, M; Munakata, K; Kitoh, K; Seto, N; Kanazawa, T; Takeuchi, H; Yoshida, O

    1981-07-01

    With the aim of finding a prospective therapeutic compound with a promising potential for the treatment of urolithiasis, we evaluated the effectiveness of a new potent inhibitor of urease, N-(pivaloyl)glycinohydroxamic acid. The present study revealed that N-(pivaloyl)glycinohydroxamic acid effectively inhibited the alkalinization of urine and the stone formation in vitro and in vivo, due to its strong inhibitory potency against the ureolytic activity of intact Proteus mirabilis. The possibility of the clinical application of this compound in the prevention of struvite stone formation caused by infection of urea-splitting bacteria awaits evaluation of the safety of this compound. PMID:7028944

  6. Trail formation by ice-shoved "sailing stones" observed at Racetrack Playa, Death Valley National Park

    NASA Astrophysics Data System (ADS)

    Lorenz, R. D.; Norris, J. M.; Jackson, B. K.; Norris, R. D.; Chadbourne, J. W.; Ray, J.

    2014-08-01

    Trails in the usually-hard mud of Racetrack Playa in Death Valley National Park attest to the seemingly-improbable movement of massive rocks on an exceptionally flat surface. The movement of these rocks, previously described as "sliding stones", "playa scrapers", "sailing stones" etc., has been the subject of speculation for almost a century but is an exceptionally rare phenomenon and until now has not been directly observed. Here we report documentation of multiple rock movement and trail formation events in the winter of 2013-2014 by in situ observation, video, timelapse cameras, a dedicated meteorological station and GPS tracking of instrumented rocks. Movement involved dozens of rocks, forming fresh trails typically of 10s of meters length at speeds of ~5 cm s-1 and were caused by wind stress on a transient thin layer of floating ice. Fracture and local thinning of the ice decouples some rocks from the ice movement, such that only a subset of rocks move in a given event.

  7. Kidney Stones

    PubMed Central

    Kleeman, Charles R.; Coburn, Jack W.; Brickman, Arnold S.; Lee, David B. N.; Narins, Robert G.; Ehrlich, Richard M.

    1980-01-01

    The prevalence of kidney stones has steadily risen during this century; passage of a calculus and a positive family history increase the probability of recurrence. Findings from recent studies on the cause of renal calculi have stressed crystallization and crystal aggregation of stone minerals from supersaturated urine, rather than excessive organic matrix. Absence of normal urine inhibitors of calcium salts is also stressed. Formation of calcium oxalate stones is the major problem. Therapy with decreased calcium and oxalate intake, thiazides, phosphate salts and allopurinol in various combinations has substantially decreased the prevalence of recurrent stones. The rationale for the use of allopurinol is that uric acid salts enhance the tendency for calcium oxalate to crystallize from supersaturated urine. The hypercalciuria seen in 30 percent to 40 percent of patients with oxalate stones is usually caused by intestinal hyperabsorption of calcium. Although patients with uric acid calculi constitute only a small fraction of those in whom stones form, they represent a group in whom good medical therapy, based on sound physiologic principles, has proved extremely successful. Renal tubular syndromes lead to nephrocalcinosis and lithiasis through hypercalciuria, alkaline urine and hypocitraturia, the latter an inhibitor of calcium salt precipitation. Recent advances in surgical techniques are discussed, including the rationale for removing staghorn calculi. The ileal ureter and coagulum pyelolithotomy deserve special emphasis. ImagesFigure 2.Figure 4.Figure 5.Figure 7. PMID:7385835

  8. GENETIC BASIS OF RENAL CELLULAR DYSFUNCTION AND THE FORMATION OF KIDNEY STONES

    PubMed Central

    Khan, Saeed R.; Canales, Benjamin K.

    2013-01-01

    Nephrolithiasis is a result of formation and retention of crystals within the kidneys. The driving force behind crystal formation is urinary supersaturation with respect to the stone forming salts, which means that crystals form when the concentrations of participating ions are higher than the thermodynamic solubility for that salt. Levels of supersaturation are kept low and under control by proper functioning of a variety of cells including those that line the renal tubules. It is our hypothesis that crystal deposition i.e. formation and retention in the kidneys, is a result of impaired cellular function, which may be intrinsic and inherent or triggered by external stimuli and challenges. Cellular impairment or dysfunction affects the supersaturation, by influencing the excretion of participating ions such as calcium, oxalate and citrate and causing hypercalciuria, hyperoxaluria or hypocitraturia. The production and excretion of macromolecular promoters and inhibitors of crystallization is also dependent upon proper functioning of the renal epithelial cells. Insufficient or ineffective crystallization modulators such as osteopontin (OPN), Tamm Horsfall protein (THP), bikunin (BK) etc are most likely produced by the impaired cells. PMID:19517103

  9. The potential role of salt abuse on the risk for kidney stone formation.

    PubMed

    Sakhaee, K; Harvey, J A; Padalino, P K; Whitson, P; Pak, C Y

    1993-08-01

    The kidney stone-forming risk of a high sodium diet was evaluated by assessing the effect of such a diet on the crystallization of stone-forming salts in urine. Fourteen normal subjects participated in 2 phases of study of 10 days duration each, comprising a low sodium phase (basal metabolic diet containing 50 mmol. sodium per day) and a high sodium phase (basal diet plus 250 mmol. sodium chloride per day). The high sodium intake significantly increased urinary sodium (34 +/- 12 to 267 +/- 56 mmol. per day), calcium (2.73 +/- 1.03 to 3.93 +/- 1.51 mmol. per day) and pH (5.79 +/- 0.44 to 6.15 +/- 0.25), and significantly decreased urinary citrate (3.14 +/- 1.19 to 2.52 +/- 0.83 mmol. per day). Arterialized venous blood bicarbonate and total serum carbon dioxide concentrations decreased significantly during the high sodium diet, whereas serum chloride concentration increased. However, no change in arterialized venous pH was detected. Thus, a high sodium intake not only increased calcium excretion, but also increased urinary pH and decreased citrate excretion. The latter effects are probably due to sodium-induced bicarbonaturia and a significant decrease in serum bicarbonate concentration, respectively. Commensurate with these changes, the urinary saturation of calcium phosphate (brushite) and monosodium urate increased, and the inhibitor activity against calcium oxalate crystallization (formation product) decreased. The net effect of a high sodium diet was an increased propensity for the crystallization of calcium salts in urine. PMID:8326549

  10. The potential role of salt abuse on the risk for kidney stone formation

    NASA Technical Reports Server (NTRS)

    Sakhaee, K.; Harvey, J. A.; Padalino, P. K.; Whitson, P.; Pak, C. Y.

    1993-01-01

    The kidney stone-forming risk of a high sodium diet was evaluated by assessing the effect of such a diet on the crystallization of stone-forming salts in urine. Fourteen normal subjects participated in 2 phases of study of 10 days duration each, comprising a low sodium phase (basal metabolic diet containing 50 mmol. sodium per day) and a high sodium phase (basal diet plus 250 mmol. sodium chloride per day). The high sodium intake significantly increased urinary sodium (34 +/- 12 to 267 +/- 56 mmol. per day), calcium (2.73 +/- 1.03 to 3.93 +/- 1.51 mmol. per day) and pH (5.79 +/- 0.44 to 6.15 +/- 0.25), and significantly decreased urinary citrate (3.14 +/- 1.19 to 2.52 +/- 0.83 mmol. per day). Arterialized venous blood bicarbonate and total serum carbon dioxide concentrations decreased significantly during the high sodium diet, whereas serum chloride concentration increased. However, no change in arterialized venous pH was detected. Thus, a high sodium intake not only increased calcium excretion, but also increased urinary pH and decreased citrate excretion. The latter effects are probably due to sodium-induced bicarbonaturia and a significant decrease in serum bicarbonate concentration, respectively. Commensurate with these changes, the urinary saturation of calcium phosphate (brushite) and monosodium urate increased, and the inhibitor activity against calcium oxalate crystallization (formation product) decreased. The net effect of a high sodium diet was an increased propensity for the crystallization of calcium salts in urine.

  11. Combined vitamin D and calcium supplementation in vitamin D inadequate patients with urolithiasis: Impact on hypercalciuria and de novo stone formation

    PubMed Central

    Hesswani, Charles; Noureldin, Yasser A.; Elkoushy, Mohamed A.; Andonian, Sero

    2015-01-01

    Introduction: We examined the effect of combined vitamin D and calcium supplementation (VDCS) on urinary calcium excretion and de novo stone formation in vitamin D inadequate (VDI) urolithiasis patients. Methods: We retrospectively reviewed the data of VDI patients (serum 25-hydroxyvitamin D <75 nmol/L) followed at a tertiary stone centre between September 2009 and December 2014. VDI patients with history of urolithiasis, who were placed on VDCS for abnormal bone mineral density or hyperoxaluria, were included. Hypercalciuric patients and patients on thiazide diuretics were excluded. Metabolic stone workup and two 24-hour urine collections were performed before and after VDCS. Results: In total, we included 34 patients, with a mean age of 54.8 years and a mean body mass index of 25.7 kg/m2. After VDCS, there was a significant increase in the mean serum 25-hydroxyvitamin D (52.0 vs. 66.4 nmol/L, p < 0.001) and the mean urinary calcium excretion (3.80 vs. 5.64 mmol/d, p < 0.001). Eight (23.5%) patients developed de novo hypercalciuria. After a median follow-up of 39 (range: 7–60) months, 50% of hypercalciuric patients developed stones compared with 11.5% of non-hypercalciuric patients (p = 0.038). Conclusion: This study showed a significant effect of combined VDCS on mean urinary calcium excretion, de novo hypercalciuria, and stone development in VDI patients with history of urolithiasis. Therefore, VDI urolithiasis patients receiving VDCS are advised to have monitoring with 24-hour urine collections and imaging studies. Although small, our sample size was good enough to validate the statistical outcomes. Prospective studies are needed to confirm these results. PMID:26788229

  12. Biomimetic Randall's plaque as an in vitro model system for studying the role of acidic biopolymers in idiopathic stone formation.

    PubMed

    Chidambaram, Archana; Rodriguez, Douglas; Khan, Saeed; Gower, Laurie

    2015-01-01

    Randall's plaque (RP) deposits seem to be consistent among the most common type of kidney stone formers, idiopathic calcium oxalate stone formers. This group forms calcium oxalate renal stones without any systemic symptoms, which contributes to the difficulty of understanding and treating this painful and recurring disease. Thus, the development of an in vitro model system to study idiopathic nephrolithiasis, beginning with RP pathogenesis, can help in identifying how plaques and subsequently stones form. One main theory of RP formation is that calcium phosphate deposits initially form in the basement membrane of the thin loops of Henle, which then fuse and spread into the interstitial tissue, and ultimately make their way across the urothelium, where upon exposure to the urine, the mineralized tissue serves as a nidus for overgrowth with calcium oxalate into a stone. Our group has found that many of the unusual morphologies found in RP and stones, such as concentrically laminated spherulites and mineralized collagenous tissue, can be reproduced in vitro using a polymer-induced liquid precursor (PILP) process, in which acidic polypeptides induce a liquid phase amorphous precursor to the mineral, yielding non-equilibrium crystal morphologies. Given that there are many acidic proteins and polysaccharides present in the renal tissue and urine, we have put forth the hypothesis that the PILP system may be involved in urolithiasis. Therefore, our goal is to develop an in vitro model system of these two stages of composite stone formation to study the role that various acidic macromolecules may play. In our initial experiments presented here, the development of "biomimetic" RP was investigated, which will then serve as a nidus for calcium oxalate overgrowth studies. To mimic the tissue environment, MatriStem(®) (ACell, Inc.), a decellularized porcine urinary bladder matrix was used, because it has both an intact epithelial basement membrane surface and a tunica propria layer, thus providing the two types of matrix constituents found associated with mineral in the early stages of RP formation. We found that when using the PILP process to mineralize this tissue matrix, the two sides led to dramatically different mineral textures, and they bore a striking resemblance to native RP, which was not seen in the tissue mineralized via the classical crystal nucleation and growth process. The interstitium side predominantly consisted of collagen-associated mineral, while the luminal side had much less mineral, which appeared to be tiny spherules embedded within the basement membrane. Although these studies are only preliminary, they support our hypothesis that kidney stones may involve non-classical crystallization pathways induced by the large variety of macromolecular species in the urinary environment. We believe that mineralization of native tissue scaffolds is useful for developing a model system of stone formation, with the ultimate goal of developing strategies to avoid RP and its detrimental consequences in stone formation, or developing therapeutic treatments to prevent or cure the disease. Supported by NIDDK grant RO1DK092311. PMID:25119505

  13. AFM and pulsed laser ablation methods for Cultural Heritage: application to archeometric analysis of stone artifacts

    NASA Astrophysics Data System (ADS)

    Barberio, M.; Veltri, S.; Stranges, F.; Bonanno, A.; Xu, F.; Antici, P.

    2015-09-01

    In this paper, we introduce the use of the atomic force microscope (AFM) and of the pulsed laser ablation as methods for morphological diagnostic with nanoscale precision of archeological artifacts and corrosive patina removal from stone artifacts. We test our methodology on stone artifacts extracted from the Church of Sotterra (located in Calabria, South Italy). The AFM microscopy was compared with different petrographic, chemical, optical and morphological analysis methods for identifying the textural characteristics, evaluating the state of preservation and formulating some hypotheses about the provenance and composition of the impurity patina located on the artifact surfaces. We demonstrate that with the nanometric precision obtained with AFM microscopy, it is possible to distinguish the different states of preservation, much better than using conventional petrographic methods. The surface's roughness is evaluated from very small artifact's fragments, reducing the coring at micrometric scale with a minimal damage to the artworks. After the diagnosis, we performed restoration tests using the pulsed laser ablation (PLA) method and compared it with the more common micro-sandblasting under dry conditions. We find that the PLA is highly effective for the removal of the surficial patina, with a control of a few hundreds of nanometers in the cleaning of surface, without introducing chemical or morphological damages to the artifacts. Moreover, PLA can be easily implemented in underwater conditions; this has the great advantage that stone and pottery artifacts for marine archeological sites do not need to be removed from the site.

  14. Calcium Oxalate Stone Formation in the Inner Ear as a Result of an Slc26a4 Mutation*♦

    PubMed Central

    Dror, Amiel A.; Politi, Yael; Shahin, Hashem; Lenz, Danielle R.; Dossena, Silvia; Nofziger, Charity; Fuchs, Helmut; Hrabé de Angelis, Martin; Paulmichl, Markus; Weiner, Steve; Avraham, Karen B.

    2010-01-01

    Calcium oxalate stone formation occurs under pathological conditions and accounts for more than 80% of all types of kidney stones. In the current study, we show for the first time that calcium oxalate stones are formed in the mouse inner ear of a genetic model for hearing loss and vestibular dysfunction in humans. The vestibular system within the inner ear is dependent on extracellular tiny calcium carbonate minerals for proper function. Thousands of these biominerals, known as otoconia, are associated with the utricle and saccule sensory maculae and are vital for mechanical stimulation of the sensory hair cells. We show that a missense mutation within the Slc26a4 gene abolishes the transport activity of its encoded protein, pendrin. As a consequence, dramatic changes in mineral composition, size, and shape occur within the utricle and saccule in a differential manner. Although abnormal giant carbonate minerals reside in the utricle at all ages, in the saccule, a gradual change in mineral composition leads to a formation of calcium oxalate in adult mice. By combining imaging and spectroscopy tools, we determined the profile of mineral composition and morphology at different time points. We propose a novel mechanism for the accumulation and aggregation of oxalate crystals in the inner ear. PMID:20442411

  15. Renal stone risk assessment during Space Shuttle flights

    NASA Technical Reports Server (NTRS)

    Whitson, P. A.; Pietrzyk, R. A.; Pak, C. Y.

    1997-01-01

    PURPOSE: The metabolic and environmental factors influencing renal stone formation before, during, and after Space Shuttle flights were assessed. We established the contributing roles of dietary factors in relationship to the urinary risk factors associated with renal stone formation. MATERIALS AND METHODS: 24-hr. urine samples were collected prior to, during space flight, and following landing. Urinary and dietary factors associated with renal stone formation were analyzed and the relative urinary supersaturation of calcium oxalate, calcium phosphate (brushite), sodium urate, struvite and uric acid were calculated. RESULTS: Urinary composition changed during flight to favor the crystallization of calcium-forming salts. Factors that contributed to increased potential for stone formation during space flight were significant reductions in urinary pH and increases in urinary calcium. Urinary output and citrate, a potent inhibitor of calcium-containing stones, were slightly reduced during space flight. Dietary intakes were significantly reduced for a number of variables, including fluid, energy, protein, potassium, phosphorus and magnesium. CONCLUSIONS: This is the first in-flight characterization of the renal stone forming potential in astronauts. With the examination of urinary components and nutritional factors, it was possible to determine the factors that contributed to increased risk or protected from risk. In spite of the protective components, the negative contributions to renal stone risk predominated and resulted in a urinary environment that favored the supersaturation of stone-forming salts. Dietary and pharmacologic therapies need to be assessed to minimize the potential for renal stone formation in astronauts during/after space flight.

  16. Delayed migration of embolized coil with large renal stone formation: a rare presentation.

    PubMed

    Kumar, Santosh; Jayant, Kumar; Singh, Shrawan K; Parmar, Kalpesh M; Devana, Sudheer K; Choudhari, Gautam R; Mittal, Ankur

    2014-01-01

    Delayed bleeding following percutaneous nephrolithotomy (PCNL) usually occurs due to development of the pseudoaneurysm which can be successfully managed with coil embolization. However very few cases of such complications have been reported in the literature. Here we are reporting a case of delayed post-PCNL bleeding that occurred in a 53-year-old diabetic patient operated on for renal stone. Computed tomography scan revealed a presence of the pseudoaneurysm in the segmental branch of right renal artery, which was successfully managed with coiling. Patient remained asymptomatic for the next 9 years after which he again presented with similar complaints. X-ray KUB was done which revealed a 2.7 cms renal pelvic calculus with the migrated coil in its center and a left upper ureteric calculus. His routine haemogram, coagulogram, serum electrolytes, and liver function tests, renal function tests, vitamin D3, and PTH (parathyroid hormone) were within normal limits. He underwent left laparoscopic ureterolithotomy and right percutaneous nephrolithotomy (PCNL). Intraoperatively the migrated stainless steel embolization coil was seen engulfed all around by the multiple stones in the right renal pelvis. Postoperative period was uneventful. Later he was followed in the outpatient department and was doing well. To conclude, this is the only case report of development of a large calculus around a migrated embolization coil which was successfully managed with PCNL. PCNL offers better stone clearance in cases of stones being formed over foreign bodies like fragmented double J stents, fragmented nephrostomies, or migrated embolization coil. PMID:25610700

  17. Rosetta stone method for detecting protein function and protein-protein interactions from genome sequences

    DOEpatents

    Eisenberg, David; Marcotte, Edward M.; Pellegrini, Matteo; Thompson, Michael J.; Yeates, Todd O.

    2002-10-15

    A computational method system, and computer program are provided for inferring functional links from genome sequences. One method is based on the observation that some pairs of proteins A' and B' have homologs in another organism fused into a single protein chain AB. A trans-genome comparison of sequences can reveal these AB sequences, which are Rosetta Stone sequences because they decipher an interaction between A' and B. Another method compares the genomic sequence of two or more organisms to create a phylogenetic profile for each protein indicating its presence or absence across all the genomes. The profile provides information regarding functional links between different families of proteins. In yet another method a combination of the above two methods is used to predict functional links.

  18. Enhanced affordable methods for assessment of material characteristics and consolidation effects on stone and mortar

    NASA Astrophysics Data System (ADS)

    Drdacky, M.; Slizkova, Z.

    2012-04-01

    In situ considerate testing of surface cohesion of historic stone and mortar materials suffers from a lack of suitable affordable non-destructive methods. The problem is mainly important for assessment of surface degradation characteristics and/or evaluation of effectiveness of consolidation treatment of degraded historic materials. The paper presents two innovations of simple testing methods which provide reliable data on material cohesion and water uptake. The so called "Scotch Tape Test" or peeling test has been introduced into the field of conservation for testing the cohesion qualities of historic materials mainly stone and renders in sixties without any standards or reliably verified recommendations for the above mentioned application in the conservation practice. Licentious use without adequate knowledge and sufficient understanding leads to non-comparable and non-reproducible as well as in many cases incorrect and severely biased results and assessments. Therefore, the authors after a research and comparative testing have established limits for its application, reliable procedures and a "standard" protocol for testing of cohesion characteristics of brittle and quasi brittle materials mainly mortars and stones. This article presents a detailed analysis of the peeling test procedures, and suggests recommendations for performing peeling tests and for evaluating the obtained results. Also in situ testing of material water uptake is a very basic and indispensable technique in conservation practice and it correlates significantly with some other material characteristics. The capillary properties of porous materials can be measured in situ using a Karsten tube and modified tools or methods which are quite cumbersome, and cannot be performed on inclined surfaces, e.g. vaults or ceilings. There are other difficulties with Karsten tube measurements, e.g. problems with fixing a heavy glass tube on vertical surfaces, a need for two operators, and soiling of the surface by the sealing putty. An innovative method has therefore been developed and tested at ITAM AS CR for measuring water absorption under low pressure. It enables continuous or manually controlled electronic measurements of water infusion into the surface and recording the acquired data. This measurement procedure reduces the number of operators, and it is more precise, more effective and faster. Two prototypes will be presented: one for continuous laboratory measurements and a portable device for in situ applications. The portable device has been tested in laboratory conditions and also in situ for its basic performance on various types of stone and plaster surfaces, including treated and untreated historic materials. The acquired data was evaluated using software specially written for this purpose in MatLab, and the results were compared with standard capillary water uptake measurements on prismatic columns. Working with the innovated tubes, measurements can be made on complex stone or plaster surfaces, e.g. sculptures in a dense network. This feature is especially appreciated by restorers making interventions on materials that have been treated previously.

  19. Effects of boron-nitride substrates on Stone-Wales defect formation in graphene: An ab initio molecular dynamics study

    SciTech Connect

    Jin, K.; Xiao, H. Y.; Zhang, Y.; Weber, W. J.

    2014-05-19

    Ab initio molecular dynamics simulations are performed to investigate the effects of a boron nitride (BN) substrate on Stone-Wales (SW) defect formation and recovery in graphene. It is found that SW defects can be created by an off-plane recoil atom that interacts with the BN substrate. A mechanism with complete bond breakage for formation of SW defects in suspended graphene is also revealed for recoils at large displacement angles. In addition, further irradiation can result in recovery of the SW defects through a bond rotation mechanism in both graphene and graphene/BN, and the substrate has little effect on the recovery process. This study indicates that the BN substrate enhances the irradiation resistance of graphene.

  20. Method for measuring pollutant formation

    NASA Technical Reports Server (NTRS)

    Annen, Kurt (Inventor); Stickler, David B. (Inventor)

    2001-01-01

    Diagnostic methods for determining an instantaneous rate of pollutant formation in a combustion system are based on measurement of chemiluminescence intensity generated simultaneously with the formation of the pollutant. The chemiluminescent signal is generated by an analog reaction which occurs in parallel with a key step in the formation of a specific pollutant of interest. The connection between the analog reaction and the pollution reaction is such that the chemiluminescent signal indicates the local, instantaneous formation rate of the pollutant of interest.

  1. Ambient temperature as a contributor to kidney stone formation: implications of global warming.

    PubMed

    Fakheri, Robert J; Goldfarb, David S

    2011-06-01

    Nephrolithiasis is a common disease across the world that is becoming more prevalent. Although the underlying cause for most stones is not known, a body of literature suggests a role of heat and climate as significant risk factors for lithogenesis. Recently, estimates from computer models predicted up to a 10% increase in the prevalence rate in the next half century secondary to the effects of global warming, with a coinciding 25% increase in health-care expenditures. Our aim here is to critically review the medical literature relating stones to ambient temperature. We have categorized the body of evidence by methodology, consisting of comparisons between geographic regions, comparisons over time, and comparisons between people in specialized environments. Although most studies are confounded by other factors like sunlight exposure and regional variation in diet that share some contribution, it appears that heat does play a role in pathogenesis in certain populations. Notably, the role of heat is much greater in men than in women. We also hypothesize that the role of a significant human migration (from rural areas to warmer, urban locales beginning in the last century and projected to continue) may have a greater impact than global warming on the observed worldwide increasing prevalence rate of nephrolithiasis. At this time the limited data available cannot substantiate this proposed mechanism but further studies to investigate this effect are warranted. PMID:21451456

  2. Type 2 diabetes mellitus and renal stones

    PubMed Central

    Nerli, Rajendra; Jali, Mallikarjuna; Guntaka, Ajay Kumar; Patne, Pravin; Patil, Shivagouda; Hiremath, Murigendra Basayya

    2015-01-01

    Background: The incidence of urinary stone disease has shown a steep rise in recent decades along with marked modifications in dietary habits and life- style. There has been an increased prevalence of urinary stone disease in patients with diabetes. We took up this study to determine the association of diabetes mellitus with kidney stones in patients undergoing surgical treatment. Materials and Methods: Patients presenting with renal stones for surgical management formed the study group. Body mass index (BMI) was calculated by noting the weight and height of the patient. The extracted stone/stone fragments were analyzed to determine the chemical composition. Urinary pH was similarly noted in all. Results: The mean BMI among the diabetics was 26.35 ± 5.20 (range 17.75-35.60), whereas the mean BMI among the non-diabetics was 23.41 ± 2.85 (range 17.71-31.62) (P < 0.0004). The incidence of uric acid calculi in the diabetics was significantly high (P < 0.03). The mean urinary pH among the diabetics was 5.61 ± 0.36 and among the non-diabetics was 6.87 ± 0.32, which was significantly lower (P < 0.000044). Conclusions: There is a strong association between type 2 diabetes and uric acid stone formation. There is also a strong association between diabetes mellitus, BMI, and also with lower urinary pH. PMID:26605219

  3. Bladder stones

    MedlinePlus

    Stones - bladder; Urinary tract stones; Bladder calculi ... Benway BM, Bhayani SM. Lower urinary tract calculi. In: Wein AJ, ed. Campbell-Walsh Urology . 10th ed. Philadelphia, PA: Elsevier Saunders; 2011:chap 89. Sharma R, Dill CE, Gelman DY. Urinary ...

  4. Kidney stones

    MedlinePlus

    ... dissolved in the urine can crystallize, forming a kidney stone (renal calculus). Usually the calculus is the size ... painful. Often, people may not know they have kidney stones until they feel the painful symptoms resulting from ...

  5. Androgen Receptor Enhances Kidney Stone-CaOx Crystal Formation via Modulation of Oxalate Biosynthesis & Oxidative Stress

    PubMed Central

    Liang, Liang; Li, Lei; Tian, Jing; Lee, Soo Ok; Dang, Qiang; Huang, Chiung-Kuei; Yeh, Shuyuan; Erturk, Erdal; Bushinsky, David; Chang, Luke S.

    2014-01-01

    Males develop kidney stones far more frequently than females with a ratio of 2–3:1, suggesting that androgen receptor (AR) signaling might play a key role in the development of nephrolithiasis. Using the cre-loxP system to selectively knock out AR in glyoxylate-induced calcium oxalate (CaOx) crystal mouse models, we found that the mice lacking hepatic AR had less oxalate biosynthesis, which might lead to lower CaOx crystal formation, and that the mice lacking kidney proximal or distal epithelial AR also had lower CaOx crystal formation. We found that AR could directly up-regulate hepatic glycolate oxidase and kidney epithelial NADPH oxidase subunit p22-PHOX at the transcriptional level. This up-regulation might then increase oxalate biosynthesis and oxidative stress that resulted in induction of kidney tubular injury. Targeting AR with the AR degradation enhancer ASC-J9 led to suppression of CaOx crystal formation via modulation of oxalate biosynthesis and oxidative stress in both in vitro and in vivo studies. Taken together, these results established the roles of AR in CaOx crystal formation. PMID:24956378

  6. Androgen receptor enhances kidney stone-CaOx crystal formation via modulation of oxalate biosynthesis & oxidative stress.

    PubMed

    Liang, Liang; Li, Lei; Tian, Jing; Lee, Soo Ok; Dang, Qiang; Huang, Chiung-Kuei; Yeh, Shuyuan; Erturk, Erdal; Bushinsky, David; Chang, Luke S; He, Dalin; Chang, Chawnshang

    2014-08-01

    Males develop kidney stones far more frequently than females with a ratio of 2-3:1, suggesting that androgen receptor (AR) signaling might play a key role in the development of nephrolithiasis. Using the cre-loxP system to selectively knock out AR in glyoxylate-induced calcium oxalate (CaOx) crystal mouse models, we found that the mice lacking hepatic AR had less oxalate biosynthesis, which might lead to lower CaOx crystal formation, and that the mice lacking kidney proximal or distal epithelial AR also had lower CaOx crystal formation. We found that AR could directly up-regulate hepatic glycolate oxidase and kidney epithelial NADPH oxidase subunit p22-PHOX at the transcriptional level. This up-regulation might then increase oxalate biosynthesis and oxidative stress that resulted in induction of kidney tubular injury. Targeting AR with the AR degradation enhancer ASC-J9 led to suppression of CaOx crystal formation via modulation of oxalate biosynthesis and oxidative stress in both in vitro and in vivo studies. Taken together, these results established the roles of AR in CaOx crystal formation. PMID:24956378

  7. Enhanced affordable methods for assessing material characteristics and consolidation effects on stone and mortar

    NASA Astrophysics Data System (ADS)

    Drdácký, Miloš; Slížková, Zuzana

    2013-12-01

    It is rather difficult to set up non-destructive or considerate in situ tests for assessing material characteristics and consolidation effects on historic stone and mortar. However, some simple methods have proved to be helpful when applied appropriately and this paper provides brief information about two such methods: peeling tests, also known as the ‘Scotch tape’ method, and surface water uptake measurements using a digitized microtube. Both methods have some history of development and use Mora and Torraca (1965 Bollettino Istituto Centrale del Restauro (Rome) pp 109-32), Giorgi et al (2000 Stud. Conserv. 45 154-61), Tiano et al (2006 J. Cult. Heritage 7 49-55), Lehmann (2004 Thesis, Hochschule für Bildende Künste, Dresden pp 33-34), Drdácký et al (2011 Proc. European Workshop on Cultural Heritage Preservation pp 126-30) and Zíma (2011 Proc. 49th Int. Scientific Conf. on Experimental Stress Analysis pp 441-8) without any standardized support. This lack of a validated procedure can lead to some deficiencies and misinterpretations for applying the peeling test. Also, in the case of the digitized micro-tube, there can be some difficulties when the device is applied, which could prevent its wider adoption or even lead to rejection of the micro-tube technique. The paper summarizes basic principles for the application of both methods and reports illustrative results for laboratory and historic building investigations.

  8. Stones and urinary tract infections.

    PubMed

    Miano, Roberto; Germani, Stefano; Vespasiani, Giuseppe

    2007-01-01

    The term infection stones refers to calculi that occur following urinary tract infections (UTIs) caused by urease-producing gram-negative organisms. They consist of magnesium ammonium phosphate, carbonate apatite and monoammonium urate. Alkaline urine is most favorable to their formation. Urinary tract obstruction, neurogenic bladder, voiding dysfunction, temporary or indwelling urinary catheters, distal renal tubular acidosis and medullary sponge kidney are considered the main risk factors for developing infection stones. Urinalysis and urine culture are essential for diagnosis. A typical finding on imaging is a moderately radiopaque, staghorn or branched stone. Curative treatment is possible only by eliminating all of the stone fragments and by eradicating UTI. A variety of operative and pharmaceutical approaches is available. Metaphylactic treatment is mandatory to prevent recurrences. The relationship between urinary stones and UTIs is well known and shows two different clinical pictures: (1) stones that develop following UTIs (infection stones) which play a key role in stone pathogenesis, and (2) stones complicated by UTIs (stones with infection) which are metabolic stones that passively trap bacteria from coexistent UTIs and may consist of calcium or non-calcium. This article presents an overview of infection stones, analyzing the epidemiology, composition, pathogenesis, diagnosis, treatment and prevention of this type of calculi. PMID:17726350

  9. Bacterial bio-mediated calcite precipitation for monumental stones conservation: methods of evaluation.

    PubMed

    Tiano, P; Biagiotti, L; Mastromei, G

    1999-05-01

    The weathering of monumental stones is a complex process inserted in the more general 'matter transformation cycle' operated by physical, chemical and biological factors. The consequence of these combined actions is a loss of cohesion with dwindling and scaling of stone material and the induction of a progressive mineral matrix dissolution. In the case of calcareous stones, calcite leaching increases the material porosity and decreases its mechanical features with a general weakening of the superficial structural strength. Attempts to stop, or at least to slow down, deterioration of monumental stones has been made by conservative treatments with both inorganic or organic products. More recent studies show a new approach to hinder these phenomena by inducing a bio-mediated precipitation of calcite directly inside the stone porosity. This can be achieved either through the application of organic matrix macromolecules extracted from sea shells or of living bacteria. The effectiveness of the treatment using calcinogenic bacteria has been evaluated with laboratory tests specifically developed to evaluate the parameters such as : porosity, superficial strength and chromatic changes, influenced by the treatment itself. The results obtained seem to indicate that this type of treatment might not be suitable for monumental stone conservation. PMID:10353808

  10. Ion chromatography to detect salts in stone structures and to assess salt removal methods

    NASA Astrophysics Data System (ADS)

    Alvarez de Buergo, M.; Lopez-Arce, P.; Fort, R.

    2012-04-01

    Stone - and in general all materials- from built heritage is very often damaged by salt crystallisation processes. Such processes usually derive into a loss of material compactness, as salts - given specific conditions and parameters- crystallize inside the material pores, exerting a pressure against the material pore walls higher than what they can resist - similar to the effect of liquid water when converts to solid water or ice-, thus breaking and disrupting the material by generating fissures and increasing the pore volume ratio, loosing its initial cohesion. When these deterioration processes take place inside a structure, salts - from different sources: material itself, restoration materials, from the ground, etc.- may come up to the stone surface - either temporarily or in permanently-, from beneath it, as efflorescences, depending mainly on the microclimatic conditions of the environment and the salts source. Efflorescences can be analysed and their nature identified (e.g. by means of X ray diffraction, in which the mineralogical composition of the salt is obtained), which can be, general, of aid not only for restoration but for preventive conservation measures. But what we do not know a priori when only characterising salt compounds- is the extent of the damage due to the presence of salts inside a structure (sub- and cryptoefflorescences). In this work we present a procedure in which the depth of the salt content can be measured, and its nature identified, based on the use of the ion chromatography technique. This technique allows identifying the existing ions in a specific sample, both anions and cations. The procedure consists of drilling (with a drilling core ranging from 5 to 8 mm in diameter, therefore causing the minimum damage to the material) in a same point at different depths from the surface and several depths from the bottom. The samples obtained are analysed and the ion content determined, qualitative and quantitatively. By means of a thorough previous inspection, we can select the most representative points by a drilling net - as minimum as possible- and make some profiles of the inner salt content of a structure. Moreover, this procedure is not only reliable for determining the nature and extent of salts damage, but to assess the efficacy of salts removal methods in cultural heritage. Here we present two case studies from relevant buildings of the Spanish cultural heritage in which this procedure was performed with successful and useful results, in both terms of understanding what types of salts were decaying the stones structures, and also whether the salts removal methods that were planned in the restoration project were efficient or not. It should be remarked that even ion chromatography is not a non destructive technique (can be considered as a minimally destructive one due to the few quantity it is needed for the analysis), the information it can provide is so useful that should not be ruled out from the beginning, depending of each specific case.

  11. Mechanism by which shock wave lithotripsy can promote formation of human calcium phosphate stones

    PubMed Central

    Evan, Andrew P.; Coe, Fredric L.; Connors, Bret A.; Handa, Rajash K.; Lingeman, James E.

    2015-01-01

    Human stone calcium phosphate (CaP) content correlates with higher urine CaP supersaturation (SS) and urine pH as well as with the number of shock wave lithotripsy (SWL) treatments. SWL does damage medullary collecting ducts and vasa recta, sites for urine pH regulation. We tested the hypothesis that SWL raises urine pH and therefore Cap SS, resulting in CaP nucleation and tubular plugging. The left kidney (T) of nine farm pigs was treated with SWL, and metabolic studies were performed using bilateral ureteral catheters for up to 70 days post-SWL. Some animals were given an NH4Cl load to sort out effects on urine pH of CD injury vs. increased HCO3− delivery. Histopathological studies were performed at the end of the functional studies. The mean pH of the T kidneys exceeded that of the control (C) kidneys by 0.18 units in 14 experiments on 9 pigs. Increased HCO3− delivery to CD is at least partly responsible for the pH difference because NH4Cl acidosis abolished it. The T kidneys excreted more Na, K, HCO3−, water, Ca, Mg, and Cl than C kidneys. A single nephron site that could produce losses of all of these is the thick ascending limb. Extensive injury was noted in medullary thick ascending limbs and collecting ducts. Linear bands showing nephron loss and fibrosis were found in the cortex and extended into the medulla. Thus SWL produces tubule cell injury easily observed histopathologically that leads to functional disturbances across a wide range of electrolyte metabolism including higher than control urine pH. PMID:25656372

  12. Method for treating underground formations

    SciTech Connect

    Noles, J.R.; Walker, C.O.; White, N.F.

    1981-04-14

    Disclosed is a method for treating subterranean formations such as underground petroleum-containing formations penetrated by a well, and particularly a formation penetrated by a producing well which formation contain a plurality of zones, one or more of which are producing petroleum and one or more of which are producing water. The treatment selectively reduces the permeability of the water-producing intervals without adversely affecting the permeability of the oil producing intervals, thereby reducing the production of water and reducing the water-oil ratio of the fluid being produced from the well. The treatment method involves introducing an effective amount of a liquid comprising a hydrocarbon having dispersed therein an unhydrated water swellable clay such as bentonite, a sodium montmorillonite. The clay swells on contacting water in the water-producing intervals and plugs or reduces the permeability of the flow channels in the water-producing intervals.

  13. Stones in cats and dogs: What can be learnt from them?

    PubMed Central

    Syme, Harriet M.

    2012-01-01

    Objective To review the clinical features of stone disease in dogs and cats for a non-veterinary audience. Methods Relevant peer-reviewed scientific reports were reviewed. Results Lower urinary tract stones are more common in dogs and cats than they are in humans. In addition to struvite stones, calcium oxalate, urate and cystine stones are all commonly found in the bladder and the urethra. The genetic basis for stone disease in some breeds of dog has been elucidated. The small size of cats creates technical challenges when managing ureterolithiasis. Conclusions Naturally occurring stone disease in companion animals is a valuable area for further study. The structure of the canine genome might facilitate the identification of novel disease loci in breeds of dog predisposed to stone formation. PMID:26558031

  14. Dimension stone

    USGS Publications Warehouse

    Dolley, T.P.

    2003-01-01

    Dimension stone can be defined as natural rock material quarried to obtain blocks or slabs that meet specifications as to size (width, length and thickness) and shape for architectural or engineering purposes. Color, grain texture and pattern, and surface finish of the stone are also normal requirements. Other important selection criteria are durability (based on mineral composition, hardness and past performance), strength and the ability of the stone to take a polish.

  15. Application of combined rigid choledochoscope and accurate positioning method in the adjuvant treatment of bile duct stones

    PubMed Central

    Wang, Ping; Chen, Xiaowu; Sun, Beiwang; Liu, Yanmin

    2015-01-01

    To explore the clinical effect of percutaneous transhepatic cholangioscopic lithotomy (PTCSL) combined with rigid choledochoscope and accurate positioning in the treatment of calculus of bile duct. This study retrospectively reviewed 162 patients with hepatolithiasis at the First Affiliated Hospital of Guangzhou Medical University between 2001 and 2013 were assigned to hard lens group or traditional PTCSL group. Compared with the traditional PTCSL, PTCSL with rigid choledochoscope can shorten the interval time which limit the PTCSL application. The operation time (45 vs 78, P=0.003), the number of operation (1.62 vs 1.97, P=0.031), and blood loss (37.8 vs 55.1, P=0.022) were better in hard lens group while the stone residual and complication had no significant differences. Rigid choledochoscope is a safe, minimally invasive and effective method in the treatment of bile duct stones. Accurate positioning method can effectively shorten operation process time. PMID:26629183

  16. Chemical composition and binary mixture of human urinary stones using FT-Raman spectroscopy method

    NASA Astrophysics Data System (ADS)

    Selvaraju, R.; Raja, A.; Thiruppathi, G.

    2013-10-01

    In the present study the human urinary stones were observed in their different chemical compositions of calcium oxalate monohydrate, calcium oxalate dihydrate, calcium phosphate, struvite (magnesium ammonium phosphate), uric acid, cystine, oxammite (ammonium oxalate monohydrate), natroxalate (sodium oxalate), glushinkite (magnesium oxalate dihydrate) and moolooite (copper oxalate) were analyzed using Fourier Transform-Raman (FT-Raman) spectroscopy. For the quantitative analysis, various human urinary stone samples are used for ratios calculation of binary mixtures compositions such as COM/COD, HAP/COD, HAP/COD, Uric acid/COM, uric acid/COD and uric acid/HAP. The calibration curve is used for further analysis of binary mixture of human urinary stones. For the binary mixture calculation the various intensities bands at 1462 cm-1 (ICOM), 1473 cm-1 (ICOD), 961 cm-1 (IHAP) and 1282 cm-1 (IUA) were used.

  17. Does the Use of Chitosan Contribute to Oxalate Kidney Stone Formation?

    PubMed Central

    Queiroz, Moacir Fernandes; Teodosio Melo, Karoline Rachel; Sabry, Diego Araujo; Sassaki, Guilherme Lanzi; Rocha, Hugo Alexandre Oliveira

    2014-01-01

    Chitosan is widely used in the biomedical field due its chemical and pharmacological properties. However, intake of chitosan results in renal tissue accumulation of chitosan and promotes an increase in calcium excretion. On the other hand, the effect of chitosan on the formation of calcium oxalate crystals (CaOx) has not been described. In this work, we evaluated the antioxidant capacity of chitosan and its interference in the formation of CaOx crystals in vitro. Here, the chitosan obtained commercially had its identity confirmed by nuclear magnetic resonance and infrared spectroscopy. In several tests, this chitosan showed low or no antioxidant activity. However, it also showed excellent copper-chelating activity. In vitro, chitosan acted as an inducer mainly of monohydrate CaOx crystal formation, which is more prevalent in patients with urolithiasis. We also observed that chitosan modifies the morphology and size of these crystals, as well as changes the surface charge of the crystals, making them even more positive, which can facilitate the interaction of these crystals with renal cells. Chitosan greatly influences the formation of crystals in vitro, and in vivo analyses should be conducted to assess the risk of using chitosan. PMID:25551781

  18. Kidney Stones

    MedlinePlus

    ... when you urinate Your doctor will diagnose a kidney stone with urine, blood, and imaging tests. If you have a stone that won't pass on its own, you may need treatment. It can be done with shock waves; with ...

  19. Stone chewing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Picking stones up into the mouth and chewing them has been commonly reported in pigs and also in dogs. It has variously been described as play behavior, redirected foraging behavior or a stereotypic behavior. In pigs, stone chewing is often observed in sows housed on paddocks, and most frequently o...

  20. The role of polymer nanosurface roughness and submicron pores in improving bladder urothelial cell density and inhibiting calcium oxalate stone formation

    NASA Astrophysics Data System (ADS)

    Chun, Young Wook; Khang, Dongwoo; Haberstroh, Karen M.; Webster, Thomas J.

    2009-02-01

    Synthetic polymers have been proposed for replacing resected cancerous bladder tissue. However, conventional (or nanosmooth) polymers used in such applications (such as poly(ether) urethane (PU) and poly-lactic-co-glycolic acid (PLGA)) often fail clinically due to poor bladder tissue regeneration, low cytocompatibility properties, and excessive calcium stone formation. For the successful reconstruction of bladder tissue, polymer surfaces should be modified to combat these common problems. Along these lines, implementing nanoscale surface features that mimic the natural roughness of bladder tissue on polymer surfaces can promote appropriate cell growth, accelerate bladder tissue regeneration and inhibit bladder calcium stone formation. To test this hypothesis, in this study, the cytocompatibility properties of both a non-biodegradable polymer (PU) and a biodegradable polymer (PLGA) were investigated after etching in chemicals (HNO3 and NaOH, respectively) to create nanoscale surface features. After chemical etching, PU possessed submicron sized pores and numerous nanometer surface features while PLGA possessed few pores and large amounts of nanometer surface roughness. Results from this study strongly supported the assertion that nanometer scale surface roughness produced on PU and PLGA promoted the density of urothelial cells (cells that line the interior of the bladder), with the greatest urothelial cell densities observed on nanorough PLGA. In addition, compared to respective conventional polymers, the results provided evidence that nanorough PU and PLGA inhibited calcium oxalate stone formation; submicron pored nanorough PU inhibited calcium oxalate stone formation the most. Thus, results from the present study suggest the importance of nanometer topographical cues for designing better materials for bladder tissue engineering applications.

  1. Renal Stone Risk during Spaceflight: Assessment and Countermeasure Validation

    NASA Technical Reports Server (NTRS)

    Whitson, Peggy A.; Pietrzyk, Robert A.; Jones, Jeffery A.; Sams, Clarence F.; Hudson, Ed K.; Nelman-Gonzalez, Mayra

    2009-01-01

    NASA's Vision for Space Exploration centers on exploration class missions including the goals of returning to the moon and landing on Mars. One of NASA's objectives is to focus research on astronaut health and the development of countermeasures that will protect crewmembers during long duration voyages. Exposure to microgravity affects human physiology and results in changes in the urinary chemical composition favoring urinary supersaturation and an increased risk of stone formation. Nephrolithiasis is a multifactorial disease and development of a renal stone is significantly influenced by both dietary and environmental factors. Previous results from long duration Mir and short duration Shuttle missions have shown decreased urine volume, pH, and citrate levels and increased calcium. Citrate, an important inhibitor of calcium-containing stones, binds with urinary calcium reducing the amount of calcium available to form stones. Citrate inhibits renal stone recurrence by preventing crystal growth, aggregation, and nucleation and is one of the most common therapeutic agents used to prevent stone formation. Methods: Thirty long duration crewmembers (29 male, 1 female) participated in this study. 24-hour urines were collected and dietary monitoring was performed pre-, in-, and postflight. Crewmembers in the treatment group received two potassium citrate (KCIT) pills, 10 mEq/pill, ingested daily beginning 3 days before launch, all in-flight days and through 14 days postflight. Urinary biochemical and dietary analyses were completed. Results: KCIT treated subjects exhibited decreased urinary calcium excretion and maintained the levels of calcium oxalate supersaturation risk at their preflight levels. The increased urinary pH levels in these subjects reduced the risk of uric acid stones. Discussion: The current study investigated the use of potassium citrate as a countermeasure to minimize the risk of stone formation during ISS missions. Results suggest that supplementation with potassium citrate decreases the risk of stone formation during and immediately after spaceflight.

  2. A Guideline for the Management of Renal Stones in Astronauts

    NASA Technical Reports Server (NTRS)

    Reyes, David; Locke, James; Johnston, Smith

    2014-01-01

    There are no specific guidelines for the management of renal stones in astronauts. Given the increased risk for bone loss, hypercalcuria, and stone formation due to microgravity, a clinical practice guideline is needed. Methods An extensive review of the literature and current aeromedical standards for the management of renal stones was done. The NASA Flight Medicine Clinic's electronic medical record and Longitudinal Survey of Astronaut Health were also reviewed. This information was used to create an algorithm for the management of renal stones in astronauts. Results Guidelines are proposed based on accepted standards of care, with consideration to the environment of spaceflight. In a usual medical setting, asymptomatic, small stones less than 7 mm are often observed over time. Given the constraints of schedule, and the risks to crew health and mission, this approach is too liberal. An upper limit of 3 mm stone diameter was adopted before requiring intervention, because this is the largest size that has a significant chance of spontaneous passage on its own. Other specific guidelines were also created. Discussion The spaceflight environment requires more aggressive treatment than would otherwise be found with the usual practice of medicine. A small stone can become a major problem because it may ultimately require medical evacuation from orbit. Thus renal stones are a significant mission threat and should be managed in a systematic way to mitigate risks to crew health and mission success.

  3. Gastrolithiasis in prehensile-tailed porcupines (Coendou prehensilis): nine cases and pathogenesis of stone formation.

    PubMed

    Spriggs, Maria; Thompson, Kimberly A; Barton, Douglas; Talley, John; Volle, Kurt; Stasiak, Iga; Beyea, Louise; Guthrie, Amanda; Roda, Aldo; Camborata, Cecilia; Hofmann, Alan F; Hagey, Lee R

    2014-12-01

    Gastrolithiasis was diagnosed in nine prehensile-tailed (PT) porcupines (Coendou prehensilis) housed at six zoologic institutions in the United States and Canada. Affected animals were either asymptomatic or had clinical signs, including weight loss, diarrhea, and depression. Abdominal palpation was adequate for diagnosis in all six antemortem cases, and radiographs confirmed a soft tissue density mass effect produced by the concretion. These gastroliths were all successfully surgically removed. Recurrence of gastrolith formation was common and occurred in four of the cases. Three cases were diagnosed postmortem, with the gastrolith causing gastric perforation in one case. Gastroliths from four cases were identified by mass spectrometry as bile acid precipitates consisting of the insoluble acid form of endogenous glycine-conjugated bile acids. PMID:25632677

  4. Renal Stone Risk During Spaceflight: Assessment and Countermeasure Validation

    NASA Technical Reports Server (NTRS)

    Pietrzyk, Robert A.; Whitson, Peggy A.; Sams, Clarence F.; Jones, Jeffery A.; Smith, Scott M.

    2009-01-01

    This viewgraph presentation describes the risks of renal stone formation in manned space flight. The contents include: 1) Risk; 2) Evidence; 3) Nephrolithiasis -A Multifactorial Disease; 4) Symptoms/signs; 5) Urolithiasis and Stone Passage; 6) Study Objectives; 7) Subjects; 8) Methods; 9) Investigation Results; 10) Potassium Citrate; 11) Calcium Balance; 12) Case Study; 13) Significant Findings; 14) Risk Mitigation Strategies and Recommended Actions; and 15) Future Potential.

  5. [MICROBIAL COMMUNITIES ON KIDNEY STONES].

    PubMed

    Romanova, Yu M; Mulabaev, N S; Tolordava, E R; Seregin, A V; Seregin, I V; Alexeeva, N V; Stepanova, T V; Levina, G A; Barhatova, O I; Gamova, N A; Goncharova, S A; Didenko, L V; Rakovskaya, I V

    2015-01-01

    The clinical material obtained surgically in patients with kidney stone disease (KSD) was tested for content of the stone microflora using PCR and standard microbiological methods. It was demonstrated that about 50% of stones in patients with KSD were infected with various infection agents as observed using standard microbiological and molecular genetic methods. The percentage of detection of the Mycoplasma hominis using cultural method is lower than the percentage detected using PCR, which is due to difficult isolation and cultivation, as well as DNA fragments of mycoplasma observed after antibiotic therapy. Studies based on modern microscopy methods showed that microorganisms on the surface of the kidney stone formed multispecies biofilms. PMID:26182663

  6. Medical management of renal stones.

    PubMed

    Morgan, Monica S C; Pearle, Margaret S

    2016-01-01

    The prevalence of kidney stones is increasing in industrialized nations, resulting in a corresponding rise in economic burden. Nephrolithiasis is now recognized as both a chronic and systemic condition, which further underscores the impact of the disease. Diet and environment play an important role in stone disease, presumably by modulating urine composition. Dietary modification as a preventive treatment to decrease lithogenic risk factors and prevent stone recurrence has gained interest because of its potential to be safer and more economical than drug treatment. However, not all abnormalities are likely to be amenable to dietary therapy, and in some cases drugs are necessary to reduce the risk of stone formation. Unfortunately, no new drugs have been developed for stone prevention since the 1980s when potassium citrate was introduced, perhaps because the long observation period needed to demonstrate efficacy discourages investigators from embarking on clinical trials. Nonetheless, effective established treatment regimens are currently available for stone prevention. PMID:26977089

  7. Laser beam pulse formatting method

    DOEpatents

    Daly, Thomas P.; Moses, Edward I.; Patterson, Ralph W.; Sawicki, Richard H.

    1994-01-01

    A method for formatting a laser beam pulse (20) using one or more delay loops (10). The delay loops (10) have a partially reflective beam splitter (12) and a plurality of highly reflective mirrors (14) arranged such that the laser beam pulse (20) enters into the delay loop (10) through the beam splitter (12) and circulates therein along a delay loop length (24) defined by the mirrors (14). As the laser beam pulse (20) circulates within the delay loop (10) a portion thereof is emitted upon each completed circuit when the laser beam pulse (20) strikes the beam splitter (12). The laser beam pulse (20) is thereby formatted into a plurality of sub-pulses (50, 52, 54 and 56). The delay loops (10) are used in combination to produce complex waveforms by combining the sub-pulses (50, 52, 54 and 56) using additive waveform synthesis.

  8. Calcium carbonate precipitation by heterotrophic bacteria isolated from biofilms formed on deteriorated ignimbrite stones: influence of calcium on EPS production and biofilm formation by these isolates.

    PubMed

    López-Moreno, Angélica; Sepúlveda-Sánchez, José David; Mercedes Alonso Guzmán, Elia Mercedes; Le Borgne, Sylvie

    2014-01-01

    Heterotrophic CaCO3-precipitating bacteria were isolated from biofilms on deteriorated ignimbrites, siliceous acidic rocks, from Morelia Cathedral (Mexico) and identified as Enterobacter cancerogenus (22e), Bacillus sp. (32a) and Bacillus subtilis (52g). In solid medium, 22e and 32a precipitated calcite and vaterite while 52g produced calcite. Urease activity was detected in these isolates and CaCO3 precipitation increased in the presence of urea in the liquid medium. In the presence of calcium, EPS production decreased in 22e and 32a and increased in 52g. Under laboratory conditions, ignimbrite colonization by these isolates only occurred in the presence of calcium and no CaCO3 was precipitated. Calcium may therefore be important for biofilm formation on stones. The importance of the type of stone, here a siliceous stone, on biological colonization is emphasized. This calcium effect has not been reported on calcareous materials. The importance of the effect of calcium on EPS production and biofilm formation is discussed in relation to other applications of CaCO3 precipitation by bacteria. PMID:24689777

  9. The Middle Stone Age archaeology of the Lower Omo Valley Kibish Formation: excavations, lithic assemblages, and inferred patterns of early Homo sapiens behavior.

    PubMed

    Shea, John J

    2008-09-01

    This paper describes the excavation, stratigraphy, and lithic assemblages of Middle Stone Age sites from the Omo Kibish Formation (Lower Omo Valley, southwestern Ethiopia). Three sites were excavated, two in Kibish Member I (KHS and AHS) and one at the base of Member III (BNS). The assemblages are dominated by relatively high-quality raw materials procured as pebbles from local gravels. The principal modes of core preparation are radial/centripetal Levallois and discoidal. Retouched tools are rare. Foliate bifaces are present, as are larger tools, such as handaxes, picks, and lanceolates, but these are more common among surface finds than among excavated assemblages. Middle Stone Age assemblages shed light on the adaptations of the earliest-known Homo sapiens populations in Africa. PMID:18691735

  10. Wanted: suitable replacement stones for the Lede stone (Belgium)

    NASA Astrophysics Data System (ADS)

    De Kock, T.; Dewanckele, J.; Boone, M. A.; De Boever, W.; De Schutter, G.; Jacobs, P.; Cnudde, V.

    2012-04-01

    The Lede stone is an arenaceous limestone with a Lutetian age, occurring as discrete (most of the times three) stone banks in the marine sandy sediments of the Lede Formation (Belgium). It has a quartz content of approximate 40%. This increases abrasion strength and together with the cementation results in an average compressive strength of about 80-85 MPa. The cement is a microsparitic calcite cement. Other carbonate particles are both microfossils (mainly foraminifers) and macrofossils (bivalves, serpulids, echinoderms, …). This great diversity gives the stone a heterogeneous, animated appearance. The intra- and interparticle porosity is in total 5-10 % in average and the apparent density is 2400-2550 kg/m3. Another important constituent is glauconite, present in a few percent. In fresh state, the stone has a greenish-grey colour, but when it is exposed to atmospheric conditions for a couple of years, the stone acquires a yellowish to rust-coloured patina due to the weathering of glauconite. Sulphatation causes severe damage to the stone, and black gypsum crusts are common in urban environments on stones protected from runoff. This stone was excavated in both open air and underground quarries in the areas of Brussels and Ghent. The proximity of main rivers such as the Scheldt and Zenne provided transport routes for export towards the north (e.g. Antwerp and The Netherlands). Its first known use dates back to Roman times but the stone flourished in Gothic architecture due to its easy workability and its 'divine' light coloured patina. This results nowadays in a dominant occurrence in the cultural heritage of northwestern Belgium and the south of The Netherlands. Socio-economical reasons caused several declines and revivals of Lede stone in use. In the beginning of the 20th century, only a few excavation sites remained, with as main quarry the one located at Bambrugge (Belgium). By the end of the first half of the 20th century, however, no quarry sites remained. In the sixties, a sand quarry located in Balegem (Belgium) started with the extraction of Lede stone combined with its other activities. Until now, only this site supplies blocks of fresh Lede stones and it doesn't seem there will rise an opportunity of a new site in the near future. Therefore, during the huge amount of renovation works in the past century, the Lede stone was often replaced by imported (mostly French) limestones such as Massangis stone, Savonnières stone and Euville stone. The commercial value seems to have had a large impact and too little attention was paid on the optical appearance, ageing and technical compatibility of the stones. The use of especially Massangis stone was taken for granted. In the 21st century, there is a growing awareness of the impact of such consequent replacement for the historical value of our cultural heritage and several alternative stones are suggested and even used. These include stones from France, Spain and Portugal, but also from other regions in Belgium. For the moment, there is no consensus on the most appropriate replacement stone and further research should be done in order to evaluate compatibility of the different stone types with Lede stone. In this context, it is also very important to actively search for better alternatives, which resemble the Lede stone in both a mechanical and aesthetical point of view. Therefore, this abstract is an open question to its readers. Any commercial natural stone suggestions with affiliation to the aforementioned properties are welcome by e-mailing the corresponding author.

  11. Meckel's stone ileus.

    PubMed

    Rudge, F W

    1992-02-01

    Meckel's diverticulum is the most common congenital abnormality of the small bowel; it occurs in approximately 2% of the population. Complications of Meckel's diverticulum include hemorrhage, usually associated with heterotopic tissue within the diverticulum, intussusception, development of benign or malignant neoplasms, and inflammation. Formation of one or more enteroliths within a diverticulum is rare. An extremely rare complication is mechanical small bowel obstruction secondary to extrusion of an enterolith from a Meckel's diverticulum (Meckel's stone ileus). A case of Meckel's stone ileus is described herein, with a review of the literature of this extremely rare complication. PMID:1603394

  12. Villamayor stone (Golden Stone) as a Global Heritage Stone Resource from Salamanca (NW of Spain)

    NASA Astrophysics Data System (ADS)

    Garcia-Talegon, Jacinta; Iñigo, Adolfo; Vicente-Tavera, Santiago

    2013-04-01

    Villamayor stone is an arkosic stone of Middle Eocene age and belongs to the Cabrerizos Sandstone Formation that comprising braided fluvial systems and paleosoils at the top of each stratigraphic sequence. The sandstone is known by several names: i) the Villamayor Stone because the quarries are located in Villamayor de Armuña village that are situated at 7 km to the North from Salamanca city; ii) the Golden Stone due to its patina that produced a ochreous/golden color on the façades of monuments of Salamanca (World Heritage City,1988) built in this Natural stone (one of the silicated rocks utilised). We present in this work, the Villamayor Stone to be candidate as Global Heritage Stone Resource. The Villamayor Stone were quarrying for the construction and ornamentation of Romanesque religious monuments as the Old Cathedral and San Julian church; Gothic (Spanish plateresc style) as the New Cathedral, San Esteban church and the sculpted façade of the Salamanca University, one of the oldest University in Europe (it had established in 1250); and this stone was one of the type of one of the most sumptuous Baroque monuments is the Main Square of the its galleries and arcades (1729). Also, this stone was used in building palaces, walls and reconstruction of Roman bridge. Currently, Villamayor Stone is being quarried by small and family companies, without a modernized processing, for cladding of the façades of the new buildings until that the construction sector was burst (in 2008 the international economic crisis). However, Villamayor Stone is the main stone material used in the city of Salamanca for the restoration of monuments and, even in small quantities when compared with just before the economic crisis, it would be of great importance for future generations protect their quarries and the craft of masonry. Villamayor Stone has several varieties from channels facies to floodplains facies, in this work the selected varieties are: i) the fine-grained stone, microporous, is partially cemented by dolomite, 27% (bulk porosity), ii) the ochre and fine-grained stone, microporous, with smectite, 30% (bulk porosity), iii) the medium-grained stone, 38% (bulk porosity). Main components for all three varieties: Quartz (up to 60%), feldspars, 2:1 layered silicates (smectites), palygorskite-type fibrous silicates, and small amounts of micaceous minerals (illite/mica).

  13. Quantification of asymptomatic kidney stone burden by computed tomography for predicting future symptomatic stone events

    PubMed Central

    Selby, Michael G.; Vrtiska, Terri J.; Krambeck, Amy E.; McCollough, Cynthia H.; Elsherbiny, Hisham; Bergstralh, Eric J.; Lieske, John C.; Rule, Andrew D.

    2014-01-01

    Objective To find the optimal characterization of asymptomatic radiographic stone burden on computed tomographic (CT) scans. Methods A survey was sent to stone formers who underwent a CT scan while asymptomatic during a stone clinic evaluation. Symptomatic stone passage events after CT scan were detected by survey and medical record review. Radiographic stone burden was quantified by number of stones, largest stone diameter, automated total stone volume (TSV), and bilateral stones and then compared as predictors of stone events. Results There were 550 stone formers; 43% had a stone event a median 4.7 years after the CT scan. Stone burden by quartiles was 0–1, 2–3, 4–6, ≥7 for number of stones; 0–2, 3–4, 5–7, ≥8 mm for largest stone diameter; and 0–8, 9–78, 79–280, and ≥ 281 mm3 for TSV; 48% had bilateral stones. The hazard ratios (HRs) for symptomatic event was 1.30 (p<0.001) for the number of stones per quartile, 1.26 (p<0.001) for largest stone diameter per quartile, 1.38 (p<0.001) for TSV per quartile, and 1.80 (p<0.001) for bilateral stones. On multivariable analysis, only TSV was an independent predictor of symptomatic events (HR=1.35 per quartile, p=0.01). This risk of events with TSV was also independent of demographics, urine chemistries, and stone composition. Among the 53 patients with interim events between CT scans, a rapid increase in TSV between CT scans (>570 mm3/year) predicted subsequent events (HR=2.8, p=0.05). Conclusions Automated TSV is more predictive of symptomatic events than manual methods for quantifying stone burden on CT scan. PMID:25440821

  14. Acute oral calcium-sodium citrate load in healthy males. Effects on acid-base and mineral metabolism, oxalate and other risk factors of stone formation in urine.

    PubMed

    Schwille, P O; Schmiedl, A; Herrmann, U; Schwille, R; Fink, E; Manoharan, M

    1997-01-01

    The currently preferred calcium preparations for supplementation of food vary widely with respect to calcium availability, effects on systemic mineral metabolism, acid-base status, and the calciuria-induced risk of urinary tract stone formation. In eight healthy males we studied the response to an acute load with alkali(sodium)-containing soluble calcium citrate (CSC) (molar ratio calcium/sodium/citrate approx. = 1/1/1), when taken in three different doses (10, 20, 30 mmol calcium) together with a continental breakfast. Intestinal calcium absorption, serum calcium, calcitonin, parathyroid hormone (PTH) other markers of bone metabolism, net acid excretion and calcium oxalate crystallization in urine were evaluated. CSC evoked a dose-dependent increase in calcium absorption, calcium in serum and urine, but no overt hypercalcemia, and calciuria was low relative to the excess calcium ingested; PTH fell and calcitonin rose (p < 0.05 vs. breakfast alone), but the diet-independent markers of bone resorption declined only insignificantly, while the markers of bone formation and turnover remained unchanged. There was a significant "once-daily" effect (= cumulative 24 h postload response) of CSC: a decrease in urinary cyclic AMP, phosphorus, and ammonium, and an increase in urinary bicarbonate. Soon after CSC intake, urinary calcium oxalate and hydroxyapatite supersaturation increased dose-dependently, the calcium oxalate crystal diameter was increased, but crystal aggregation time, which is crucial for stone formation, remained statistically unchanged. Thus, CSC provides calcium in a bioavailable form, creates mild systemic alkalinisation and inhibition of bone resorption, but leaves the risk of developing urinary stones unchanged. Comparative long-term studies on bone growth and the maintenance of bone health, using alkali-containing versus alkali-free calcium citrate, appear worthwhile. PMID:9385591

  15. Urinary stones in Eastern Saudi Arabia

    PubMed Central

    Alkhunaizi, Ahmed Mansour

    2016-01-01

    Introduction: Nephrolithiasis is a common problem worldwide especially in areas of the hot climate like Saudi Arabia. The aim of this analysis was to study the characteristics of urinary stones in Eastern Saudi Arabia and to report the following: Composition of urinary stones, age and gender distribution, seasonal variation of stone development, comorbid conditions associated with stone development and the incidence of urinary stones. Methods: All urinary stones that were submitted to the Johns Hopkins Aramco Healthcare, previously Saudi Aramco Medical Services Organization for analysis from January 2011 through January 2013 were analyzed. Results: A total of 384 urinary stones were collected and submitted for analysis from 347 patients. There was a male predominance with a male: female ratio of 3.9:1. The average age was 48.5 ± 12.8 years. Weight abnormality was predominant in both genders, and especially females. Calcium-based stones constituted the great majority (84.6%) followed by uric acid stones (12.8%). The other forms of stones were rare. More stones were recovered during the hot season, May to September. The calculated annual incidence of urolithiasis was 111/100,000 individuals. Conclusion: Calcium based stones are the most common urinary stones observed in Eastern Saudi Arabia. There is a clear association between the diagnosis of urinary stones and the hot season PMID:26834393

  16. Effects of microgravity on renal stone risk assessment

    NASA Technical Reports Server (NTRS)

    Pietrzyk, R. A.; Pak, C. Y. C.; Cintron, N. M.; Whitson, P. A.

    1992-01-01

    Physiologic changes induced during human exposure to the microgravity environment of space may contribute to an increased potential for renal stone formation. Renal stone risk factors obtained 10 days before flight and immediately after return to earth indicated that calcium oxalate and uric acid stone-forming potential was increased after space flights of 4-10 days. These data describe the need for examining renal stone risk during in-flight phases of space missions. Because of limited availability of space and refrigerated storage on spacecraft, effective methods must be developed for collecting urine samples in-flight and for preserving (or storing) them at temperatures and under conditions commensurate with mission constraints.

  17. Potential contribution of optional urease-positive bacteria to idiopathic urinary calcium stone formation. II. Microlith formation kinetics in a fermenter model of the urinary tract infected by optional urease-positive microorganisms.

    PubMed

    Leusmann, D B; Sabinski, F

    1996-01-01

    We investigated the effects of weak to moderate urease hydrolysis by optional urease-positive microorganisms in an artificial urine model enriched with calcium phosphate and calcium oxalate in respect of calcium stone formation. The incubation experiments were performed using a discontinuously running fermenter device to simulate the urinary system. The kinetics of cell division rates, pH and ammonium ion production were measured and correlated to crystallite appearance in the incubation medium. Qualitative analyses of the sediments revealed apatite. Investigations using light microscopy and scanning electron microscopy (SEM) confirmed the matrix effect of bacterial glycoproteins. It was shown that initiation of calcium oxalate stone formation is in all probability equally determined by matrix effects and by heteronuclear crystallization if the urinary tract is infected by optional urease-positive bacteria. When urinary inorganic phosphate is present, calcium phosphate nidi are always initially formed, and may subsequently be coated by calcium oxalate. PMID:8740975

  18. An Additional Potential Factor for Kidney Stone Formation during Space Flights: Calcifying Nanoparticles (Nanobacteria): A Case Report

    NASA Technical Reports Server (NTRS)

    Jones, Jeffrey A.; Ciftcioglu, Neva; Schmid, Joseph; Griffith, Donald

    2007-01-01

    Spaceflight-induced microgravity appears to be a risk factor for the development of urinary calculi due to skeletal calcium liberation and other undefined factors, resulting in stone disease in crewmembers during and after spaceflight. Calcifying nanoparticles, or nanobacteria, reproduce at a more rapid rate in simulated microgravity conditions and create external shells of calcium phosphate in the form of apatite. The questions arises whether calcifying nanoparticles are niduses for calculi and contribute to the development of clinical stone disease in humans, who possess environmental factors predisposing to the development of urinary calculi and potentially impaired immunological defenses during spaceflight. A case of a urinary calculus passed from an astronaut post-flight with morphological characteristics of calcifying nanoparticles and staining positive for a calcifying nanoparticle unique antigen, is presented.

  19. Method of fracturing a geological formation

    DOEpatents

    Johnson, James O.

    1990-01-01

    An improved method of fracturing a geological formation surrounding a well bore is disclosed. A relatively small explosive charge is emplaced in a well bore and the bore is subsequently hydraulically pressurized to a pressure less than the formation breakdown pressure and preferably greater than the fracture propagation pressure of the formation. The charge is denoted while the bore is so pressurized, resulting in the formation of multiple fractures in the surrounding formation with little or no accompanying formation damage. Subsequent hydraulic pressurization can be used to propagate and extend the fractures in a conventional manner. The method is useful for stimulating production of oil, gas and possibly water from suitable geologic formations.

  20. Diagnosis of rare inherited glyoxalate metabolic disorders through in-situ analysis of renal stones

    NASA Astrophysics Data System (ADS)

    Jacob, D. E.; Grohe, B.; Hoppe, B.; Beck, B. B.; Tessadri, R.

    2012-04-01

    The primary hyperoxalurias type I - III constitute rare autosomal-recessive inherited disorders of the human glyoxylate metabolism. By mechanisms that are ill understood progressive nephrocalcinosis and recurrent urolithiasis (kidney stone formation) often starting in early childhood, along with their secondary complications results in loss of nephron mass which progresses to end-stage renal failure over time. In the most frequent form, end-stage renal failure (ESRF) is the rule and combined liver/kidney transplantation respectively pre-emptive liver transplantation are the only causative treatment today. Hence, this contributes significantly to healthcare costs and early diagnosis is extremely important for a positive outcome for the patient. We are developing a stone-based diagnostic method by in-detail multi-methods investigation of the crystalline moiety in concert with urine and stone proteomics. Stone analysis will allow faster analysis at low-impact for the patients in the early stages of the disease. First results from combined spectroscopic (Raman, FTIR)and geochemical micro-analyses (Electron Microprobe and Laser Ablation ICP-MS) are presented here that show significant differences between stones from hyperoxaluria patients and those formed by patients without this disorder (idiopathic stones). Major differences exist in chemistry as well as in morphology and phase composition of the stones. Ca/P ratios and Mg contents differentiate between oxalate-stones from hyperoxaluria patients and idiopathic stones. Results show that also within the different subtypes of primary hyperoxaluria significant differences can be found in stone composition. These imply differences in stone formation which could be exploited for new therapeutic pathways. Furthermore, the results provide important feedback for suspected but yet unconfirmed cases of primary hyperoxaluria when used in concert with the genetic methods routinely applied.

  1. Management of Asymptomatic Renal Stones in Astronauts

    NASA Technical Reports Server (NTRS)

    Reyes, David; Locke, James

    2016-01-01

    Introduction: Management guidelines were created to screen and manage asymptomatic renal stones in U.S. astronauts. The risks for renal stone formation in astronauts due to bone loss and hypercalcuria are unknown. Astronauts have a stone risk which is about the same as commercial aviation pilots, which is about half that of the general population. However, proper management of this condition is still crucial to mitigate health and mission risks in the spaceflight environment. Methods: An extensive review of the literature and current aeromedical standards for the monitoring and management of renal stones was done. The NASA Flight Medicine Clinic's electronic medical record and Longitudinal Survey of Astronaut Health were also reviewed. Using this work, a screening and management algorithm was created that takes into consideration the unique operational environment of spaceflight. Results: Renal stone screening and management guidelines for astronauts were created based on accepted standards of care, with consideration to the environment of spaceflight. In the proposed algorithm, all astronauts will receive a yearly screening ultrasound for renal calcifications, or mineralized renal material (MRM). Any areas of MRM, 3 millimeters or larger, are considered a positive finding. Three millimeters approaches the detection limit of standard ultrasound, and several studies have shown that any stone that is 3 millimeters or less has an approximately 95 percent chance of spontaneous passage. For mission-assigned astronauts, any positive ultrasound study is followed by low-dose renal computed tomography (CT) scan, and flexible ureteroscopy if CT is positive. Other specific guidelines were also created. Discussion: The term "MRM" is used to account for small areas of calcification that may be outside the renal collecting system, and allows objectivity without otherwise constraining the diagnostic and treatment process for potentially very small calcifications of uncertain significance. However, a small asymptomatic MRM or stone within the renal collecting system may become symptomatic, and so affect launch and flight schedules, cause incapacitation during flight, and ultimately require medical evacuation. For exploration class missions, evacuation is unlikely. The new screening and management algorithm allows better management of mission risks, and will define the true incidence of renal stones in U.S. astronauts. This information will be used to refine future screening, countermeasures and treatment methods; and will also inform the needed capabilities to be flown on exploration-class missions.

  2. The effects of cooking on wire and stone barbecue at different cooking levels on the formation of heterocyclic aromatic amines and polycyclic aromatic hydrocarbons in beef steak.

    PubMed

    Oz, Fatih; Yuzer, M Onur

    2016-07-15

    The effects of type of barbecue (wire and stone) and cooking levels (rare, medium, well-done and very well-done) on the formation of heterocyclic aromatic amines (HCAs) and polycyclic aromatic hydrocarbons (PAHs) in beef steak were investigated. Varying levels of IQx (up to 0.29ng/g), IQ (up to 0.93ng/g), MeIQx (up to 0.08ng/g), MeIQ (up to 0.75ng/g), 7,8-DiMeIQx (up to 0.08ng/g), 4,8-DiMeIQx (up to 4.95ng/g), PhIP (up to 6.24ng/g) and AαC (up to 0.20ng/g) were determined, while MeAαC was not detected. The total HCA amounts in wire barbecued samples were higher than stone barbecued samples. Total HCA contents of the samples ranged between nd and 13.52ng/g. In terms of PAHs, varying levels of BaA (up to 0.34ng/g), Chry (up to 0.28ng/g), BbF (up to 0.39ng/g), BkF (up to 0.90ng/g), BaP (up to 0.29ng/g) and Bghip (up to 0.43ng/g) were determined, while DahA and IncdP were not detected. The total PAH amounts in stone barbecued samples were higher than those of wire barbecued samples. Total PAH amounts of the samples ranged between nd and 2.63ng/g. PMID:26948589

  3. Targeted microbubbles: a novel application for the treatment of kidney stones

    PubMed Central

    Ramaswamy, Krishna; Marx, Vanessa; Laser, Daniel; Kenny, Thomas; Chi, Thomas; Bailey, Michael; Sorensen, Mathew D.; Grubbs, Robert H.; Stoller, Marshall L.

    2015-01-01

    Kidney stone disease is endemic. Extracorporeal shockwave lithotripsy was the first major technological breakthrough where focused shockwaves were used to fragment stones in the kidney or ureter. The shockwaves induced the formation of cavitation bubbles, whose collapse released energy at the stone, and the energy fragmented the kidney stones into pieces small enough to be passed spontaneously. Can the concept of microbubbles be used without the bulky machine? The logical progression was to manufacture these powerful microbubbles ex vivo and inject these bubbles directly into the collecting system. An external source can be used to induce cavitation once the microbubbles are at their target; the key is targeting these microbubbles to specifically bind to kidney stones. Two important observations have been established: (i) bisphosphonates attach to hydroxyapatite crystals with high affinity; and (ii) there is substantial hydroxyapatite in most kidney stones. The microbubbles can be equipped with bisphosphonate tags to specifically target kidney stones. These bubbles will preferentially bind to the stone and not surrounding tissue, reducing collateral damage. Ultrasound or another suitable form of energy is then applied causing the microbubbles to induce cavitation and fragment the stones. This can be used as an adjunct to ureteroscopy or percutaneous lithotripsy to aid in fragmentation. Randall’s plaques, which also contain hydroxyapatite crystals, can also be targeted to pre-emptively destroy these stone precursors. Additionally, targeted microbubbles can aid in kidney stone diagnostics by virtue of being used as an adjunct to traditional imaging methods, especially useful in high-risk patient populations. This novel application of targeted microbubble technology not only represents the next frontier in minimally invasive stone surgery, but a platform technology for other areas of medicine. PMID:25402588

  4. Treatment Outcomes of Retrograde Intrarenal Surgery for Renal Stones and Predictive Factors of Stone-Free

    PubMed Central

    Lim, Soo Hyun; Jeong, Byong Chang; Seo, Seong Il; Jeon, Seong Soo

    2010-01-01

    Purpose The aim of this study was to evaluate the efficacy and safety of retrograde intrarenal surgery (RIRS) for the treatment of renal stones and to analyze the predictive factors for stone-free. Materials and Methods We retrospectively reviewed the records of patients who underwent RIRS for renal stones from January 2000 to July 2009. We identified 66 RIRSs (63 patients with 3 bilateral renal stones) and collected data. Stone-free and success were respectively defined as no visible stones and clinically insignificant residual stones less than 3 mm on postoperative imaging; predictive factors for stone-free were evaluated. Results Of the 66 renal stones, 18 stones (27.3%) were located in the upper pole or midpole or renal pelvis and 48 (72.7%) in the lower pole with or without others, respectively. The mean cumulative stone burden was 168.9±392.5 mm2. The immediate postoperative stone-free rate was 69.7%, and it increased to 72.7% at 1 month after surgery. The success rate was 80.3% both immediately after the operation and 1 month later. In the multivariate analysis, stone location except at the lower pole (p=0.049) and small cumulative stone burden (p=0.002) were significantly favorable predictive factors for the immediate postoperative stone-free rate. The overall complication rate was 6%. Conclusions RIRS is a safe and effective treatment for renal stones. The stone-free rate of RIRS was particularly high for renal stones with a small burden, except for those located in the lower pole. RIRS could be considered in selective patients with renal stones. PMID:21165199

  5. The exposome for kidney stones.

    PubMed

    Goldfarb, David S

    2016-02-01

    The exposome is the assembly and measure of all the exposures of an individual in a lifetime. An individual's exposures begin before birth and include insults from environmental and occupational sources. The associated field is called exposomics, which relies on the application of internal and external exposure assessment methods. Exposomics has not yet been thoroughly applied to the study of kidney stones although much is known about how diet and fluid intake affect nephrolithiasis. Some other novel exposures that may contribute to kidney stones are discussed including use of antibiotics, urbanization and migration to urban heat islands, and occupation. People whose school and jobs limit their access to fluids and adequate bathroom facilities may have higher prevalence of stones. Examples include athletes, teachers, heathcare workers, and cab drivers. Occupational kidney stones have received scant attention and may represent a neglected, and preventable, type of stone. An exposomic-oriented history would include a careful delineation of occupation and activities. PMID:26615595

  6. Method for fracturing subterranean formations

    SciTech Connect

    Almond, S. W.; Conway, M. W.

    1985-11-19

    The present invention relates to a thermally stable crosslinked gel fracturing fluid for use in the treatment of subterranean formations penetrated by a well bore. The fracturing fluid comprises an aqueous liquid, a gelling agent comprising a selected modified cellulose ether, a crosslinking agent and any additional additives that may be present. The fracturing fluid is thermally stable under shear at temperatures in excess of about 200/sup 0/ F.

  7. Composition and method of stimulating subterranean formations

    SciTech Connect

    Dill, W.R.; Walker, M.L.; Ford, G.F.

    1987-07-14

    This patent describes a method of treating a subterranean formation containing iron comprising contacting a subterranean formation with an aqueous fluid containing a compound consisting essentially of at least one member selected from the group consisting of: dihydroxymaleic acid, salts of dihydroxymaleic acid, glucono-deltalactone present in an amount sufficient to prevent the precipitation of ferric iron during contact with the subterranean formation.

  8. Stone formation in peach fruit exhibits spatial coordination of the lignin and flavonoid pathways and similarity to Arabidopsis dehiscence

    PubMed Central

    2010-01-01

    Background Lignification of the fruit endocarp layer occurs in many angiosperms and plays a critical role in seed protection and dispersal. This process has been extensively studied with relationship to pod shatter or dehiscence in Arabidopsis. Dehiscence is controlled by a set of transcription factors that define the fruit tissue layers and whether or not they lignify. In contrast, relatively little is known about similar processes in other plants such as stone fruits which contain an extremely hard lignified endocarp or stone surrounding a single seed. Results Here we show that lignin deposition in peach initiates near the blossom end within the endocarp layer and proceeds in a distinct spatial-temporal pattern. Microarray studies using a developmental series from young fruits identified a sharp and transient induction of phenylpropanoid, lignin and flavonoid pathway genes concurrent with lignification and subsequent stone hardening. Quantitative polymerase chain reaction studies revealed that specific phenylpropanoid (phenylalanine ammonia-lyase and cinnamate 4-hydroxylase) and lignin (caffeoyl-CoA O-methyltransferase, peroxidase and laccase) pathway genes were induced in the endocarp layer over a 10 day time period, while two lignin genes (p-coumarate 3-hydroxylase and cinnamoyl CoA reductase) were co-regulated with flavonoid pathway genes (chalcone synthase, dihydroflavanol 4-reductase, leucoanthocyanidin dioxygen-ase and flavanone-3-hydrosylase) which were mesocarp and exocarp specific. Analysis of other fruit development expression studies revealed that flavonoid pathway induction is conserved in the related Rosaceae species apple while lignin pathway induction is not. The transcription factor expression of peach genes homologous to known endocarp determinant genes in Arabidopsis including SHATTERPROOF, SEEDSTCK and NAC SECONDARY WALL THICENING PROMOTING FACTOR 1 were found to be specifically expressed in the endocarp while the negative regulator FRUITFUL predominated in exocarp and mesocarp. Conclusions Collectively, the data suggests, first, that the process of endocarp determination and differentiation in peach and Arabidopsis share common regulators and, secondly, reveals a previously unknown coordination of competing lignin and flavonoid biosynthetic pathways during early fruit development. PMID:20144217

  9. A Case of Recurrent Renal Aluminum Hydroxide Stone

    PubMed Central

    Cakıroglu, Basri; Dogan, Akif Nuri; Tas, Tuncay; Gozukucuk, Ramazan; Uyanik, Bekir Sami

    2014-01-01

    Renal stone disease is characterized by the differences depending on the age, gender, and the geographic location of the patients. Seventy-five percent of the renal stone components is the calcium (Ca). The most common type of the stones is the Ca oxalate stones, while Ca phosphate, uric acid, struvite, and sistine stones are more rarely reported. Other than these types, triamterene, adenosine, silica, indinavir, and ephedrine stones are also reported in the literature as case reports. However, to the best of our knowledge, aluminum hydroxide stones was not reported reported before. Herein we will report a 38-years-old woman with the history of recurrent renal colic disease whose renal stone was determined as aluminum hydroxide stone in type. Aluminum mineral may be considered in the formation of kidney stones as it is widely used in the field of healthcare and cosmetics. PMID:25013740

  10. Multielement analysis of human hair and kidney stones by instrumental neutron activation analysis with the k0-standardization method.

    PubMed

    Abugassa, I; Sarmani, S B; Samat, S B

    1999-06-01

    This paper focuses on the evaluation of the k0 method of instrumental neutron activation analysis in biological materials. The method has been applied in multielement analysis of human hair standard reference materials from IAEA, No. 085, No. 086 and from NIES (National Institute for Environmental Sciences) No. 5. Hair samples from people resident in different parts of Malaysia, in addition to a sample from Japan, were analyzed. In addition, human kidney stones from members of the Malaysian population have been analyzed for minor and trace elements. More than 25 elements have been determined. The samples were irradiated in the rotary rack (Lazy Susan) at the TRIGA Mark II reactor of the Malaysian Institute for Nuclear Technology and Research (MINT). The accuracy of the method was ascertained by analysis of other reference materials, including 1573 tomato leaves and 1572 citrus leaves. In this method the deviation of the 1/E1+ alpha epithermal neutron flux distribution from the 1/E law (P/T ratio) for true coincidence effects of the gamma-ray cascade and the HPGe detector efficiency were determined and corrected for. PMID:10355102

  11. A comparison of turtle sampling methods in a small lake in Standing Stone State Park, Overton County, Tennessee

    USGS Publications Warehouse

    Weber, A.; Layzer, James B.

    2011-01-01

    We used basking traps and hoop nets to sample turtles in Standing Stone Lake at 2-week intervals from May to November 2006. In alternate weeks, we conducted visual basking surveys. We collected and observed four species of turtles: spiny softshell (Apalone spinifera), northern map turtle (Graptemys geographica), pond slider (Trachernys scripta), and snapping turtle (Chelydra serpentina). Relative abundances varied greatly among sampling methods. To varying degrees, all methods were species selective. Population estimates from mark and recaptures of three species, basking counts, and hoop net catches indicated that pond sliders were the most abundant species, but northern map turtles were 8× more abundant than pond sliders in basking trap catches. We saw relatively few snapping turtles basking even though population estimates indicated they were the second most abundant species. Populations of all species were dominated by adult individuals. Sex ratios of three species differed significantly from 1:1. Visual surveys were the most efficient method for determining the presence of species, but capture methods were necessary to obtain size and sex data.

  12. Change in inhibitory potential in urine of hyperuricosuric calcium oxalate stone formers effected by allopurinol and orthophosphates.

    PubMed

    Goldwasser, B; Sarig, S; Azoury, R; Wax, Y; Hirsch, D; Perlberg, S; Many, M

    1984-11-01

    Allopurinol and orthophosphates were used in the treatment of 25 hyperuricosuric calcium oxalate stone formers. Their urines were tested by the Discriminating Index method, which measures the potential of a urine to retard calcium oxalate precipitation in vitro. The tests were performed before any treatment was begun and about 10 days after the commencement of drug intake. An insignificant effect by allopurinol and a markedly significant effect of orthophosphates on Discriminating Index were found. In a few of the patients, allopurinol seemed to cause a decrease in the urine's potential to retard calcium oxalate precipitation. Therefore the effect of allopurinol in 11 hyperuricosuric patients with no history of calcium oxalate stone formation was tested. In 5 of the 11 patients, the urine's potential to retard calcium oxalate precipitation decreased to levels similar to those of calcium oxalate stone formers. The results of this study suggest that hyperuricosuric calcium oxalate stone formers suffer from the same yet-undefined etiology of stone formation as other calcium oxalate stone formers. The results also question the role of uric acid in calcium oxalate stone formation and the efficacy of allopurinol in preventing this disease. It is suggested that allopurinol may even be related to stone formation in some patients. PMID:6492268

  13. Nutrition and renal stone disease in space

    NASA Technical Reports Server (NTRS)

    Zerwekh, Joseph E.

    2002-01-01

    There is a growing body of evidence from the National Aeronautics and Space Administration and the Russian space program showing that humans exposed to the microgravity environment of space have a greater risk for developing renal stones. Increased bone resorption and the attendant hypercalciuria and hyperphosphaturia contribute significantly to raising the urinary state of saturation with respect to the calcium salts, namely calcium oxalate and calcium phosphate. In addition, other environmental and dietary factors may adversely affect urine composition and increase stone formation risk during space flight. For example, reductions in urinary volume, pH, and citrate contribute to raising stone formation risk. In addition to raising the risk for calcium stone formation, this metabolic profile is conducive to the formation of uric acid stones. Although observations to date have suggested that there may actually be a reduced food intake during the early phase of flight, crew members on longer-duration flights may increase food intake and be at increased risk for stone formation. Taken together, these findings support the use of nutritional recommendations for crew members that would serve to reduce the stone-forming propensity of the urinary environment. Pharmacologic intervention should be directed at raising urinary volumes, diminishing bone losses, and preventing reductions in urinary pH and citrate. Success in reducing the risk for stone formation in astronauts would also be of potential major benefit to the estimated 20 million Americans with nephrolithiasis.

  14. Relationship of roughness of building stones on the effective thermal conductivity determined by transient hot-wire method

    NASA Astrophysics Data System (ADS)

    Benoit, Merckx; Jean-Didier, Mertz; Patrick, Dudoignon; David, Giovannacci; Jean-Philippe, Garnier

    2013-04-01

    Alteration of inorganic materials in monuments is mainly related to relative humidity change in the porous network. Characterization of water content is a complex issue, specially in case of non-intrusive measurement. An innovative method is developed to quantify the water content using a direct calculation of the thermal conductivity. In order to validate the non-intrusive application to heritage stone, a control of the influence of the rock-sensor interface is required. The study was carried out on five sedimentary french rocks : three limestones (lithographic, oolithic and micritic), a sandstone of Fontainebleau and the so-called Tuffeau limestone. The textural properties are characterized by optical and electronical microscopy, X-ray diffraction, and mercury intrusion porosimetry. The transient hot-wire method is useful to obtain a quick value of effective conductivity of material. Initially used in liquids and gas, It's now more and more used for solid materials. The calculation of one effective thermal conductivity is formulated by the slope of recorded DT/ln(t) diagrams. In case of continuous and homogeneous media, only one slope can be measured. For heterogeneous solids a typical curve present two slopes : the first one measured in the short time acquisitions (<1s) mainly depends on the contact between the wire and grains and thus micro texture of the material. The second one, measured for longer time acquisitions, characterizes the mean effective thermal conductivity of the material. In the case of surface measurement, the first part of curve is relevant from the texture and roughness of the material. Roughness properties are determined by an interferometer system on different polished surfaces of the materials. For all studied stones, the arithmetic average roughness (Sa) is ranged between 44 µm and 1 µm, respectively for the coarse-grained limestone (Bretigny) and the finest one (Migné). According to the relative error of the apparatus (10%), the conductivity value is constant, independently of the surface polishing state. Thus, this evolution confirms that the method could be used on many stony materials as they are present in the built cultural heritage.

  15. Visceral obesity: A new risk factor for stone disease

    PubMed Central

    Akarken, Ilker; Tarhan, Hüseyin; Ekin, Rahmi Gökhan; Çakmak, Özgür; Koç, Gökan; İlbey, Yusuf Özlem; Zorlu, Ferruh

    2015-01-01

    Introduction: We examined the relationship between stone disease and the amount of visceral adipose tissue measured with unenhanced computed tomography (CT). Methods: We included 149 patients with complaints of flank pain and kidney stones detected by CT, from August 2012 to April 2013. In addition, as the control group we included 139 healthy individuals, with flank pain within the same time period, with no previous history of urological disease and no current kidney stones identified by CT. Patients were analyzed for age, gender, body mass index, amount of visceral and subcutaneous adipose tissue, and serum level of low-density lipoprotein and triglyceride. Results: There were no differences between groups in terms of gender and age (p = 0.27 and 0.06, respectively). Respective measurements for the stone and control groups for body mass index were 29.1 and 27.6 kg/m2; for visceral fat measurement 186.0 and 120.2 cm2; and for subcutaneous fat measurements 275.9 and 261.9 cm2 (p = 0.01; 0.01 and 0.36, respectively). Using multivariate analysis, the following factors were identified as increasing the risk of kidney stone formation: hyperlipidemia (p = 0.003), hypertension (p = 0.001), and ratio of visceral fat tissue to subcutaneous fat tissue (p = 0.01). Our study has its limitations, including its retrospective nature, its small sample size, possible selection bias, and missing data. The lack of stone composition data is another major limitation of our study. Conclusion: The ratio of visceral to subcutaneous adipose tissue, in addition to obesity, hyperlipidemia, and hypertension, was identified as an emerging factor in the formation of kidney stones. PMID:26600887

  16. The bioreceptivity of building stone

    NASA Astrophysics Data System (ADS)

    Mauko Pranjić, Alenka; Mulec, Janez; Muck, Tadeja; Hladnik, Aleš; Mladenovič, Ana

    2015-04-01

    Bioreceptivity is an intrinsic property of stone, and is defined as the ability of a material to be colonized by living organisms. The fouling and staining of building stone material due to the activity of microorganisms presents a serious problem in modern as well as historical buildings, not only due to the aesthetic impact but also due to the deterioration of the material. Biological colonisation on stone materials is influenced by a number of factors, e.g. the intrinsic properties of the stone (porosity, roughness, permeability, mineral composition), environmental parameters (e.g. solar radiation, temperature, water regime, climate, etc.), and specific microclimatic parameters (e.g. orientation, exposure to shadow, permanent capillary humidity, etc.). In order to assess the bioreceptivity of building stones, use is often made of artificial colonisation experiments compromising the inoculation of stones with a single species or a few isolated strains under laboratory conditions. In the present work the authors present the development of a method for the determination of bioreceptivity, as well as a study of the bioreceptivity of selected natural stone versus the latter's intrinsic properties. Field examples of biodeterioration are also presented. The study was supported by the Slovenian Research Agency (L1-5453).

  17. Methods for forming wellbores in heated formations

    SciTech Connect

    Guimerans, Rosalvina Ramona; Mansure, Arthur James

    2012-09-25

    A method for forming a wellbore in a heated formation includes flowing liquid cooling fluid to a bottom hole assembly in a wellbore in a heated formation. At least a portion of the liquid cooling fluid is vaporized at or near a region to be cooled. Vaporizing the liquid cooling fluid absorbs heat from the region to be cooled.

  18. Urinary stone composition in Oman: with high incidence of cystinuria.

    PubMed

    Al-Marhoon, Mohammed S; Bayoumi, Riad; Al-Farsi, Yahya; Al-Hinai, Abdullhakeem; Al-Maskary, Sultan; Venkiteswaran, Krishna; Al-Busaidi, Qassim; Mathew, Josephkunju; Rhman, Khalid; Sharif, Omar; Aquil, Shahid; Al-Hashmi, Intisar

    2015-06-01

    Urinary stones are a common problem in Oman and their composition is unknown. The aim of this study is to analyze the components of urinary stones of Omani patients and use the obtained data for future studies of etiology, treatment, and prevention. Urinary stones of 255 consecutive patients were collected at the Sultan Qaboos University Hospital. Stones were analyzed by Fourier transform infrared spectrophotometer. The biochemical, metabolic, and radiological data relating to the patients and stones were collected. The mean age was 41 years, with M:F ratio of 3.7:1. The common comorbidities associated with stone formation were hypertension; diabetes, benign prostate hyperplasia; urinary tract infection; obesity; and atrophic kidney. The common presentation was renal colic and flank pain (96%). Stones were surgically retrieved in 70% of patients. Mean stone size was 9 ± 0.5 mm (range 1.3-80). Stone formers had a BMI ≥ 25 in 56% (P = 0.006) and positive family history of stones in 3.8%. The most common stones in Oman were as follows: Calcium Oxalates 45% (114/255); Mixed calcium phosphates & calcium oxalates 22% (55/255); Uric Acid 16% (40/255); and Cystine 4% (10/255). The most common urinary stones in Oman are Calcium Oxalates. Overweight is an important risk factor associated with stone formation. The hereditary Cystine stones are three times more common in Oman than what is reported in the literature that needs further genetic studies. PMID:25805105

  19. Modern management of common bile duct stones.

    PubMed

    Buxbaum, James

    2013-04-01

    It is imperative for gastroenterologists to understand the different formations of bile duct stones and the various medical treatments available. To minimize the complications of endoscopic retrograde cholangiopancreatography (ERCP), it is critical to appropriately assess the risk of bile duct stones before intervention. Biliary endoscopists should be comfortable with the basic techniques of stone removal, including sphincterotomy, mechanical lithotripsy, and stent placement. It is important to be aware of advanced options, including laser and electrohydraulic stone fragmentation, and papillary dilatation for problematic cases. The timing and need for ERCP in those who require a cholecystectomy is also a consideration. PMID:23540960

  20. Bioremediation of weathered-building stone surfaces.

    PubMed

    Webster, Alison; May, Eric

    2006-06-01

    Atmospheric pollution and weathering of stone surfaces in urban historic buildings frequently results in disfigurement or damage by salt crust formation (often gypsum), presenting opportunities for bioremediation using microorganisms. Conventional techniques for the removal of these salt crusts from stone have several disadvantages: they can cause colour changes; adversely affect the movement of salts within the stone structure; or remove excessive amounts of the original surface. Although microorganisms are commonly associated with detrimental effects to the integrity of stone structures, there is growing evidence that they can be used to treat this type of stone deterioration in objects of historical and cultural significance. In particular, the ability and potential of different microorganisms to either remove sulfate crusts or form sacrificial layers of calcite that consolidate mineral surfaces have been demonstrated. Current research suggests that bioremediation has the potential to offer an additional technology to conservators working to restore stone surfaces in heritage buildings. PMID:16647149

  1. [Prevention of infected urinary stones by urease inhibitor. IV. Treatment of infection stones in rats by a new hydroxamic acid and cefalexin].

    PubMed

    Takeuchi, H; Tomoyoshi, T; Okada, Y; Yoshida, O; Kobashi, K

    1983-03-01

    We investigated the combined effectiveness of a new urease inhibitor, N-( pivaroyl ) glycinohydroxamic acid, with Cefalexin in the treatment of infection stones in rats. Combination therapy with the hydroxamic acid and Cefalexin inhibited bladder stone formation, and dissolved the stone dose dependently, while separate therapy was not significantly effective against stone formation or bacterial growth. This compound may become a useful medicine for the treatment of infection stones. PMID:6375315

  2. Protecting Space Travelers from Kidney Stones: Renal Stone Risk During Space Flight

    NASA Technical Reports Server (NTRS)

    Whitson, Peggy; Bloomberg, Jacob; Lee, Angie (Technical Monitor)

    2002-01-01

    Renal stones, popularly known as kidney or bladder stones, are small rock-like objects formed in the kidneys or urinary tract by deposits of calcium and other minerals. The problem arises when the stones block the drainage of the kidney, resulting in urinary obstruction and pain. Passing these stones can be one of the most painful experiences a person will endure so doctors often prescribe pain relievers to ease the experience. Drinking plenty of fluids, which help flush waste out of the body, and eating a well-balanced diet are the first steps to preventing stones. For individuals at risk, this may not be enough, and a doctor may recommend a special diet and medications. Unfortunately, approximately 60 percent of people who have had a renal stone will experience a recurrence. This is particularly true of men, who are four to five times more likely to develop stones than women. Renal stones do not discriminate based on age; even children are at risk. Astronauts are particularly at risk of developing renal stones because they lose bone and muscle mass; calcium, other minerals, and protein normally used for bone and muscle end up in the bloodstream and then in the kidneys. Without plenty of fluid to wash them away, crystals can form and then grow into stones. This factor compounds the risk for astronauts, since they also perceive that they are less thirsty in space and will drink less than normal during the mission. To minimize all of these factors, doctors must instead treat the stone-forming compounds with medication. This study will use potassium citrate to reduce the risk of stone formation. Renal stones are never convenient, but they are a particular concern for astronauts who have limited access to treatment during flight. Researchers are examining how earthbound preventions for renal stone formation work in flight, ensuring missions are not ended prematurely due to this medical condition. During STS-107, earthbound preventions and treatments become astronauts' gain.

  3. Trace elements in urinary stones: a preliminary investigation in Fars province, Iran.

    PubMed

    Keshavarzi, Behnam; Yavarashayeri, Nasrin; Irani, Dariush; Moore, Farid; Zarasvandi, Alireza; Salari, Mehrdad

    2015-04-01

    In view of the high incidence rate of urinary stones in the south and southwest of Iran, this paper investigates trace elements content including heavy metals in 39 urinary stones, collected from patients in Fars province, Iran. The mineralogy of the stones is investigated using X-ray diffractometry. The samples are classified into five mineral groups (calcium oxalate, uric acid, cystine, calcium phosphate and mixed stone). Major and trace elements in each group were determined using ICP-MS method. P and Ca constitute the main elements in urinary stones with Ca being more affine to oxalates while other alkali and alkaline earths precipitate with phosphate. Significant amounts of trace elements, especially Zn and Sr, were found in urinary calculi (calcium oxalate and phosphates) relative to biominerals (uric acid and cystine). Among urinary calculi, calcium phosphate contains greater amounts of trace metal than calcium oxalate. Phosphates seem to be the most important metal-bearing phases in urinary stones. Results indicate that concentrations of elements in urinary stones depend on the type of mineral phases. Significant differences in elements content across various mineralogical groups were found by applying statistical methods. Kruskal-Wallis test reveals significant difference between Ca, P, K, Na, Mg, S, Zn, Sr, Se, Cd, and Co content in different investigated mineral groups. Moreover, Mann-Whitney test differentiates Ca, Na, Zn, Sr, Co, and Ni between minerals in oxalate and uric acid stones. This study shows that urinary stone can provide complementary information on human exposure to elements and estimate the environmental risks involved in urinary stones formation. PMID:25433503

  4. Estimating the Risk of Renal Stone Events During Long-Duration Spaceflight

    NASA Technical Reports Server (NTRS)

    Reyes, David; Kerstman, Eric; Locke, James

    2014-01-01

    Introduction: Given the bone loss and increased urinary calcium excretion in the microgravity environment, persons participating in long-duration spaceflight may have an increased risk for renal stone formation. Renal stones are often an incidental finding of abdominal imaging studies done for other reasons. Thus, some crewmembers may have undiscovered, asymptomatic stones prior to their mission. Methods: An extensive literature search was conducted concerning the natural history of asymptomatic renal stones. For comparison, simulations were done using the Integrated Medical Model (IMM). The IMM is an evidence-based decision support tool that provides risk analysis and has the capability to optimize medical systems for missions by minimizing the occurrence of adverse mission outcomes such as evacuation and loss of crew life within specified mass and volume constraints. Results: The literature of the natural history of asymptomatic renal stones in the general medical population shows that the probability of symptomatic event is 8% to 34% at 1 to 3 years for stones < 7 mm. Extrapolated to a 6-month mission, for stones < 5 to 7 mm, the risk for any stone event is about 4 to 6%, with a 0.7% to 4% risk for intervention, respectively. IMM simulations compare favorably with risk estimates garnered from the terrestrial literature. The IMM forecasts that symptomatic renal stones may be one of the top drivers for medical evacuation of an International Space Station (ISS) mission. Discussion: Although the likelihood of a stone event is low, the consequences could be severe due to limitations of current ISS medical capabilities. Therefore, these risks need to be quantified to aid planning, limit crew morbidity and mitigate mission impacts. This will be especially critical for missions beyond earth orbit, where evacuation may not be an option.

  5. Surface analysis of stone and bone tools

    NASA Astrophysics Data System (ADS)

    Stemp, W. James; Watson, Adam S.; Evans, Adrian A.

    2016-03-01

    Microwear (use-wear) analysis is a powerful method for identifying tool use that archaeologists and anthropologists employ to determine the activities undertaken by both humans and their hominin ancestors. Knowledge of tool use allows for more accurate and detailed reconstructions of past behavior, particularly in relation to subsistence practices, economic activities, conflict and ritual. It can also be used to document changes in these activities over time, in different locations, and by different members of society, in terms of gender and status, for example. Both stone and bone tools have been analyzed using a variety of techniques that focus on the observation, documentation and interpretation of wear traces. Traditionally, microwear analysis relied on the qualitative assessment of wear features using microscopes and often included comparisons between replicated tools used experimentally and the recovered artifacts, as well as functional analogies dependent upon modern implements and those used by indigenous peoples from various places around the world. Determination of tool use has also relied on the recovery and analysis of both organic and inorganic residues of past worked materials that survived in and on artifact surfaces. To determine tool use and better understand the mechanics of wear formation, particularly on stone and bone, archaeologists and anthropologists have increasingly turned to surface metrology and tribology to assist them in their research. This paper provides a history of the development of traditional microwear analysis in archaeology and anthropology and also explores the introduction and adoption of more modern methods and technologies for documenting and identifying wear on stone and bone tools, specifically those developed for the engineering sciences to study surface structures on micro- and nanoscales. The current state of microwear analysis is discussed as are the future directions in the study of microwear on stone and bone tools.

  6. Management of stone disease in infants.

    PubMed

    Azili, Mujdem Nur; Ozturk, Fatma; Inozu, Mihriban; Çayci, Fatma Şemsa; Acar, Banu; Ozmert, Sengul; Tiryaki, Tugrul

    2015-11-01

    Evaluating and treating renal stone disease in infants are technically challenging. In this study, we evaluated the surgical treatment of renal stones in children under 1 year of age. We retrospectively reviewed the records of patients under 1 year old who were treated with ESWL, endourological or open surgical procedures for renal stone disease between January, 2009 and December, 2012. The patients' age, gender, stone size, stone location and number, complications, stone-free status, and postoperative complications were recorded. 19 of 121 infants with a mean age of 10.2 ± 3.07 months were treated with surgical procedures. Six (75%) of eight cystinuria patients required a surgical intervention. Retrograde endoscopic management was performed in thirteen patients (63.4%) as an initial surgical approach. There were three major (15.7%) complications. The rate of open surgical procedures was 31.6% (6 of 19 infants). The cutoff value of stone size for open surgery was 10 mm. There was a significant relationship between the conversion to open procedures and stone size, stone location, and symptom presentation especially the presence of obstruction (p < 0.05). After repeated treatments, the stone clearance rate of RIRS reached 84.6%. Retrograde intrarenal surgery is an effective and safe treatment method for renal stones in infants and can be used as a first-line therapy in most patients under 1 year old. This is especially important if an associated ureteral stone or lower pole stone that requires treatment is present and for patients with cystinuria, which does not respond favorably to ESWL. PMID:26036325

  7. Management of 1-2 cm renal stones

    PubMed Central

    Srivastava, Aneesh; Chipde, Saurabh S

    2013-01-01

    Introduction: The preferred treatment of >1cm stone is shockwave lithotripsy (SWL), while that of stone <2 cm is percutaneous nephrolithotomy (PCNL), but treatment of 1-2 cm renal stones is a controversial issue. We searched the literature to present a comprehensive review on this group. Material and Methods: Pubmed search of literature was done using the appropriate key words. We separately discussed the literature in lower polar and non lower polar stone groups. Results: For non lower polar renal stones of 1-2 cm, SWL is preferred approach, while for the lower polar stones; literature favors the use of PCNL. Retrograde intrarenal surgery (RIRS) is emerging as a promising technique for these calculi. Conclusions: Treatment of renal stone disease depends on stone and patient related, as well as on renal anatomical factors. Treatment should be individualized according to site of stone and available expertise. PMID:24082440

  8. The Policy Dispositif: Historical Formation and Method

    ERIC Educational Resources Information Center

    Bailey, Patrick L. J.

    2013-01-01

    This paper proposes a new way of conceptualising education policy and also begins to develop a new method of policy analysis. In both instances, it draws on the theoretical and conceptual tools of Foucault, and in particular his concept "dispositif." It posits an historical and ontological formation -- a policy dispositif -- with…

  9. As low as reasonably achievable: Methods for reducing radiation exposure during the management of renal and ureteral stones

    PubMed Central

    Cabrera, Fernando; Preminger, Glenn M.; Lipkin, Michael E.

    2014-01-01

    Imaging for urolithiasis has evolved over the past 30 years. Currently, non-contrast computed tomography (NCCT) remains the first line imaging modality for the evaluation of patients with suspected urolithiasis. NCCT is a dominant source of ionizing radiation for patients and one of its major limitation. However, new low dose NCCT protocols may help to reduce the risk. Fluoroscopy use during operating room (OR) surgical procedures can be a substantial source of radiation for patients, OR staff and surgeons. It is important to consider the amount of radiation patients are exposed to from fluoroscopy during operative interventions for stones. Radiation reduction can be accomplished by appropriate selection of imaging studies and multiple techniques, which minimize the use of fluoroscopy whenever possible. The purpose of this manuscript is to review common imaging modalities used for diagnosing and management of renal and ureteral stones associated with radiation exposure. We also review alternatives and techniques to reduce radiation exposure. PMID:24497684

  10. Analytical method, pattern and sources of polycyclic aromatic hydrocarbons (PAHs) in the stone of the Temples of Agrigento (Italy).

    PubMed

    Orecchio, Santino

    2010-04-15

    This study shows the extraction and analytical conditions for the determination of polycyclic aromatic hydrocarbons (PAHs) in the stone of archaeological and historical interest. The aim of this research was to determine the concentrations, distribution and the main sources of PAHs present in the surface layer of stone of the Temples of Agrigento. Together with PAHs, we analyzed sulphates and nitrates since it has been demonstrated that these are very destructive salts that play an important role in the deterioration of stones. Total PAHs at different sites of the Valley of Temples at Agrigento varied from 18 to 84 microg/kg. Analyses were performed by GC-MS. The relative abundance of molecular weight PAHs, together with the PAHs compound ratios and supported by the total index (by us proposed), demonstrate that the most samples in Hellenistic Agrigento historical buildings owe their PAHs to a predominant single mode of origin, i.e. anthropogenic combustion processes. The same origin of PAHs pollution was confirmed by the good correlations existing between total PAHs concentrations and the content of sulphates and nitrates of the analyzed samples. PMID:19954886

  11. Formation of a pathogen vacuole according to Legionella pneumophila: how to kill one bird with many stones.

    PubMed

    Finsel, Ivo; Hilbi, Hubert

    2015-07-01

    Legionella species are ubiquitous, waterborne bacteria that thrive in numerous ecological niches. Yet, in contrast to many other environmental bacteria, Legionella spp. are also able to grow intracellularly in predatory protozoa. This feature mainly accounts for the pathogenicity of Legionella pneumophila, which causes the majority of clinical cases of a severe pneumonia termed Legionnaires' disease. The pathomechanism underlying L. pneumophila infection is based on macrophage resistance, which in turn is largely defined by the opportunistic pathogen's resistance towards amoebae. L. pneumophila replicates in macrophages or amoebae in a unique membrane-bound compartment, the Legionella-containing vacuole (LCV). LCV formation requires the bacterial intracellular multiplication/defective for organelle trafficking (Icm/Dot) type IV secretion system and involves a plethora of translocated effector proteins, which subvert pivotal processes in the host cell. Of the ca. 300 different experimentally validated Icm/Dot substrates, about 50 have been studied and attributed a cellular function to date. The versatility and ingenuity of these effectors' mode of actions is striking. In this review, we summarize insight into the cellular functions and biochemical activities of well-characterized L. pneumophila effector proteins and the host pathways they target. Recent studies not only substantially increased our knowledge about pathogen-host interactions, but also shed light on novel biological mechanisms. PMID:25903720

  12. Dietary Intake of Fiber, Fruit, and Vegetables Decrease the Risk of Incident Kidney Stones in Women: A Women's Health Initiative (WHI) Report

    PubMed Central

    Sorensen, Mathew D.; Hsi, Ryan S.; Chi, Thomas; Shara, Nawar; Wactawski-Wende, Jean; Kahn, Arnold J.; Wang, Hong; Hou, Lifang; Stoller, Marshall L.

    2014-01-01

    Purpose We evaluated the relationship between dietary fiber, fruit, and vegetable intake, and the risk of kidney stone formation. Methods Overall, 83,922 postmenopausal women from the WHI Observational Study were included and followed prospectively. Cox proportional hazards regression analyses evaluated the associations between total dietary fiber, fruits, and vegetable intake, and the risk of incident kidney stone formation adjusting for nephrolithiasis risk factors (age, race/ethnicity, geographic region, diabetes mellitus, calcium supplementation, hormone therapy use, body mass index, calibrated caloric intake, and dietary water, sodium, animal protein, and calcium intake). Women with a prior history of kidney stones (3,471 women) were analyzed separately. Results Mean age was 64±7 years, 85% of women were Caucasian and 2,937 women (3.5%) experienced a kidney stone occurrence in 8 years median follow-up. In women with no history of kidney stones, higher total dietary fiber (6-26% decreased risk, p<0.001), higher fruit intake (12-25% decreased risk, p<0.001), and higher vegetable intake (9-22% decreased risk, p=0.002) were associated with a decreased risk of incident kidney stone formation in separate adjusted models. In women with a history of stones, there were no significant protective effects of fiber, fruits, or vegetable intake on the risk of kidney stone recurrence. Conclusions Greater dietary intake of fiber, fruits and vegetables were each associated with a reduced risk of incident kidney stones in postmenopausal women. The protective effects were independent of other known risk factors for kidney stones. In contrast, there was no reduction in risk in women with a history of stones. PMID:24859445

  13. The Initial Appearance of Ashlar Stone in Cyprus. éssues of Provenance and Use

    NASA Astrophysics Data System (ADS)

    Philokyprou, M.

    In Cyprus stone was the primary building material, either as rubble or in a dressed form (called ashlar), since the Neolithic period. Initially stone was used only as rubble but later during the Late Brone Age ashlar stone appeared for the first time on the island. The aim of this paper is the presentation of the results of a systematic research regarding the different types and uses of ashlar stone and the techniques followed during the Late Bronze Age in Cyprus in comparison with other Mediterranean areas. The macroscopic and microscopic examination of selected samples showed that sedimentary rocks of various geological formations were used as ashlars. One, two or even three different types of stones were transported from the quarries nearest to the settlements. Some characteristic methods of stone dressing, such as finishing only the visible faces and creating drafted margins around the face of the ashlar blocks, are to be found not only in Late Bronze Age settlements but also in more recent examples from the last two centuries. The choice of ashlar and the methods of construction can be related to social, religious and political factors and were not only based on aesthetic criteria and practical issues. Thus, the most impressive structural solutions were followed in the construction of temples and public buildings, whereas more simple methods can be observed in residential complexes.

  14. Treatment of the Infected Stone.

    PubMed

    Marien, Tracy; Miller, Nicole L

    2015-11-01

    Infected kidney stones refer to stones that form because of urinary tract infections with urease-producing bacteria, secondarily infected stones of any composition, or stones obstructing the urinary tract leading to pyelonephritis. The mainstay of treatment of infection stones is complete stone removal. Kidney stones that obstruct the urinary tract and cause obstructive pyelonephritis are also frequently referred to as infected stones. Obstructive pyelonephritis is a urologic emergency as it can result in sepsis and even death. Infection stones and obstructive stones causing pyelonephritis are different disease processes, and their workup and management are described separately. PMID:26475943

  15. Intravesical Migration of Missed Intrauterine Device Associated with Stone Formation: A Case Report and Review of the Literature

    PubMed Central

    Kart, Mcahit; Glecen, Turgay; stner, Murat; ifti, Seyfettin; Yavuz, Ufuk; zkrkgil, Cneyd

    2015-01-01

    Intrauterine device is the most widely used method of reversible contraception. It may cause various complications including perforation of uterus. In this case, 44-year-old woman was presented with lower urinary tract symptoms after six years of insertion. Patient has no remarkable physical or laboratory finding but abdominal ultrasound revealed a 27?mm hyperechogenicity, suggestive of foreign body or calculus on the posterior bladder wall which was removed endoscopically. This case highlights the need of immediate and periodic evaluation of women with intrauterine device to avoid missing serious complications. PMID:26246932

  16. Intravesical Migration of Missed Intrauterine Device Associated with Stone Formation: A Case Report and Review of the Literature.

    PubMed

    Kart, Mcahit; Glecen, Turgay; stner, Murat; ifti, Seyfettin; Yavuz, Ufuk; zkrkgil, Cneyd

    2015-01-01

    Intrauterine device is the most widely used method of reversible contraception. It may cause various complications including perforation of uterus. In this case, 44-year-old woman was presented with lower urinary tract symptoms after six years of insertion. Patient has no remarkable physical or laboratory finding but abdominal ultrasound revealed a 27?mm hyperechogenicity, suggestive of foreign body or calculus on the posterior bladder wall which was removed endoscopically. This case highlights the need of immediate and periodic evaluation of women with intrauterine device to avoid missing serious complications. PMID:26246932

  17. Method For Screening Microcrystallizations For Crystal Formation

    SciTech Connect

    Santarsiero, Bernard D. , Stevens, Raymond C. , Schultz, Peter G. , Jaklevic, Joseph M. , Yegian, Derek T. , Cornell, Earl W. , Nordmeyer, Robert A.

    2003-10-07

    A method is provided for performing array microcrystallizations to determine suitable crystallization conditions for a molecule, the method comprising: forming an array of microcrystallizations, each microcrystallization comprising a drop comprising a mother liquor solution whose composition varies within the array and a molecule to be crystallized, the drop having a volume of less than 1 microliter; storing the array of microcrystallizations under conditions suitable for molecule crystals to form in the drops in the array; and detecting molecule crystal formation in the drops by taking images of the drops.

  18. Idiopathic calcium nephrolithiasis. 1. Differences in urine crystalloids, urine saturation with brushite and urine inhibitors of calcification between persons with and persons without recurrent kidney stone formation.

    PubMed Central

    Pylypchuk, G.; Ehrig, U.; Wilson, D. R.

    1979-01-01

    The propensity of urine to promote calcium stone formation was compared in 64 patients with recurrent idiopathic calcium nephrolithiasis and 30 healthy individuals without such a history. The rates of excretion of urine crystalloids, the urine saturation with brushite (CaHPO4-2H2O), the ability of the urine to calcify collagen in vitro, and the concentration of urine inhibitors of collagen calcification were measured. The patients had a reduced urine citrate excretion rate in addition to an increased urine calcium excretion rate, while the rates for urine magnesium, phosphate, uric acid and oxalate were not significantly different in the two groups of subjects. The urine concentration of magnesium, phosphate and uric acid was decreased in the patients because of the higher urine volume. The urine creatinine excretion rate correlated with the rates of excretion of urine calcium, magnesium, phosphate, uric acid and oxalate in both groups, which suggested that increased lean body mass, possibly associated with greater food intake, may be an important determinant of crystalloid excretion. The urine of the patients was significantly more saturated with brushite than the urine of the control subjects and resulted in greater collagen calcification when incubated in vitro. The urine concentration of inhibitors of collagen calcification, however, was not significantly different in the two groups. Thus, the urine of patients with recurrent idiopathic calcium nephrolithiasis is more highly saturated with brushite, largely as a result of an increased urine calcium excretion rate, and contains a lower concentration of magnesium and citrate, substances that tend to prevent the precipitation and growth of crystals in urine. PMID:436047

  19. Factors governing urinary tract stone disease.

    PubMed

    Watts, R W

    1989-07-01

    Urinary stone formation depends on the degree of saturation of the urine with respect to potential stone-forming substances. Urine contains a range of electrolytes which ionise to different and variable degrees and which interact with one another in ways which influence their solubilities. These ionisations are themselves influenced by the pH of the urine which is another variable factor. Urinary organic molecules, which may or may not ionise and which may bear surface charges, also influence the solubility of the low molecular weight stone-constituents. Some other substances in the urine, such as glycosaminoglycans, can modify the ability of inorganic micro-crystals to aggregate and form stones. Environmental factors, other urinary tract pathology and genetic influences all predispose to urolithiasis, but many cases lack either an identifiable specific cause or the presence of recognisable risk factors. In the risk factor model of calcium stone formation there are pre-renal risk factors which lead to urinary risk factors and hence to the chemical risk factors of supersaturation and decreased ability to inhibit crystallisation. There are, in addition to these general factors which may act synergistically to produce urinary stones, several specific single enzyme defects which alter the urinary composition in such a way as to produce stones of a highly characteristic composition. PMID:2702116

  20. Shock Wave Lithotripsy in Ureteral Stones: Evaluation of Patient and Stone Related Predictive Factors

    PubMed Central

    Yazici, Ozgur; Tuncer, Murat; Sahin, Cahit; Demirkol, Mehmet K.; Kafkasli, Alper; Sarica, Kemal

    2015-01-01

    ABSTRACT Purpose: To evaluate the patient and stone related factors which may influence the final outcome of SWL in the management of ureteral stones. Materials and Methods: Between October 2011 and October 2013, a total of 204 adult patients undergoing SWL for single ureteral stone sizing 5 to 15 mm were included into the study program. The impact of both patient (age, sex, BMI,) and stone related factors (laterality, location, longest diameter and density as CT HU) along with BUN and lastly SSD (skin to stone distance) on fragmentation were analysed by univariate and multivariate analyses. Results: Stone free rates for proximal and distal ureteral stones were 68.8% and 72.7%, respectively with no statistically significant difference between two groups (p=0.7). According to univariate and multivariate analyses, while higher BMI (mean: 26.8 and 28.1, p=0.048) and stone density values (mean: 702 HU and 930 HU, p<0.0001) were detected as statistically significant independent predictors of treatment failure for proximal ureteral stones, the only statistically significant predicting parameter for the success rates of SWL in distal ureteral stones was the higher SSD value (median: 114 and 90, p=0.012). Conclusions: Our findings have clearly shown that while higher BMI and increased stone attenuation values detected by NCCT were significant factors influencing the final outcome of SWL treatment in proximal ureteral stones; opposite to the literature, high SSD was the only independent predictor of success for the SWL treatment of distal ureteral stones. PMID:26401859

  1. Patients with recurrent renal stones have a physico-chemically altered urinary Tamm-Horsfall glycoprotein profile.

    PubMed

    Jefferson, A; Reynolds, T M; Elves, A; Wierzbicki, A S

    1996-11-01

    We describe an immunoblotting method for examining the electrophoretic properties of urinary Tamm-Horsfall protein. Using this method we tested frozen urine samples from a group of 37 thoroughly investigated recurrent idiopathic renal calcium stone formers and compared this with fresh urine from 19 non-stone forming laboratory staff. We found that there was a statistically significant different pattern of Tamm-Horsfall protein bands in the two sets of urines, with stone formers tending to have two bands and non-stone formers tending to have three bands. This could have been due to storage artefact and therefore a further group of 13 fresh urines from unselected renal stone formers was tested. A smaller proportion of these cases showed the two-band pattern, possibly because not all of this group were idiopathic calcium stone formers. This suggests that but does not prove that there is no significant storage artefact and that there may be an in vivo effect causing stone formation. PMID:8937586

  2. Dilute Surfactant Methods for Carbonate Formations

    SciTech Connect

    Kishore K. Mohanty

    2005-10-01

    There are many carbonate reservoirs in US (and the world) with light oil and fracture pressure below its minimum miscibility pressure (or reservoir may be naturally fractured). Many carbonate reservoirs are naturally fractured. Waterflooding is effective in fractured reservoirs, if the formation is water-wet. Many fractured carbonate reservoirs, however, are mixed-wet and recoveries with conventional methods are low (less than 10%). Thermal and miscible tertiary recovery techniques are not effective in these reservoirs. Surfactant flooding (or huff-n-puff) is the best hope, yet it was developed for sandstone reservoirs in the past. The goal of this research is to evaluate dilute (hence relatively inexpensive) surfactant methods for carbonate formations and identify conditions under which they can be effective. Laboratory-scale surfactant brine imbibition experiments give high oil recovery (35-62% OOIP) for initially oil-wet cores through wettability alteration and IFT reduction. Core-scale simulation results match those of the experiments. Initial capillarity-driven imbibition gives way to a final gravity-driven process. As the matrix block height increases, surfactant alters wettability to a lesser degree, or permeability decreases, oil production rate decreases. The scale-up to field scale will be further studied in the next quarter.

  3. DILUTE SURFACTANT METHODS FOR CARBONATE FORMATIONS

    SciTech Connect

    Kishore K. Mohanty

    2005-04-01

    There are many carbonate reservoirs in US (and the world) with light oil and fracture pressure below its minimum miscibility pressure (or reservoir may be naturally fractured). Many carbonate reservoirs are naturally fractured. Waterflooding is effective in fractured reservoirs, if the formation is water-wet. Many fractured carbonate reservoirs, however, are mixed-wet and recoveries with conventional methods are low (less than 10%). Thermal and miscible tertiary recovery techniques are not effective in these reservoirs. Surfactant flooding (or huff-n-puff) is the only hope, yet it was developed for sandstone reservoirs in the past. The goal of this research is to evaluate dilute (hence relatively inexpensive) surfactant methods for carbonate formations and identify conditions under which they can be effective. Laboratory imbibition tests show about 61% oil recovery in the case of Alf-38 and 37% in the case of DTAB. A numerical model has been developed that fits the rate of imbibition of the laboratory experiment. Field-scale fracture block simulation shows that as the fracture spacing increases, so does the time of recovery. Plans for the next quarter include simulation studies.

  4. DILUTE SURFACTANT METHODS FOR CARBONATE FORMATIONS

    SciTech Connect

    Kishore K. Mohanty

    2003-01-01

    There are many carbonate reservoirs in US (and the world) with light oil and fracture pressure below its minimum miscibility pressure (or reservoir may be naturally fractured). Many carbonate reservoirs are naturally fractured. Waterflooding is effective in fractured reservoirs, if the formation is water-wet. Many fractured carbonate reservoirs, however, are mixed-wet and recoveries with conventional methods are low (less than 10%). Thermal and miscible tertiary recovery techniques are not effective in these reservoirs. Surfactant flooding (or huff-n-puff) is the only hope, yet it was developed for sandstone reservoirs in the past. The goal of this research is to evaluate dilute (hence relatively inexpensive) surfactant methods for carbonate formations and identify conditions under which they can be effective. We have acquired field oil and core samples and field brine compositions from Marathon. We have conducted preliminary adsorption and wettability studies. Addition of Na{sub 2}CO{sub 3} decreases anionic surfactant adsorption on calcite surface. Receding contact angles increase with surfactant adsorption. Plans for the next quarter include conducting adsorption, phase behavior and wettability studies.

  5. DILUTE SURFACTANT METHODS FOR CARBONATE FORMATIONS

    SciTech Connect

    Kishore K. Mohanty

    2003-07-01

    There are many carbonate reservoirs in US (and the world) with light oil and fracture pressure below its minimum miscibility pressure (or reservoir may be naturally fractured). Many carbonate reservoirs are naturally fractured. Waterflooding is effective in fractured reservoirs, if the formation is water-wet. Many fractured carbonate reservoirs, however, are mixed-wet and recoveries with conventional methods are low (less than 10%). Thermal and miscible tertiary recovery techniques are not effective in these reservoirs. Surfactant flooding (or huff-n-puff) is the only hope, yet it was developed for sandstone reservoirs in the past. The goal of this research is to evaluate dilute (hence relatively inexpensive) surfactant methods for carbonate formations and identify conditions under which they can be effective. We have conducted adsorption, phase behavior and wettability studies. Addition of Na{sub 2}CO{sub 3} decreases IFT with a minimum at about 0.2 M. Addition of surfactant decreases IFT further. In the absence of surfactant the minerals are oil wet after aging with crude oil. Addition of surfactant solution decreases the contact angle to intermediate wettability. Addition of Na{sub 2}CO{sub 3} decreases anionic surfactant adsorption on calcite surface. Plans for the next quarter include conducting adsorption, phase behavior and wettability studies.

  6. DILUTE SURFACTANT METHODS FOR CARBONATE FORMATIONS

    SciTech Connect

    Kishore K. Mohanty

    2003-07-01

    There are many carbonate reservoirs in US (and the world) with light oil and fracture pressure below its minimum miscibility pressure (or reservoir may be naturally fractured). Many carbonate reservoirs are naturally fractured. Waterflooding is effective in fractured reservoirs, if the formation is water-wet. Many fractured carbonate reservoirs, however, are mixed-wet and recoveries with conventional methods are low (less than 10%). Thermal and miscible tertiary recovery techniques are not effective in these reservoirs. Surfactant flooding (or huff-n-puff) is the only hope, yet it was developed for sandstone reservoirs in the past. The goal of this research is to evaluate dilute (hence relatively inexpensive) surfactant methods for carbonate formations and identify conditions under which they can be effective. We have conducted adsorption, phase behavior, interfacial tension (IFT) and wettability studies. Addition of Na{sub 2}CO{sub 3} decreases IFT with a minimum at about 0.2 M. Addition of surfactant decreases IFT further. In the absence of surfactant the minerals are oil-wet after aging with crude oil. Addition of surfactant solution decreases the contact angle to intermediate-wet for many surfactants and water-wet for one surfactant. Addition of Na{sub 2}CO{sub 3} decreases anionic surfactant adsorption on calcite surface. Plans for the next quarter include conducting core adsorption, phase behavior, wettability and mobilization studies.

  7. DILUTE SURFACTANT METHODS FOR CARBONATE FORMATIONS

    SciTech Connect

    Kishore K. Mohanty

    2003-10-01

    There are many carbonate reservoirs in US (and the world) with light oil and fracture pressure below its minimum miscibility pressure (or reservoir may be naturally fractured). Many carbonate reservoirs are naturally fractured. Waterflooding is effective in fractured reservoirs, if the formation is water-wet. Many fractured carbonate reservoirs, however, are mixed-wet and recoveries with conventional methods are low (less than 10%). Thermal and miscible tertiary recovery techniques are not effective in these reservoirs. Surfactant flooding (or huff-n-puff) is the only hope, yet it was developed for sandstone reservoirs in the past. The goal of this research is to evaluate dilute (hence relatively inexpensive) surfactant methods for carbonate formations and identify conditions under which they can be effective. We have conducted adsorption, phase behavior, interfacial tension (IFT) and wettability studies. Alfoterra-38 (0.05 wt%), Alfoterra-35 (0.05 wt%), SS-6656 (0.05 wt%), and DTAB (1 wt%) altered the wettability of the initially oil-wet calcite plate to an intermediate/water-wet state. Low IFT ({approx}10{sup -3} dynes/cm) is obtained with surfactants 5-166, Alfoterra-33 and Alfoterra-38. Plans for the next quarter include conducting wettability and mobilization studies.

  8. DILUTE SURFACTANT METHODS FOR CARBONATE FORMATIONS

    SciTech Connect

    Kishore K. Mohanty

    2005-07-01

    There are many carbonate reservoirs in US (and the world) with light oil and fracture pressure below its minimum miscibility pressure (or reservoir may be naturally fractured). Many carbonate reservoirs are naturally fractured. Waterflooding is effective in fractured reservoirs, if the formation is water-wet. Many fractured carbonate reservoirs, however, are mixed-wet and recoveries with conventional methods are low (less than 10%). Thermal and miscible tertiary recovery techniques are not effective in these reservoirs. Surfactant flooding (or huff-n-puff) is the only hope, yet it was developed for sandstone reservoirs in the past. The goal of this research is to evaluate dilute (hence relatively inexpensive) surfactant methods for carbonate formations and identify conditions under which they can be effective. Laboratory imbibition tests show that imbibition rate is not very sensitive to the surfactant concentration (in the range of 0.05-0.2 wt%) and small amounts of trapped gas saturation. It is however very sensitive to oil permeability and water-oil-ratio. Less than 0.5 M Na2CO3 is needed for in situ soap generation and low adsorption; NaCl can be added to reach the necessary total salinity. The simulation result matches the laboratory imbibition experimental data. Small fracture spacing and high permeability would be needed for high rate of recovery.

  9. Dilute Surfactant Methods for Carbonate Formations

    SciTech Connect

    Kishore K. Mohanty

    2004-03-31

    There are many carbonate reservoirs in US (and the world) with light oil and fracture pressure below its minimum miscibility pressure (or reservoir may be naturally fractured). Many carbonate reservoirs are naturally fractured. Waterflooding is effective in fractured reservoirs, if the formation is water-wet. Many fractured carbonate reservoirs, however, are mixed-wet and recoveries with conventional methods are low (less than 10%). Thermal and miscible tertiary recovery techniques are not effective in these reservoirs. Surfactant flooding (or huff-n-puff) is the only hope, yet it was developed for sandstone reservoirs in the past. The goal of this research is to evaluate dilute (hence relatively inexpensive) surfactant methods for carbonate formations and identify conditions under which they can be effective. Anionic surfactants (Alfoterra 35, 38) recover more than 40% of the oil in about 50 days by imbibition driven by wettability alteration in the core-scale. Anionic surfactant, Alfoterra-68, recovers about 28% of the oil by lower tension aided gravity-driven imbibition in the core-scale. Residual oil saturation showed little capillary number dependence between 10{sup -5} and 10{sup -2}. Wettability alteration increases as the number of ethoxy groups increases in ethoxy sulfate surfactants. Plans for the next quarter include conducting mobilization, and imbibition studies.

  10. DILUTE SURFACTANT METHODS FOR CARBONATE FORMATIONS

    SciTech Connect

    Kishore K. Mohanty

    2004-01-01

    There are many carbonate reservoirs in US (and the world) with light oil and fracture pressure below its minimum miscibility pressure (or reservoir may be naturally fractured). Many carbonate reservoirs are naturally fractured. Waterflooding is effective in fractured reservoirs, if the formation is water-wet. Many fractured carbonate reservoirs, however, are mixed-wet and recoveries with conventional methods are low (less than 10%). Thermal and miscible tertiary recovery techniques are not effective in these reservoirs. Surfactant flooding (or huff-n-puff) is the only hope, yet it was developed for sandstone reservoirs in the past. The goal of this research is to evaluate dilute (hence relatively inexpensive) surfactant methods for carbonate formations and identify conditions under which they can be effective. Anionic surfactants (SS-6656, Alfoterra 35, 38, 63,65,68) have been identified which can change the wettability of the calcite surface to intermediate/water-wet condition as well or better than the cationic surfactant DTAB with a West Texas crude oil in the presence of Na{sub 2}CO{sub 3}. All the carbonate surfaces (Lithographic Limestone, Marble, Dolomite and Calcite) show similar behavior with respect to wettability alteration with surfactant 4-22. Anionic surfactants (5-166, Alfoterra-33 and Alfoterra-38 and Alfoterra-68), which lower the interfacial tension with a West Texas crude oil to very low values (<10{sup -2} nM/m), have also been identified. Plans for the next quarter include conducting wettability, mobilization, and imbibition studies.

  11. DILUTE SURFACTANT METHODS FOR CARBONATE FORMATIONS

    SciTech Connect

    Kishore K. Mohanty

    2005-01-01

    There are many carbonate reservoirs in US (and the world) with light oil and fracture pressure below its minimum miscibility pressure (or reservoir may be naturally fractured). Many carbonate reservoirs are naturally fractured. Waterflooding is effective in fractured reservoirs, if the formation is water-wet. Many fractured carbonate reservoirs, however, are mixed-wet and recoveries with conventional methods are low (less than 10%). Thermal and miscible tertiary recovery techniques are not effective in these reservoirs. Surfactant flooding (or huff-n-puff) is the only hope, yet it was developed for sandstone reservoirs in the past. The goal of this research is to evaluate dilute (hence relatively inexpensive) surfactant methods for carbonate formations and identify conditions under which they can be effective. Imbibition in an originally oil-wet 2D capillary is the fastest in the case of Alf-38 and slowest in the case of DTAB (among the surfactants studied). Force of adhesion studies and contact angle measurements show that greater wettability alteration is possible with these anionic surfactants than the cationic surfactant studied. The water imbibition rate does not increase monotonically with an increase in the surfactant concentration. A numerical model has been developed that fits the rate of imbibition. Plans for the next quarter include conducting simulation and imbibition studies.

  12. DILUTE SURFACTANT METHODS FOR CARBONATE FORMATIONS

    SciTech Connect

    Kishore K. Mohanty

    2004-10-01

    There are many carbonate reservoirs in US (and the world) with light oil and fracture pressure below its minimum miscibility pressure (or reservoir may be naturally fractured). Many carbonate reservoirs are naturally fractured. Waterflooding is effective in fractured reservoirs, if the formation is water-wet. Many fractured carbonate reservoirs, however, are mixed-wet and recoveries with conventional methods are low (less than 10%). Thermal and miscible tertiary recovery techniques are not effective in these reservoirs. Surfactant flooding (or huff-n-puff) is the only hope, yet it was developed for sandstone reservoirs in the past. The goal of this research is to evaluate dilute (hence relatively inexpensive) surfactant methods for carbonate formations and identify conditions under which they can be effective. Simulation studies indicate that both wettability alteration and gravity-driven flow play significant role in oil recovery from fractured carbonates. Anionic surfactants (Alfoterra 35, 38) recover about 55% of the oil in about 150 days by imbibition driven by wettability alteration and low tension in the core-scale. Anionic surfactant, Alfoterra-68, recovers about 40% of the oil by lower tension aided gravity-driven imbibition in the core-scale. Cationic surfactant, DTAB recovers about 35% of the oil. Plans for the next quarter include conducting simulation and imbibition studies.

  13. Catechin prevents the calcium oxalate monohydrate induced renal calcium crystallization in NRK-52E cells and the ethylene glycol induced renal stone formation in rat

    PubMed Central

    2013-01-01

    Background Reactive oxygen species play important roles in renal calcium crystallization. In this study, we examined the effects of catechin, which have been shown to have antioxidant properties on the renal calcium crystallization. Methods In the vitro experiment, the changes of the mitochondrial membrane potential, expression of superoxide dismutase (SOD), 4-hydroxynonenal (4-HNE), cytochrome c, and cleaved caspase 3 were measured to show the effects of catechin treatment on the NRK-52E cells induced by calcium oxalate monohydrate (COM). In the vivo study, Sprague–Dawley rats were administered 1% ethylene glycol (EG) to generate a rat kidney stone model and then treated with catechin (2.5 and 10 mg/kg/day) for 14 days. The urine and serum variables were dected on 7 and 14 days after EG administration. The expression of cytochrome c, cleaved caspase 3, SOD, osteopontin (OPN), malondialdehyde (MDA), 8-hydroxy-2′-deoxyguanosine (8-OHdG) in kidney were measured. Furthermore, the mitochondrial microstructure in the kidney was also examined by transmission electron microscopy. Results Catechin treatment could prevent the changes in mitochondrial membrane potential and expression of SOD, 4-HNE, cytochrome c, and cleaved caspase 3 in NRK-52E cells induced by the COM. For the in vivo experiments, the EG administration induced renal calcium crystallization was also prevented by the catechin. The expression of SOD, OPN, MDA, OPN and 8-OHdG, were increased after EG administration and this increase was diminished by catechin. Moreover, catechin also prevented EG induced mitochondrial collapse in rat. Conclusions Catechin has preventive effects on renal calcium crystallization both in vivo and in vitro, and provide a potential therapeutic treatment for this disease. PMID:24044655

  14. Managing caliceal stones

    PubMed Central

    Gross, Andreas J.; Knipper, Sophie; Netsch, Christopher

    2014-01-01

    The natural course of untreated asymptomatic caliceal calculi has not been clearly defined, especially in terms of disease progression, and the indications for and outcomes of surgical intervention are not precise. Caliceal stones may remain asymptomatic but, in case of migration, ureteral calculi can cause acute ureteric colic with severe complications. The decision for an active treatment of caliceal calculi is based on stone composition, stone size and symptoms. Extracorporal shock-wave lithotripsy (ESWL) has a low complication rate and is recommended by the current guidelines of the European Association of Urology as a first-line therapy for the treatment of caliceal stones <2 cm in diameter. However, immediate stone removal is not achieved with ESWL. The primary stone-free rates (SFR) after ESWL depend on stone site and composition and, especially for lower pole calculi, the SFR differ widely from other caliceal stones. Minimally-invasive procedures including percutaneous nephrolithotomy and ureteroscopy are alternatives for the treatment of caliceal stones, associated with low morbidity and high primary SFR when performed in centers of excellence. PMID:24497690

  15. INACCURATE REPORTING OF MINERAL COMPOSITION BY COMMERCIAL STONE ANALYSIS LABORATORIES: IMPLICATIONS FOR INFECTION AND METABOLIC STONES

    PubMed Central

    Krambeck, Amy E.; Khan, Naseem F.; Jackson, Molly E.; Lingeman, James E.; McAteer, James A; Williams, James C.

    2011-01-01

    INTRODUCTION The goal of this study was to determine the accuracy of stone composition analysis by commercial laboratories. METHODS 25 human renal stones with infrared spectroscopy (IR) determined compositions were fragmented into aliquots and studied with micro-computed tomography (CT) to ensure fragment similarity. Representative fragments of each stone were submitted to 5 commercial stone laboratories for blinded analysis. RESULTS All laboratories agreed on composition for 6 pure stones. Of 4 stones known to contain struvite, only 2(50%) were identified as struvite by all laboratories. Struvite was reported as a component by some laboratories for 4 stones previously determined not to contain struvite. Overall, there was disagreement regarding struvite in 6(24%) stones. For 9 calcium oxalate (CaOx) stones, all laboratories reported some mixture of CaOx, but the quantities of subtypes differed significantly among laboratories. In 6 apatite containing stones, apatite was missed by the laboratories in 20% of the samples. None of the laboratories identified atazanavir in a stone containing that antiviral drug. One laboratory reported protein in every sample, while all others reported it in only 1 sample. Nomenclature for apatite differed among laboratories, with one reporting apatite as carbonate apatite (CA) and never hydroxyapatite (HA), another never reporting CA and always reporting HA, and a third reporting CA as apatite with calcium carbonate. CONCLUSIONS Commercial laboratories reliably recognize pure calculi; however, variability in reporting of mixed calculi suggests a problem with accuracy of stone analysis results. Furthermore, there is a lack of standard nomenclature used by laboratories. PMID:20728108

  16. Prediction of calcium oxalate monohydrate stone composition during ureteroscopy

    NASA Astrophysics Data System (ADS)

    Hamidizedah, Reza; Melnyk, Megan; Teichman, Joel M. H.

    2012-02-01

    Introduction: Prior research shows that Ho:YAG lithotripsy produces tiny dust fragments at low pulse energy (0.2J). However, calcium oxalate monohydrate (COM) stones may not fragment at this low pulse energy setting. Stone composition is rarely known until after surgery and historically, attempts to predict stone composition on the basis of endoscopic stone appearance were unsuccessful. Current endoscopic technology permits visual details that previously were not evident. As COM appears black under ambient light, we attempt to predict COM stone composition at the time of ureteroscopy based on its endoscopic appearance. Methods: Consecutive subjects undergoing ureteroscopy for stone disease were studied. Any portion of the stone that appeared black under endoscopic vision was considered clinical evidence of COM. Predicted stone composition was correlated with post-operative calculus analysis. Results: 46 consecutive ureteroscopic stone cases were analyzed prospectively. 25 of 28 subjects (89%) with black stones had stones later proven to be COM by composition analysis, versus one of 18 patients (6%) with non-black stones that were COM (p<0.0001). A black endoscopic stone appearance had a positive predictive value for COM of 89% and a non-black endoscopic stone appearance had a negative predictive value for COM of 94% (sensitivity 96%, specificity 83%). Conclusions: COM may reasonably be predicted intra-operatively by its black endoscopic appearance. The clinical utility would be to use higher laser pulse energy settings than for non-COM compositions. This data raises the possibility that more sophisticated optical characterization of endoscopic stone appearance may prove to be a useful tool to predict stone composition.

  17. Environmental factors of urinary stones mineralogy, Khouzestan Province, Iran

    NASA Astrophysics Data System (ADS)

    Zarasvandi, Alireza; Carranza, E. J. M.; Heidari, Majid; Mousapour, Esmaeil

    2014-09-01

    Urinary stone diseases in the Khouzestan province (southwest Iran) are growing in number and it required extensive studies on various factors of the urinary stones formation in this province. In this research, in addition to distribution of urinary stones in different areas of province, the role of bioenvironmental (race), climate (temperature) and geology (water hardness) factors in urinary stones diversity has been studied. Mineralogical studied using X-ray diffraction showed that uricite and whewellite are the most frequency mineral phases. Struvite, Cystine, hydroxyapatite, weddellite, and Niahite can be observed as urinary stones, too. These data show that the urinary stone in the Khouzestan province can divide into 7 groups: calcium oxalate, phosphate, calcium oxalate/ phosphate, Urate, Urate/calcium, Urate/calcium oxalate/phosphate, Cystine/calcium oxalate. Also the results which attained from temperature effect investigation on the mineralogy of urinary stones, confirms that from Mediterranean sub-humid climates (northeastern area) to warm and dry climates (south and southwest area), calcium oxalate stones and urate stones concentration decreases and increases respectively. Comparison of data related to the drinking water hardness and mineralogy of urinary stones in different areas of Khouzestan province show that the combination of drinking water (especially water hardness) affects mineralogy of urinary stones in some areas (such az Ramhormoz and Hendijan). Finally, the data suggest that frequency of calcium oxalate in women is more than that of men. Moreover, there is direct relationship between the age (>45 years) and the increase in frequency of Urate minerals.

  18. A Radiographic Correlation between Renal and Pulp Stones

    PubMed Central

    Ertas, E Tarim; Inci, M; Demirtas, A; Ertas, H; Yengil, E; Sisman, Y; Gokce, C

    2014-01-01

    ABSTRACT Aim: The purpose of this study was to determine the correlation between pulp stones and renal stones. This study also aimed to report associations between the presence of pulp stone and gender, age, tooth type, dental arches and sides. Patients and Methods: Data were collected through examination of bitewing radiographs of 116 kidney stone patients and a similar number of age-matched controls, referred to the Department of Oral and Maxillofacial Radiology, Faculty of Dentistry, Erciyes University. Two oral radiologists examined the radiographs to identify pulp stones. The Chi-squared and Mann Whitney U tests were used to investigate the correlations between the presence of pulp chamber calcification and age, gender, dental status and kidney stone. Results: Pulp chamber opacities were detected in 199 (19.3%) out of the 1031 examined teeth, and in 84 (72.4%) out of the 116 kidney stone patients. There was no statistically significant difference between the study and control group (p = 0.882). The occurrence of pulp stones was significantly higher in molars than premolars and similar prevalences were found between dental arches and sides. Conclusion: In this study, no correlation was found between the presence of pulp stones and kidney stones in the investigated group. Therefore, the presence of pulp stones does not seem to be correlated with that of kidney stones. PMID:25803378

  19. Economics of stone disease/treatment

    PubMed Central

    Strohmaier, Walter Ludwig

    2012-01-01

    Objectives Urolithiasis is a considerable economic burden for health systems, especially in industrialised countries where the incidence of stone disease has increased during the last few decades, and probably will further increase for several reasons. Methods The survey was based on investigations in collaboration with a German health insurance company and on a literature search (PubMed, and the author’s collection of proceedings of urolithiasis conferences: The keywords included economics, cost, urolithiasis, nephrolithiasis, renal stone disease, metaphylaxis, recurrence) during 1999–2011. In all, 1221 articles were found but only those cited here were sufficient for the purpose of the study. Due to the nature of the subject it is not possible to give levels of evidence, as economic data on stone treatment cannot be obtained with randomised studies. Results The costs for the treatment and diagnosis of stones vary tremendously among different healthcare systems. Several calculation models showed that metaphylaxis is medically and economically effective when used rationally. Rational metaphylaxis is restricted to patients with a high risk of recurrence (brushite, uric acid, cystine and infected stones, patients with residual fragments after stone treatment and recurrent calcium oxalate stone formers). Conclusions For the groups identified, metaphylaxis is cost-effective in almost all healthcare systems, but the cost saved differs. The savings increase even more when adding the economic loss avoided from days off work due to treatment of recurrent stones. In most countries, stone frequency must exceed one stone per patient per year before medical therapy is more cost-effective than dietary measures. PMID:26558036

  20. The nutrition consult for recurrent stone formers.

    PubMed

    Penniston, Kristina L

    2015-07-01

    Diet is implicated in stone formation and growth. Whether alone or in concert with pharmacologics, dietary changes may be useful in reducing recurrence but only when they correct dietary stone-forming risks. Patients benefit from recommendations individualized to their food preferences as well as to lifestyle, age, food knowledge and access, preparation skills, and cultural and ethnic identities. Urologists can provide general dietary recommendations but often lack the time to provide the full complement of individualized nutrition care offered by a registered dietitian nutritionist (RDN). Urologists can partner with and refer patients to a RDN for any component of the nutrition care process: assessment of diet, diagnosis of dietary factors that contribute to stone risk factors, intervention formulation and implementation, and monitoring the effectiveness of the intervention and modifying it as needed to maintain suitably low dietary risk for stone recurrence. PMID:26025494

  1. Diet for Kidney Stone Prevention

    MedlinePlus

    ... specific type of kidney stone include the following: Calcium Oxalate Stones reducing sodium reducing animal protein, such as ... with increased daily sodium consumption. People who form calcium oxalate or calcium phosphate stones should limit their intake ...

  2. SOURCE ASSESSMENT: CRUSHED STONE

    EPA Science Inventory

    This report describes a study of air emissions from crushed stone production. The potential environmental effect of the source is evaluated. Crushed stone production in 1972 was 1.07 x 10 to the 8th power metric tons (1.18 x 10 to the 8th power tons), 68% of which was traprock. C...

  3. Chimpanzee accumulative stone throwing.

    PubMed

    Kühl, Hjalmar S; Kalan, Ammie K; Arandjelovic, Mimi; Aubert, Floris; D'Auvergne, Lucy; Goedmakers, Annemarie; Jones, Sorrel; Kehoe, Laura; Regnaut, Sebastien; Tickle, Alexander; Ton, Els; van Schijndel, Joost; Abwe, Ekwoge E; Angedakin, Samuel; Agbor, Anthony; Ayimisin, Emmanuel Ayuk; Bailey, Emma; Bessone, Mattia; Bonnet, Matthieu; Brazolla, Gregory; Buh, Valentine Ebua; Chancellor, Rebecca; Cipoletta, Chloe; Cohen, Heather; Corogenes, Katherine; Coupland, Charlotte; Curran, Bryan; Deschner, Tobias; Dierks, Karsten; Dieguez, Paula; Dilambaka, Emmanuel; Diotoh, Orume; Dowd, Dervla; Dunn, Andrew; Eshuis, Henk; Fernandez, Rumen; Ginath, Yisa; Hart, John; Hedwig, Daniela; Ter Heegde, Martijn; Hicks, Thurston Cleveland; Imong, Inaoyom; Jeffery, Kathryn J; Junker, Jessica; Kadam, Parag; Kambi, Mohamed; Kienast, Ivonne; Kujirakwinja, Deo; Langergraber, Kevin; Lapeyre, Vincent; Lapuente, Juan; Lee, Kevin; Leinert, Vera; Meier, Amelia; Maretti, Giovanna; Marrocoli, Sergio; Mbi, Tanyi Julius; Mihindou, Vianet; Moebius, Yasmin; Morgan, David; Morgan, Bethan; Mulindahabi, Felix; Murai, Mizuki; Niyigabae, Protais; Normand, Emma; Ntare, Nicolas; Ormsby, Lucy Jayne; Piel, Alex; Pruetz, Jill; Rundus, Aaron; Sanz, Crickette; Sommer, Volker; Stewart, Fiona; Tagg, Nikki; Vanleeuwe, Hilde; Vergnes, Virginie; Willie, Jacob; Wittig, Roman M; Zuberbuehler, Klaus; Boesch, Christophe

    2016-01-01

    The study of the archaeological remains of fossil hominins must rely on reconstructions to elucidate the behaviour that may have resulted in particular stone tools and their accumulation. Comparatively, stone tool use among living primates has illuminated behaviours that are also amenable to archaeological examination, permitting direct observations of the behaviour leading to artefacts and their assemblages to be incorporated. Here, we describe newly discovered stone tool-use behaviour and stone accumulation sites in wild chimpanzees reminiscent of human cairns. In addition to data from 17 mid- to long-term chimpanzee research sites, we sampled a further 34 Pan troglodytes communities. We found four populations in West Africa where chimpanzees habitually bang and throw rocks against trees, or toss them into tree cavities, resulting in conspicuous stone accumulations at these sites. This represents the first record of repeated observations of individual chimpanzees exhibiting stone tool use for a purpose other than extractive foraging at what appear to be targeted trees. The ritualized behavioural display and collection of artefacts at particular locations observed in chimpanzee accumulative stone throwing may have implications for the inferences that can be drawn from archaeological stone assemblages and the origins of ritual sites. PMID:26923684

  4. Chimpanzee accumulative stone throwing

    PubMed Central

    Kühl, Hjalmar S.; Kalan, Ammie K.; Arandjelovic, Mimi; Aubert, Floris; D’Auvergne, Lucy; Goedmakers, Annemarie; Jones, Sorrel; Kehoe, Laura; Regnaut, Sebastien; Tickle, Alexander; Ton, Els; van Schijndel, Joost; Abwe, Ekwoge E.; Angedakin, Samuel; Agbor, Anthony; Ayimisin, Emmanuel Ayuk; Bailey, Emma; Bessone, Mattia; Bonnet, Matthieu; Brazolla, Gregory; Buh, Valentine Ebua; Chancellor, Rebecca; Cipoletta, Chloe; Cohen, Heather; Corogenes, Katherine; Coupland, Charlotte; Curran, Bryan; Deschner, Tobias; Dierks, Karsten; Dieguez, Paula; Dilambaka, Emmanuel; Diotoh, Orume; Dowd, Dervla; Dunn, Andrew; Eshuis, Henk; Fernandez, Rumen; Ginath, Yisa; Hart, John; Hedwig, Daniela; Ter Heegde, Martijn; Hicks, Thurston Cleveland; Imong, Inaoyom; Jeffery, Kathryn J.; Junker, Jessica; Kadam, Parag; Kambi, Mohamed; Kienast, Ivonne; Kujirakwinja, Deo; Langergraber, Kevin; Lapeyre, Vincent; Lapuente, Juan; Lee, Kevin; Leinert, Vera; Meier, Amelia; Maretti, Giovanna; Marrocoli, Sergio; Mbi, Tanyi Julius; Mihindou, Vianet; Moebius, Yasmin; Morgan, David; Morgan, Bethan; Mulindahabi, Felix; Murai, Mizuki; Niyigabae, Protais; Normand, Emma; Ntare, Nicolas; Ormsby, Lucy Jayne; Piel, Alex; Pruetz, Jill; Rundus, Aaron; Sanz, Crickette; Sommer, Volker; Stewart, Fiona; Tagg, Nikki; Vanleeuwe, Hilde; Vergnes, Virginie; Willie, Jacob; Wittig, Roman M.; Zuberbuehler, Klaus; Boesch, Christophe

    2016-01-01

    The study of the archaeological remains of fossil hominins must rely on reconstructions to elucidate the behaviour that may have resulted in particular stone tools and their accumulation. Comparatively, stone tool use among living primates has illuminated behaviours that are also amenable to archaeological examination, permitting direct observations of the behaviour leading to artefacts and their assemblages to be incorporated. Here, we describe newly discovered stone tool-use behaviour and stone accumulation sites in wild chimpanzees reminiscent of human cairns. In addition to data from 17 mid- to long-term chimpanzee research sites, we sampled a further 34 Pan troglodytes communities. We found four populations in West Africa where chimpanzees habitually bang and throw rocks against trees, or toss them into tree cavities, resulting in conspicuous stone accumulations at these sites. This represents the first record of repeated observations of individual chimpanzees exhibiting stone tool use for a purpose other than extractive foraging at what appear to be targeted trees. The ritualized behavioural display and collection of artefacts at particular locations observed in chimpanzee accumulative stone throwing may have implications for the inferences that can be drawn from archaeological stone assemblages and the origins of ritual sites. PMID:26923684

  5. Kidney Stones in Adults

    MedlinePlus

    ... specific type of kidney stone include the following: Calcium Oxalate Stones reducing sodium reducing animal protein, such as ... fish getting enough calcium from food or taking calcium supplements with food avoiding foods high in oxalate, such as spinach, rhubarb, nuts, and wheat bran ...

  6. Old Stone Field Marker

    This is a stone field marker that marked boundaries for land ownership. In the early days of Land Office Recordings, this is one type of monument used. Trees, Posts, Iron Pipes and as shown stones were used to mark off land during the Land Rush days. Later, when mapping was being done, Brass Caps wi...

  7. Famous building stones of our Nation's capital

    USGS Publications Warehouse

    U.S. Geological Survey

    2012-01-01

    The buildings of our Nation's Capital are constructed with rocks from quarries located throughout the United States and many distant lands. The earliest Government buildings, however, were constructed with stones from nearby sources because it was too difficult and expensive to move heavy materials such as stone any great distance without the aid of modern transportation methods, including large cargo ships, trains, and trucks. This fact sheet describes the source and appearance of three frequently used local stones employed in building Washington, D.C., and the geologic environment in which they were formed.

  8. Do Kidney Stone Formers Have A Kidney Disease?

    PubMed Central

    Zisman, Anna L.; Evan, Andrew P.; Coe, Fredric L.; Worcester, Elaine M.

    2015-01-01

    Nephrolithiasis is a highly prevalent disorder affecting approximately one in eleven people and is associated with multiple complications including hypertension, cardiovascular disease, and chronic kidney disease. Significant epidemiologic associations with chronic kidney disease and ESRD have been noted and are reviewed herein, but debate persists in the literature as to whether kidney stone formation is a pathogenic process contributing to kidney disease. Corroborating evidence supporting the presence of kidney disease in stone formers includes the variability of renal function by stone type, the positive association of stone size with renal dysfunction, the presence of markers of renal injury in the urine of even asymptomatic stone formers, and direct evidence of renal tissue injury on histopathology. Proposed pathogenic mechanisms include recurrent obstruction and comorbid conditions such as recurrent urinary tract infections and structural abnormalities. Recent work evaluating the renal histopathology of different groups of stone formers adds further granularity, suggesting variability in mechanisms of renal injury by stone type and confirming the pathogenic effects of crystal formation. Genetic abnormalities leading to stone formation including cystinuria and primary hyperoxaluria, among others, contribute to the burden of disease in the stone-forming population. PMID:26376133

  9. Renal Stone Risk During Space Flight

    NASA Technical Reports Server (NTRS)

    Whitson, Peggy A.; Pietrzyk, Robert A.; Sams, Clarence F.; Pak, Charles Y. C.; Jones, Jeffrey A.

    1999-01-01

    Space flight produces a number of metabolic and physiological changes in the crewmembers exposed to microgravity. Following launch, body fluid volumes, electrolyte levels, and bone and muscle undergo changes as the human body adapts to the weightless environment. Changes in the urinary chemical composition may lead to the potentially serious consequences of renal stone formation. Previous data collected immediately after space flight indicate changes in the urine chemistry favoring an increased risk of calcium oxalate and uric acid stone formation (n = 323). During short term Shuttle space flights, the changes observed include increased urinary calcium and decreased urine volume, pH and citrate resulting in a greater risk for calcium oxalate and brushite stone formation (n = 6). Results from long duration Shuttle/Mir missions (n = 9) followed a similar trend and demonstrated decreased fluid intake and urine volume and increased urinary calcium resulting in a urinary environment saturated with the calcium stone-forming salts. The increased risk occurs rapidly upon exposure to microgravity, continues throughout the space flight and following landing. Dietary factors, especially fluid intake, or pharmacologic intervention can significantly influence the urinary chemical composition. Increasing fluid intake to produce a daily urine output of 2 liters/day may allow the excess salts in the urine to remain in solution, crystals formation will not occur and a renal stone will not develop. Results from long duration crewmembers (n = 2) who had urine volumes greater than 2.5 L/day minimized their risk of renal stone formation. Also, comparisons of stone-forming risk in short duration crewmembers clearly identified greater risk in those who produced less than 2 liters of urine/day. However, hydration and increased urine output does not correct the underlying calcium excretion due to bone loss and only treats the symptoms and not the cause of the increased urinary salts. Dietary modification and promising pharmacologic treatments may also be used to reduce the potential risk for renal stone formation. Potassium citrate is being used clinically to increase the urinary inhibitor levels to minimize the development of crystals and the growth of renal stones. Bisphosphonates are a class of drugs recently shown to help in patients with osteoporosis by inhibiting the loss of bones in elderly patients. This drug could potentially prevent the bone loss observed in astronauts and thereby minimize the increase in urinary calcium and reduce the risk for renal stone development. Results of NASA's renal stone risk assessment program clearly indicate that exposure to microgravity changes the urinary chemical environment such that there is an increased risk for supersaturation of stone-forming salts, including calcium oxalaie and brushite. These studies have indicated specific avenues for development of countermeasures for the increased renal stone risk observed during and following space flight. Increased hydration and implementation of pharmacologic countermeasures should largely mitigate the in-flight risk of renal stones.

  10. Percutaneous nephrolithotomy for isolated calyceal stones: How important is the stone location?

    PubMed Central

    Özgör, Faruk; Küçüktopcu, Onur; Şimşek, Abdulmuttalip; Sarılar, Ömer; Binbay, Murat; Gürbüz, Gökhan

    2015-01-01

    Objective To evaluate the effect of percutaneous access site on the success and complication rates of isolated calyceal stones. Material and methods We retrospectively evaluated 2700 patients who underwent percutaneous nephrolithotomy (PNL) in our clinic between October 2002 and August 2014. We selected only the patients with isolated lower, middle or upper calyceal stones and we grouped the patients according to the location of their stones. Successful operation was defined as complete stone clearence or retention of stone fragments smaller than 4 mm which do not lead to infection, obstruction or pain requiring treatment. Intraoperative and postoperative complications were also recorded. Results Totally 360 patients underwent PNL for their isolated upper, middle and lower calyceal stones. Access sites for those patients were selected based on stone location. The stones were localized in the lower (n=304), middle (n=14), and upper (n=42) calices. There was no statistically significant difference between the groups with respect to operation and scopy times. Hemoglobin drop was seen more frequently in the upper calyceal access group, without any significant intergroup difference. Thoracic complications including hemothorax, pneumothorax and pleural effusion were more common in the upper calyceal access group (11.9%; p<0.001). Complete stone clerance was accomplished in 81.9%, 92.9% and 78.6% of the patients with lower, middle and upper calyceal stones respectively without any significant intergroup difference (p=0.537). Conclusion PNL is an effective and safe treatment modality for isolated calyceal kidney stones and upper calyceal access causes thoracic complications more than other access sites. PMID:26623144

  11. Sedimentary rocks in our mouth: dental pulp stones made by nanobacteria

    NASA Astrophysics Data System (ADS)

    Ciftcioglu, Neva; Ciftcioglu, Vefa; Vali, Hojatollah; Turcott, Eduardo; Kajander, E. Olavi

    1998-07-01

    The mechanisms of dental pulp stone formation are still largely unknown. Pulp stones are mainly composed of carbonate apatite. Only few experimental reports have elucidated the potential of some selected bacteria to produce apatite under in vitro conditions using special calcification media. The tested stone forming bacteria were, in fact, often better known for their cariogenic potential. Our preliminary work with 18 dental pulp stones from Turkey, selected only by severity of the stone formation, indicated the presence of nanobacterial antigens in the demineralized stones. Furthermore, high incidence of kidney stones and gall stones in the patient group and in their parents was found. This raises the implication that nanobacteria may enter the body also via oral route, in addition to the parenteral and transplacental routes. The role of nanobacteria in dental pulp stone formation was further studied by following nanobacterial colonization and mineral formation on human tooth in vitro. Two molar teeth, one having pulp stone and one without, were vertically cut into two pieces, sterilized by autoclaving and incubated with or without nanobacteria in DMEM. Electron microscopic observations indicate that nanobacteria can cause apatite stone formation on tooth surface. The sever from of dental pulp stone formation might be associated with nanobacteria. This form of dental disease results in loss of teeth due to osteolytic processes. This addresses the necessity for a study on unconventional mineral-forming bacteria as a cause for human diseases.

  12. Combined studies of chemical composition of urine sediments and kidney stones by means of infrared microspectroscopy

    NASA Astrophysics Data System (ADS)

    Tamošaitytė, Sandra; Hendrixson, Vaiva; Želvys, Arūnas; Tyla, Ramūnas; Kučinskienė, Zita A.; Jankevičius, Feliksas; Pučetaitė, Milda; Jablonskienė, Valerija; Šablinskas, Valdas

    2013-02-01

    Results of the structural analysis of urinary sediments by means of infrared spectral microscopy are presented. The results are in good agreement with the results of standard optical microscopy in the case of single-component and crystalline urinary sediments. It is found that for noncrystalline or multicomponent sediments, the suggested spectroscopic method is superior to optical microscopy. The chemical structure of sediments of any molecular origin can be elucidated by this spectroscopic method. The method is sensitive enough to identify solid particles of drugs present in urine. Sulfamethoxazole and traces of other medicines are revealed in this study among the other sediments. We also show that a rather good correlation exists between the type of urinary sediments and the renal stones removed from the same patient. Spectroscopic studies of urinary stones and corresponding sediments from 76 patients suffering from renal stone disease reveal that in 73% of cases such correlation exists. This finding is a strong argument for the use of infrared spectral microscopy to prevent kidney stone disease because stones can be found in an early stage of formation by using the nonintrusive spectroscopic investigation of urinary sediments. Some medical recommendations concerning the overdosing of certain pharmaceuticals can also be derived from the spectroscopic studies of urinary sediments.

  13. 12. FLOOR 2; STONE CRANE IN PLACE FOR ROCK STONES; ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. FLOOR 2; STONE CRANE IN PLACE FOR ROCK STONES; STONE CRANE HAS OAK SPAR, JIB AND BRACE, METAL SCREW, IRON YOKE AND DOGS; IRON PINS FIT THROUGH HOLES IN DOGS INTO HOLES DRILLED IN RUNNER STONE - Hook Windmill, North Main Street at Pantigo Road, East Hampton, Suffolk County, NY

  14. A Prototype Ultrasound Instrument To Size Stone Fragments During Ureteroscopy

    NASA Astrophysics Data System (ADS)

    Sorensen, Mathew D.; Teichman, Joel M. H.; Bailey, Michael R.

    2008-09-01

    An intraoperative tool to measure the size of kidney stones or stone fragments during ureteroscopy would help urologists assess if a fragment is small enough to be removed through the ureter or ureteral access sheath. The goal of this study was to determine the accuracy and precision of a prototype ultrasound device used to measure in vitro stone fragments compared to caliper measurements. A 10-MHz, 10-french ultrasound transducer probe was used to send an ultrasound pulse and receive ultrasound reflections from the stone using two methods. In Method 1 the instrument was aligned over the stone and the ultrasound pulse traveled through the stone. The time between reflections from the proximal and the distal surface of the stone were used along with the sound speed to calculate the stone size. Although the sound speed varied between stones, it was unlikely to be known during surgery and thus was estimated at 3000 m/s for calculations. In Method 2 the instrument was aligned partially over the stone and the ultrasound pulse traveled through water with a sound speed of 1481 m/s. Time was determined between the reflection from the proximal stone surface and the reflection from the tissue phantom on which the stone rested. Methods 1 and 2 were compared by linear regression to caliper measurements of the size of 19 human stones of 3 different stone types. Accuracy was measured by the difference of the mean ultrasound and mean caliper measurement and precision was measured as the standard deviation in the ultrasound measurements. For Method 1, the correlation between caliper-determined stone size and ultrasound-determined stone size was r2 = 0.71 (p<0.0001). In all but two stones accuracy and precision were less than 1 mm. For Method 2, the correlation was r2 = 0.99 (p<0.0001) and measurements were accurate and precise to within 0.25 mm. We conclude that the prototype device and either method measure stone size with good accuracy.

  15. Focused ultrasound guided relocation of kidney stones

    PubMed Central

    Abrol, Nitin; Kekre, Nitin S.

    2015-01-01

    Purpose: Complete removal of all fragments is the goal of any intervention for urinary stones. This is more important in lower pole stones where gravity and spatial orientation of lower pole infundibulum may hinder spontaneous passage of fragments. Various adjuvant therapies (inversion, diuresis, percussion, oral citrate, etc.) are described to enhance stone-free rate but are not widely accepted. Focused ultrasound-guided relocation of fragments is a recently described technique aimed at improving results of intervention for stone disease. Purpose of this review is to discuss development of this technology and its potential clinical applications. Materials and Methods: Pubmed search was made using key words “Focused ultrasound” and “kidney stone”. All English language articles were reviewed by title. Relevant studies describing development and application of focused ultrasound in renal stones were selected for review. Results: Focused ultrasound has proven its efficacy in successfully relocating up to 8 mm stone fragments in vitro and in pigs. Relocation is independent of stone composition. The latest model allows imaging and therapy with a single handheld probe facilitating its use by single operator. The acoustic energy delivered by the new prototype is even less than that used for extracorporeal shock wave lithotripsy. Therapeutic exposure has not caused thermal injury in pig kidneys. Conclusion: Focused ultrasound-guided relocation of stones is feasible. Though it is safe in application in pigs, technology is awaiting approval for clinical testing in human beings. This technology has many potential clinical applications in the management of stone disease. PMID:25624572

  16. Kidney stones are common after bariatric surgery

    PubMed Central

    Lieske, John C.; Mehta, Ramila A.; Milliner, Dawn S.; Rule, Andrew D; Bergstralh, Eric J.; Sarr, Michael G.

    2014-01-01

    Obesity, a risk factor for kidney stones and chronic kidney disease (CKD), is effectively treated with bariatric surgery. However, it is unclear if surgery alters stone or CKD risk. To determine this we studied 762 Olmsted County, Minnesota residents who underwent bariatric surgery and matched them with equally obese control individuals who did not undergo surgery. The majority of bariatric patients underwent standard Roux-en-Y gastric bypass (RYGB) (78%), with the remainder having more malabsorptive procedures (very long limb RYGB or biliopancreatic diversion/duodenal switch; 14%), or restrictive procedures (laparoscopic banding or sleeve gastrectomy; 7%). Mean age was 45 years with 80% female. The mean preoperative BMI was 46.7 kg/m2 for both cohorts. Rates of kidney stones were similar between surgery patients and controls at baseline, but new stone formation significantly increased in surgery patients (11.0%) compared to controls (4.3%) during 6.0 years of follow up. After malabsorptive and standard surgery, the comorbidity-adjusted hazard ratio of incident stones was significantly increased to 4.15 and 2.13, respectively but not significantly changed for restrictive surgery. The risk of CKD significantly increased after the malabsorptive procedures (adjusted hazard ratio of 1.96). Thus, while RYGB and malabsorptive procedures are more effective for weight loss, both are associated with increased risk of stones, while malabsorptive procedures also increase CKD risk. PMID:25354237

  17. Method for laser drilling subterranean earth formations

    DOEpatents

    Shuck, Lowell Z.

    1976-08-31

    Laser drilling of subterranean earth formations is efficiently accomplished by directing a collimated laser beam into a bore hole in registry with the earth formation and transversely directing the laser beam into the earth formation with a suitable reflector. In accordance with the present invention, the bore hole is highly pressurized with a gas so that as the laser beam penetrates the earth formation the high pressure gas forces the fluids resulting from the drilling operation into fissures and pores surrounding the laser-drilled bore so as to inhibit deleterious occlusion of the laser beam. Also, the laser beam may be dynamically programmed with some time dependent wave form, e.g., pulsed, to thermally shock the earth formation for forming or enlarging fluid-receiving fissures in the bore.

  18. Kidney stone erosion by micro scale hydrodynamic cavitation and consequent kidney stone treatment.

    PubMed

    Perk, Osman Yavuz; Şeşen, Muhsincan; Gozuacik, Devrim; Koşar, Ali

    2012-09-01

    The objective of this study is to reveal the potential of micro scale hydrodynamic bubbly cavitation for the use of kidney stone treatment. Hydrodynamically generated cavitating bubbles were targeted to the surfaces of 18 kidney stone samples made of calcium oxalate, and their destructive effects were exploited in order to remove kidney stones in in vitro experiments. Phosphate buffered saline (PBS) solution was used as the working fluid under bubbly cavitating conditions in a 0.75 cm long micro probe of 147 μm inner diameter at 9790 kPa pressure. The surface of calcium oxalate type kidney stones were exposed to bubbly cavitation at room temperature for 5 to 30 min. The eroded kidney stones were visually analyzed with a high speed CCD camera and using SEM (scanning electron microscopy) techniques. The experiments showed that at a cavitation number of 0.017, hydrodynamic bubbly cavitation device could successfully erode stones with an erosion rate of 0.31 mg/min. It was also observed that the targeted application of the erosion with micro scale hydrodynamic cavitation may even cause the fracture of the kidney stones within a short time of 30 min. The proposed treatment method has proven to be an efficient instrument for destroying kidney stones. PMID:22476893

  19. Introduction: Kidney Stone Research, Lessons From Human Studies

    NASA Astrophysics Data System (ADS)

    Coe, Fredric L.

    2007-04-01

    About 5% of American women and 12% of men will develop a kidney stone at some time in their life, the prevalence has been rising in both sexes. Approximately 80% of stones are composed of calcium oxalate, and calcium phosphate; 10% of struvite; 9% of uric acid; and the remaining 1% are composed of cystine or ammonium acid urate or are diagnosed as drug-related stone. Stones ultimately arise because of an unwanted phase change of these substances from liquid to solid state. In this introduction, I have outlined our current thinking of the possible mechanisms involved in stone formation based on our biopsy data collected from a series of human kidney stone formers. In addition, I have presented a set of questions as a means of focusing future research in this field.

  20. Kidney stones in anorexia nervosa: a case report and review of the literature.

    PubMed

    Jonat, L M; Birmingham, C L

    2003-12-01

    Nephrolithiasis (kidney stones) is a recognized complication of anorexia nervosa (AN). We present the case of a 41-year-old woman with a 25-year history of AN. Between 1978 and 1986, she had two episodes of calcium oxalate kidney stones. Proper management of kidney stones in AN requires collection of the stone, laboratory analysis of the stone to determine its composition, and laboratory evaluation of the urine and blood to determine what treatment is necessary to prevent recurrent kidney stone formation. PMID:15018386

  1. Mathematical model to estimate risk of calcium-containing renal stones

    NASA Technical Reports Server (NTRS)

    Pietrzyk, R. A.; Feiveson, A. H.; Whitson, P. A.

    1999-01-01

    BACKGROUND/AIMS: Astronauts exposed to microgravity during the course of spaceflight undergo physiologic changes that alter the urinary environment so as to increase the risk of renal stone formation. This study was undertaken to identify a simple method with which to evaluate the potential risk of renal stone development during spaceflight. METHOD: We used a large database of urinary risk factors obtained from 323 astronauts before and after spaceflight to generate a mathematical model with which to predict the urinary supersaturation of calcium stone forming salts. RESULT: This model, which involves the fewest possible analytical variables (urinary calcium, citrate, oxalate, phosphorus, and total volume), reliably and accurately predicted the urinary supersaturation of the calcium stone forming salts when compared to results obtained from a group of 6 astronauts who collected urine during flight. CONCLUSIONS: The use of this model will simplify both routine medical monitoring during spaceflight as well as the evaluation of countermeasures designed to minimize renal stone development. This model also can be used for Earth-based applications in which access to analytical resources is limited.

  2. Laparoscopic Stone Surgery With the Aid of Flexible Nephroscopy

    PubMed Central

    Jung, Jae Hyun; Cho, Sung Yong; Jeong, Chang Wook; Jeong, Hyeon; Son, Hwancheol; Woo, Seung Hyo; Kim, Dae Kyung; Min, Sun-Ho; Oh, Seung-June; Kim, Hyeon-Hoe

    2014-01-01

    Purpose To report the outcome of laparoscopic pyelo- and ureterolithotomies with the aid of flexible nephroscopy. Materials and Methods A retrospective analysis was performed in 71 patients with complex renal stones or large and impacted proximal ureteral stones. Patients underwent laparoscopic pyelo- or ureterolithotomies with or without the removal of small residual stones by use of flexible nephroscopy between July 2005 and July 2010. Operative success was defined as no residual stones in the intravenous pyelogram at 12 weeks postoperatively. Perioperative results and surgical outcomes were analyzed. Results The patients' mean age was 54.7±13.7 years, and 53 males (74.6%) and 18 females (25.4%) were included. The mean maximal stone size was 19.4±9.4 mm. A total of 47 cases were complex renal stones and 24 cases were impacted ureteral stones. Mean operative time was 139.0±63.7 minutes. Stones were completely removed in 61 cases (85.9%), and no further ancillary treatment was needed for clinically insignificant residual fragments in 7 cases (9.9%). For complex renal stones, the complete stone-free rate and clinically significant stone-free rate were 80.9% and 93.6%, respectively. Multivariate analysis showed that the use of flexible nephroscopy for complex renal stones can reduce the risk of residual stones. A major complication occurred in one case, in which open conversion was performed. Conclusions Laparoscopic stone surgery is a safe and minimally invasive procedure with a high success rate, especially with the aid of flexible nephroscopy, and is not associated with procedure-specific complications. PMID:25045447

  3. Skimming and Skipping Stones

    ERIC Educational Resources Information Center

    Humble, Steve

    2007-01-01

    This article presents an example of skimming and skipping stone motion in mathematical terms available to students studying A-level mathematics. The theory developed in the article postulates a possible mathematical model that is verified by experimental results.

  4. Bariatric Surgery and Stone Disease

    NASA Astrophysics Data System (ADS)

    Lieske, John C.; Kumar, Rajiv

    2008-09-01

    Bariatric surgery is an effective treatment strategy for patients with morbid obesity that can result in effective weight loss, resolution of diabetes mellitus and other weight related complications, and even improved mortality. However, it also appears that hyperoxaluria is common after modern bariatric surgery, perhaps occurring in up to 50% of patients after Rouxen-Y gastric bypass. Although increasing numbers of patients are being seen with calcium oxalate kidney stones after bariatric surgery, and even a few with oxalosis and renal failure, the true risk of these outcomes remains unknown. The mechanisms that contribute to this enteric hyperoxaluria are also incompletely defined, although fat malabsorption may be an important component. Since increasing numbers of these procedures are likely to be performed in the coming years, further study regarding the prevalence and mechanisms of hyperoxaluria and kidney stones after bariatric surgery is needed to devise effective methods of treatment in order to prevent such complications.

  5. Method for preventing the formation of sludge in crude oil

    SciTech Connect

    Dill, W.R.; Lane, J.L. Jr.

    1991-10-22

    This patent describes a method of increasing the permeability of a subterranean calcatreous formation containing a sludging crude oil while preventing the precipittion in the formation of slude, ferric compounds and calcium compounds.

  6. External Validation of the STONE Score, a Clinical Prediction Rule for Ureteral Stone: An Observational Multi-institutional Study

    PubMed Central

    Wang, Ralph C.; Rodriguez, Robert M.; Moghadassi, Michelle; Noble, Vicki; Bailitz, John; Mallin, Mike; Corbo, Jill; Kang, Tarina L.; Chu, Phillip; Shiboski, Steve; Smith-Bindman, Rebecca

    2015-01-01

    Study objective The STONE score is a clinical decision rule that classifies patients with suspected nephrolithiasis into low-, moderate-, and high-score groups, with corresponding probabilities of ureteral stone. We evaluate the STONE score in a multi-institutional cohort compared with physician gestalt and hypothesize that it has a sufficiently high specificity to allow clinicians to defer computed tomography (CT) scan in patients with suspected nephrolithiasis. Methods We assessed the STONE score with data from a randomized trial for participants with suspected nephrolithiasis who enrolled at 9 emergency departments between October 2011 and February 2013. In accordance with STONE predictors, we categorized participants into low-, moderate-, or high-score groups. We determined the performance of the STONE score and physician gestalt for ureteral stone. Results Eight hundred forty-five participants were included for analysis; 331 (39%) had a ureteral stone. The global performance of the STONE score was superior to physician gestalt (area under the receiver operating characteristic curve=0.78 [95% confidence interval {CI} 0.74 to 0.81] versus 0.68 [95% CI 0.64 to 0.71]). The prevalence of ureteral stone on CT scan ranged from 14% (95% CI 9% to 19%) to 73% (95% CI 67% to 78%) in the low-, moderate-, and high-score groups. The sensitivity and specificity of a high score were 53% (95% CI 48% to 59%) and 87% (95% CI 84% to 90%), respectively. Conclusion The STONE score can successfully aggregate patients into low-, medium-, and high-risk groups and predicts ureteral stone with a higher specificity than physician gestalt. However, in its present form, the STONE score lacks sufficient accuracy to allow clinicians to defer CT scan for suspected ureteral stone. PMID:26440490

  7. Monitoring for Renal Stone Recurrence in Astronauts With History of Stone

    NASA Technical Reports Server (NTRS)

    Reyes, David P.; Sargsyan, Ashot; Locke, James; Davis, Jeffrey

    2014-01-01

    After an initial stone episode persons are at increased risk for future stone formation. A systematic approach is required to monitor the efficacy of treatment and preventive measures, and to assess the risk of developing new stones. This is important for persons working in critical jobs or austere environments, such as astronauts. A literature review of the current standards of care for renal stone monitoring and imaging was done. Military and civil aviation standards were also reviewed, as well as the medical precedents from the space program. Additionally, a new, more effective, renal stone ultrasound protocol has been developed. Using this work, a monitoring algorithm was proposed that takes into consideration the unique mission and operational environment of spaceflight. The approach to imaging persons with history of renal stones varies widely in the literature. Imaging is often done yearly or biannually, which may be too long for mission critical personnel. In the proposed algorithm astronauts with a history of renal stone, who may be under consideration for assignment, are imaged by a detailed, physiciandriven, ultrasound protocol. Unassigned personnel are monitored by yearly ultrasound and urine studies. Any positive ultrasound study is then followed by low-dose renal computed tomography scan. Other criteria are also established. The proposed algorithm provides a balanced approach between efficacy and reduced radiation exposure for the monitoring of astronauts with a renal stone history. This may eventually allow a transition from a risk-averse, to a risk-modifying approach that can enable continued service of individuals with history of renal stone that have adequately controlled risk factors.

  8. Effects of calcium carbonate, magnesium oxide and sodium citrate bicarbonate health supplements on the urinary risk factors for kidney stone formation.

    PubMed

    Allie, Shameez; Rodgers, Allen

    2003-01-01

    We describe a model to illustrate different chemical interactions that can occur in urine following ingestion of individual and combined health supplements. Two types of interactions are defined: synergism and addition. The model was applied to eight healthy males who participated in a study to investigate the chemical interactions between calcium carbonate, magnesium oxide and sodium citrate-bicarbonate health supplements on calcium oxalate urinary stone risk factors. Subjects ingested these components individually and in combination for 7 days. Twenty-four-hour urines were collected at baseline and during the final day of supplementation. These were analysed using standard laboratory techniques. Three different chemical interactions, all involving citrate, were identified: magnesium and citrate exerted a synergistic effect on lowering the relative superaturation (RS) of brushite; the same two components produced a synergistic effect on raising pH; finally, calcium and citrate exerted an additive effect on lowering the RS of uric acid. We propose that the novel approach described in this paper allows for the evaluation of individual, additive and synergistic interactions in the assessment of the efficacy of stone-risk reducing preparations. PMID:12636048

  9. The History of Kidney Stone Dissolution Therapy: 50 Years of Optimism and Frustration With Renacidin

    PubMed Central

    Gonzalez, Ricardo D.; Whiting, Bryant M.

    2012-01-01

    Abstract Background and Purpose Over the last 50 years, chemolysis as a primary or adjuvant treatment for urinary stones has fallen in and out of favor. We review the literature for a historical perspective on the origins and chronology of Renacidin therapy, focusing on landmark studies and impracticalities that have seemingly condemned it to history. Materials and Methods A MEDLINE search was performed on the topic of chemolysis of urinary calculi. Historical literature was reviewed with regard to stone composition, treatment modalities, outcomes, and complications. Results A total of 61 articles were reviewed, 40 of which were case series, representing a total of 817 patients studied. Mulvaney first introduced Renacidin in 1959 as a modification of Suby and Albright's 1943 solution. Because of an overabundance of nonstandardized irrigation protocols, six deaths were reported in the early 1960s resulting in a Food and Drug Administration ban on the practice of upper urinary tract stone dissolution. Over time, Renacidin returned to the urologist's arsenal, appearing first as an adjunct to dissolve catheter and bladder calculi and later (1990) as an approved agent for renal pelvis and ureter use. This feat was almost single-handedly the result of a successful hemiacidrin case series published in 1971 by Nemoy and Stamey. By using daily urine cultures, prophylactic antibiotics, and meticulous intrarenal pressure monitoring, Nemoy and Stamey virtually eliminated all major irrigation complications, paving the way for a flurry of studies. More importantly, they established the link between residual struvite stones, persistent infection, and recurrent staghorn stone formation. Conclusions Dissolution of urinary calculi by chemolysis has been shown to be safe and effective if performed with sterile urine cultures, prophylactic antibiotics, and low intrapelvic pressures. The pioneers of this therapy are remembered for their attempts to develop an alternative to open surgery, and, in the process, solidified the stone-free concept for infection-based stones. PMID:21999455

  10. Method for controlling permeability of subterranean formations

    SciTech Connect

    Givens, S.P.; Mcdonald, C.J.; Van Landingham, J.V.

    1981-08-11

    In the recovery of hydrocarbon materials from subterranean formations, the simultaneous production or loss of other fluids such as water is inhibited by the selective introduction into the subterranean porous structure of discrete spheroidal microgels of a water-swollen or water-swellable, crosslinked polymer such as crosslinked polyacrylamide.

  11. Method for controlling permeability of subterranean formations

    SciTech Connect

    Givens, S.P.; Mcdonald, C.J.; Van L.J.

    1980-01-08

    In the recovery of hydrocarbon materials from subterranean formations, the simultaneous production or loss of other fluids such as water is inhibited by the selective introduction into the subterranean porous structure of discrete spheroidal microgels of a water-swollen or water-swellable, crosslinked polymer such as crosslinked polyacrylamide.

  12. Mineralogy and chemistry of urinary stones: patients from North Jordan.

    PubMed

    Abboud, Iyad Ahmed

    2008-10-01

    Urinary stone diseases are increasing in the Middle East. The majority of urinary stone cases are found in the northern part of the country. Stone samples taken from patients living in the Irbid area were collected from Princess Basma Hospital. The present study concentrates on the mineralogical and chemical composition of the urinary stones and on the effective environmental factors that assist in developing the different types of urinary stones. Using X-ray diffraction techniques, the mineralogical composition of the urinary stones was found to be as follows: oxalate, cholesten, and uric acid, with cystine stones occuring more frequently than the others. Cholesten and calcium oxalate stones are the most dominant types of stones. Calcium oxalate is the most common type of oxalate stone. Calcium oxalate is represented in: whewellite, wheddellite, and calcium carbonate oxalate hydrate minerals, in addition to other minerals such as brushite, ammonium phosphate, vaterite, valleriite, and bobierrite from other types of stones. Bobierrite (phosphate group) is a new mineral reported in urinary stones, and this has not been determined in any previous study worldwide. Apatite (calcium phosphate) is deduced using scanning electron microscope (SEM) images. The SEM technique determined crystal forms and systems, shapes, morphological features, and the names of the minerals forming urine stones, while optical properties are studied by polarizing microscope. X-ray fluorescence technique determined the concentrations of major and some trace elements. It revealed that Ca is the main constituent of the urinary stones, especially those composed of calcium oxalate and calcium phosphate. The concentration of trace elements was Ba = 1.57, P = 3.61, Fe = 1.78, S = 2.08, Zr = 4.63, Mo = 3.92, Cu = 1.89, Co = 1.56, and F = 4.2% and was higher in the urinary stones of Jordanian patients than in foreigners in the country. Questionnaires completed by patients suggest that the most significant factors directly effecting the formation of stones are water, climate conditions, food rich in protein and rich in different chemicals. Moreover, some drugs and diseases might also help in developing other stones. PMID:18064405

  13. Investigation on laser induced salivary stone fragmentation

    NASA Astrophysics Data System (ADS)

    Sroka, Ronald; Pongratz, Thomas; Eder, Matthias; Domes, Mona; Vogeser, Michael; Johnson, Thorsten; Siedeck, Vanessa; Schroetzlmair, Florian; Zengel, Pamela

    2014-03-01

    Objective: It was the objective of this in-vitro study to investigate photon-based techniques for identifying the composition and fragmentation of salivary stones using a Ho:YAG laser. Materials and Method: Salivary stones (n=47) extracted from patients with clinical symptoms of sialolithiasis were examined in-vitro. After extraction, the stones were kept in Ringers solution until size and volume measurements could be performed. Thereafter, dual-energy CT scans (DECT) were performed to classify the composition of the stones. Subsequently, fluorescence measurements were performed by taking images under blue light excitation as well as by fluorescence spectroscopy, measuring excitation-emission-matrixes (EEM). Further investigation to identify the exact composition of the stone was performed by Raman spectroscopy and FTIR spectroscopy of stone fragments and debris. Fragmentation was performed in an aquarium set-up equipped with a mesh (hole: 1.5mm) using a Ho:YAG-laser to deliver laser pulses of 0.5, 1.0 and 1.5J/pulse at a frequency of 3Hz through a 200?m-fibre to the stone surface. The collected data were analyzed and fragmentation rates were calculated. Finally, correlation between stone composition and fragmentation was performed. Results: Blue light fluorescence excitation resulted in either fluorescence in the green spectral region or in a combination of green and red fluorescence emission. EEM-measurement showed the corresponding spectra. Raman spectroscopy showed a mixture of carbonate apatite and keratin. DECT results in evidence of calcium containing components. FTIR-spectroscopy results showed that carbonate apatite is the main component. Fragmentation experiment showed a dependency on the energy per pulse applied if the evaluation implies the ratio of fragmented weight to pulse, while the ratio fragmented weight to energy remains about constant for the three laser parameter used. Conclusion: The composition of salivary stones could be determined using different photonic techniques. Attempts to correlate salivary stone composition to fragmentation rates resulted in no correlation. Thus it could be concluded that each salivary stone could be easily destroyed using Ho:YAG-laser light by means of a 200?m bare fibre at lowest energy per pulse.

  14. Dilute Surfactant Methods for Carbonate Formations

    SciTech Connect

    Kishore K. Mohanty

    2006-02-01

    There are many fractured carbonate reservoirs in US (and the world) with light oil. Waterflooding is effective in fractured reservoirs, if the formation is water-wet. Many fractured carbonate reservoirs, however, are mixed-wet and recoveries with conventional methods are low (less than 10%). The process of using dilute anionic surfactants in alkaline solutions has been investigated in this work for oil recovery from fractured oil-wet carbonate reservoirs both experimentally and numerically. This process is a surfactant-aided gravity drainage where surfactant diffuses into the matrix, lowers IFT and contact angle, which decrease capillary pressure and increase oil relative permeability enabling gravity to drain the oil up. Anionic surfactants have been identified which at dilute concentration of 0.05 wt% and optimal salinity can lower the interfacial tension and change the wettability of the calcite surface to intermediate/water-wet condition as well or better than the cationic surfactant DTAB with a West Texas crude oil. The force of adhesion in AFM of oil-wet regions changes after anionic surfactant treatment to values similar to those of water-wet regions. The AFM topography images showed that the oil-wetting material was removed from the surface by the anionic surfactant treatment. Adsorption studies indicate that the extent of adsorption for anionic surfactants on calcite minerals decreases with increase in pH and with decrease in salinity. Surfactant adsorption can be minimized in the presence of Na{sub 2}CO{sub 3}. Laboratory-scale surfactant brine imbibition experiments give high oil recovery (20-42% OOIP in 50 days; up to 60% in 200 days) for initially oil-wet cores through wettability alteration and IFT reduction. Small (<10%) initial gas saturation does not affect significantly the rate of oil recovery in the imbibition process, but larger gas saturation decreases the oil recovery rate. As the core permeability decreases, the rate of oil recovery reduces, and this reduction can be scaled by the gravitational dimensionless time. Mechanistic simulation of core-scale surfactant brine imbibition matches the experimentally observed imbibition data. In-situ distributions observed through simulation indicate that surfactant diffusion (which depends on temperature and molecular weight) is the rate limiting step. Most of the oil is recovered through gravitational forces. Oil left behind at the end of this process is at its residual oil saturation. The capillary and Bond numbers are not large enough to affect the residual oil saturation. At the field-scale, 50% of the recoverable oil is produced in about 3 years if the fracture spacing is 1 m and 25% if 10 m, in the example simulated. Decreasing fracture spacing and height, increasing permeability, and increasing the extent of wettability alteration increase the rate of oil recovery from surfactant-aided gravity drainage. This dilute surfactant aided gravity-drainage process is relatively cheap. The chemical cost for a barrel of oil produced is expected to be less than $1.

  15. Analysis of urinary stone composition in Eastern India by X-ray diffraction crystallography

    PubMed Central

    Jindal, Tarun; Mandal, Soumendra Nath; Sonar, Pankaj; Kamal, Mir Reza; Ghosh, Nabankur; Karmakar, Dilip

    2014-01-01

    Background: Stones in the urinary system are common in our country. This study was done to assess the composition of the urinary stones in eastern part of India. Materials and Methods: A prospective study was done over a period of thirty months. A total of 90 stones were analyzed in this time period by using X-ray diffraction crystallography. Results: Of the 90 stones analyzed, 77 were renal stones, 12 were ureteric stones and one was a bladder stone. Six stones (all renal) did not have properties to be represented by X-ray diffraction crystallography. The overall prevalence of the oxalate containing stones was 85.7% with calcium oxalate monohydrate (COM) being the major constituent. Calcium oxalate dihydrate (COD) was the next most common constituent. Struvite stones constituted 9.5% of the stones analyzed. Pure calcium phosphate stones were found in 4.7% of the cases. Conclusion: Our study reveals that the stone composition in the eastern part of India is different from that in other parts of the country. We have a comparatively lower prevalence of oxalate stones while a higher prevalence of phosphate and struvite stones. PMID:25337533

  16. Urinary Stone Disease: Progress, Status, and Needs.

    PubMed

    Kirkali, Ziya; Rasooly, Rebekah; Star, Robert A; Rodgers, Griffin P

    2015-10-01

    Urinary stone disease (USD) is an important healthcare problem in the US affecting both adults and children, and costs $10 billion to the nation. Prevalence of USD has nearly doubled during the last 15 years in parallel to the obesity and type 2 diabetes epidemic. Despite the advances in the management of an acute episode, one of three stone formers experience recurrence. A better understanding of stone formation is necessary to develop secondary prevention strategies. There are many unanswered research questions that require a multidisciplinary approach. National Institute of Diabetes and Digestive and Kidney Diseases recently held a workshop on USD, and is committed to continue conducting and supporting research in this field. PMID:26190090

  17. Method for monitoring the hydraulic fracturing of a subsurface formation

    SciTech Connect

    Stromswold, D.C.

    1990-05-22

    This patent describes a method for monitoring the hydraulic fracturing of a subsurface formation of interest. It comprises: logging a subsurface formation through a measurement of delayed gamma rays from the neutron activation of a characteristic element of the formation, injecting a fracturing fluid into the formation to hydraulically create a fracture within the formation, injecting a proppant into the fracture containing the element which emits delayed gamma rays in response to neutron activation, logging the proppant containing the fractured formation through a measurement of delayed gamma rays from the neutron activation of the proppant containing fractured formation, and identifying the extent of proppant deposition within the fractured formation from the difference in the delayed gamma ray measurements of the formation before and after the proppant injection.

  18. [The influence of two methods of disinfection on dimensional stability of silicone impressions and stone models poured from them].

    PubMed

    Nespriad'ko, V P; Shevchuk, V O; Mykha?lov, A A; Omel'ianenko, M D

    2011-01-01

    In this experimental investigation was matched the method of chemical disinfection as more custom and the physical method of microwave energy using the plant with flowing regulation of the power of microwave radiation which calls "micro-UndaDent". We estimated the influence of these two methods on the alteration of dimensional stability of silicone impressions and gypsum casts poured from them comparing to an invariable parameters of metal die. PMID:22768746

  19. Method and apparatus for vibrating a substrate during material formation

    DOEpatents

    Bailey, Jeffrey A. [Richland, WA; Roger, Johnson N. [Richland, WA; John, Munley T. [Benton City, WA; Walter, Park R. [Benton City, WA

    2008-10-21

    A method and apparatus for affecting the properties of a material include vibrating the material during its formation (i.e., "surface sifting"). The method includes the steps of providing a material formation device and applying a plurality of vibrations to the material during formation, which vibrations are oscillations having dissimilar, non-harmonic frequencies and at least two different directions. The apparatus includes a plurality of vibration sources that impart vibrations to the material.

  20. Global stone heritage: larvikite, Norway

    NASA Astrophysics Data System (ADS)

    Heldal, Tom; Dahl, Rolv

    2013-04-01

    Larvikite has for more than hundred years been appreciated as one of the world's most attractive dimension-stones, and at present time its production and use is more extensive than ever. The main reason for the continuous success of the larvikite on the world market is the blue iridescence displayed on polished surfaces, which is caused by optical interference in microscopic lamellae within the ternary feldspars. The larvikite complex consists of different intrusions defining several ring-shaped structures, emplaced during a period of approximately five million years. Following this pattern, several commercial subtypes of larvikite, characterised by their colour and iridescence, have been identified. The name "larvikite" was first applied by Waldemar Brøgger, in his descriptions of the monzonitic rocks within the southern part of the Carboniferous-Permian Oslo Igneous Province. The name has its origin in the small coastal town of Larvik, situated almost right in the centre of the main plutonic complex of larvikite. From a geologist's point of view, the larvikites are important for understanding the igneous mechanisms behind the formation of the Oslo rift, representing a series of semi-circular intrusions, varying from quartz-bearing monzonites in the east (earliest phases) towards nepheline-bearing monzonites and nepheline syenite in the west (latest phases). However, most other people see larvikite as a particularly beautiful rock. Production started already in the 1880s, and at present time the export value of rough blocks of dimension-stone from the Larvik Region is close to 100 million euro, distributed on approximately 20 individual quarries. Different types of larvikite have different market value, and the customers can choose between a range of types and qualities under trade names such as "Blue Pearl", "Emerald Pearl" and "Marina Pearl". Globally, larvikite has put a significant mark on architecture around the world, and should be included in the global stone heritage.

  1. Geo-engineering evaluation of Termaber basalt rock mass for crushed stone aggregate and building stone from Central Ethiopia

    NASA Astrophysics Data System (ADS)

    Engidasew, Tesfaye Asresahagne; Barbieri, Giulio

    2014-11-01

    The geology of the central part of Ethiopia exhibits a variety of rock types that can potentially be developed for construction stone production, of which the most wide spread and important one is the Termaber basalt. Even though some preliminary work is done on these rocks towards construction material application, it remains largely that this resource is untouched and needs further scientific characterization for the use in large scale industrial application. Basaltic rocks have been widely used in many parts of the world as concrete aggregate and dimension stone for various civil structures. The present research study was carried out for Geo-engineering evaluation of Termaber basalt rock mass for crushed stone aggregate and building stone from Central Ethiopia (around Debre Birhan). The main objective of the present research study was to assess the general suitability of the Termaber basalt to be used as coarse aggregate for concrete mix and/or to utilize it as cut stone at industrial level. Only choice made with full knowledge of the basic characteristics of the material, of its performance and durability against the foreseen solicitations will ensure the necessary quality of the stone work and thereby a possibility to reach its intended service life. In order to meet out the objective of the present study, data from both field and laboratory were collected and analyzed. The field data included geological investigations based on different methods and sample collection while the laboratory work included, uniaxial compressive strength, ultrasonic pulse velocity, dynamic elasticity modulus, bulk density, water absorption, specific gravity, open porosity, aggregate impact value, petrographic examination and XRF, aggregate crushing value, Los Angeles abrasion value, sodium sulfate soundness, X-ray diffraction and alkali silica reactivity tests. The field and laboratory data were compiled and compared together to reveal the engineering performance of the rock mass in terms of cut stone and coarse aggregates. The basaltic rock shows a variety of textural and mineralogical characteristics which could affect their physical and mechanical properties as well as their use as construction material. The compressive strength of the basaltic rock ranges from 130 MPa to 350 MPa, ultrasonic pulse velocity from 4000 m/s to 7000 m/s, open porosity from 0.33% to 3.08%, bulk density from 2.6 g/cm3 to 3.1 g/cm3, dynamic elasticity modulus from 64 GPa to 129 GPa, etc. The petrographic examination also indicated some deleterious constituents within the middle basaltic flow layers however; there are distinct flow layers which could be used as dimension stone and coarse aggregate for concrete and asphalt mix. The field investigation as well as the laboratory tests conducted indicated the high potential of the Termaber basalt formation to be used as construction material with further refining works. The study presented in this paper was carried out on basalts that are widespread in the central highland of Ethiopia and that comprise the major source of local crushed rock aggregates and building stone.

  2. Kidney Stone Treatment with Lithotripsy

    MedlinePlus Videos and Cool Tools

    Kidney Stone Treatment with Lithotripsy Broward Health Medical Center Fort Lauderdale, FL November 11, 2011 I'm ... got at least three stones in his left kidney. He's been having pain and blood in his ...

  3. Morphology of Major Stone Types, As Shown by Micro Computed Tomography (micro CT)

    SciTech Connect

    Jackson, Molly E.; Beuschel, Christian A.; McAteer, James A.; Williams, James C.

    2008-09-18

    Micro CT offers the possibility of providing a non-destructive method of stone analysis that allows visualization of 100% of the stone's volume. For the present study, micro CT analysis was completed on stones of known composition with isotropic voxel sizes of either 7 or 9.1 {mu}m. Each mineral type was distinctive, either by x-ray attenuation values or by morphology. Minor components, such as the presence of apatite in oxalate stones, were easily seen. The analysis of stones by micro CT opens up the possibility of exploring the stone as an encapsulated history of the patient's disease, showing changes in mineral deposition with time.

  4. Milk of calcium stones: radiological signs and management outcome.

    PubMed

    El-Shazly, M

    2015-06-01

    Milk of calcium (MOC) is a rare type of stone that was first described in 1940 by Ludin and Howald who reported MOC in renal cysts. Milk of calcium is a viscous colloidal suspension of calcium salts. Stasis, obstruction and infection are important predisposing factors. Due to a layering effect, characteristic radiological signs especially in CT can help in diagnosis to avoid unsuccessful shock wave lithotripsy. This is the largest reported case series, in which radiological signs by CT scan to predict renal MOC stones, clinical picture and management outcome are described in detail. Cases with suspected renal milk of calcium stones were studied over 7 years (2008-2015). All cases were diagnosed preoperatively by non-contrast CT. Urine cultures were performed in all patients preoperatively. Intra-operative and postoperative findings were reported. Stones retrieved were sent for chemical analysis using an infrared method. Seven cases of milk of calcium renal stones were included in this study. These stones were faint radio-opaque in two cases and radiolucent in five cases. All cases were diagnosed preoperatively with non-contrast CT. Their Hounsfield units (HU) ranged from 114 to 612. All stones were located in a dependent position (gravitational effect) in the posterior aspect of dilated calyces. Five cases exhibited the typical fluid level and two cases demonstrated semilunar (half moon) pattern in the anterior surface of the stones. All cases underwent PCNL with suction and retrieval of soft stones without the need for disintegration. When stones demonstrate a low Hounsfield unit, are arranged in dependent positions within dilated calyces and exhibit fluid level or semilunar pattern on non-contrast CT, milk of calcium stones should be considered. PCNL is an effective modality for management of renal milk of calcium stones. PMID:25820293

  5. Renal-Stone Risk Assessment During Space Shuttle Flights

    NASA Technical Reports Server (NTRS)

    Whitson, Peggy A.; Pietrzyk, Robert A.; Pak, Charles Y. C.

    1996-01-01

    The metabolic and environmental factors influencing renal stone formation before, during, and after Space Shuttle flights were assessed. We established the contributing roles of dietary factors in relationship to the urinary risk factors associated with renal stone formation. 24-hr urine samples were collected prior to, during space flight, and following landing. Urinary factors associated with renal stone formation were analyzed and the relative urinary supersaturation ratios of calcium oxalate, calcium phosphate (brushite), sodium urate, struvite and uric acid were calculated. Food and fluid consumption was recorded for a 48-hr period ending with the urine collection. Urinary composition changed during flight to favor the crystallization of stone-forming salts. Factors that contributed to increased potential for stone formation during space flight were significant reductions in urinary pH and increases in urinary calcium. Urinary output and citrate, a potent inhibitor of calcium-containing stones, were slightly reduced during space flight. Dietary intakes were significantly reduced for a number of variables, including fluid, energy, protein, potassium, phosphorus and magnesium. This is the first in-flight characterization of the renal stone forming potential in astronauts. With the examination of urinary components and nutritional factors, it was possible to determine the factors that contributed to increased risk or protected from risk. In spite of the protective components, the negative contributions to renal stone risk predominated and resulted in a urinary environment that favored the supersaturation of stone-forming salts. The importance of the hypercalciuria was noted since renal excretion was high relative to the intake.

  6. The problematic construction of 'Palaeolithic Man': The Old Stone Age and the difficulties of the comparative method, 1859-1914.

    PubMed

    Manias, Chris

    2015-06-01

    The growth of a prehistoric timescale was one of the most dramatic developments in nineteenth-century ideas of humanity, massively extending the assumed course of human development and placing it within the deep chronologies of geological time. A dominant motif linking prehistory with wider studies of humanity and notions of historical change was the 'comparative method'-the idea that modern 'savages' were analogous to prehistoric Europeans, and that the two sets of peoples could explain one another. The importance of this mode of reasoning has been well-studied, and shown to have had great significance for concepts of progress and social evolution. What has been less investigated are cases when the comparative method broke down, and where 'modern savages' and 'prehistoric man' seemed to be dissimilar and analogies hard to make. This paper examines how a series of authors engaged with problems in the comparative method when they attempted to place human development within this deep prehistoric past. In doing so, it highlights the changing interactions between the Victorian deep time sciences and the 'sciences of man,' and how notions of European prehistory and modern 'primitives' often rested on a notion of variability in the 'savage' condition. PMID:25746292

  7. When Stones Teach.

    ERIC Educational Resources Information Center

    Lucier, Todd

    2001-01-01

    Creating towers of balanced stones is a versatile outdoor learning activity that can be experienced in the classroom, school yard, forest, or parking lot. Students discover hidden talents, learn to work and communicate clearly with others, and reconnect with the natural world. Several variations on the exercise are given, along with principles of…

  8. Kidney stones - lithotripsy - discharge

    MedlinePlus

    ... days after this procedure. Drink a lot of water in the weeks after treatment. This helps pass any pieces of stone that still remain. Your health care provider may give you a medicine ... take and drink a lot of water if you have pain. You may need to ...

  9. Kidney Stones (For Parents)

    MedlinePlus

    ... as urine (pee). Urine contains substances — such as calcium, oxalate, phosphate, carbonate, cystine, and uric acid — that in ... high in sodium can increase the risk of calcium stones. Obesity can ... lead to concentrated levels of oxalate (a substance made in the body and found ...

  10. Dynamic cluster formation using level set methods.

    PubMed

    Yip, Andy M; Ding, Chris; Chan, Tony F

    2006-06-01

    Density-based clustering has the advantages for 1) allowing arbitrary shape of cluster and 2) not requiring the number of clusters as input. However, when clusters touch each other, both the cluster centers and cluster boundaries (as the peaks and valleys of the density distribution) become fuzzy and difficult to determine. We introduce the notion of cluster intensity function (CIF) which captures the important characteristics of clusters. When clusters are well-separated, CIFs are similar to density functions. But, when clusters become closed to each other, CIFs still clearly reveal cluster centers, cluster boundaries, and degree of membership of each data point to the cluster that it belongs. Clustering through bump hunting and valley seeking based on these functions are more robust than that based on density functions obtained by kernel density estimation, which are often oscillatory or oversmoothed. These problems of kernel density estimation are resolved using Level Set Methods and related techniques. Comparisons with two existing density-based methods, valley seeking and DBSCAN, are presented which illustrate the advantages of our approach. PMID:16724583

  11. Epidemiology of bladder stone of children: precipitating events.

    PubMed

    Halstead, Scott B

    2016-04-01

    Urological surgery evolved from the ancient practice of removing primary bladder stones from young boys. Bladder stones, once ubiquitous, long ago disappeared from the developed world while pockets of disease still exist in developing countries. Two epidemiological studies identified as precipitating events of bladder stone formation the practice of substitutive carbohydrate feedings to newborns. In Southeast Asia, masticated rice is fed to newborns in stone-endemic villages while in England, during the eighteenth and nineteenth centuries pap or panada was used to hand-feed infants when breast milk was not available. Fresh milk from dairy animals was deemed preferable to pap. Lack of access to dairy cattle enhanced need for hand-feeding. In an epidemiological study, during mid-nineteenth century in England the prevalence of dairy cattle was inversely related to the prevalence of bladder stones. These epidemiological data relate stone formation to nutrition during the first few days or weeks of life. It is surmised that frequent use of or exclusive reliance on carbohydrate foods replacing milk feedings leads to a relative dietary deficiency in phosphates and the formation of insoluble urinary salts. Girls, with short, nontortuous urethras may pass much of the calculus debris without retaining nuclei in the bladder. In some males, stone nuclei are formed and retained. The growth of stones is determined thereafter by the net effect of depository and resorptive mechanisms operating over time distributing over many years the age that patients present for surgical stone removal. The role of early introduction of carbohydrate foods and reduced milk intake of neonates has not been incorporated into recommendations for feeding newborns in endemic countries nor comprehensively modeled in animals. PMID:26559057

  12. Compatibility study and adaption of stone repair mortars for the Lede stone (Belgium)

    NASA Astrophysics Data System (ADS)

    De Kock, T.; Vandevoorde, D.; Boone, M. A.; Dewanckele, J.; De Boever, W.; Lanzón, M.; De Schutter, G.; Van Hoorebeke, L.; Jacobs, P.; Cnudde, V.

    2012-04-01

    One of the main historic building materials in northern Belgium is the Lede stone. This arenaceous limestone from Lutetian age was excavated in the region of Ghent and Brussels and was transported northwards by main rivers such as the Scheldt and Zenne. Thanks to this natural transport route, the stone in also found in many cities which lie abroad the excavation area, such as Antwerp (Belgium) and various cities in the Netherlands (Breda, Zierikzee, …). Due to its dominant occurrence in our cultural heritage, it is frequently subjected to restoration and renovation works. Depending on the degree of decay, most frequent stone operations are cleaning, healing with mortar or replacing it by (often exotic) fresh blocks. Originally, this limestone has a greenish-gray colour, but when being exposed to atmospheric conditions it acquires a yellowish to rusty coloured patina. The origin of the latter is most likely the oxidation of glauconite minerals which are present in a few percent in the stone. In addition, the stone often demonstrates black crust formation due to sulphation. Cleaning of the stone often results in an excess removal of this black gypsum crusts and patina, thus exposing deeper parts of the stone which appear more greenish-gray again. When the stone is subsequently healed by adding repair mortar to damaged parts, the question rises which mortar colour is more appropriate. The choice of repair mortar is greatly depending on commercial aspects. When handling entire facades on monuments, a mineral mortar based on ZnCl is most often applied in Belgium. The big advantage of this mortar is its fast curing. Three colour types have been developed for the Lede stone in specific. However, the hardness of this mortar is sometimes in conflict with reversibility. For the handling of individual sculptures some conservators choose for the application of (hydraulic) lime mortars. The advantage of using such mortars is their high compatibility and reversibility. The disadvantage, besides being more labour intensive than mineral mortars based on ZnCl, is that no specific recipes are yet developed for Lede stone and the result is thus dependent on the knowledge of the restorer. Both of the repair mortars have the problem that Lede stone changes its colour due to ageing while the mortar itself remains colour stable. This means that if the mortar colour was adapted for a resemblance at the moment of application, the colour difference between stone and mortar will increase in time. In this study, the compatibility of the different stone repair mortars with the Lede stone are tested. Further, a study was made whether the mortar recipes can be adapted for a better compatibility. In addition, the effect of glauconite addition in the mortar is studied to resolve the possibility of ageing of the mortar similar to the stone.

  13. Method for consolidating sand or water control in subterranean formations

    SciTech Connect

    Golinkin, H.S.

    1980-03-18

    A description is given of a method and composition for fracturing a subterranean formation which comprises (1) contacting a subterranean formation with an aqueous liquid comprising a propping agent and a composition containing water, acrylamide:methacrylate copolymer cross-linked with chromium (III) ion, in presence of carbonate ion, oxalate ion, and, optionally, persulfate ion, (2) applying pressure to said liquid, (3) maintaining said pressure to fracture said formation, (4) and said gel breaking within 24 hours of gel formation. The composition without the persulfate gel breaking is also useful for sand consolidation and fluid control.

  14. Renal Stone Risk During Space Flight: Assessment and Countermeasure Validation

    NASA Technical Reports Server (NTRS)

    Whitson, P. A.; Sams, C. F.; Jones, J. A.; Pietrzke, R. A.; Nelman-Gonzalez, M. A.; Hudson, E. K.

    2007-01-01

    NASA has focused its future on exploration class missions including the goal of returning to the moon and landing on Mars. With these objectives, humans will experience an extended exposure to the harsh environment of microgravity and the associated negative effects on all the physiological systems of the body. Exposure to microgravity affects human physiology and results in changes to the urinary chemical composition during and after space flight. These changes are associated with an increased risk of renal stone formation. The development of a renal stone would have health consequences for the crewmember and negatively impact the success of the mission. As of January 2007, 15 known symptomatic medical events consistent with urinary calculi have been experienced by 13 U.S. astronauts and Russian cosmonauts. Previous results from both MIR and Shuttle missions have demonstrated an increased risk for renal stone formation. These data have shown decreased urine volume, urinary pH and citrate levels and increased urinary calcium. Citrate, an important urinary inhibitor of calcium-containing renal stones binds with calcium in the urine, thereby reducing the amount of calcium available to form calcium oxalate stones. Urinary citrate also prevents calcium oxalate crystals from aggregating into larger crystals and into renal stones. In addition, citrate makes the urine less acidic which inhibits the development of uric acid stones. Potassium citrate supplementation has been successfully used to treat patients who have formed renal stones. The evaluation of potassium citrate as a countermeasure has been performed during the ISS Expeditions 3-6, 8, 11-13 and is currently in progress during the ISS Expedition 14 mission. Together with the assessment of stone risk and the evaluation of a countermeasure, this investigation provides an educational opportunity to all crewmembers. Individual urinary biochemical profiles are generated and the risk of stone formation is estimated. Increasing fluid intake is recommended to all crewmembers. These results can be used to lower the risk for stone formation through lifestyle, diet changes or therapeutic administration to minimize the risk for stone development. With human presence in microgravity a continuing presence and exploration class missions being planned, maintaining the health and welfare of all crewmembers is critical to the exploration of space.

  15. Use of a calcium tracer to detect stone increments in a rat calcium oxalate xenoplantation model.

    PubMed

    Wang, Shuo; Xu, Qingquan; Huang, Xiaobo; Lin, Jingxing; Wang, Jinxing; Wang, Xiaofeng

    2013-10-01

    The majority of urinary stones have been observed to grow by circular increments in the clinic and in animal studies. However, the mechanism of stone formation has not yet been elucidated. Marking the stone at specific time-points during the growth of the stone is likely to enable the clarification of the mechanisms behind lithogenesis. The objective of this study was to evaluate the role and efficacy of calcium-tracing fluorescence in the labeling of stone lamination in a rat calcium oxalate xenoplantation model. In the rat calcium oxalate xenoplantation model, human renal stone particles, extracted by percutaneous nephrolithotomy, were xenoplanted into the bladders of Wistar rats in a sterile manner. The rats received 1% ethylene glycol in their drinking water, starting from the day following the stone xenoplantation. Two weeks subsequent to this, three calcium-tracing fluorochromes, alizarin complexone, calcein and xylenol orange were administered by intraperitoneal injection. The newly-formed bladder stones were cut into slices and examined using light and fluorescence microscopy. The newly-formed bladder stones had a large variance in size, and circular increments were observed in the sections of the stones. The stones were successfully labeled with calcein and alizarin complexone, although calcein labeling provided superior results. However, the use of xylenol orange did not result in clear labeling. The calcium-tracing fluorochromes, calcein and alizarin complexone may be effectively used to label stone lamination in rat models. PMID:24137297

  16. Solution mining systems and methods for treating hydrocarbon containing formations

    SciTech Connect

    Vinegar, Harold J.; de Rouffignac, Eric Pierre; Schoeling, Lanny Gene

    2009-07-14

    A method for treating an oil shale formation comprising nahcolite is disclosed. The method includes providing a first fluid to a portion of the formation through at least two injection wells. A second fluid is produced from the portion through at least one injection well until at least two injection wells are interconnected such that fluid can flow between the two injection wells. The second fluid includes at least some nahcolite dissolved in the first fluid. The first fluid is injected through one of the interconnected injection wells. The second fluid is produced from at least one of the interconnected injection wells. Heat is provided from one or more heaters to the formation to heat the formation. Hydrocarbon fluids are produced from the formation.

  17. Calcium Oxalate Stones Are Frequently Found Attached to Randall's Plaque

    SciTech Connect

    Matlaga, Brian R.

    2007-04-05

    The exact mechanisms of the crystallization processes that occur during the formation of calcium oxalate calculi are controversial. Over six decades ago, Alexander Randall reported on a series of cadaveric renal units in which he observed calcium salt deposits on the tips of the renal papilla. Randall hypothesized that these deposits, eponymously termed Randall's plaque, would be the ideal site for stone formation, and indeed in a number of specimens he noted small stones attached to the papillae. With the recent advent of digital endoscopic imaging and micro computerized tomography (CT) technology, it is now possible to inspect the renal papilla of living, human stone formers and to study the attached stone with greater scrutiny.

  18. Calcium Oxalate Stones Are Frequently Found Attached to Randall's Plaque

    NASA Astrophysics Data System (ADS)

    Matlaga, Brian R.; Williams, James C.; Evan, Andrew P.; Lingeman, James E.

    2007-04-01

    The exact mechanisms of the crystallization processes that occur during the formation of calcium oxalate calculi are controversial. Over six decades ago, Alexander Randall reported on a series of cadaveric renal units in which he observed calcium salt deposits on the tips of the renal papilla. Randall hypothesized that these deposits, eponymously termed Randall's plaque, would be the ideal site for stone formation, and indeed in a number of specimens he noted small stones attached to the papillae. With the recent advent of digital endoscopic imaging and micro computerized tomography (CT) technology, it is now possible to inspect the renal papilla of living, human stone formers and to study the attached stone with greater scrutiny.

  19. Complicated bile duct stones

    PubMed Central

    Roy, Ashwin; Martin, Derrick

    2013-01-01

    Common bile duct stones (CBDSs) are solid deposits that can either form within the gallbladder or migrate to the common bile duct (CBD), or form de novo in the biliary tree. In the USA around 15% of the population have gallstones and of these, 3% present with symptoms annually. Because of this, there have been major advancements in the management of gallstones and related conditions. Management is based on the patient's risk profile; young and healthy patients are likely to be recommended for surgery and elderly patients with comorbidities are usually recommended for endoscopic procedures. Imaging of gallstones has advanced in the last 30 years with endoscopic retrograde cholangiopancreatography evolving from a diagnostic to a therapeutic procedure in removing CBDSs. We present a complicated case of a patient with a CBDS and periampullary diverticulum and discuss the techniques used to diagnose and remove the stone from the biliary system. PMID:23946532

  20. Complicated bile duct stones.

    PubMed

    Roy, Ashwin; Martin, Derrick

    2013-01-01

    Common bile duct stones (CBDSs) are solid deposits that can either form within the gallbladder or migrate to the common bile duct (CBD), or form de novo in the biliary tree. In the USA around 15% of the population have gallstones and of these, 3% present with symptoms annually. Because of this, there have been major advancements in the management of gallstones and related conditions. Management is based on the patient's risk profile; young and healthy patients are likely to be recommended for surgery and elderly patients with comorbidities are usually recommended for endoscopic procedures. Imaging of gallstones has advanced in the last 30 years with endoscopic retrograde cholangiopancreatography evolving from a diagnostic to a therapeutic procedure in removing CBDSs. We present a complicated case of a patient with a CBDS and periampullary diverticulum and discuss the techniques used to diagnose and remove the stone from the biliary system. PMID:23946532

  1. Field measurement of erosion rates: time-lapse monitoring of rapid stone flaking at Howden Minster, UK

    NASA Astrophysics Data System (ADS)

    Doehne, E.; Pinchin, S.

    2012-04-01

    The use of a solar-powered, field time-lapse camera and environmental monitoring system enabled measurements of the pattern and rate of loss of stone from the surface of Howden Minster, an abandoned monastery in Yorkshire dating to 1380 AD. Acquiring a photograph every 1-3 hours allowed the stone damage to be correlated with local environmental conditions. Image comparison techniques borrowed from observational astronomy, such as blink comparison, were used to determine what elements had changed from image to image. Results indicate that loss is episodic rather than continuous and in several cases is related to specific environmental conditions, such as condensation/dew formation or high winds. Damage was found also to be synchronous, with surface change (flaking, granular disintegration, and loss of flakes) occurring at the same time on different stone blocks. Crystallization pressure from magnesium sulfate phase transitions appear to be the main cause of the loss of stone surfaces. Significant variation in surface loss rates was observed and appears to be related to variations in salt concentration. An examination of stone texture by ESEM/EDS revealed signification variations and suggests that salt concentrations are controlled in part by stone micromorphology. Quantitative data on rates of surface loss are not available from most monuments. Time-lapse methods permit the relatively inexpensive acquisition of this type of data, which is needed to aid conservation decision-making and the evaluation of interventions. Such tools should also prove useful to geomorphologists studying honeycomb weathering, the moving rocks on Death Valley's Racetrack Playa, and other phenomena that are otherwise difficult to study. Context: The rapid deterioration of magnesian limestone structures in the north of England has been a serious problem for more than one hundred years. While air quality in England has improved during this period, the rate of stone loss in these carved stone structures has not slowed. Thus far, conventional stone conservation treatments have not been successful in mitigating this decay, and large-scale stone replacement has been proposed to deal with the problem for buildings such as York Minster and the world heritage site of Fountains Abbey.

  2. Tracking kidney stones with sound during shock wave lithotripsy

    NASA Astrophysics Data System (ADS)

    Kracht, Jonathan M.

    The prevalence of kidney stones has increased significantly over the past decades. One of the primary treatments for kidney stones is shock wave lithotripsy which focuses acoustic shock waves onto the stone in order to fragment it into pieces that are small enough to pass naturally. This typically requires a few thousand shock waves delivered at a rate of about 2 Hz. Although lithotripsy is the only non-invasive treatment option for kidney stories, both acute and chronic complications have been identified which could be reduced if fewer shock waves were used. One factor that could be used to reduce the number of shock waves is accounting for the motion of the stone which causes a portion of the delivered shock waves to miss the stone, yielding no therapeutic benefit. Therefore identifying when the stone is not in focus would allow tissue to be spared without affecting fragmentation. The goal of this thesis is to investigate acoustic methods to track the stone in real-time during lithotripsy in order to minimize poorly-targeted shock waves. A relatively small number of low frequency ultrasound transducers were used in pulse-echo mode and a novel optimization routine based on time-of-flight triangulation is used to determine stone location. It was shown that the accuracy of the localization may be estimated without knowing the true stone location. This method performed well in preliminary experiments but the inclusion of tissue-like aberrating layers reduced the accuracy of the localization. Therefore a hybrid imaging technique employing DORT (Decomposition of the Time Reversal Operator) and the MUSIC (Multiple Signal Classification) algorithm was developed. This method was able to localize kidney stories to within a few millimeters even in the presence of an aberrating layer. This would be sufficient accuracy for targeting lithotripter shock waves. The conclusion of this work is that tracking kidney stones with low frequency ultrasound should be effective clinically.

  3. Technetium Getters to Improve Cast Stone Performance

    SciTech Connect

    Neeway, James J.; Lawter, Amanda R.; Serne, R. Jeffrey; Asmussen, Robert M.; Qafoku, Nikolla

    2015-10-15

    The cementitious material known as Cast Stone has been selected as the preferred waste form for solidification of aqueous secondary liquid effluents from the Hanford Tank Waste Treatment and Immobilization Plant (WTP) process condensates and low-activity waste (LAW) melter off-gas caustic scrubber effluents. Cast Stone is also being evaluated as a supplemental immobilization technology to provide the necessary LAW treatment capacity to complete the Hanford tank waste cleanup mission in a timely and cost effective manner. Two radionuclides of particular concern in these waste streams are technetium-99 (99Tc) and iodine-129 (129I). These radioactive tank waste components contribute the most to the environmental impacts associated with the cleanup of the Hanford site. A recent environmental assessment of Cast Stone performance, which assumes a diffusion controlled release of contaminants from the waste form, calculates groundwater in excess of the allowable maximum permissible concentrations for both contaminants. There is, therefore, a need and an opportunity to improve the retention of both 99Tc and 129I in Cast Stone. One method to improve the performance of Cast Stone is through the addition of “getters” that selectively sequester Tc and I, therefore reducing their diffusion out of Cast Stone. In this paper, we present results of Tc and I removal from solution with various getters with batch sorption experiments conducted in deionized water (DIW) and a highly caustic 7.8 M Na Ave LAW simulant. In general, the data show that the selected getters are effective in DIW but their performance is comprised when experiments are performed with the 7.8 M Na Ave LAW simulant. Reasons for the mitigated performance in the LAW simulant may be due to competition with Cr present in the 7.8 M Na Ave LAW simulant and to a pH effect.

  4. The Efficacy of Medical Expulsive Therapy (MET) in Improving Stone-free Rate and Stone Expulsion Time, After Extracorporeal Shock Wave Lithotripsy (SWL) for Upper Urinary Stones: A Systematic Review and Meta-analysis.

    PubMed

    Skolarikos, Andreas; Grivas, Nikolaos; Kallidonis, Panagiotis; Mourmouris, Panagiotis; Rountos, Thomas; Fiamegos, Alexandros; Stavrou, Sotirios; Venetis, Chris

    2015-12-01

    In this meta-analysis, we included randomized studies on medical expulsive therapy implemented following shock wave lithotripsy for renal and ureteral stones. Pooled results demonstrated the efficacy of α-blockers, nifedipine, Rowatinex, and Uriston in increasing stone clearance. In addition, the time to stone elimination, the intensity of pain, the formation of steinstrasse, and the need for auxiliary procedures were reduced mainly with α-blockers. Expulsion rate was not correlated with the type of α-blocker, the diameter, and the location of stone. Our results show that medical expulsive therapy for residual fragments after shock wave lithotripsy should be implemented in clinical practice. PMID:26383613

  5. The effect of preincubation of seed crystals of uric acid and monosodium urate with undiluted human urine to induce precipitation of calcium oxalate in vitro : implications for urinary stone formation.

    PubMed Central

    Grover, Phulwinder K.; Ryall, Rosemary L.

    2002-01-01

    BACKGROUND: Previous studies demonstrated that crystals of uric acid (UA) and sodium urate (NaU) can induce the precipitation of calcium oxalate (CaOx) from its inorganic metastable solutions, but similar effects have not been unequivocally shown to occur in urine. The aim of this investigation was to determine whether preincubation of these seeds with urine alter their ability to induce deposition of CaOx from solution and thus provide a possible explanation for discrepancy of results obtained from aqueous inorganic solutions and undiluted urine. MATERIALS AND METHODS: The effects of commercial seed crystals of UA, NaU and CaOx (6 mg/100 ml) on CaOx crystallization were compared in a solution with the same crystals that had been preincubated for 3 hours with healthy male urine. A Coulter Counter was used to follow the crystallization and decrease in soluble (14) C-oxalate was measured to determine the deposition of CaOx. The precipitated particles were examined by scanning electron microscopy (SEM). The preincubated seeds were demineralized and proteins released were analyzed by sodium dodecylsulphate polyacrylamide gel electrophoresis (SDS-PAGE). RESULTS: Analysis of (14) C-oxalate data revealed that while treated UA seeds did not affect CaOx deposition, those of NaU and CaOx inhibited the process by 51.9 (p<0.05) and 8.5% (p<0.05) relative to their respective untreated counterparts. Particle size analysis showed that the average modal sizes of particles precipitated in the presence of treated seed crystals of UA, NaU, and CaOx were very similar to those deposited in the presence of their respective untreated controls. These findings were confirmed by SEM which also showed that seed crystals of UA and NaU, untreated and treated, were attached like barnacles upon the surfaces of CaOx crystals which themselves were bigger than those precipitated in the presence of CaOx seeds. SDS-PAGE analysis of the demineralized treated seeds showed that they all selectively adsorbed urinary proteins, and perhaps other urinary macromolecules and low molecular weight components, on their surface. CONCLUSIONS: It was concluded that preincubation with urine, such as occurs in vivo, only slightly reduces the ability of seed crystals of CaOx, but not of UA, to cause deposition of CaOx. The most striking effect was on NaU seeds where the preincubation quite dramatically attenuated their promotory effect on the mineral deposition. This may explain the discrepancy between findings of studies carried out in inorganic solutions and undiluted human urine. This stresses the invalidity of directly extrapolating results obtained in inorganic solutions to likely effects in urine and more importantly, on stone formation. PMID:12456991

  6. [Reproduction of interocclusal relationship on stone casts].

    PubMed

    Arai, Y

    2000-12-01

    We fabricate a prosthesis by the indirect method. To fabricate a prosthesis functionally harmonized with the stomatognathic system, the interocclusal relationship must be reproduced on stone casts as accurately as possible. In this study, two subjects (one male, age 28; one female, age 31) were selected, and the occlusal contacts of complete arch stone casts made by three different impression methods were observed and compared with the true occlusal contacts in the intercuspal position in the mouth. To take the interocclusal records, we used a silicone bite checker. The following results were obtained. The occlusal contact points reproduced on the stone casts made by a conventional custom tray and a stock tray were rather low; that is, the number of occlusal contact points was less, and the size of the occlusal contact area was smaller, than in vivo. The states of the occlusal contact on the casts made by the same method differed from each other. On the bite-impression technique, the reproduction of occlusal contact was superior to that of the others. The shape, area, and number of contact regions under 60 micrometers were similar to contact regions under 30 micrometers in the mouth. There was no significant difference in reproduction between the custom tray and the stock tray. It is likely that the results were due to the distortion of the jaws and periodontal tissue during clenching at the intercuspal position, which could not be reproduced on the stone casts made by both the conventional custom and stock trays. PMID:11201196

  7. Peeping into Human Renal Calcium Oxalate Stone Matrix: Characterization of Novel Proteins Involved in the Intricate Mechanism of Urolithiasis

    PubMed Central

    Tandon, Chanderdeep

    2013-01-01

    Background The increasing number of patients suffering from urolithiasis represents one of the major challenges which nephrologists face worldwide today. For enhancing therapeutic outcomes of this disease, the pathogenic basis for the formation of renal stones is the need of hour. Proteins are found as major component in human renal stone matrix and are considered to have a potential role in crystal–membrane interaction, crystal growth and stone formation but their role in urolithiasis still remains obscure. Methods Proteins were isolated from the matrix of human CaOx containing kidney stones. Proteins having MW>3 kDa were subjected to anion exchange chromatography followed by molecular-sieve chromatography. The effect of these purified proteins was tested against CaOx nucleation and growth and on oxalate injured Madin–Darby Canine Kidney (MDCK) renal epithelial cells for their activity. Proteins were identified by Matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF MS) followed by database search with MASCOT server. In silico molecular interaction studies with CaOx crystals were also investigated. Results Five proteins were identified from the matrix of calcium oxalate kidney stones by MALDI-TOF MS followed by database search with MASCOT server with the competence to control the stone formation process. Out of which two proteins were promoters, two were inhibitors and one protein had a dual activity of both inhibition and promotion towards CaOx nucleation and growth. Further molecular modelling calculations revealed the mode of interaction of these proteins with CaOx at the molecular level. Conclusions We identified and characterized Ethanolamine-phosphate cytidylyltransferase, Ras GTPase-activating-like protein, UDP-glucose:glycoprotein glucosyltransferase 2, RIMS-binding protein 3A, Macrophage-capping protein as novel proteins from the matrix of human calcium oxalate stone which play a critical role in kidney stone formation. Thus, these proteins having potential to modulate calcium oxalate crystallization will throw light on understanding and controlling urolithiasis in humans. PMID:23894559

  8. Method for ion implantation induced embedded particle formation via reduction

    DOEpatents

    Hampikian, Janet M; Hunt, Eden M

    2001-01-01

    A method for ion implantation induced embedded particle formation via reduction with the steps of ion implantation with an ion/element that will chemically reduce the chosen substrate material, implantation of the ion/element to a sufficient concentration and at a sufficient energy for particle formation, and control of the temperature of the substrate during implantation. A preferred embodiment includes the formation of particles which are nano-dimensional (<100 m-n in size). The phase of the particles may be affected by control of the substrate temperature during and/or after the ion implantation process.

  9. Stone Polygons: Self-Organization Assisted by Noise

    NASA Astrophysics Data System (ADS)

    Fang, M.; Hager, B. H.

    2002-12-01

    Polygonal patterns formed by sorted gravel are commonly found on flat surfaces where water drainage is poor because of underlying permafrost. The similarity in pattern of these stone polygons with Rayleigh-Benard thermal convection cells is intriguing. There is even a suggestion that stone polygons are formed by Rayleigh-Benard convection of water through the underlying porous soil (Kranz et al, 1983). Recent developments in understanding the microphysical mechanisms of frost heaving (e.g. Wettlaufer, 1999; Zhu et al 2000) reinforce the conventional view that the freeze-thawing cycle of ice is the primary natural agent for this pattern formation. Mathematically, a large body of solutions to problems in pattern formation can be attributed to the reaction-diffusion system. There is a subtle difference, however, between systems like Rayleigh-Benard convection cells and stone polygons: The latter are formed in a noisy natural environment, the former in a highly controlled laboratory environment. In other words, the effects of large sources of noise must be accounted for explicitly in understanding the pattern formation of stone polygons. A distribution of stone polygons formed cooperatively results from sorting among water, soil, and stones controlled by weather changes. We propose a nonlinear reaction-diffusion type of model for this coupled process. We consider the incremental population density of stones (positive or negative relative to the initial uniform distribution). The positive feedback between freeze-thaw cycles and the local stone accumulation (positive or negative) is modeled by a linear production term, while the gravitational reconfiguration gives rise to a cubic nonlinear saturation term. Noise due to fluctuations of the environment is represented by the diffusion term. Similar systems have emerged in wide ranges of physical and chemical problems, yet most of the investigations in the other fields are on stability fields associated with varying control parameters. Our interest here is on pattern formation, especially the role played by the nonlinear effects. We use the difference equation to represent inaccuracy in the physical model and the discreteness of the stones. Preliminary calculations at steady state demonstrate that the cubic nonlinear term has a strong influence, and mostly favors the formation of hexagonal patterns. Formation of stone stripes can be accounted for by adding a gradient term along the downhill direction.

  10. Ultrasonic propulsion of kidney stones

    PubMed Central

    May, Philip C.; Bailey, Michael R.; Harper, Jonathan D.

    2016-01-01

    Purpose of review Ultrasonic propulsion is a novel technique that uses short bursts of focused ultrasonic pulses to reposition stones transcutaneously within the renal collecting system and ureter. The purpose of this review is to discuss the initial testing of effectiveness and safety, directions for refinement of technique and technology, and opinions on clinical application. Recent findings Preclinical studies with a range of probes, interfaces, and outputs have demonstrated feasibility and consistent safety of ultrasonic propulsion with room for increased outputs and refinement toward specific applications. Ultrasonic propulsion was used painlessly and without adverse events to reposition stones in 14 of 15 human study participants without restrictions on patient size, stone size, or stone location. The initial feasibility study showed applicability in a range of clinically relevant situations, including facilitating passage of residual fragments following ureteroscopy or shock wave lithotripsy, moving a large stone at the UPJ with relief of pain, and differentiating large stones from a collection of small fragments. Summary Ultrasonic propulsion shows promise as an office-based system for transcutaneously repositioning kidney stones. Potential applications include facilitating expulsion of residual fragments following ureteroscopy or shock wave lithotripsy, repositioning stones prior to treatment, and repositioning obstructing UPJ stones into the kidney to alleviate acute renal colic. PMID:26845428

  11. Automated visual inspection for polished stone manufacture

    NASA Astrophysics Data System (ADS)

    Smith, Melvyn L.; Smith, Lyndon N.

    2003-05-01

    Increased globalisation of the ornamental stone market has lead to increased competition and more rigorous product quality requirements. As such, there are strong motivators to introduce new, more effective, inspection technologies that will help enable stone processors to reduce costs, improve quality and improve productivity. Natural stone surfaces may contain a mixture of complex two-dimensional (2D) patterns and three-dimensional (3D) features. The challenge in terms of automated inspection is to develop systems able to reliably identify 3D topographic defects, either naturally occurring or resulting from polishing, in the presence of concomitant complex 2D stochastic colour patterns. The resulting real-time analysis of the defects may be used in adaptive process control, in order to avoid the wasteful production of defective product. An innovative approach, using structured light and based upon an adaptation of the photometric stereo method, has been pioneered and developed at UWE to isolate and characterize mixed 2D and 3D surface features. The method is able to undertake tasks considered beyond the capabilities of existing surface inspection techniques. The approach has been successfully applied to real stone samples, and a selection of experimental results is presented.

  12. Stone Columns - Determination of the soil improvement factor

    NASA Astrophysics Data System (ADS)

    Pivar?, J.

    2011-09-01

    A stone column is one of the soil stabilizing methods that is used to increase strength, decrease the compressibility of soft and loose fine graded soils, accelerate a consolidation effect and reduce the liquefaction potential of soils. The columns consist of compacted gravel or crushed stone arranged by a vibrator. This paper deals with Priebe's theory (1976) on the design of an improvement factor, which belongs among the most used analytical methods and also describes the numerical and laboratory models of stone columns. The improvement factors calculated from numerical and laboratory models are compared with the improvement factors resulting from Priebe's theory.

  13. Calcium Stone Growth in Urine from Cystic Fibrosis Patients and Healthy Controls

    NASA Astrophysics Data System (ADS)

    McSorley, Anita; Jones, Andrew M.; Webb, A. Kevin; Rao, P. Nagaraj; Kavanagh, John P.

    2007-04-01

    Cystic fibrosis patients have an increased risk of renal stone disease. There is some evidence that this may be related to a different excretory pattern of stone risk factors, but an alternative hypothesis, that the urine of cystic fibrosis patients is deficient in urinary inhibitors of crystallization and stone formation has not been tested. Here we have grown calcium stones, in vitro, in the presence of urine from healthy controls and compared this with growth in the presence of urine from cystic fibrosis patients. A stone farm was used to grow twelve calcium stones simultaneously, firstly in artificial urine for about 200 hours and then in 90% whole human urine for another 500 hours. Six of the stones received urine from healthy controls and six received urine from adult cystic fibrosis patients. There were no significant differences in stone mass at any of the key time points or in the overall growth pattern (p>0.05) between stones destined for, or treated with, urine from CF patients and the controls. Human urine greatly inhibited stone growth in vitro but there was no difference in the growth rate in urine from healthy controls and CF patients. This refutes the hypothesis that a tendency for a higher prevalence of urinary stones in CF patients is related to a deficiency in inhibitory activity.

  14. Semi-rigid ureteroscopy: Proximal versus distal ureteral stones

    PubMed Central

    Alameddine, Mahmoud; Azab, Mohamad M.; Nassir, Anmar A.

    2016-01-01

    Objective: To evaluate the safety and efficacy of semi-rigid ureteroscopy in proximal and distal ureteral stones, and to compare the operative and perioperative characteristics between the two stone groups. Materials and Methods: We retrospectively reviewed the medical records of patients who underwent semi-rigid ureteroscopy for management of ureteral stones at the International Medical Center between June 2007 and September 2012. All stones were fragmented using Holmium: yttrium-aluminum-garnet (YAG) laser lithotripter. Stones located above the pelvic brim are considered proximal and below it are distal. Results: One hundred and ninety-one patients were included. One hundred and three patients (54%) underwent ureteroscopy for proximal stones and 88 (46%) for distal stones. The stone size in the proximal group was 10 mm (±5.5) versus 8.6 mm (±5) in the distal group. The initial stone-free rate for proximal and distal calculi were 89–98.2%, respectively. The perioperative complication rate was higher in the proximal group 10% compared to the distal group which is 1.5% (P = 0.06). Both groups have the same average of hospital stay 1.2 days. Conclusion: Although there is a clinical difference between proximal and distal calculi groups in terms of complication and stone-free rates, this difference remained statistically insignificant (P = 0.06). Using a smaller caliber semi-rigid ureteroscopy combined with Holmium-YAG laser can be carried out as a day care procedure and showed a slightly higher risk in patients with proximal ureteral calculi which should be explained to the patient PMID:26834409

  15. Lunar tractive forces and renal stone incidence.

    PubMed

    Arampatzis, Spyridon; Thalmann, George N; Zimmermann, Heinz; Exadaktylos, Aristomenis K

    2011-01-01

    Background. Several factors are implicated in renal stone formation and peak incidence of renal colic admissions to emergency departments (ED). Little is known about the influence of potential environmental triggers such as lunar gravitational forces. We conducted a retrospective study to test the hypothesis that the incidence of symptomatic renal colics increases at the time of the full and new moon because of increased lunar gravitational forces. Methods. We analysed 1500 patients who attended our ED between 2000 and 2010 because of nephrolithiasis-induced renal colic. The lunar phases were defined as full moon ± 1 day, new moon ± 1 day, and the days in-between as "normal" days. Results. During this 11-year period, 156 cases of acute nephrolithiasis were diagnosed at the time of a full moon and 146 at the time of a new moon (mean of 0.4 per day for both). 1198 cases were diagnosed on "normal" days (mean 0.4 per day). The incidence of nephrolithiasis in peak and other lunar gravitational phases, the circannual variation and the gender-specific analysis showed no statistically significant differences. Conclusion. In this adequate powered longitudinal study, changes in tractive force during the different lunar phases did not influence the incidence of renal colic admissions in emergency department. PMID:22046548

  16. Our Modern Stone Age

    NASA Astrophysics Data System (ADS)

    Lowry, W. D.

    Unlike most books dealing with industrial minerals and rocks, Our Modern Stone Age is a pleasure to read. Within a matter of several hours, one can get an excellent introduction to nonmetallic mineral resources and industries exclusive o f the mineral fuels. The book is very well written and well illustrated with photographs and drawings; although pitched for the intelligent layman, it is in no way dull reading for even a well-versed economic geologist. Nearly every geologist, mining engineer, mineral economist, planner, and politician will find points of interest in this book.

  17. Decay and preservation of stone in modern environments

    NASA Astrophysics Data System (ADS)

    Gauri, K. Lal

    1990-01-01

    Stone objects decay in all environments, but the modes of decay vary from one region to another. In the modern industrial countries acid deposition has accelerated the decay of stone. Many objects that survived centuries of weathering without serious damage have, in the present century, decomposed beyond recognition. The black crusts seen on stone structures mostly contain gypsum formed by SO2 reactions with calcareous minerals. These crusts exfoliate, destroying the sculptural form. Because of the absence of proven technology to treat and restore these objects, the caryatids at the Acropolis had to be moved indoors to save them from further disfiguration. In arid climates, the salts in stone and the meteorologic conditions combine to disrupt stone structures. The Great Sphinx at Giza is a prominent example of this mode of stone decay. In humid, tropical regions, such as in southern India, hydrolysis disrupts the mineral structure, causing rapid damage even to such durable stone as granite. The human effort to save the deteriorating structures has often aggravated the problem. The sandstone at the Legislative Building in Olympia, Washington has, because of the “protective” acrylic coating, suffered greater damage than the similar but unprotected sandstone at a nearby school building. It appears that proper management can greatly help to reduce the decay of the stone. A scientifically designed cleaning can inhibit the formation of crusts and the accumulation of efflorescences. The absence of the crusts and efflorescence and application of appropriate impregnants, which consolidate yet maintain the "breathability" of stone, may prolong the life of historic structures.

  18. Method for maximizing shale oil recovery from an underground formation

    DOEpatents

    Sisemore, Clyde J.

    1980-01-01

    A method for maximizing shale oil recovery from an underground oil shale formation which has previously been processed by in situ retorting such that there is provided in the formation a column of substantially intact oil shale intervening between adjacent spent retorts, which method includes the steps of back filling the spent retorts with an aqueous slurry of spent shale. The slurry is permitted to harden into a cement-like substance which stabilizes the spent retorts. Shale oil is then recovered from the intervening column of intact oil shale by retorting the column in situ, the stabilized spent retorts providing support for the newly developed retorts.

  19. Method for formation stimulation in horizontal wellbores using hydraulic fracturing

    SciTech Connect

    Jennings, A.R. Jr.

    1990-07-03

    This patent describes a method for stimulating a formation penetrated by a horizontal wellbore. It comprises: perforating a horizontal wellbore along its top side at desired intervals so as to enable fluid communication with the formation; fracturing hydraulically the formation through perforations in the wellbore with a fracturing fluid containing a substantially lightweight proppant which has a density substantially equal to the fluid thereby creating a fracture within a first interval of the formation and maximizing multilayer proppant placement within the fracture; releasing hydraulic pressure on the formation thereby causing the fracture to be propped with the proppant; placing ball sealers in the fracturing fluid in an amount sufficient to close perforations in the wellbore adjacent the first interval; applying pressure in an amount sufficient to fracture the formation in an area adjacent to the first interval. This causes the ball sealers to seal off perforations in the first interval and direct fluid into a second perforated interval of the wellbore thereby fracturing the formation adjacent to the second interval; and releasing pressure applied to the fluid thereby maximizing multilayer proppant placement and causing the ball sealers to float upwardly with the fluid through the wellbore where they are recovered.

  20. Kidney Stones in Children and Teens

    MedlinePlus

    ... Issues Listen Español Text Size Email Print Share Kidney Stones in Children and Teens Page Content Article Body ​ ... teen girls having the highest incidence. Types of Kidney Stones There are many different types of kidney stones ...

  1. Environmental management of the stone cutting industry.

    PubMed

    Nasserdine, Khaled; Mimi, Ziad; Bevan, Blair; Elian, Belal

    2009-01-01

    Environmental Management of the stone cutting industry in Hebron is required to reduce the industry's adverse impact on the downstream agricultural land and the adverse impact on the drinking water aquifers. This situation requires the implementation of an industrial wastewater management strategic approach and technology, within the available technical and financial resources. Ten pilot projects at different locations were built at Hebron to reduce or eliminate the incompatible discharge of the liquid and solid waste to the environment and improve the stone cutting industry's effluent quality. A review of existing practices and jar test experiments were used to optimize the water recycling and treatment facilities. The factors reviewed included influent pumping rates and cycles, selection of the optimal coagulant type and addition methods, control of the sludge recycling process, control over flow rates, control locations of influent and effluent, and sludge depth. Based on the optimized doses and Turbidity results, it was determined that the use of Fokland polymer with an optimal dose of 1.5mg/L could achieve the target turbidity levels. The completion of the pilot projects resulted in the elimination of stone cutting waste discharges and an improvement in the recycled effluent quality of 44-99%. This in turn reduced the long term operating costs for each participating firm. A full-scale project that includes all the stone cutting firms in Hebron industrial area is required. PMID:18248874

  2. Hyaluronan and Stone Disease

    NASA Astrophysics Data System (ADS)

    Asselman, Marino

    2008-09-01

    Kidney stones cannot be formed as long as crystals are passed in the urine. However, when crystals are retained it becomes possible for them to aggregate and form a stone. Crystals are expected to be formed not earlier than the distal tubules and collecting ducts. Studies both in vitro and in vivo demonstrate that calcium oxalate monohydrate crystals do not adhere to intact distal epithelium, but only when the epithelium is proliferating or regenerating, so that it possesses dedifferentiated cells expressing hyaluronan, osteopontin (OPN) and their mutual receptor CD44 at the apical cell membrane. The polysaccharide hyaluronan is an excellent crystal binding molecule because of its negative ionic charge. We hypothesized that the risk for crystal retention in the human kidney would be increased when tubular cells express hyaluronan at their apical cell membrane. Two different patient categories in which nephrocalcinosis frequently occurs were studied to test this hypothesis (preterm neonates and kidney transplant patients). Hyaluronan (and OPN) expression at the luminal membrane of tubular cells indeed was observed, which preceded subsequent retention of crystals in the distal tubules. Tubular nephrocalcinosis has been reported to be associated with decline of renal function and thus further studies to extend our knowledge of the mechanisms of retention and accumulation of crystals in the kidney are warranted. Ultimately, this may allow the design of new strategies for the prevention and treatment of both nephrocalcinosis and nephrolithiasis in patients.

  3. Scottish Short Stone Rows

    NASA Astrophysics Data System (ADS)

    Ruggles, Clive L. N.

    Short stone rows received a good deal of attention during the 1980s and 1990s, at a time when archaeoastronomy in prehistoric Britain and Ireland was moving beyond reassessments of Alexander Thom's "megalithic observatories" by identifying coherent groups of similar monuments with clear orientation trends. Many such rows are found in western Scotland, with the main concentration in Argyll and the island of Mull. Systematic analyses of their orientations produced credible evidence of an awareness of the 18.6-year lunar node cycle, within a "primary-secondary" pattern whereby isolated rows were oriented close to moonrise or moonset at the southern major standstill limit, while others oriented in this way were accompanied by a second row oriented in a declination range that could be interpreted either as lunar or solar. A detailed investigation of the landscape situation of the sites in northern Mull, accompanied by excavations at two of the sites, suggested that they were deliberately placed in locations where critical moonsets would be seen against prominent distant landscape features, but where the distant horizon in most or all other directions was hidden from view. A lack of independent archaeological evidence may help to explain why archaeoastronomical investigations at short stone rows have never progressed beyond "data-driven" studies of orientations and landscape situation. Nonetheless, the work that was done at these sites raised important general methodological issues, and pioneered techniques, that remain relevant across archaeoastronomy today.

  4. Recumbent Stone Circles

    NASA Astrophysics Data System (ADS)

    Ruggles, Clive L. N.

    During the 1970s and early 1980s, British archaeoastronomers were striving to bridge the interpretative gulf between the "megalithic observatories" of Alexander Thom and an archaeological mainstream that, generally speaking, was hostile to any mention of astronomy in relation to the megalithic monuments of Neolithic and Early Bronze Age Britain. The Scottish recumbent stone circles (RSCs) came to represent an example where sounder methodology could overcome many of the data selection issues that had beset earlier studies and, with due restraint, produce credible interpretations. Systematic studies of their orientations consistently concluded that the RSCs had a strong lunar connection, and it was widely envisaged that they were the setting for ceremonies associated with the appearance of the moon over the recumbent stone. Other evidence such as the presence of white quartz and the spatial distribution of cupmarks appeared to back up this conclusion. New archaeological investigations since 1999 have challenged and modified these conclusions, confirming in particular that the circles were built to enclose cairns rather than to demarcate open spaces. Yet the restricted pattern of orientations of these structures could only have been achieved by reference to the basic diurnal motions of the skies, and orientation in relation to simple observations of the midsummer moon remains the most likely reading of the alignment evidence taken as a whole. On the other hand, a consideration of the broader context, which includes the nearby Clava cairns, highlights instead the symbolic importance of the sun.

  5. Physicochemical basis for formation of renal stones of calcium phosphate origin: calculation of the degree of saturation of urine with respect to brushite

    PubMed Central

    Pak, Charles Y. C.

    1969-01-01

    Brushite (CaHPO4·2H2O) was considered to govern the formation of renal calculus of calcium phosphate origin. The degree of saturation of urine with respect to this phase was therefore calculated. This value was obtained from the ratio of the activity product of Ca++ and HPO4m (Ksp) before and after incubation of urine with brushite. The errors in the calculation of Ksp were largely eliminated by this procedure. The urine of patients with idiopathic hypercalciuria and recurrent calcium-containing renal calculi was supersaturated with respect to brushit largely because of the high urinary concentration of Ca++. The urine of normocalciuric subjects was undersaturated except at high urinary pH. This technique of estimating the degree of saturation of urine should allow a quantitative assessment of the various therapeutic regimens recommended for patients with nephrolithiasis. PMID:5822595

  6. A New Group-Formation Method for Student Projects

    ERIC Educational Resources Information Center

    Borges, Jose; Dias, Teresa Galvao; Cunha, Joao Falcao E.

    2009-01-01

    In BSc/MSc engineering programmes at Faculty of Engineering of the University of Porto (FEUP), the need to provide students with teamwork experiences close to a real world environment was identified as an important issue. A new group-formation method that aims to provide an enriching teamwork experience is proposed. Students are asked to answer a…

  7. A New Group-Formation Method for Student Projects

    ERIC Educational Resources Information Center

    Borges, Jose; Dias, Teresa Galvao; Cunha, Joao Falcao E.

    2009-01-01

    In BSc/MSc engineering programmes at Faculty of Engineering of the University of Porto (FEUP), the need to provide students with teamwork experiences close to a real world environment was identified as an important issue. A new group-formation method that aims to provide an enriching teamwork experience is proposed. Students are asked to answer a

  8. Methods for retarding coke formation during pyrolytic hydrocarbon processing

    SciTech Connect

    Forester, D.R.

    1989-12-26

    This patent describes a method of inhibiting the formation and deposition of pyrolytic coke on the heated metal surfaces of the structural and associated parts of a pyrolysis furnace which is being used to crack a petroleum feedstock to produce lower and/or olefinic hydrocarbon fractions. The method comprises adding to the feedstock a coke inhibiting amount of a compound selected from the group consisting of calcium acetate, magnesium acetate, magnesium nitrate and calcium nitrate.

  9. Extracorporeal shockwave lithotripsy vs. percutaneous nephrolithotomy vs. flexible ureterorenoscopy for lower-pole stones

    PubMed Central

    Knoll, Thomas; Buchholz, Noor; Wendt-Nordahl, Gunnar

    2012-01-01

    Objectives To review previous reports and discuss current trends in extracorporeal shockwave lithotripsy (ESWL), percutaneous nephrolithotomy (PCNL) and ureterorenoscopy (URS). ESWL was recommended as the first-line treatment for small and intermediate-sized stones in the lower pole, while it is the standard treatment for large stones. However, the stone clearance rate after ESWL seems to be lower than that of stones in other locations. This seems to result from a lower rate of fragment passage, due to anatomical factors. Methods Reports on urinary stone disease were reviewed, assessing only publications in peer-reviewed, Medline-listed journals in the English language (publication years 1990–2011). Results Recent experience with flexible URS (fURS) for intrarenal stones showed that excellent stone-free rates can be achieved. With increasing experience and technically improved equipment, fURS has become an alternative to ESWL for small and intermediate-sized renal stones. Furthermore, several authors reported successful retrograde treatment for large renal stones, proposing fURS as an alternative to PCNL. However, the major drawbacks are long operating times and commonly, staged procedures, which is why PCNL remains the method of choice for such stones. Conclusions Considering the currents trends and evidence, the 2012 update of the European Association of Urology Guidelines on Urolithiasis has upgraded the endourological treatment of kidney stones. Individual factors such as body habitus, renal anatomy, costs and patient preference must be considered. PMID:26558046

  10. Predicting stone composition before treatment – can it really drive clinical decisions?

    PubMed Central

    Bres–Niewada, Ewa; Radziszewski, Piotr

    2014-01-01

    Introduction Determination of stone composition is considered to be crucial for the choice of an optimal treatment algorithm. It is especially important for uric acid stones, which can be dissolved by oral chemolysis and for renal stones smaller than 2 cm, which can be treated with extracorporeal shockwave lithotripsy (ESWL). Material and methods This short review identifies the latest papers on radiological assessment of stone composition and presents a comprehensive evaluation of current scientific findings. Results Stone chemical composition is difficult to predict using standard CT imaging, however, attenuation index measured in Hounsfield units (HU) is related to ESWL outcome. Stone density >1000 HU can be considered predictive for ESWL failure. It seems that stone composition is meaningless in determining the outcome of ureterolithotripsy and percutaneous surgery. Alternative imaging techniques such as Dual–Energy CT or analysis of shape, density and homogeneity of stones on plain X–rays are used as promising methods of predicting stone composition and ESWL outcome. Conclusions New imaging techniques facilitate the identification of uric acid stones and ESWL–resistant stones. Therefore, they may help in selecting the best therapeutic option. PMID:25667761

  11. A 2x2 multi-chip reconfigurable MOEMS mask: a stepping stone to large format microshutter arrays for coded aperture applications

    NASA Astrophysics Data System (ADS)

    McNie, Mark E.; Brown, Alan G.; King, David O.; Smith, Gilbert W.; Gordon, Neil T.; Riches, Stephen; Rogers, Stanley

    2010-08-01

    Coded aperture imaging has been used for astronomical applications for several years. Typical implementations used a fixed mask pattern and are designed to operate in the X-Ray or gamma ray bands. Recently applications have emerged in the visible and infra red bands for low cost lens-less imaging systems and system studies have shown that considerable advantages in image resolution may accrue from the use of multiple different images of the same scene - requiring a reconfigurable mask. Previously reported work focused on realising a 2x2cm single chip mask in the mid-IR based on polysilicon micro-optoelectro- mechanical systems (MOEMS) technology and its integration with ASIC drive electronics using conventional wire bonding. It employs interference effects to modulate incident light - achieved by tuning a large array of asymmetric Fabry-Perot optical cavities via an applied voltage and uses a hysteretic row/column scheme for addressing. In this paper we report on the latest results in the mid-IR for the single chip reconfigurable MOEMS mask, trials in scaling up to a mask based on a 2x2 multi-chip array and report on progress towards realising a large format mask comprising 44 MOEMS chips. We also explore the potential of such large, transmissive IR spatial light modulator arrays for other applications and in the current and alternative architectures.

  12. Large proximal ureteral stones: Ideal treatment modality?

    PubMed Central

    Kadyan, B.; Sabale, V.; Mane, D.; Satav, V.; Mulay, A.; Thakur, N.; Kankalia, S. P.

    2016-01-01

    Background and Purpose: Ideal treatment modality for patients with large impacted proximal ureteral stone remains controversial. We compared laparoscopic transperitoneal ureterolithotomy (Lap-TPUL) and semirigid ureteroscopy for large proximal ureteric stones to evaluate their efficacy and safety. Patients and Methods: From November 2012 to December 2014, we enrolled 122 patients with large (≥1.5 cm) proximal ureteral stone in the study. Patients were randomly divided into two groups: Group A (60 patients), retrograde ureteroscopic lithotripsy using a semirigid ureteroscope; Group B (62 patients), transperitoneal LU (Lap-TPUL). Results: The overall stone-free rate was 71.6% and 93.5% for Group A and Group B respectively (P = 0.008). Auxiliary procedure rate was higher in Group A than in Group B (27.3% vs. 5.6%). The complication rate was 11.2% in Group B versus 25% in Group A. Mean procedure time was higher in laparoscopy group as compared to ureterorenoscopy (URS) groups (84.07 ± 16.80 vs. 62.82 ± 12.71 min). Hospital stay was 4.16 ± 0.67 days in laparoscopy group and 1.18 ± 0.38 days in URS group (P < 0.0001). Conclusion: Laparoscopic transperitoneal ureterolithotomy is a minimally invasive, safe and effective treatment modality and should be recommended to all patients of impacted large proximal stones, which are not amenable to URS or extracorporeal shock-wave lithotripsy or as a primary modality of choice especially if patient is otherwise candidate for open surgery. PMID:27141190

  13. Method for temporarily reducing permeability of subterranean formations

    SciTech Connect

    Williamson, C.D.; Allenson, S.J.; Gabel, R.K.

    1991-04-23

    This patent describes an improved method for hydraulic fracturing of subterranean formations penetrated by a wellbore. It comprises dispersing in a fracturing media a fluid loss additive to form an improved fracturing media, the fluid loss additive comprising a blend of two or more modified starches; and pumping the improved fracturing media into a wellbore at a pressure sufficient to lift the overburden and fracture the formation, whereby a filter cake with low permeability will be rapidly formed, the filter cake being readily degraded after completion of the fracturing process.

  14. Pears and renal stones: possible weapon for prevention? A comprehensive narrative review.

    PubMed

    Manfredini, R; De Giorgi, A; Storari, A; Fabbian, F

    2016-02-01

    Urinary stones have been recognized as a human disease since dawn of history and treatment of this condition is reported by Egyptian medical writings. Also, pears have a very long history, being one of the earliest cultivated fruit trees and also known for medicinal use. Urinary tract stone formation represents a common condition and also a significant burden for health care service, due also to possible frequent relapses. Furthermore, urinary stones have been reported to have relationship with different metabolic derangements, and appropriate diet could contribute to avoid or reduce urinary stone formation. Citrate is an inhibitor of crystal growth in the urinary system, and hypocitraturia represents a main therapeutical target in stone formers. Pears contain a significant amount of malic acid, a precursor of citrate, and have antioxidant activity as well. A diet supplemented with pears, and associated with low consumption of meat and salt could impact positively cardiometabolic risk and urinary tract stone formation. However, very few studies evaluated the impact of pears utilization on health, and none on urinary tract stone formation in particular. High content in malate could warrant protection against stone formation, avoiding patients at high risk to be compelled to assume a considerable and expensive amount of pills. PMID:26914114

  15. Mitigation of Liquefaction in Sandy Soils Using Stone Columns

    NASA Astrophysics Data System (ADS)

    Selcuk, Levent; Kayabalı, Kamil

    2010-05-01

    Soil liquefaction is one of the leading causes of earthquake-induced damage to structures. Soil improvement methods provide effective solutions to reduce the risk of soil liquefaction. Thus, soil ground treatments are applied using various techniques. However, except for a few ground treatment methods, they generally require a high cost and a lot of time. Especially in order to prevent the risk of soil liquefaction, stone columns conctructed by vibro-systems (vibro-compaction, vibro-replacement) are one of the traditional geotechnical methods. The construction of stone columns not only enhances the ability of clean sand to drain excess pore water during an earthquake, but also increases the relative density of the soil. Thus, this application prevents the development of the excess pore water pressure in sand during earthquakes and keeps the pore pressure ratio below a certain value. This paper presents the stone column methods used against soil liquefaction in detail. At this stage, (a) the performances of the stone columns were investigated in different spacing and diameters of columns during past earthquakes, (b) recent studies about design and field applications of stone columns were presented, and (c) a new design method considering the relative density of soil and the capacity of drenage of columns were explained in sandy soil. Furthermore, with this new method, earthquake performances of the stone columns constructed at different areas were investigated before the 1989 Loma Prieta and the 1994 Northbridge earthquakes, as case histories of field applications, and design charts were compiled for suitable spacing and diameters of stone columns with consideration to the different sandy soil parameters and earhquake conditions. Key Words: Soil improvement, stone column, excess pore water pressure

  16. Ureteral Stone Associated With a Middle Blind Ending of a Bifid Ureter

    PubMed Central

    Çalışkan, Selahattin

    2016-01-01

    A blind-ending bifid ureter is an anatomic variant of ureteral duplications. There are three forms of blind-ending bifid ureter, classified depending on their location. A proximal blind-ending bifid ureter is the most common subtype of this congenital anomaly. Most patients are asymptomatic and only show symptoms after the complication has occurred. These complications include stone formation, vesicoureteric reflux, and ureteral tumor. Intravenous urography is usually used to diagnose bifid ureter; voiding cystourethrography, photofluoroscopy, cineroentgenography, cystoscopy with retrograde pyelography, computed tomography (CT), multidetector CT, and magnetic resonance urographies are other imaging methods used. This is a case of a ureteral stone associated with a middle blind ending of a bifid ureter.

  17. AB094. Upper urinary stone management in China

    PubMed Central

    Wang, Shaogang; Liu, Jihong; Ye, Zhangqun

    2015-01-01

    Objective To give an overview of the contemporary management for upper urinary stones in China. Methods Contemporary treatment methods, especially novel or developing modality with Chinese characteristics, for upper urinary stones in China has been reviewed and introduced. Results Urolithiasis is one of the most prevalent diseases in the urologic clinic and usually affects people aged 20 to 60 years. In recent years, the overall morbidity of urolithiasis in Chinese population has increased with a significant reduction of lower urinary stone and an increase of upper urinary stone. Upper urinary stone may induce more severe complications and have been considered to be the main cause of nephrectomy besides urinary tumor. The management of upper urinary stone can be challenging somehow. Extracorporeal shock wave lithotripsy (ESWL) is usually the first choice for patients with simple upper urinary stone sized 2 cm or less. Recent years, according to the mechanism of lithecbole by vibration and body position, some Chinese urologists have developed a novel machine, external physical vibration lithecbole (EPVL), which can facilitate removal of urinary stone after ESWL or endoscopic lithotripsy. The combination of EPVL therapy with ESWL or endoscopic lithotripsy significantly improves the stone-free rate. Percutaneous nephrolithotomy (PCNL) is increasingly employed as a major modality for patients with large and complex upper urinary stone. The minimally invasive PCNL (mPCNL), which was performed with a miniature endoscope by way of a small size tract (12-20 F), could decrease morbidity, especially uncontrolled hemorrhage. However, its efficiency of removing stone fragments is lower. The Chinese urologists have modified PCNL technique by using an 8/9.8 F rigid ureteroscope through the 14-18 F percutaneous tract under the guidance of ultrasound or X-ray. The results from a series of studies demonstrate that Chinese mPCNL is a safe, feasible and efficient method for treating upper urinary stone with a low complication rate. With the development of technology, flexible ureteroscopy has become one of the main actors in clinical practice over the past several years. Flexible ureteroscopy can reach most parts of the kidney so that all stones can be removed or vaporised provided they are of an appropriate size and accessible. Moreover, flexible ureteroscopy is well tolerated and effective which allows us to obtain a high success rate, low morbidity, and a brief hospital stay. It could be the best option in managing the special patients with multiple intrarenal stones, stone-bearing caliceal diverticula, anticoagulated history, obesity, anomalous kidneys and pregnancy, which are not applicable for ESWL or PCNL. However, the flexible ureteroscopy is much more difficult to handle than the rigid ureteroscope. In addition, the flexible ureteroscope is expensive and easy to be damaged or broken, the treatment cost usually higher than ordinary treatment. In the past decades, some Chinese urologists and engineers have put in a great effort to design novel types of flexible ureteroscope which is cheaper and easier to operate. The integrated flexible and rigid ureteroscope is one of the new designed instruments of which the body is an ordinary rigid ureteroscope but have a flexible end. This novel device could be operated as easy as rigid ureteroscope and the end of ureteroscope could move flexiblely after its entry of the renal pelvis. Several different types of the Chinese flexible ureteroscope have completed the clinical trials and are going to be commercially available. Conclusions Generally, upper urinary stone is one of the most common diseases in urologic department in China and some novel treatment methods with Chinese characteristics has been developed. Each treatment method has advantages and disadvantages. The urologists’ choice of the treatment strategy should be made individually according to the properties of stone and the patient’s body condition.

  18. Bath Stone - a Possible Global Heritage Stone from England

    NASA Astrophysics Data System (ADS)

    Marker, Brian

    2014-05-01

    The Middle Jurassic strata of England have several horizons of oolitic and bioclastic limestones that provide high quality dimension stone. One of the most important is found in and near the City of Bath. The Great Oolite Group (Upper Bathonian) contains the Combe Down and Bath Oolites, consisting of current bedded oolites and shelly oolites, that have been used extensively as freestones for construction nearby, for prestigious buildings through much of southern England and more widely. The stone has been used to some extent since Roman times when the city, then known as Aquae Sulis, was an important hot spa. The stone was used to a limited extent through medieval times but from the early 18th century onwards was exploited on a large scale through surface quarrying and underground mining. The City was extensively redeveloped in the 18th to early 19th century, mostly using Bath Stone, when the spas made it a fashionable resort. Buildings from that period include architectural "gems" such as the Royal Crescent and Pulteney Bridge, as well as the renovated Roman Baths. Many buildings were designed by some of the foremost British architects of the time. The consistent use of this stone gives the City an architectural integrity throughout. These features led to the designation of the City as a World Heritage Site. It is a requirement in current City planning policy documents that Bath Stone should be used for new building to preserve the appearance of the City. More widely the stone was used in major houses (e.g. Buckingham Palace and Apsley House in London; King's Pavilion in Brighton); civic buildings (e.g. Bristol Guildhall; Dartmouth Naval College in Devon); churches and cathedrals (e.g. Truro Cathedral in Cornwall); and engineered structures (e.g. the large Dundas Aqueduct on the Kennet and Avon Canal). More widely, Bath Stone has been used in Union Station in Washington DC; Toronto Bible College and the Town Hall at Cape Town, South Africa. Extraction declined in the late 20th century but several quarries and underground mines remain operational providing stone for the local market, repair and maintenance of historic buildings and for special international projects. Reserves permitted for extraction are substantial and resources are fairly extensive so the stone will be accessible in the long term. Taking such points into account, it is suggested that Bath Stone should be recognised as a Global Heritage Stone Resource.

  19. Treatment options for active removal of renal stones.

    PubMed

    Warmerdam, G J J; De Laet, K; Wijn, R P W F; Wijn, P F F

    2012-04-01

    This study provides an update on the technological aspects of the methods for active removal of renal stones. Currently, extracorporeal shock wave lithotripsy (ESWL), ureteroscopy (URS) and percutaneous nephrolithotomy (PCNL) are the available options. Findings are based upon recent literature from the PubMed database and the European Association of Urology (EAU) guidelines. ESWL remains the option of choice for stones with diameter ≤ 20 mm due to its low invasive character, whereas PCNL is the standard for stones with diameter > 20 mm because of its high stone-free rates. Although ESWL treatment has become more patient friendly, its efficacy has not improved. On the other hand, URS has gained renewed interest due to new technological developments and improved treatment methods. PMID:22384986

  20. Calcium oxalate crystal growth in human urinary stones

    SciTech Connect

    Kim, K.M.; Johnson, F.B.

    1981-01-01

    Calcium oxalate stones are very common and increasing. Crystal growth is no less important than the crystal nucleation in the pathogenesis of stone formation. The crystal growth was studied in human calcium oxalate stones by a combined electron microscopy and x-ray diffraction. The main mode of weddellite growth was interpenetration twinning of tetrahedral bipyramids. Bipyramids may form as initial crystal seeds, develop from anhedral crystals (crystals which lack flat symmetric faces) of spherular or mulberry shape, develop on the surface of preformed bipyramids by spiral dislocation mechanisms, or develop on whewellite crystal by heterogeneous nucleation and epitaxy. Heterogeneous nucleations of whewellite on weddellite, and calcium apatite on whewellite were also observed. Whewellite grew mainly by parallel twinning. Interpenetration twinning was exceptional. Transformation of anhedral to euhedral (completely bounded by flat faces that are set ar fixed angles to one another) whewellite occurred by parallel fissurations followed by brick wall like stacking of the crystals, while euhedral transformation of weddellite occurred by protrusion of bipyramids frm anhedral crystal surface. Occasionally, an evidence of crystal dissolution was noted. Although an aggregation of crystals is believed to play a pivotal role in stone nidus formation, growth in size of the formed crystals, and twinning and epitactic crystal intergrowth apparently play a significant role in the obstructive urinary stone formation.

  1. A Simple, Powerful Method for Optimal Guidance of Spacecraft Formations

    NASA Technical Reports Server (NTRS)

    Hughes, Steven P.

    2006-01-01

    One of the most interesting and challenging aspects of formation guidance law design is the coupling of the orbit design and the science return. The analyst's role is more complicated than simply to design the formation geometry and evolution. He or she is also involved in designing a significant portion of the science instrument itself. The effectiveness of the formation as a science instrument is intimately coupled with the relative geometry and evolution of the collection of spacecraft. Therefore, the science return can be maximized by optimizing the orbit design according to a performance metric relevant to the science mission goals. In this work, we present a simple method for optimal formation guidance that is applicable to missions whose performance metric, requirements, and constraints can be cast as functions that are explicitly dependent upon the orbit states and spacecraft relative positions and velocities. We present a general form for the cost and constraint functions, and derive their semi-analytic gradients with respect to the formation initial conditions. The gradients are broken down into two types. The first type are gradients of the mission specific performance metric with respect to formation geometry. The second type are derivatives of the formation geometry with respect to the orbit initial conditions. The fact that these two types of derivatives appear separately allows us to derive and implement a general framework that requires minimal modification to be applied to different missions or mission phases. To illustrate the applicability of the approach, we conclude with applications to two missions: the Magnetospheric Multiscale mission (MMS) , and the Laser Interferometer Space Antenna (LISA).

  2. A Simple, Powerful Method for Optimal Guidance of Spacecraft Formations

    NASA Technical Reports Server (NTRS)

    Hughes, Steven P.

    2005-01-01

    One of the most interesting and challenging aspects of formation guidance law design is the coupling of the orbit design and the science return. The analyst s role is more complicated than simply to design the formation geometry and evolution. He or she is also involved in designing a significant portion of the science instrument itself. The effectiveness of the formation as a science instrument is intimately coupled with the relative geoniet,ry and evolution of the collection of spacecraft. Therefore, the science return can be maximized by optimizing the orbit design according to a performance metric relevant to the science mission goals. In this work, we present a simple method for optimal formation guidance that is applicable to missions whose performance metric, requirements, and constraints can be cast as functions that are explicitly dependent upon the orbit states and spacecraft relative positions and velocities. We present a general form for the cost and constraint functions, and derive their semi-analytic gradients with respect to the formation initial conditions. The gradients are broken down into two types. The first type are gradients of the mission specific performance metric with respect to formation geometry. The second type are derivatives of the formation geometry with respect to the orbit initial conditions. The fact that these two types of derivatives appear separately allows us to derive and implement a general framework that requires minimal modification to be applied to different missions or mission phases. To illustrate the applicability of the approach, we conclude with applications to twc missims: the Magnetospheric Mu!tiscale mission (MMS), a,nd the TJaser Interferometer Space Antenna (LISA).

  3. Balloon dilator versus telescopic metal dilators for tract dilatation during percutaneous nephrolithotomy for staghorn stones and calyceal stones

    PubMed Central

    El-Shazly, Mohamed; Salem, Shady; Allam, Adel; Hathout, Badawy

    2015-01-01

    Objective To compare the results of balloon dilatation (BD) vs. telescopic metal dilators (TMDs) in establishing the tract for percutaneous nephrolithotomy (PCNL) in patients with calyceal stones or staghorn stones, but with no hydronephrosis. Patients and methods Data from selected patients over 4years were recorded retrospectively. Patients with complex staghorn stones, an undilated targeted calyx, or the stone filling the targeted calyx, were included in the study. In all, 97 patients were included, of 235 undergoing PCNL between March 2010 and March 2014, and were divided into two groups according to the technique of primary tract dilatation. Group A included patients who had BD and group B those treated using TMDs. Results In group A (BD, 55 patients) dilatation was successful in 34 (62%). The dilatation failed or there was a need for re-dilatation using TMD in 21 patients (38%). In one of these 21 patients the dilatation failed due to extravasation. In group B (TMD, 42 patients) dilatation was successful in 38 (90%) patients, with incomplete dilatation and a need for re-dilatation in four (10%) patients, and no failed procedures. Group A had a significantly higher failure rate than group B (P<0.001). Differences in operative duration, blood loss, stone-removal success rate and complication rate were statistically insignificant. Conclusion BD has a higher failure rate than TMD when establishing access for calyceal stones or staghorn stones that have little space around them. PMID:26413325

  4. Assessing applicants to the NASA flight program for their renal stone-forming potential

    NASA Technical Reports Server (NTRS)

    Pak, Charles Y. C.; Hill, Kathy; Cintron, Nitza M.; Huntoon, Carolyn

    1989-01-01

    Because spaceflight can provoke the formation of kidney stones, 24-hour urine samples for 104 male applicants were analyzed for stone-forming risk factors prior to their selection into the NASA astronaut-mission specialist corps. A high level of supersaturation (with either calcium oxalate, brushite, or monosodium urate) was noted in these applicants which predisposes them to the crystallization of stone-forming calcium salts. It is suggested that most of the abnormal stone risk factors found were environmental, rather than metabolic, in origin.

  5. Liver Resection for Intrahepatic Stones

    PubMed Central

    Tranberg, Karl-Göran; Beng-Mark, Stig

    1990-01-01

    Intrahepatic stones are difficult to manage, especially when they are associated with bile duct stricture, cholangitis and destruction of liver parenchyma. Suggested modes of treatment include surgical bile duct exploration, endoscopic procedures, transhepatic cholangiolithotomy and liver resection. This paper reports 2 patients in whom liver resection was performed because of intrahepatic ductal stones, bile duct strictures and repeated episodes of cholangitis. Liver resection was uncomplicated and long-term results were satisfactory. Our results support the view that liver resection is indicated in rare instances of intrahepatic bile duct stones associated with bile duct strictures. PMID:2278909

  6. 'Nose method' of calculating critical cooling rates for glass formation

    NASA Technical Reports Server (NTRS)

    Weinberg, Michael C.; Uhlmann, Donald R.; Zanotto, Edgar D.

    1989-01-01

    The use of the so-called 'nose method' for computing critical cooling rates for glass formation is examined and compared with other methods, presenting data for the glass-forming systems SiO2, GeO2, and P2O5. It is shown that, for homogeneous crystallization, the nose-method will give an overestimate of Rc, a conclusion which was drawn after assessing the enfluence of a range of values for the parameters which control crystal growth and nucleation. The paper also proposes an alternative simple procedure (termed the 'cutoff method') for computing critical cooling rates from T-T-T diagrams, which was shown in the SiO2 and GeO2 systems to be superior to the nose method.

  7. Alterations in renal stone risk factors after space flight

    NASA Technical Reports Server (NTRS)

    Whitson, P. A.; Pietrzyk, R. A.; Pak, C. Y.; Cintron, N. M.

    1993-01-01

    Exposure to the microgravity environment of space produces a number of physiological changes of metabolic and environmental origin that could increase the potential for renal stone formation. Metabolic, environmental and physicochemical factors that influence renal stone risk potential were examined in 24-hour urine samples from astronauts 10 days before launch and on landing day to provide an immediate postflight assessment of these factors. In addition, comparisons were made between male and female crewmembers, and between crewmembers on missions of less than 6 days and those on 6 to 10-day missions. Results suggest that immediately after space flight the risk of calcium oxalate and uric acid stone formation is increased as a result of metabolic (hypercalciuria, hypocitraturia, pH) and environmental (lower urine volume) derangements, some of which could reflect residual effects of having been exposed to microgravity.

  8. Predictive Factors of the Outcome of Extracorporeal Shockwave Lithotripsy for Ureteral Stones

    PubMed Central

    Choi, Ji Woong; Song, Phil Hyun

    2012-01-01

    Purpose Extracorporeal Shock Wave Lithotripsy (ESWL) has shown successful outcomes for ureteral stones. We investigated predictive factors for failure of ESWL for treating ureteral stones. Materials and Methods A total of 153 patients who underwent ESWL between July 2006 and July 2009 for ureteral stones diagnosed by non-enhanced spiral computed tomography were divided into two groups: (group A, stone size ≤10 mm; and group B, stone size >10 mm). The failure was defined as remnant stones >4 mm. We assessed age, sex, body mass index, stone size, laterality, location, skin-to-stone distance (SSD), Hounsfield unit, and the presence of secondary signs (hydronephrosis, renal enlargement, perinephric fat stranding, and tissue rim sign). We analyzed predictive factors by using logistic regression in each group. Results The success rates were 90.2% and 68.6% in group A and B, respectively. In the univariate analysis of each group, stone size, SSD, and all secondary signs showed statistically significant differences in terms of the outcome of ESWL (p<0.05). In the multivariate logistic regression, stone size (odds ratio [OR], 50.005; 95% confidence interval [CI], 6.207 to 402.852) was an independent predictive factor in group A. The presence of perinephric fat standing (OR, 77.634; 95% CI, 1.349 to 446.558) and stone size (OR, 19.718; 95% CI, 1.600 to 243.005) were independent predictive factors in group B. Conclusions Stone size is an independent predictive factor influencing failure of ESWL for treating ureteral stones. In larger ureteral stones (>10 mm), the presence of perinephric fat stranding is also an independent predictive factor. PMID:22741053

  9. Cholecystectomy for Prevention of Recurrence after Endoscopic Clearance of Bile Duct Stones in Korea

    PubMed Central

    Song, Myung Eun; Lee, Dong-Jun; Oh, Tak Geun; Park, Jeong Youp; Bang, Seungmin; Park, Seung Woo; Song, Si Young; Chung, Jae Bock

    2016-01-01

    Purpose Cholecystectomy in patients with an intact gallbladder after endoscopic removal of stones from the common bile duct (CBD) remains controversial. We conducted a case-control study to determine the risk of recurrent CBD stones and the benefit of cholecystectomy for prevention of recurrence after endoscopic removal of stones from the CBD in Korean patients. Materials and Methods A total of 317 patients who underwent endoscopic CBD stone extraction between 2006 and 2012 were included. Possible risk factors for the recurrence of CBD stones including previous cholecystectomy history, bile duct diameter, stone size, number of stones, stone composition, and the presence of a periampullary diverticulum were analyzed. Results The mean duration of follow-up after CBD stone extraction was 25.4±22.0 months. A CBD diameter of 15 mm or larger [odds ratio (OR), 1.930; 95% confidence interval (CI), 1.098 to 3.391; p=0.022] and the presence of a periampullary diverticulum (OR, 1.859; 95% CI, 1.014 to 3.408; p=0.045) were independent predictive factors for CBD stone recurrence. Seventeen patients (26.6%) in the recurrence group underwent elective cholecystectomy soon after endoscopic extraction of CBD stones, compared to 88 (34.8%) in the non-recurrence group; the difference was not statistically significant (p=0.212). Conclusion A CBD diameter of 15 mm or larger and the presence of a periampullary diverticulum were found to be potential predictive factors for recurrence after endoscopic extraction of CBD stones. Elective cholecystectomy after clearance of CBD stones did not reduce the incidence of recurrent CBD stones in Korean patients. PMID:26632393

  10. Kidney stones - self-care

    MedlinePlus

    ... stones: Eat less salt. Chinese and Mexican food, tomato juice, regular canned foods, and processed foods are ... beets, leeks, summer squash, sweet potatoes, spinach, and tomato soup Drinks: tea and instant coffee Other foods: ...

  11. Stone weathering in Southeast England

    NASA Astrophysics Data System (ADS)

    Jaynes, Suzanne M.; Cooke, R. U.

    A 2-year exposure programme of Portland stone and Monk's Park stone at 25 sites in SE England revealed significant differences in weight losses, changes in surface roughness and chemistry at each location that can be attributed to the activity of air pollutants and salts. In particular it was shown that weight loss of exposed samples can be attributed to both solution and sulphation (the latter probably contributing an average of at least 39% for Portland stone, 44% of Monk's Park stone); that salt attack of sheltered samples is evident at Bletchley (brickmaking) and coastal locations; and surface roughness changes, measured by Ra values on a Surfcom plotter, appear to be particularly sensitive to processes of surface disruption, such as salt weathering. Analysis of SO 2 data at the sites showed significantly higher concentrations at London sites. The corresponding gradient in weight loss was gentler, probably as the result of the influence of other atmospheric variables.

  12. Can a dual-energy computed tomography predict unsuitable stone components for extracorporeal shock wave lithotripsy?

    PubMed Central

    Ahn, Sung Hoon; Oh, Tae Hoon

    2015-01-01

    Purpose To assess the potential of dual-energy computed tomography (DECT) to identify urinary stone components, particularly uric acid and calcium oxalate monohydrate, which are unsuitable for extracorporeal shock wave lithotripsy (ESWL). Materials and Methods This clinical study included 246 patients who underwent removal of urinary stones and an analysis of stone components between November 2009 and August 2013. All patients received preoperative DECT using two energy values (80 kVp and 140 kVp). Hounsfield units (HU) were measured and matched to the stone component. Results Significant differences in HU values were observed between uric acid and nonuric acid stones at the 80 and 140 kVp energy values (p<0.001). All uric acid stones were red on color-coded DECT images, whereas 96.3% of the nonuric acid stones were blue. Patients with calcium oxalate stones were divided into two groups according to the amount of monohydrate (calcium oxalate monohydrate group: monohydrate≥90%, calcium oxalate dihydrate group: monohydrate<90%). Significant differences in HU values were detected between the two groups at both energy values (p<0.001). Conclusions DECT improved the characterization of urinary stone components and was a useful method for identifying uric acid and calcium oxalate monohydrate stones, which are unsuitable for ESWL. PMID:26366277

  13. Acrylamide: formation, occurrence in food products, detection methods, and legislation.

    PubMed

    Arvanitoyannis, Ioannis S; Dionisopoulou, Niki

    2014-01-01

    This review aims at summarizing the most recent updates in the field of acrylamide (AA) formation (mechanism, conditions) and the determination of AA in a number of foods (fried or baked potatoes, chips, coffee, bread, etc). The methods applied for AA detection [Capillary Electrophoresis-Mass Spectrometry (CE-MS), Liquid Chromatography-Mass Spectrometry (LC-MS), Non-Aqueous Capillary Electrophoresis (NACE), High Performance Liquid Chromatography-Mass Spectrometry (HPLC-MS), Pressurized Fluid Extraction (PFE), Matrix Solid-Phase Dispersion (MSPD), Gas Chromatography-Mass Spectrometry (GC-MS), Solid-Phase MicroExtraction-Gas Chromatography (SPME-GC), Enzyme Linked Immunosorbent Assay (ELISA), and MicroEmulsion ElectroKinetic Chromatography (MEEKC) are presented and commented. Several informative figures and tables are included to show the effect of conditions (temperature, time) on the AA formation. A section is also included related to AA legislation in EU and US. PMID:24345045

  14. Methods and systems for detection of ice formation on surfaces

    NASA Technical Reports Server (NTRS)

    Alfano, Robert R. (Inventor); Wang, Wubao (Inventor); Sztul, Henry (Inventor); Budansky, Yury (Inventor)

    2007-01-01

    A system for detecting ice formation on metal, painted metal and other material surfaces can include a transparent window having an exterior surface upon which ice can form; a light source and optics configured and arranged to illuminate the exterior surface of the window from behind the exterior surface; and a detector and optics configured and arranged to receive light backscattered by the exterior surface and any ice disposed on the exterior surface and determine the thickness of the ice layer. For example, the system can be used with aircraft by placing one or more windows in the wings of the aircraft. The system is used for a novel optical method for real-time on-board detection and warning of ice formation on surfaces of airplanes, unmanned aerial vehicles (UAVs), and other vehicles and stationary structures to improve their safety and operation.

  15. Ranging methods for developing wellbores in subsurface formations

    SciTech Connect

    MacDonald, Duncan

    2011-09-06

    A method for forming two or more wellbores in a subsurface formation includes forming a first wellbore in the formation. A second wellbore is directionally drilled in a selected relationship relative to the first wellbore. At least one magnetic field is provided in the second wellbore using one or more magnets in the second wellbore located on a drilling string used to drill the second wellbore. At least one magnetic field is sensed in the first wellbore using at least two sensors in the first wellbore as the magnetic field passes by the at least two sensors while the second wellbore is being drilled. A position of the second wellbore is continuously assessed relative to the first wellbore using the sensed magnetic field. The direction of drilling of the second wellbore is adjusted so that the second wellbore remains in the selected relationship relative to the first wellbore.

  16. The Stepping Stone Approach

    NASA Astrophysics Data System (ADS)

    Brumfitt, A.

    Education is a profession in its own right. It has its own parameters, passions and language. Having the responsibility both of educare and educere, education has a focus of delivering specific factual knowledge whilst drawing out the creative mind. Space Science is a special vehicle having the properties of both educare and educere. It has a magic and wonder that touches the very essence of an individual and his place in time and space; it offers the "wow" factor that all teachers strive for. Space Science is the wrapping paper for other elements in the curriculum, e.g. cross-curricula and skill-based activities, such as language development, creativity, etc. as well as the pure sciences which comprise of engineering, physics and other natural sciences from astronomy to chemistry to biology. Each of these spheres of influence are relevant from kindergarten to undergraduate studies and complement, and in addition support informal education in museums, science centers and the world of e-learning. ESA Science Education has devised the "Stepping Stone Approach" to maximize the greatest outreach to all education stakeholders in Europe. In this paper we illustrate how to best reach these target groups with very specific activities to trigger and sustain enthusiasm whilst supporting the pedagogical, subject content and skill-based needs of a prescribed curriculum.

  17. Lunar stone saw

    NASA Technical Reports Server (NTRS)

    Clark, Tom; Croker, Todd; Hines, Ken; Knight, Mike; Walton, Todd

    1988-01-01

    This project addresses the problem of cutting lunar stones into blocks to be used to construct shelters to protect personnel and equipment from harmful solar radiation. This plant will manufacture 6 in x 1 ft x 2 ft blocks and will be located near the south pole to allow it to be in the shade at all times. This design uses a computer controlled robot, a boulder handler that uses hydraulics for movement, a computer system that used 3-D vision to determine the size of boulders, a polycrystalline diamond tipped saw blade that utilizes radiation for cooling, and a solar tower to collect solar energy. Only two electric motors are used in this plant because of the heavy weight of electric motors and the problem of cooling them. These two motors will be cooled by thermoelectric cooling. All other motors and actuators are to be hydraulic. The architectural design for the building as well as the conceptual design of the machines for cutting the blocks are described.

  18. Microbial-mediated method for metal oxide nanoparticle formation

    DOEpatents

    Rondinone, Adam J.; Moon, Ji Won; Love, Lonnie J.; Yeary, Lucas W.; Phelps, Tommy J.

    2015-09-08

    The invention is directed to a method for producing metal oxide nanoparticles, the method comprising: (i) subjecting a combination of reaction components to conditions conducive to microbial-mediated formation of metal oxide nanoparticles, wherein said combination of reaction components comprise: metal-reducing microbes, a culture medium suitable for sustaining said metal-reducing microbes, an effective concentration of one or more surfactants, a reducible metal oxide component containing one or more reducible metal species, and one or more electron donors that provide donatable electrons to said metal-reducing microbes during consumption of the electron donor by said metal-reducing microbes; and (ii) isolating said metal oxide nanoparticles, which contain a reduced form of said reducible metal oxide component. The invention is also directed to metal oxide nanoparticle compositions produced by the inventive method.

  19. Method for formation of subsurface barriers using viscous colloids

    DOEpatents

    Apps, John A.; Persoff, Peter; Moridis, George; Pruess, Karsten

    1998-01-01

    A method for formation of subsurface barriers using viscous liquids where a viscous liquid solidifies at a controlled rate after injection into soil and forms impermeable isolation of the material enclosed within the subsurface barriers. The viscous liquid is selected from the group consisting of polybutenes, polysilotanes, colloidal silica and modified colloidal silica of which solidification is controlled by gelling, cooling or cross-linking. Solidification timing is controlled by dilution, addition of brines, coating with alumina, stabilization with various agents and by temperature.

  20. Method for formation of subsurface barriers using viscous colloids

    DOEpatents

    Apps, J.A.; Persoff, P.; Moridis, G.; Pruess, K.

    1998-11-17

    A method is described for formation of subsurface barriers using viscous liquids where a viscous liquid solidifies at a controlled rate after injection into soil and forms impermeable isolation of the material enclosed within the subsurface barriers. The viscous liquid is selected from the group consisting of polybutenes, polysiloxanes, colloidal silica and modified colloidal silica of which solidification is controlled by gelling, cooling or cross-linking. Solidification timing is controlled by dilution, addition of brines, coating with alumina, stabilization with various agents and by temperature. 17 figs.

  1. Purbeck Stone - A possible Global Heritage Stone from England

    NASA Astrophysics Data System (ADS)

    Marker, Brian

    2014-05-01

    By definition, a Global Heritage Stone Resource (GHSR) should have international significance. The Purbeck Group of uppermost Jurassic to lowermost Cretaceous age (Tithonian- Berriasian) outcrops mainly in the Purbeck area of Dorset, England. It was deposited in shallow freshwater to brackish lagoons with occasional marine incursions. Limestones, mainly biosparites, occur at 6 main levels. Differences in bed thickness, jointing and hardness make it suitable for a variety of purposes including dimension stone, monumental and ornamental stone, roofing tiles, paving, flooring and rockery stone. Near the top of the sequence is a dark gastropod biosparite, traditionally called Purbeck Marble, easily carved, which has been extensively used for decorative interior work in churches and cathedrals particularly for fonts, tombs, flooring and facings on columns for example in the medieval cathedrals of Salisbury, Exeter, Durham, York and Wells and Worcester and Westminster Abbey. The stone was extracted at least from Roman times (1st century AD) through the medieval period. Quarrying expanded from about 1700 reaching a peak in the late 18th and 19th centuries. Stone was transported first by sea but later by rail for wider use. Used in many local buildings, it gives an important element of local character. Many of the villages are designated conservation areas with a requirement for repair, maintenance and new building using local stone. Initially the stone was taken from quarries but was later mined. The number of operating companies declined from 15 to 5 over the past 40 years, with 10 active small quarries. Outputs are from few hundred tonnes to a few thousand tonnes per annum or about 9 to 12 years of permitted reserves but the Planning Authority intends to make sufficient provision for production at recent levels for their development plan period. The extraction sites are in an Area of Outstanding Natural Beauty and close to Jurassic Coast World Heritage Site. This might be a test case for considering whether a stone with this history is significant enough to be designated as a GHSR or is, rather, of national significance.

  2. The agencies method for coalition formation in experimental games

    PubMed Central

    Nash, John F.; Nagel, Rosemarie; Ockenfels, Axel; Selten, Reinhard

    2012-01-01

    In society, power is often transferred to another person or group. A previous work studied the evolution of cooperation among robot players through a coalition formation game with a non-cooperative procedure of acceptance of an agency of another player. Motivated by this previous work, we conduct a laboratory experiment on finitely repeated three-person coalition formation games. Human players with different strength according to the coalition payoffs can accept a transfer of power to another player, the agent, who then distributes the coalition payoffs. We find that the agencies method for coalition formation is quite successful in promoting efficiency. However, the agent faces a tension between short-term incentives of not equally distributing the coalition payoff and the long-term concern to keep cooperation going. In a given round, the strong player in our experiment often resolves this tension approximately in line with the Shapley value and the nucleolus. Yet aggregated over all rounds, the payoff differences between players are rather small, and the equal division of payoffs predicts about 80% of all groups best. One reason is that the voting procedure appears to induce a balance of power, independent of the individual player's strength: Selfish subjects tend to be voted out of their agency and are further disciplined by reciprocal behaviors. PMID:23175792

  3. The agencies method for coalition formation in experimental games.

    PubMed

    Nash, John F; Nagel, Rosemarie; Ockenfels, Axel; Selten, Reinhard

    2012-12-11

    In society, power is often transferred to another person or group. A previous work studied the evolution of cooperation among robot players through a coalition formation game with a non-cooperative procedure of acceptance of an agency of another player. Motivated by this previous work, we conduct a laboratory experiment on finitely repeated three-person coalition formation games. Human players with different strength according to the coalition payoffs can accept a transfer of power to another player, the agent, who then distributes the coalition payoffs. We find that the agencies method for coalition formation is quite successful in promoting efficiency. However, the agent faces a tension between short-term incentives of not equally distributing the coalition payoff and the long-term concern to keep cooperation going. In a given round, the strong player in our experiment often resolves this tension approximately in line with the Shapley value and the nucleolus. Yet aggregated over all rounds, the payoff differences between players are rather small, and the equal division of payoffs predicts about 80% of all groups best. One reason is that the voting procedure appears to induce a balance of power, independent of the individual player's strength: Selfish subjects tend to be voted out of their agency and are further disciplined by reciprocal behaviors. PMID:23175792

  4. Determination of minor and trace elements in kidney stones by x-ray fluorescence analysis

    NASA Astrophysics Data System (ADS)

    Srivastava, Anjali; Heisinger, Brianne J.; Sinha, Vaibhav; Lee, Hyong-Koo; Liu, Xin; Qu, Mingliang; Duan, Xinhui; Leng, Shuai; McCollough, Cynthia H.

    2014-03-01

    The determination of accurate material composition of a kidney stone is crucial for understanding the formation of the kidney stone as well as for preventive therapeutic strategies. Radiations probing instrumental activation analysis techniques are excellent tools for identification of involved materials present in the kidney stone. In particular, x-ray fluorescence (XRF) can be very useful for the determination of minor and trace materials in the kidney stone. The X-ray fluorescence measurements were performed at the Radiation Measurements and Spectroscopy Laboratory (RMSL) of department of nuclear engineering of Missouri University of Science and Technology and different kidney stones were acquired from the Mayo Clinic, Rochester, Minnesota. Presently, experimental studies in conjunction with analytical techniques were used to determine the exact composition of the kidney stone. A new type of experimental set-up was developed and utilized for XRF analysis of the kidney stone. The correlation of applied radiation source intensity, emission of X-ray spectrum from involving elements and absorption coefficient characteristics were analyzed. To verify the experimental results with analytical calculation, several sets of kidney stones were analyzed using XRF technique. The elements which were identified from this techniques are Silver (Ag), Arsenic (As), Bromine (Br), Chromium (Cr), Copper (Cu), Gallium (Ga), Germanium (Ge), Molybdenum (Mo), Niobium (Nb), Rubidium (Rb), Selenium (Se), Strontium (Sr), Yttrium (Y), Zirconium (Zr). This paper presents a new approach for exact detection of accurate material composition of kidney stone materials using XRF instrumental activation analysis technique.

  5. Stone-isolated carbonatogenic bacteria as inoculants in bioconsolidation treatments for historical limestone.

    PubMed

    Jroundi, Fadwa; Gómez-Suaga, Patricia; Jimenez-Lopez, Concepción; González-Muñoz, Maria Teresa; Fernandez-Vivas, Maria Antonia

    2012-05-15

    Stone consolidation treatments that use bacterial biomineralization are mainly based on two strategies: (1) the inoculation of a bacterial culture with proven carbonatogenic ability and/or (2) the application of a culture medium capable of activating those bacteria able to induce the formation of calcium carbonate, from amongst the bacterial community of the stone. While the second strategy has been demonstrated to be effective and, unlike first strategy, it does not introduce any exogenous microorganism into the stone, problems may arise when the bacterial community of the stone is altered, for instance by the use of biocides in the cleaning process. In this study we isolate bacteria that belong to the natural microbial community of the stone and which have proven biomineralization capabilities, with the aim of preparing an inoculum that may be used in stone consolidation treatments wherein the natural community of those stones is altered. With this aim, outdoor experiments were undertaken to activate and isolate bacteria that display high biomineralization capacity from altered calcarenite stone. Most of the bacteria precipitated calcium carbonate in the form of calcite. The selected bacteria were phylogenetically affiliated with members of Actinobacteria, Gamma-proteobacteria and Firmicutes. Furthermore, the capability of these selected carbonatogenic bacteria to consolidate altered calcarenite stone slabs was studied in in vitro experiments, both in the presence and the absence of Myxococcus xanthus, as a potential reinforcement for the bacterial biomineralization. Herein, Acinetobacter species, belonging to the microbial community of the stone, are proposed as powerful carbonatogenic bacteria that, inoculated under appropriate conditions, may be used as inoculum for calcareous stone conservation/consolidation in restoration interventions where the microbial community of the stone is altered. PMID:22464961

  6. Nonoperative options for management of residual stones after cholecystostomy in high-risk patients

    NASA Astrophysics Data System (ADS)

    Reed, David M.; Daye, S. S.; Lincer, R. M.

    1993-05-01

    Cholecystostomy is frequently performed to obtain control of sepsis in high risk patients with acute cholecystitis. Retained stones in the gallbladder may cause future clinical problems. We present two patients with cholecystostomy tubes managed non-operatively. A review of other reported methods for stone extraction or destruction is also presented. Knowledge of safe and effective techniques for removal of these stones, using minimally invasive techniques is useful to the general surgeon.

  7. A Drosophila model identifies a critical role for zinc in mineralization for kidney stone disease.

    PubMed

    Chi, Thomas; Kim, Man Su; Lang, Sven; Bose, Neelanjan; Kahn, Arnold; Flechner, Lawrence; Blaschko, Sarah D; Zee, Tiffany; Muteliefu, Gulinuer; Bond, Nichole; Kolipinski, Marysia; Fakra, Sirine C; Mandel, Neil; Miller, Joe; Ramanathan, Arvind; Killilea, David W; Brückner, Katja; Kapahi, Pankaj; Stoller, Marshall L

    2015-01-01

    Ectopic calcification is a driving force for a variety of diseases, including kidney stones and atherosclerosis, but initiating factors remain largely unknown. Given its importance in seemingly divergent disease processes, identifying fundamental principal actors for ectopic calcification may have broad translational significance. Here we establish a Drosophila melanogaster model for ectopic calcification by inhibiting xanthine dehydrogenase whose deficiency leads to kidney stones in humans and dogs. Micro X-ray absorption near edge spectroscopy (μXANES) synchrotron analyses revealed high enrichment of zinc in the Drosophila equivalent of kidney stones, which was also observed in human kidney stones and Randall's plaques (early calcifications seen in human kidneys thought to be the precursor for renal stones). To further test the role of zinc in driving mineralization, we inhibited zinc transporter genes in the ZnT family and observed suppression of Drosophila stone formation. Taken together, genetic, dietary, and pharmacologic interventions to lower zinc confirm a critical role for zinc in driving the process of heterogeneous nucleation that eventually leads to stone formation. Our findings open a novel perspective on the etiology of urinary stones and related diseases, which may lead to the identification of new preventive and therapeutic approaches. PMID:25970330

  8. The elementome of calcium-based urinary stones and its role in urolithiasis.

    PubMed

    Ramaswamy, Krishna; Killilea, David W; Kapahi, Pankaj; Kahn, Arnold J; Chi, Thomas; Stoller, Marshall L

    2015-10-01

    Urolithiasis affects around 10% of the US population with an increasing rate of prevalence, recurrence and penetrance. The causes for the formation of most urinary calculi remain poorly understood, but obtaining the chemical composition of these stones might help identify key aspects of this process and new targets for treatment. The majority of urinary stones are composed of calcium that is complexed in a crystalline matrix with organic and inorganic components. Surprisingly, mitigation of urolithiasis risk by altering calcium homeostasis has not been very effective. Thus, studies to identify other therapeutic stone-specific targets, using proteomics, metabolomics and microscopy techniques, have been conducted, revealing a high level of complexity. The data suggest that numerous metals other than calcium and many nonmetals are present within calculi at measurable levels and several have distinct distribution patterns. Manipulation of the levels of some of these elemental components of calcium-based stones has resulted in clinically beneficial changes in stone chemistry and rate of stone formation. The elementome--the full spectrum of elemental content--of calcium-based urinary calculi is emerging as a new concept in stone research that continues to provide important insights for improved understanding and prevention of urinary stone disease. PMID:26334088

  9. [Preventive measures in stones due to infection, uric acid and cystine].

    PubMed

    Hess, B; Ackermann, D

    1992-01-01

    General prophylaxis of renal stone formation consists of 1. high fluid intake and 2. modest consumption of protein-rich foods. Specific prophylactic measures are based on pathophysiologic mechanisms of stone formation. In infection-induced renal stones, combined treatment with culture specific antibiotics and complete stone removal is of utmost importance. In all cases where stone fragments cannot be removed completely and/or partial obstruction remains, long-term antibiotics in combination with urine acidification by methionine (urine pH 5.6 to 6.2) are most appropriate. Prophylaxis of uric acid stones primarily consists of reducing purine intake and alkalizing the urine by potassium citrate. Only if this regimen failed or gout occurred, allopurinol should be administered. In patients with cystine stones, urine volume should be increased to greater than 3000 ml/die. Alkalizing the urine to a pH greater than 7.5 rises cystine solubility, whereas cystine excretion may be reduced by a diet low in sodium and/or low in methionine/cysteine. Thiols form mixed thiol-cysteine disulfides that are many times more soluble than cystine in urine; because of their high rate of adverse side-effects, however, these compounds are of lowest priority in the treatment of cystine stones. There is no convincing evidence for the efficacy of high dose ascorbic acid treatment in cystinuria. PMID:1736401

  10. A Drosophila Model Identifies a Critical Role for Zinc in Mineralization for Kidney Stone Disease

    PubMed Central

    Lang, Sven; Bose, Neelanjan; Kahn, Arnold; Flechner, Lawrence; Blaschko, Sarah D.; Zee, Tiffany; Muteliefu, Gulinuer; Bond, Nichole; Kolipinski, Marysia; Fakra, Sirine C.; Mandel, Neil; Miller, Joe; Ramanathan, Arvind; Killilea, David W.; Brückner, Katja; Kapahi, Pankaj; Stoller, Marshall L.

    2015-01-01

    Ectopic calcification is a driving force for a variety of diseases, including kidney stones and atherosclerosis, but initiating factors remain largely unknown. Given its importance in seemingly divergent disease processes, identifying fundamental principal actors for ectopic calcification may have broad translational significance. Here we establish a Drosophila melanogaster model for ectopic calcification by inhibiting xanthine dehydrogenase whose deficiency leads to kidney stones in humans and dogs. Micro X-ray absorption near edge spectroscopy (μXANES) synchrotron analyses revealed high enrichment of zinc in the Drosophila equivalent of kidney stones, which was also observed in human kidney stones and Randall’s plaques (early calcifications seen in human kidneys thought to be the precursor for renal stones). To further test the role of zinc in driving mineralization, we inhibited zinc transporter genes in the ZnT family and observed suppression of Drosophila stone formation. Taken together, genetic, dietary, and pharmacologic interventions to lower zinc confirm a critical role for zinc in driving the process of heterogeneous nucleation that eventually leads to stone formation. Our findings open a novel perspective on the etiology of urinary stones and related diseases, which may lead to the identification of new preventive and therapeutic approaches. PMID:25970330

  11. The elementome of calcium-based urinary stones and its role in urolithiasis

    PubMed Central

    Ramaswamy, Krishna; Killilea, David W.; Kapahi, Pankaj; Kahn, Arnold J.; Chi, Thomas; Stoller, Marshall L.

    2016-01-01

    Urolithiasis affects around 10% of the US population with an increasing rate of prevalence, recurrence and penetrance. The causes for the formation of most urinary calculi remain poorly understood, but obtaining the chemical composition of these stones might help identify key aspects of this process and new targets for treatment. The majority of urinary stones are composed of calcium that is complexed in a crystalline matrix with organic and inorganic components. Surprisingly, mitigation of urolithiasis risk by altering calcium homeostasis has not been very effective. Thus, studies to identify other therapeutic stone-specific targets, using proteomics, metabolomics and microscopy techniques, have been conducted, revealing a high level of complexity. The data suggest that numerous metals other than calcium and many nonmetals are present within calculi at measurable levels and several have distinct distribution patterns. Manipulation of the levels of some of these elemental components of calcium-based stones has resulted in clinically beneficial changes in stone chemistry and rate of stone formation. The elementome—the full spectrum of elemental content—of calcium-based urinary calculi is emerging as a new concept in stone research that continues to provide important insights for improved understanding and prevention of urinary stone disease. PMID:26334088

  12. Real-Time Imaging of the Process of Stone Crushing by Ultrasound

    NASA Astrophysics Data System (ADS)

    Ito, Akira; Yoshizawa, Shin; Kaneko, Yukio; Kume, Haruki; Kitamura, Tadaichi; Matsumoto, Yoichiro

    2007-05-01

    A new method of lithotripsy combining high and low frequency ultrasound has been investigated. This method controls generation of cavitation only on the stone surface and utilizes collapse pressure of the bubbles. In order to apply this method for clinical practice, it is important to monitor the process of stone crushing and behavior of cavitation from outside the body. In this study, ultrasound imaging was coupled with a therapeutic ultrasound system for real-time monitoring and targeting of stones. Stone crushing tests have been conducted in vitro and in vivo experiments. In vitro experiment, crushing process of a model stone in a polyacrylamide gel was observed with both ultrasound imaging and a digital video camera. It was observed with ultrasound imaging that the stone was crushed with ultrasound. In vivo experiment, a stone crushing experiment has been conducted in a pig bladder. And a mark of crushing was found on the surface of the stone taken out from the bladder after the irradiation, as well as in vitro experiment. The process of stone crushing in a pig bladder could be monitored with bi-plane ultrasound imaging from outside the body.

  13. Bone Genes in the Kidney of Stone Formers

    NASA Astrophysics Data System (ADS)

    Evan, Andrew P.; Bledsoe, Sharon B.

    2008-09-01

    Intraoperative papillary biopsies from kidneys of idiopathic-calcium oxalate stone formers (ICSF) have revealed a distinct pattern of mineral deposition in the interstitium of the renal papilla. The earliest sites of these deposits, termed Randall's plaque, are found in the basement membrane of thin loops of Henle and appear to spread into the surrounding interstitium down to the papillary epithelium. Recent studies show kidney stones of ICSF patients grow attached to the renal papilla and at sites of Randall's plaque. Together these observations suggest that plaque formation may be the critical step in stone formation. In order to control plaque formation and thereby reduce future kidney stone development, the mechanism of plaque deposition must be understood. Because the renal papilla has unique anatomical features similar to bone and the fact that the interstitial deposits of ICSF patients are formed of biological apatite, this paper tests the hypothesis that sites of interstitial plaque form as a result of cell-mediated osteoblast-like activity.

  14. Method for prolonging the useful life of scale inhibitors injected within a formation

    SciTech Connect

    Shuler, P.J.

    1991-08-13

    This patent describes a method for prolonging useful life of scale inhibitors injected within a formation. It comprises injecting an aqueous solution of the scale inhibitors into the formation: and injecting an aqueous solution of polyquaternary amines into the formation.

  15. Is scoring system of computed tomography based metric parameters can accurately predicts shock wave lithotripsy stone-free rates and aid in the development of treatment strategies?

    PubMed Central

    Badran, Yasser Ali; Abdelaziz, Alsayed Saad; Shehab, Mohamed Ahmed; Mohamed, Hazem Abdelsabour Dief; Emara, Absel-Aziz Ali; Elnabtity, Ali Mohamed Ali; Ghanem, Maged Mohammed; ELHelaly, Hesham Abdel Azim

    2016-01-01

    Objective: The objective was to determine the predicting success of shock wave lithotripsy (SWL) using a combination of computed tomography based metric parameters to improve the treatment plan. Patients and Methods: Consecutive 180 patients with symptomatic upper urinary tract calculi 20 mm or less were enrolled in our study underwent extracorporeal SWL were divided into two main groups, according to the stone size, Group A (92 patients with stone ≤10 mm) and Group B (88 patients with stone >10 mm). Both groups were evaluated, according to the skin to stone distance (SSD) and Hounsfield units (≤500, 500–1000 and >1000 HU). Results: Both groups were comparable in baseline data and stone characteristics. About 92.3% of Group A rendered stone-free, whereas 77.2% were stone-free in Group B (P = 0.001). Furthermore, in both group SWL success rates was a significantly higher for stones with lower attenuation <830 HU than with stones >830 HU (P < 0.034). SSD were statistically differences in SWL outcome (P < 0.02). Simultaneous consideration of three parameters stone size, stone attenuation value, and SSD; we found that stone-free rate (SFR) was 100% for stone attenuation value <830 HU for stone <10 mm or >10 mm but total number SWL sessions and shock waves required for the larger stone group were higher than in the smaller group (P < 0.01). Furthermore, SFR was 83.3% and 37.5% for stone <10 mm, mean HU >830, SSD 90 mm and SSD >120 mm, respectively. On the other hand, SFR was 52.6% and 28.57% for stone >10 mm, mean HU >830, SSD <90 mm and SSD >120 mm, respectively. Conclusion: Stone size, stone density (HU), and SSD is simple to calculate and can be reported by radiologists to applying combined score help to augment predictive power of SWL, reduce cost, and improving of treatment strategies. PMID:27141192

  16. AB109. Upper urinary stone management in China

    PubMed Central

    Wang, Shaogang; Liu, Jihong; Ye, Zhangqun

    2015-01-01

    Objective Urolithiasis is one of the most prevalent diseases in the urologic clinic and usually affects people aged 20 to 60 years. In recent years, the overall morbidity of urolithiasis in Chinese population has increased with significant reduction in patients with lower urinary stone and an increase in patients with upper urinary stone. Upper urinary stone may induce more severe complications and have been considered to be the main cause of nephrectomy besides urinary tumor. Methods The management of upper urinary stone may still challenging somehow. Extracorporeal shock wave lithotripsy (ESWL) usually is the first choice for the patients with simple upper urinary stone of 2 cm and down. Recent years, according to the mechanism of lithecbole by vibration and body position, some Chinese urologists have developed a novel machine, external physical vibration lithecbole (EPVL), which can facilitate removal of urinary stone after ESWL or endoscopic lithotripsy. The combination of EPVL therapy with ESWL or endoscopic lithotripsy significantly increases the stone-free rate. Percutaneous nephrostolithotomy (PCNL) is increasingly employed as a major modality for patients with large and complex upper urinary stone. The minimally invasive PCNL (mPCNL), which was performed with a miniature endoscope by way of a small size tract (12-20 F), could decrease morbidity, especially uncontrolled hemorrhage but have the disadvantages of low efficiency to remove stone fragment. The Chinese urologists have modified PCNL technique by using an 8/9.8 F rigid ureteroscope through the 14-18 F percutaneous tract under ultrasound or X-ray guidance. The results from a series of studies demonstrate that Chinese mPCNL is safe, feasible and efficient for treating upper urinary stone with a low complicate rate. Results With the development of techology, the flexible ureteroscope have become the main actors in clinical practice over the past several years. Flexible ureteroscopy allows entry into all parts of the kidney so that all stones can be removed or vaporised provided they are of an appropriate size and accessible. Moreover, flexible ureteroscopy is well tolerated and effective which allowed us to obtain a high success rate, low morbidity, and a brief hospital stay. It could be the best option in managing the special patients with multiple intrarenal stones, stone-bearing caliceal diverticula、anticoagulated history, obesity, anomalous kidneys and pregnancy, which are not applicable for ESWL or PCN. However, the flexible ureteroscope is much more difficult to handle than the rigid ureteroscope. In addition, the flexible ureteroscope is expensive and easy to damage or break, the treatment cost usually higher than ordinary treatment. In past decades, some Chinese urologists and engineers have put in a great effort to design novel types of flexible ureteroscope which more cheap and easy to operate. The integrated flexible and rigid uroteroscope is the one of the new designed instruments of which the body is the ordinary rigid ureteroscope but have a flexible end. This novel device could be operated as easy as rigid ureterosope and the end of uroteroscope could move flexible after it entry the renal pelvis. Several different types of the Chinese flexible uroteroscope have completed the clinical trials and are going to be commercially available. Conclusions Generally, Upper urinary stone is one of the most common diseases in urologic department in China. Each treatment has advantages and disadvantages. The urologist’s choice of the treatment strategy should be made individually according to the properties of stone and the patient’s body condition.

  17. Use of the Acoustic Shadow Width to Determine Kidney Stone Size with Ultrasound

    PubMed Central

    Dunmire, Barbrina; Harper, Jonathan D.; Cunitz, Bryan W.; Lee, Franklin C.; Hsi, Ryan; Liu, Ziyue; Bailey, Michael R.; Sorensen, Mathew D.

    2016-01-01

    Purpose Ultrasound is known to overestimate kidney stone size. We explored measuring the acoustic shadow behind kidney stones combined with different ultrasound imaging modalities to improve stone sizing accuracy. Materials and Methods A total of 45 calcium oxalate monohydrate stones were imaged in vitro at 3 different depths with the 3 different ultrasound imaging modalities of conventional ray line, spatial compound and harmonic imaging. The width of the stone and the width of the acoustic shadow were measured by 4 operators blinded to the true size of the stone. Results Average error between the measured and true stone width was 1.4 ± 0.8 mm, 1.7 ± 0.9 mm, 0.9 ± 0.8 mm for ray line, spatial compound and harmonic imaging, respectively. Average error between the shadow width and true stone width was 0.2 ± 0.7 mm, 0.4 ± 0.7 mm and 0.0 ± 0.8 mm for ray line, spatial compound and harmonic imaging, respectively. Sizing error based on the stone width worsened with greater depth (p <0.001) while the sizing error based on the shadow width was independent of depth. Conclusions Shadow width was a more accurate measure of true stone size than a direct measurement of the stone in the ultrasound image (p <0.0001). The ultrasound imaging modality also impacted the measurement accuracy. All methods performed similarly for shadow size while harmonic imaging was the most accurate stone size modality. Overall 78% of the shadow sizes were accurate to within 1 mm, which is similar to the resolution obtained with clinical computerized tomography. PMID:26301788

  18. What I Need to Know about Kidney Stones

    MedlinePlus

    ... Alternate Language URL Español What I need to know about Kidney Stones Page Content On this page: ... stones? To prevent kidney stones, you need to know what caused your kidney stone. Your doctor may ...

  19. Quantifying Oldowan Stone Tool Production at Olduvai Gorge, Tanzania.

    PubMed

    Reti, Jay S

    2016-01-01

    Recent research suggests that variation exists among and between Oldowan stone tool assemblages. Oldowan variation might represent differential constraints on raw materials used to produce these stone implements. Alternatively, variation among Oldowan assemblages could represent different methods that Oldowan producing hominins utilized to produce these lithic implements. Identifying differential patterns of stone tool production within the Oldowan has implications for assessing how stone tool technology evolved, how traditions of lithic production might have been culturally transmitted, and for defining the timing and scope of these evolutionary events. At present there is no null model to predict what morphological variation in the Oldowan should look like. Without such a model, quantifying whether Oldowan assemblages vary due to raw material constraints or whether they vary due to differences in production technique is not possible. This research establishes a null model for Oldowan lithic artifact morphological variation. To establish these expectations this research 1) models the expected range of variation through large scale reduction experiments, 2) develops an algorithm to categorize archaeological flakes based on how they are produced, and 3) statistically assesses the methods of production behavior used by Oldowan producing hominins at the site of DK from Olduvai Gorge, Tanzania via the experimental model. Results indicate that a subset of quartzite flakes deviate from the null expectations in a manner that demonstrates efficiency in flake manufacture, while some basalt flakes deviate from null expectations in a manner that demonstrates inefficiency in flake manufacture. The simultaneous presence of efficiency in stone tool production for one raw material (quartzite) and inefficiency in stone tool production for another raw material (basalt) suggests that Oldowan producing hominins at DK were able to mediate the economic costs associated with stone tool procurement by utilizing high-cost materials more efficiently than is expected and low-cost materials in an inefficient manner. PMID:26808429

  20. Quantifying Oldowan Stone Tool Production at Olduvai Gorge, Tanzania

    PubMed Central

    Reti, Jay S.

    2016-01-01

    Recent research suggests that variation exists among and between Oldowan stone tool assemblages. Oldowan variation might represent differential constraints on raw materials used to produce these stone implements. Alternatively, variation among Oldowan assemblages could represent different methods that Oldowan producing hominins utilized to produce these lithic implements. Identifying differential patterns of stone tool production within the Oldowan has implications for assessing how stone tool technology evolved, how traditions of lithic production might have been culturally transmitted, and for defining the timing and scope of these evolutionary events. At present there is no null model to predict what morphological variation in the Oldowan should look like. Without such a model, quantifying whether Oldowan assemblages vary due to raw material constraints or whether they vary due to differences in production technique is not possible. This research establishes a null model for Oldowan lithic artifact morphological variation. To establish these expectations this research 1) models the expected range of variation through large scale reduction experiments, 2) develops an algorithm to categorize archaeological flakes based on how they are produced, and 3) statistically assesses the methods of production behavior used by Oldowan producing hominins at the site of DK from Olduvai Gorge, Tanzania via the experimental model. Results indicate that a subset of quartzite flakes deviate from the null expectations in a manner that demonstrates efficiency in flake manufacture, while some basalt flakes deviate from null expectations in a manner that demonstrates inefficiency in flake manufacture. The simultaneous presence of efficiency in stone tool production for one raw material (quartzite) and inefficiency in stone tool production for another raw material (basalt) suggests that Oldowan producing hominins at DK were able to mediate the economic costs associated with stone tool procurement by utilizing high-cost materials more efficiently than is expected and low-cost materials in an inefficient manner. PMID:26808429

  1. Method of optimizing the conductivity of a propped fractured formation

    SciTech Connect

    Brannon, H.D.; Gulbis, J.; King, M.T.; Hawkins, G.W.

    1992-04-14

    This patent describes a method of reducing viscosity of a fracturing fluid containing proppant, a polymer, a delayed breaker and a nondelayed breaker, it comprises: introducing the fracturing fluid into a subterranean formation to form at least one fracture; depositing the proppant and the polymer in the fracture; determining an after closure polymer viscosity of the deposited polymer in the fracture; selecting a proppant pack permeability in the fracture; calculating an amount of breaker necessary to reduce the after closure viscosity of the deposited polymer to attain the selected permeability of; determining a minimum viscosity of the fracturing fluid which maintains the proppant in suspension in the fluid during pumping in the fracture; and introducing an effective amount of delayed breaker and nondelayed breaker into the fracturing fluid to attain the selected proppant pack permeability while maintaining the minimum viscosity to maintain the proppant in suspension in the fluid during pumping in the fracture.

  2. Examination of Hydrate Formation Methods: Trying to Create Representative Samples

    SciTech Connect

    Kneafsey, T.J.; Rees, E.V.L.; Nakagawa, S.; Kwon, T.-H.

    2011-04-01

    Forming representative gas hydrate-bearing laboratory samples is important so that the properties of these materials may be measured, while controlling the composition and other variables. Natural samples are rare, and have often experienced pressure and temperature changes that may affect the property to be measured [Waite et al., 2008]. Forming methane hydrate samples in the laboratory has been done a number of ways, each having advantages and disadvantages. The ice-to-hydrate method [Stern et al., 1996], contacts melting ice with methane at the appropriate pressure to form hydrate. The hydrate can then be crushed and mixed with mineral grains under controlled conditions, and then compacted to create laboratory samples of methane hydrate in a mineral medium. The hydrate in these samples will be part of the load-bearing frame of the medium. In the excess gas method [Handa and Stupin, 1992], water is distributed throughout a mineral medium (e.g. packed moist sand, drained sand, moistened silica gel, other porous media) and the mixture is brought to hydrate-stable conditions (chilled and pressurized with gas), allowing hydrate to form. This method typically produces grain-cementing hydrate from pendular water in sand [Waite et al., 2004]. In the dissolved gas method [Tohidi et al., 2002], water with sufficient dissolved guest molecules is brought to hydrate-stable conditions where hydrate forms. In the laboratory, this is can be done by pre-dissolving the gas of interest in water and then introducing it to the sample under the appropriate conditions. With this method, it is easier to form hydrate from more soluble gases such as carbon dioxide. It is thought that this method more closely simulates the way most natural gas hydrate has formed. Laboratory implementation, however, is difficult, and sample formation is prohibitively time consuming [Minagawa et al., 2005; Spangenberg and Kulenkampff, 2005]. In another version of this technique, a specified quantity of gas is placed in a sample, then the sample is flooded with water and cooled [Priest et al., 2009]. We have performed a number of tests in which hydrate was formed and the uniformity of the hydrate formation was examined. These tests have primarily used a variety of modifications of the excess gas method to make the hydrate, although we have also used a version of the excess water technique. Early on, we found difficulties in creating uniform samples with a particular sand/ initial water saturation combination (F-110 Sand, {approx} 35% initial water saturation). In many of our tests we selected this combination intentionally to determine whether we could use a method to make the samples uniform. The following methods were examined: Excess gas, Freeze/thaw/form, Freeze/pressurize/thaw, Excess gas followed by water saturation, Excess water, Sand and kaolinite, Use of a nucleation enhancer (SnoMax), and Use of salt in the water. Below, each method, the underlying hypothesis, and our results are briefly presented, followed by a brief conclusion. Many of the hypotheses investigated are not our own, but were presented to us. Much of the data presented is from x-ray CT scanning our samples. The x-ray CT scanner provides a three-dimensional density map of our samples. From this map and the physics that is occurring in our samples, we are able to gain an understanding of the spatial nature of the processes that occur, and attribute them to the locations where they occur.

  3. Bioreceptivity of building stones: a review.

    PubMed

    Miller, A Z; Sanmartín, P; Pereira-Pardo, L; Dionísio, A; Saiz-Jimenez, C; Macedo, M F; Prieto, B

    2012-06-01

    In 1995, Guillitte defined bioreceptivity, a new term in ecology, as the ability of a material to be colonized by living organisms. Information about the bioreceptivity of stone is of great importance since it will help us to understand the material properties which influence the development of biological colonization in the built environment, and will also provide useful information as regards selecting stones for the conservation of heritage monuments and construction of new buildings. Studies of the bioreceptivity of stone materials are reviewed here with the aim of providing a clear set of conclusions on the topic. Definitions of bioreceptivity are given, stone bioreceptivity experiments are described, and finally the stone properties related to bioreceptivity are discussed. We suggest that a standardized laboratory protocol for evaluating stone bioreceptivity and definition of a stone bioreceptivity index are required to enable creation of a database on the primary bioreceptivity of stone materials. PMID:22534363

  4. Gender Distribution of Pediatric Stone Formers

    NASA Astrophysics Data System (ADS)

    Novak, Thomas E.; Trock, Bruce J.; Lakshmanan, Yegappan; Gearhart, John P.; Matlaga, Brian R.

    2008-09-01

    Recent epidemiologic evidence suggests that the gender prevalence among adult stone-formers is changing, with an increasing incidence of stone disease among women. No similar data have ever been reported for the pediatric stone-forming population. We performed a study to define the gender distribution among pediatric stone-formers using a large-scale national pediatric database. Our findings suggest that gender distribution among stone formers varies by age with male predominance in the first decade of life shifting to female predominance in the second decade. In contrast to adults, females in the pediatric population are more commonly affected by stones than are males. The incidence of pediatric stone disease appears to be increasing at a great rate in both sexes. Further studies should build on this hypothesis-generating work and define the effects of metabolic and environmental risk factors that may influence stone risk in the pediatric patient population

  5. "Stone Age" Fun: Releasing the Animal Within.

    ERIC Educational Resources Information Center

    Geist, Janet Marie

    2000-01-01

    Discusses a fifth-grade sculpture project that uses a subtractive, rather than additive, technique. Students carve an animal sculpture from a block of simulated stone compound. Explains the process and how to make the simulated stone compound. (CMK)

  6. Luserna Stone: A nomination for "Global Heritage Stone Resource"

    NASA Astrophysics Data System (ADS)

    Primavori, Piero

    2015-04-01

    Luserna Stone (Pietra di Luserna) is the commercial name of a grey-greenish leucogranitic orthogneiss, probably from the Lower Permian Age, that outcrops in the Luserna-Infernotto basin (Cottian Alps, Piedmont, NW Italy) on the border between the Turin and Cuneo provinces. Geologically speaking, it pertains to the Dora-Maira Massif that represents a part of the ancient European margin annexed to the Cottian Alps during the Alpine orogenesis; from a petrographic point of view, it is the metamorphic result of a late-Ercinian leucogranitic rock transformation. Lithological features and building applications allow the recognition of two main varieties: 1) a micro-augen gneiss with very regular schistosity planes with centimetric spacing and easy split workability, known as Splittable facies; 2) a micro-Augen gneiss characterized by lower schistosity and poor split, suitable for blocks cutting machines (diamond wires, gang-saws, traditional saws), known as Massive facies. A third, rare, white variety also exists, called "Bianchetta". Luserna stone extends over an area of approximately 50 km2, where more than fifty quarries are in operation, together with a relevant number of processing plants and artisanal laboratories. The stone is quarried and processed since almost the Middle Age, and currently represents one of the three most important siliceous production cluster in Italy (together with the Ossola and Sardegna Island granites). Some characteristics of this stone - such as the relevant physical-mechanical properties, an intrinsic versatility and its peculiar splittability - have made it one of the most widely used stone materials in Italy and in the countries surrounding the North Western border of Italy. Apart from its intrinsic geological, petrographic, commercial and technical properties, several issues related to the Luserna Stone are considered to be of relevant importance for its designation as a Global Heritage Stone Resource, such as the distinctive mark on the architecture and urban landscape of many areas in NW Italy, some quite peculiar applications (for ex.: the "so-called "loze" or "lose", for the traditional roofing in alpine buildings) and the related constructive culture, the presence of an Eco-Museum, the occurrence of a local Fair (Pietra & Meccanizzazione), and many other important aspects.

  7. 77 FR 27245 - Big Stone National Wildlife Refuge, Big Stone and Lac Qui Parle Counties, MN

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-09

    ... Fish and Wildlife Service Big Stone National Wildlife Refuge, Big Stone and Lac Qui Parle Counties, MN... comprehensive conservation plan (CCP) and environmental assessment (EA) for Big Stone National Wildlife Refuge...: r3planning@fws.gov . Include ``Big Stone Draft CCP/ EA'' in the subject line of the message. Fax:...

  8. After urgent drainage of an obstructed kidney by internal ureteric stenting; is ureteroscopic stone extraction always needed?

    PubMed Central

    Taha, Diaa-Eldin; Elshal, Ahmed M.; Zahran, Mohamed H.; Harraz, Ahmed M.; El-Nahas, Ahmed R.; Shokeir, Ahmed A.

    2015-01-01

    Objectives To assess the probability of spontaneous stone passage and its predictors after drainage of obstructed kidney by JJ stent, as insertion of an internal ureteric stent is often used for renal drainage in cases of calcular ureteric obstruction. Patients and methods Between January 2011 and June 2013, patients for whom emergent drainage by ureteric stents were identified. The patients’ demographics, presentation, and stone characteristics were reviewed. The primary endpoint for this study was stone-free status at the time of stent removal, where all patients underwent non-contrast spiral computed tomography (NCCT) before stent removal. Ureteroscopic stone extraction was performed for CT detectable ureteric stones at the time of stent removal. Potential factors affecting the need for ureteroscopic stone extraction at the time of stent removal were assessed using univariate and multivariate statistical analyses. Results Emergent ureteric stents were undertaken in 196 patients (112 males, 84 females) with a mean (SD) age of 53.7 (16.2) years, for renal obstruction drainage. At the time of stent removal, 83 patients (42.3%) were stone free; with the remaining 113 patients (57.7%) undergoing ureteroscopic stone extraction. On multivariate analysis, stone width [odds ratio (OR) 15.849, 95% confidence interval (CI) 2.83; P = 0.002) and radio-opaque stones (OR 12.035, 95% CI 4.65; P < 0.001) were independent predictors of the need for ureteroscopic stone extraction at the time of stent removal. Conclusion Spontaneous ureteric stone passage is possible after emergent drainage of an obstructed kidney by ureteric stenting. Stone opacity, larger stone width, and positive preoperative urine culture are associated with a greater probability of requiring ureteroscopic stone extraction after emergent drainage by ureteric stenting. PMID:26609444

  9. Intrarenal Surgery vs Percutaneous Nephrolithotomy in the Management of Lower Pole Stones Greater than 2 cm

    PubMed Central

    Koyuncu, Hakan; Yencilek, Faruk; Kalkan, Mehmet; Bastug, Yavuz; Yencilek, Esin; Ozdemir, Ahmet Tunc

    2015-01-01

    Purpose To compare the efficacy of RIRS and PNL in lower pole stones ≥2 cm. Materials and and Methods: A total of 109 patients who underwent PNL or RIRS for solitary lower pole stone between April 2009 and December 2012, were retrospectively analyzed. Lower pole stone was diagnosed with CT scan. Stone size was assessed as the longest axis of the stone. All patients were informed about the advantages, disadvantages and probable complications of both PNL and RIRS before the selection of the procedure. Patients decided the surgery type by themselves without being under any influences and written informed consent was obtained from all patients prior to the surgery. Patients were divided into two groups according to the patients’ preference of surgery type. Group 1 consisted of 77 patients who underwent PNL and Group 2 consisted of 32 patients treated with RIRS. Stone free statuses, postoperative complications, operative time and hospitalization time were compared in both groups. Results There was no statistical significance between the two groups in mean age, stone size, stone laterality, mean follow-up periods and mean operative times. In PNL group, stone-free rate was 96.1% at first session and 100% after the additional procedure. In Group 2, stone-free rate was 90.6% at the first procedure and 100% after the additional procedure. The final stone-free rates and operative times were similar in both groups. Conclusions RIRS should be an effective treatment alternative to PNL in lower pole stones larger than 2 cm, especially in selected patients. PMID:26005965

  10. Forests of Stone.

    ERIC Educational Resources Information Center

    Davidow, Beth

    1992-01-01

    Presents a geological tour of Arizona's Petrified Forest National Park, cited as containing the greatest record of life in the Triassic Period. Discusses ancient ecosystems, fossil records, geologic formations, petroglyphs, the Anasazi settlements, Painted Desert, and other park features. Includes an illustration of the fossilization process,…

  11. Keep Your Kidneys Clear: Kicking Kidney Stones

    MedlinePlus

    ... Your Kidneys Clear Keep Your Kidneys Clear Kicking Kidney Stones Some say that passing a kidney stone is like delivering a baby made of razor ... is that, although they can be excruciatingly painful, kidney stones rarely cause permanent damage, and you may be ...

  12. Management of lower ureteric stones: a prospective study

    PubMed Central

    Morsi, Gamal A.M.; Beshir, Mansour S.M.; Soliman, Sheri S.; Galal, Hussein A.; Ortiz–Vanderdys, Cervando

    2013-01-01

    Objective To discuss the current concepts in lower ureteric stone management. Material and methods Between October 2008 and November 2010, 190 patients of both sexes and of different age groups with lower ureteric stones, underwent in situ extracorporeal shock wave lithotripsy (ESWL) (48 cases), ureterorenoscopy (URS) (120 cases) and open stone surgery (OSS) (22 cases). The patients’ clinical and radiological findings, as well as stone characteristics, were reviewed and correlated with the stone–free status. Results In the ESWL group, the operative time was 43.13 +22.5 min; the average number of sessions/patients was 1.5 sessions; the average number of SW/patients was 4500 SW/patients; the average energy was 16.5 kV; the average stone burden was 7.8/mm; the overall stone–free rate was 75% (36/48); and the average radiation exposure time was 3.5 min. In the URS group, the operative time was 49.21 +16.09 min; the average stone burden was 10.81mm; the overall stone–free rate was 97.5% (117/120); the average hospital stay was 3.99 days; and the average radiation exposure time was 0.75 min. In the OSS group, the operative time was 112.38 +37.1 min; the overall stone–free rate was 100% (22/22); and the average hospital stay was 9.74 days. Conclusion In the management of patients with lower ureteral stones, URS, SWL and OSS were considered acceptable treatment options. This recommendation was based on the stone–free results, morbidity and retreatment rates for each therapy. PMID:24757544

  13. A Common Bile Duct Stone formed by Suture Material after Open Cholecystectomy

    PubMed Central

    Kim, Kook-Hyun; Jang, Byung-Ik

    2007-01-01

    The use of non-absorbable suture materials for cystic duct ligation after cholecystectomy can expose patients to the risk of recurrent stone formation in the common bile duct (CBD). However, in Korea suture materials have rarely been found to act as a nidus for common bile duct calculus formation. Recently, we experienced a case in which suture material, that had migrated from a previous cholecystectomy site into the CBD, probably served as a nidus for common bile duct stone formation. The stone was confirmed by endoscopic retrograde cholangiopancreatography (ERCP) and removed successfully using a basket. The authors report a case of surgical suture migration and discuss its subsequent role as a stone forming nucleus within the CBD in a patient who underwent open cholecystectomy; and include a review of the literature. PMID:18309688

  14. Urinary pH as a Risk Factor for Stone Type

    NASA Astrophysics Data System (ADS)

    Sakhaee, Khashayar

    2007-04-01

    A high urinary pH is main risk factor for the calcium phosphate stone formation; however, its pathophysiologic mechanism has not been fully understood. The introduction of Topiramate in the treatment of various neurological disorders has been complicated by metabolic acidosis, significant hypocitraturia, elevated urinary pH, and calcium phosphate stone formation. This model provides a probe to investigate the pathophysiologic mechanism of calcium phosphate stone formation and perhaps to develop appropriate countermeasures in the future. On the other hand an unduly acidic urine predisposes one to uric acid nephrolithiasis. Our recent investigation linking low urinary pH, and defective renal ammoniagenesis to insulin resistance provides new knowledge to unfold the pathophysiology of uric acid nephrolithiasis. The metabolic profile leading to uric acid stone may emerge as one of the components of metabolic syndrome.

  15. Ultrasonic Destruction of Kidney Stones

    PubMed Central

    Brannen, George E.; Bush, William H.

    1984-01-01

    Kidney stones may be removed without using a surgical incision by a combination of techniques and skills recently developed in the fields of urology and radiology. Percutaneous access to the kidney is established under fluoroscopic control. A guide wire placed into the renal pelvis allows a nephroscope to be inserted and the collecting system visualized. A long hollow metal probe is advanced through the nephroscope and placed in contact with the stone. This probe conducts the ultrasonic energy. The stone absorbs the energy and breaks into fine granules, which are evacuated by suction. Twenty-three consecutively seen patients presenting with 27 upper urinary tract calculi for which removal was indicated underwent successful percutaneous ultrasonic lithotripsy. Fifteen stones were located in the renal pelvis, eight in a calix, three at the ureteropelvic junction and one in the upper ureter. One infected staghorn calculus was removed. Two complications resulted in extended hospital stays, but in no patients were surgical incisions required. Of the 23 patients, 9 had previously had a surgical lithotomy. The authors believe that most renal and upper ureteral calculi for which removal is indicated may be extracted percutaneously with the aid of the ultrasonic lithotriptor. The patients may expect a rapid convalescence with diminished pain. Images PMID:6730470

  16. Developing disease resistant stone fruits

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Stone fruit (Prunus spp.) (peach, nectarine, plum, apricot, cherry) and almonds are susceptible to a number of pathogens. These pathogens can cause extensive losses in the field, during transport and storage, and in the market. Breeding for disease resistance requires an extensive knowledge of the...

  17. Effects of particulate matter from gasoline and diesel vehicle exhaust emissions on silicate stones sulfation

    NASA Astrophysics Data System (ADS)

    Simão, J.; Ruiz-Agudo, E.; Rodriguez-Navarro, C.

    The effects of particulate matter (PM) from diesel and leaded gasoline motor vehicles exhaust emissions on sulfation of granites, syenite and gabbro stones have been experimentally studied. Abundant gypsum crystals and corrosion features developed on stones covered with diesel PM (DPM) following 72 h exposure to 100 ppm SO 2 at a relative humidity of 100%. In contrast, very small amounts of gypsum were observed on stones covered with gasoline PM (GPM), while no effect was observed on naked control stones. Abundant elemental C and Fe-rich particles in DPM play a critical role in the catalytic oxidation of SO 2 and the formation of H 2SO 4, which is responsible for silicate stone sulfation. Conversely, organic C and Pb-rich particles that are main components of GPM, do not play a significant role in sulfation. The response of each stone type towards sulfation is related to the stability of their constituent silicate minerals towards acid attack. Thus, the stones most susceptible to sulfation are those including nepheline (syenite), olivine, and pyroxene (gabbro), while granites in general, are most resistant to sulfation-related chemical weathering. These results help to explain how black (gypsum) crusts develop on silicate stones, and support limitations for (diesel) vehicular traffic and emission loads in urban centers.

  18. Analysis of factors affecting spontaneous expulsion of ureteral stones that may predict unfavorable outcomes during watchful waiting periods: What is the influence of diabetes mellitus on the ureter?

    PubMed Central

    Choi, Taesoo; Choi, Seung-Kwon; Kim, Dong Soo; Lee, Dong-Gi; Min, Gyeong Eun; Jeon, Seung Hyun; Lee, Hyung-Lae; Jeong, In-Kyung

    2015-01-01

    Purpose The aim of our study was to evaluate the association of several factors with spontaneous stone expulsion, including ureteral stone characteristics (size, location, hydronephrosis, perinephric stranding), types of medications prescribed (?-blocker, low-dose steroid), and other possible demographic and health-history factors (gender, age, serum creatinine, underlying diabetes mellitus [DM], and hypertension). Materials and Methods A total of 366 patients with ureteral stones were enrolled. All patients underwent watchful waiting without any invasive procedures. Initial diagnoses of ureteral stones were confirmed by computed tomography scans, which were taken at approximately 1-month intervals to check for stone expulsion. Univariate and multivariate analyses were conducted to identify significant factors that contributed to stone expulsion. Results Among 366 patients, 335 patients (91.5%) experienced spontaneous stone passage during a mean follow-up period of 2.952.62 weeks. The patients were divided into two groups depending on the success of spontaneous stone passage. Univariate analyses revealed that stone location (p=0.003), stone size (p=0.021), and underlying DM (p<0.001) were significant predictors of stone passage. Multivariate analyses confirmed that stone size (p=0.010), stone location (p=0.008), and underlying DM (p=0.003) were independent predictive factors affecting stone passage. Conclusions Stone size, location, and underlying DM were confirmed to be significant predictive factors for spontaneous passage of ureteral stones. Urologists should consider active procedures, such as shock wave lithotripsy or ureteroscopy, rather than conservative management in patients presenting with proximally located stones, large ureteral stones, or underlying DM. PMID:26078843

  19. Muckraking Free Speech: I.F. Stone and the Trial of Socrates.

    ERIC Educational Resources Information Center

    Birkhead, Douglas

    1989-01-01

    Reviews I.F. Stone's "The Trial of Socrates," discussing the application of Stone's particular perspective (vintage American liberalism) and method (the muckraking tradition) to his reassessment of democracy and free speech in ancient Athens via Socrates' trial and condemnation. Compares Ancient Greek and modern concepts of free speech and…

  20. Method of altering the permeability of a subterranean formation

    SciTech Connect

    Hanlon, D. J.; Almond, S. W.

    1985-06-25

    The production of water from a subterranean formation is reduced by contacting the formation with a water dispersible hydrophilic organic polymer having a molecular weight greater than 100,000 and containing carboxyl functionality and a crosslinking composition comprising water, a zirconium compound having a value of 4+, an alpha-hydroxy acid and an amine compound.

  1. Method of condensing vaporized water in situ to treat tar sands formations

    DOEpatents

    Hsu, Chia-Fu

    2010-03-16

    Methods for treating a tar sands formation are described herein. Methods may include heating at least a section of a hydrocarbon layer in the formation from a plurality of heaters located in the formation. Heat may be allowed to transfer from the heaters to at least a first portion of the formation. Conditions may be controlled in the formation so that water vaporized by the heaters in the first portion is selectively condensed in a second portion of the formation. At least some of the fluids may be produced from the formation.

  2. KIDNEY STONE INCIDENCE AND METABOLIC URINARY CHANGES AFTER MODERN BARIATRIC SURGERY: REVIEW OF CLINICAL STUDIES, EXPERIMENTAL MODELS, AND PREVENTION STRATEGIES

    PubMed Central

    Canales, Benjamin K.; Hatch, Marguerite

    2014-01-01

    Bariatric surgery has been associated with increased metabolic kidney stone risk and post-operative stone formation. A MEDLINE search, performed for articles published between January 2005 and November 2013, identified 24 pertinent studies containing 683 bariatric patients with 24-hour urine profiles, 6,777 bariatric patients with kidney stone incidence, and 7,089 non-stone forming controls. Of all procedures reviewed, only Roux-en-Y gastric bypass (RYGB) was linked to post-operative kidney stone development, increasing stone incidence two-fold in non-stone formers (8.5%) and four-fold in patients with previous stone history (16.7%). High quality evidence from 7 studies (n=277 patients) before and after RYGB identified the following post-RYGB urinary lithogenic risk factors: 30% reduction in urine volume (the main driver of urinary crystal saturation), 40% reduction in urinary citrate (a potent stone inhibitor), and 50% increase in urinary oxalate (a stone promotor). Based on this, a summary of strategies to reduce calcium oxalate stone risk following RYGB is provided. Furthermore, recent experimental RYGB studies are assessed for insights into the pathophysiology of oxalate handling, and the literature in gut anion (oxalate) transport is reviewed. Finally, as a potential probiotic therapy for hyperoxaluria, primary data from our laboratory is presented, demonstrating a 70% reduction in urinary oxalate levels in four experimental RYGB animals after colonization with Oxalobacter formigines, a non-pathogenic gut commensal that uses oxalate as an energy source. Overall, urine profiles and kidney stone risk following bariatric surgery appear modifiable by dietary adjustments, appropriate supplementation, and lifestyle changes. For hyperoxaluria resistant to dietary oxalate restriction and calcium binding, well-designed human investigations are needed to identify additional means of lowering urinary oxalate, such as Oxalobacter colonization or empiric pyridoxine therapy. Further investigations are also needed to determine tolerability and compliance of stone prevention strategies, such as citrate supplementation and hydration, in this population. PMID:24969092

  3. Impact of Stone Removal on Renal Function: A Review

    PubMed Central

    Wood, Kyle; Keys, Tristan; Mufarrij, Patrick; Assimos, Dean G

    2011-01-01

    Stone removal can improve renal function by eradicating obstruction and, in certain cases, an underlying infection. Stone-removing procedures, however, may negatively impact functional integrity. Many things may impact the latter, including the procedures used, the methods of assessing function, the time when these assessments are made, the occurrence of complications, the baseline condition of the kidney, and patient-related factors. In the majority of cases, little significant functional impairment occurs. However, there are gaps in our knowledge of this subject, including the cumulative effects of multiple procedures violating the renal parenchyma and long-term functional outcomes. PMID:21935339

  4. [Development of bladder stone following a tension-free vaginal tape procedure: a case report].

    PubMed

    Tolosa Eizaguirre, Egoitz; Rincn Mayans, Anbal; Zuazu, Jorge Rioja; Bergera, Juan J Zudaire; Abad, Javier Barba; Polo, Jos Ma Berin

    2009-06-01

    The bladder stone formation due to intravesical mesh erosion of tension-free vaginal tape (TVT) is an infrequent complication. We report a case of 73 years old woman, treated in two occasions by means of the positioning of a TVT with the intention of treating its urinary incontinence. The symptoms, of a year of evolution, was characterized by disuria, pelvic pain, diarrea and constitutional syndrome. RM showed bladder stone fixed to bladder wall. The extraction of the bladder stone was made by the section of the polypropilene mesh on which the calculi had been developed. 6 months later, control cystoscopy revealed complete healing of bladder mucosa. PMID:19711756

  5. The training of a ‘stone doctor’

    PubMed Central

    Talati, Jamsheer J.

    2012-01-01

    Objective To propose alternative models of training for doctors treating patients with stones, and to identify their relative value, as such doctors are trained through urology programmes which sometimes cannot be expanded to meet the need, are short of teachers, too comprehensive and lengthy. This review explores new pathways for training to provide competence in the care of patients with stones. Methods Previous reports were identified and existing training models collectively categorised as Model 1. Three alternative models were constructed and compared in the context of advantages, acceptability, feasibility, educational impact and applicability in different geosocio-political contexts. Results In Model 2, urological and stone training diverge as options after common basic courses and experience. In Model 3, individuals access training through a common educational matrix (EM) for nurses, physicians, etc., according to the match between their capacities, entry requirements, personal desires and willingness for further responsibility. Stone doctors with no urological background cannot fulfil other service and educational commitments, and might create unwelcome dependence on other colleagues for complex situations. Programmes involving a common EM affect professional boundaries and are not easily acceptable. There is a lack of clarity on methods for medical certification and re-certification. However, the lack of technically competent stone experts in developing worlds requires an exploration of alternative models of training and practice. Conclusions The ability to provide exemplary care after abbreviated training makes alternative models attractive. Worldwide debate, further exploration and pilot implementation are required, perhaps first in the developing world, in which much of the ‘stone belt’ exists. PMID:26558030

  6. Systems and methods for producing hydrocarbons from tar sands formations

    SciTech Connect

    Li, Ruijian; Karanikas, John Michael

    2009-07-21

    A system for treating a tar sands formation is disclosed. A plurality of heaters are located in the formation. The heaters include at least partially horizontal heating sections at least partially in a hydrocarbon layer of the formation. The heating sections are at least partially arranged in a pattern in the hydrocarbon layer. The heaters are configured to provide heat to the hydrocarbon layer. The provided heat creates a plurality of drainage paths for mobilized fluids. At least two of the drainage paths converge. A production well is located to collect and produce mobilized fluids from at least one of the converged drainage paths in the hydrocarbon layer.

  7. Dietary recommendations and treatment of patients with recurrent idiopathic calcium stone disease.

    PubMed

    Robertson, W G

    2016-02-01

    This review describes the various dietary regimens that have been used to advise patients on how to prevent the recurrence of their calcium-containing kidney stones. The conclusion is that although there is some general advice that may be useful to many patients, it is more efficacious to screen each patient individually to identify his/her main urinary, metabolic, nutritional, environmental, and lifestyle risk factors for stone-formation and then tailor specific advice for that particular patient based on the findings from these investigations. If the patient can be motivated to adhere strictly to this conservative approach to the prophylactic management of their stone problem over a long time period, then it is possible to prevent them from forming further stones. This approach to stone management is considerably less expensive than any of the procedures currently available for stone removal or disintegration. In the UK, for each new stone episode prevented by this conservative approach to prophylaxis it is calculated to save the Health Authority concerned around £2000 for every patient treated successfully. In the long term, this accumulates to a major saving within each hospital budget if most stone patients can be prevented from forming further stones and when the savings are totalled up country-wide saves the National Exchequer considerable sums in unclaimed Sick Pay and industry a significant number of manpower days which would otherwise be lost from work. It is also of immense relief and benefit to the patients not to have to suffer the discomfort and inconvenience of further stone episodes. PMID:26645870

  8. Preclinical safety and effectiveness studies of ultrasonic propulsion of kidney stones

    PubMed Central

    Harper, Jonathan D.; Dunmire, Barbrina; Wang, Yak-Nam; Simon, Julianna C.; Liggitt, H. Denny; Paun, Marla; Cunitz, Bryan W.; Starr, Frank; Bailey, Michael R.; Penniston, Kristina; Lee, Franklin Chong-Ho; Hsi, Ryan S.; Sorensen, Mathew D.

    2014-01-01

    Objective To provide an update on a research device to ultrasonically reposition kidney stones transcutaneously. This paper reports preclinical safety and effectiveness studies, survival data, modifications of the system, and testing in a stone-forming porcine model. These data formed the basis for regulatory approval to test the device in humans. Materials and Methods The ultrasound burst was shortened to 50ms from previous investigations with 1s bursts. Focused ultrasound was used to expel 2–5mm calcium oxalate monohydrate stones placed ureteroscopically in five pigs. Additionally, de novo stones were imaged and repositioned in a stone-forming porcine model. Acute safety studies were performed targeting two kidneys (6 sites) and three pancreases (8 sites). Survival studies followed 10 animals for one week after simulated treatment. Serum and urine analyses were performed and tissues were evaluated histologically. Results All ureteroscopically-implanted stones (6/6) were repositioned out of the kidney in 14 ± 8 minutes with 13 ± 6 bursts. On average, three bursts moved a stone more than 4mm and collectively accounted for the majority of relocation. Stones (3mm) were detected and repositioned in the 200-kg stone-forming model. No injury was detected in the acute or survival studies. Conclusions Ultrasonic propulsion is safe and effective in the porcine model. Stones were expelled from the kidney. De novo stones formed in a large porcine model were repositioned. No adverse effects were identified with the acute studies directly targeting kidney or pancreatic tissue or during the survival studies indicating no evidence of delayed tissue injury. PMID:24975708

  9. Functional aspects of silent ureteral stones investigated with MAG-3 renal scintigraphy

    PubMed Central

    2014-01-01

    Background To investigate functional aspects of silent ureteral stones with special focus on obstruction and its relationship to renal anatomy. The present study is the first investigation of renal excretory function in patients with silent ureteral stones. Methods Patients with primarily asymptomatic ureteral stones underwent a mercapto-acetyltriglycine (MAG-3) renal scintigraphy prior to treatment, in addition to anatomic evaluation of renal units and serum creatinine levels. The primary outcome measure was the presence or absence of obstruction. Secondary outcome measures were kidney anatomy, grade of hydronephrosis, location of stones, stone size, and serum creatinine levels. Results During a ten-year period, 14 patients (median age 52.6 years; range 37.3 to 80.7 years) were included in the study. The relative frequency of primarily asymptomatic ureteral stones among all patients treated for ureteral stones in the study period was 0.7%. Eleven renal units showed some degree of hydronephrosis while 3 kidneys were not dilated. On the MAG-3 scan, 7 patients had an obstruction of the ureter, 5 had no obstruction, and 2 had dysfunction of the kidney. A statistically significant correlation was established between the grade of obstruction and stone size (p = 0.02). Conclusions At the time of presentation, only 64.3% of the patients revealed an obstruction in the stone-bearing renal unit. The degree of hydronephrosis and renal function were very diverse in this subgroup of patients with ureteral stones. The onset of ureterolithiasis and the chronological sequence of obstruction remain unclear in patients who have never experienced symptoms due to their stones. PMID:24397735

  10. Carbohydrate intolerance and kidney stones in children in the Goldfields.

    PubMed

    Baldwin, D N; Spencer, J L; Jeffries-Stokes, C A

    2003-07-01

    Renal stones have been reported as a common finding in Australian Aboriginal children. The stones are predominantly urate in composition. We report on five children with nephrolithiasis from the Goldfields region of Western Australia. All were diagnosed when under 5 years of age, the majority being under 3 years. All five children also had lactose intolerance, and we postulate that carbohydrate malabsorption, together with the ensuing chronic diarrhoea and intraluminal breakdown of sugars by enteric bacteria may result in a situation of chronic metabolic acidosis. Chronic metabolic acidosis can lead to protein catabolism, increased urate excretion and the formation of renal stones. Carbohydrate intolerance may be an aetiological factor in the development of renal stones and possibly chronic renal disease, particularly in Aboriginal Australians. Renal disease represents one of the most significant factors affecting the health of Australian Aboriginal people. The incidence of end stage renal failure in this population exceeds that of non-Aboriginals by a factor of 13:1, and this disproportionate figure is increasing. It is likely that chronic renal damage is multifactorial; however, it is probable that at least some aetiological factors have their onset during childhood. PMID:12887672

  11. The Matariki Stone of Rapanui

    NASA Astrophysics Data System (ADS)

    Hockey, T. A.

    2005-12-01

    Anthropological studies of Rapanui (Easter Island) are valuable insofar as the island's remoteness allowed its culture to develop independently until western contact. Of special importance to cultural astronomers is the indigenous inhabitants' expressed interest in the sky, through lore, monumental architecture, and rock art. 1 The Matariki Stone is a unique basaltic boulder found on Rapanui; my analysis of it is the result of in situ investigation (2000). The boulder is 1 m x 1.5 m x 2 m in approximate size and weighs in excess of 10,000 kg. According to local informants, at least six cupules, averaging 6 cm in diameter and 5 cm in depth, were placed in it prior to western contact with the island and prior to transport to the boulder's present location. Information about the Matariki Stone's original setting, orientation, and context is lost. "Matariki" means "Pleiades" (or, more generally, a group of stars). However, the pattern of the Matariki Stone cupules strongly resembles another familiar asterism of third-magnitude stars. 2 These zodiac stars were placed significantly in the Rapanui sky of 1500 CE. Yet no local ethnographic evidence mentions these stars, nor is association with these stars and other regional cultures (e. g., Australian aboriginal and Mayan) compelling. 3 Moreover, there is no Polynesian tradition of constellation depiction in rock art at all, whereas the Pleiades figure prominently in that culture's oral tradition. 4 Thus, the Matariki Stone remains a conundrum. 1 Liller, William. The Ancient Solar Observatories of Rapanui: The Archaeoastronomy of Easter Island. (1993) 2 Hockey, Thomas and Hoffman, Alice. "An Archaeoastronomical Investigation: Does A Constellation Pattern Appear in Rapanui Rock Art?" Rapa Nui Journal. 14, no. 3. (2000) 3 For example, Kelly, David H. and Milone, Eugene F. Exploring Ancient Skies: An Encyclopedic Survey of Archaeoastronomy. (2005) 4 For example, Makemson, Maude. The Morning Star Rises. (1941)

  12. Greco-Roman Stone Disease

    NASA Astrophysics Data System (ADS)

    Moran, Michael E.; Ruzhansky, Katherine

    2008-09-01

    Greek and Roman thought had a profound influence upon Western medical practice. From the fall of the Greek civilization to the fall of the Roman, remarkable progress of our understanding of human anatomy and physiology occurred. Here we review the attempts of Greek and Roman thinkers to develop the first understanding of the pathophysiology of urolithiasis, its epidemiology, differential diagnosis of renal versus bladder stones, medications for both colic and prevention, the role of familial syndromes, and dietary management.

  13. The use of non-contrast computed tomography and color Doppler ultrasound in the characterization of urinary stones - preliminary results

    PubMed Central

    Bulakçı, Mesut; Tefik, Tzevat; Akbulut, Fatih; Örmeci, Mehmet Tolgahan; Beşe, Caner; Şanlı, Öner; Oktar, Tayfun; Salmaslıoğlu, Artür

    2015-01-01

    Objective To investigate the role of density value in computed tomography (CT) and twinkling artifact observed in color Doppler analysis for the prediction of the mineral composition of urinary stones. Material and methods A total of 42 patients who were operated via percutaneous or endoscopic means and had undergone abdominal non-contrast CT and color Doppler ultrasonography examinations were included in the study. X-ray diffraction method was utilized to analyze a total of 86 stones, and the correlations between calculated density values and twinkling intensities with stone types were investigated for each stone. Results Analyses of extracted stones revealed the presence of 40 calcium oxalate monohydrate, 12 calcium oxalate dihydrate, 9 uric acid, 11 calcium phosphate, and 14 cystine stones. The density values were calculated as 1499±269 Hounsfield Units (HU) for calcium oxalate monohydrate, 1505±221 HU for calcium oxalate dihydrate, 348±67 HU for uric acid, 1106±219 HU for calcium phosphate, and 563±115 HU for cystine stones. The artifact intensities were determined as grade 0 in 15, grade 1 in 32, grade 2 in 24, and grade 3 in 15 stones. Conclusion In case the density value of the stone is measured below 780 HU and grade 3 artifact intensity is determined, it can be inferred that the mineral composition of the stone tends to be cystine. PMID:26623143

  14. Epidemiologic insights into pediatric kidney stone disease.

    PubMed

    Matlaga, Brian R; Schaeffer, Anthony J; Novak, Thomas E; Trock, Bruce J

    2010-12-01

    The epidemiology of pediatric kidney stone has not yet been as rigorously defined as that of adult kidney stone disease. Herein, we review our recent epidemiologic works characterizing pediatric stone disease using the Kids' Inpatient Database (KID). Specifically we investigated the age and gender distribution of pediatric kidney stone disease, changes in disease prevalence over time, and medical comorbidities associated with this disorder. We identified patients by International Classification of Disease 9th Edition (ICD-9) codes for renal and ureteral calculi as the primary diagnosis. Medical comorbidities were identified using specific comorbidity software. Statistical comparisons between children with and without stone disease were performed. In the first decade of life, stone disease was more prevalent among males than females; however, in the second decade of life females were more commonly affected. Of note, there was a significant increase in treated stone disease across both genders between 1997 and 2003. We also found that the risk of kidney stone diagnosis in children younger than 6 years of age was significantly associated with hypertension and diabetes mellitus. The gender distribution among pediatric stone formers varies significantly by age, although overall females have a greater prevalence than males. There is also a strong association of stone disease and both diabetes and hypertension, although this was only observed in children less than 6 years of age. Taken all together, these findings suggest that urolithiasis in the young child is a complex systemic disease process. PMID:20967433

  15. Grave Songs in Stone.

    ERIC Educational Resources Information Center

    Hunter, J. Mark

    A survey of images on gravestones yields a fascinating array of symbols and visual communication. This paper describes a project in which over 300 symbols in graveyards of the southeastern United States were examined. The method of recording the images and information about them was to photograph the symbol with a 35mm single lens reflex (SLR) and…

  16. Smartphone sensors for stone lithography authentication.

    PubMed

    Spagnolo, Giuseppe Schirripa; Cozzella, Lorenzo; Papalillo, Donato

    2014-01-01

    Nowadays mobile phones include quality photo and video cameras, access to wireless networks and the internet, GPS assistance and other innovative systems. These facilities open them to innovative uses, other than the classical telephonic communication one. Smartphones are a more sophisticated version of classic mobile phones, which have advanced computing power, memory and connectivity. Because fake lithographs are flooding the art market, in this work, we propose a smartphone as simple, robust and efficient sensor for lithograph authentication. When we buy an artwork object, the seller issues a certificate of authenticity, which contains specific details about the artwork itself. Unscrupulous sellers can duplicate the classic certificates of authenticity, and then use them to "authenticate" non-genuine works of art. In this way, the buyer will have a copy of an original certificate to attest that the "not original artwork" is an original one. A solution for this problem would be to insert a system that links together the certificate and the related specific artwork. To do this it is necessary, for a single artwork, to find unique, unrepeatable, and unchangeable characteristics. In this article we propose an innovative method for the authentication of stone lithographs. We use the color spots distribution captured by means of a smartphone camera as a non-cloneable texture of the specific artworks and an information management system for verifying it in mobility stone lithography. PMID:24811077

  17. Smartphone Sensors for Stone Lithography Authentication

    PubMed Central

    Schirripa Spagnolo, Giuseppe; Cozzella, Lorenzo; Papalillo, Donato

    2014-01-01

    Nowadays mobile phones include quality photo and video cameras, access to wireless networks and the internet, GPS assistance and other innovative systems. These facilities open them to innovative uses, other than the classical telephonic communication one. Smartphones are a more sophisticated version of classic mobile phones, which have advanced computing power, memory and connectivity. Because fake lithographs are flooding the art market, in this work, we propose a smartphone as simple, robust and efficient sensor for lithograph authentication. When we buy an artwork object, the seller issues a certificate of authenticity, which contains specific details about the artwork itself. Unscrupulous sellers can duplicate the classic certificates of authenticity, and then use them to “authenticate” non-genuine works of art. In this way, the buyer will have a copy of an original certificate to attest that the “not original artwork” is an original one. A solution for this problem would be to insert a system that links together the certificate and the related specific artwork. To do this it is necessary, for a single artwork, to find unique, unrepeatable, and unchangeable characteristics. In this article we propose an innovative method for the authentication of stone lithographs. We use the color spots distribution captured by means of a smartphone camera as a non-cloneable texture of the specific artworks and an information management system for verifying it in mobility stone lithography. PMID:24811077

  18. Vascular Calcification and Stone Disease: A New Look towards the Mechanism

    PubMed Central

    Yiu, Allen J.; Callaghan, Daniel; Sultana, Razia; Bandyopadhyay, Bidhan C.

    2015-01-01

    Calcium phosphate (CaP) crystals are formed in pathological calcification as well as during stone formation. Although there are several theories as to how these crystals can develop through the combined interactions of biochemical and biophysical factors, the exact mechanism of such mineralization is largely unknown. Based on the published scientific literature, we found that common factors can link the initial stages of stone formation and calcification in anatomically distal tissues and organs. For example, changes to the spatiotemporal conditions of the fluid flow in tubular structures may provide initial condition(s) for CaP crystal generation needed for stone formation. Additionally, recent evidence has provided a meaningful association between the active participation of proteins and transcription factors found in the bone forming (ossification) mechanism that are also involved in the early stages of kidney stone formation and arterial calcification. Our review will focus on three topics of discussion (physiological influences—calcium and phosphate concentration—and similarities to ossification, or bone formation) that may elucidate some commonality in the mechanisms of stone formation and calcification, and pave the way towards opening new avenues for further research. PMID:26185749

  19. Prevalence of and relationship between pulp and renal stones: A radiographic study

    PubMed Central

    Patil, Santosh R.

    2015-01-01

    Aim The aim of the present study was to determine the prevalence of and the relationship between pulp and renal in affected patients and in healthy adults. Materials and methods A total of 240 patients participated in the study. Group A consisted of 120 patients who had renal calculi and Group B had 120 randomly selected controls for the study. The periapical radiographs for all patients were evaluated for the presence or absence of the narrowing of dental pulp chambers and pulp canals. The radiographs were also evaluated to determine the presence or absence of pulp stones. The results were compared and analyzed using the Chi-square test (p < 0.001). Results A total of 164 patients had pulp narrowing and 112 patients had pulp stones, which included 55 controls and 57 renal calculi patients. There was no statistical correlation between pulp narrowing and renal stones (p > 0.001) and also between pulp stones and renal stones (p > 0.001). Conclusion However, there was no significant correlation between the presence of pulp stones and renal stones, and the incidental findings of pulp stones on periapical radiographs can provide useful information in the early diagnosis of the systemic calcifications. PMID:26605145

  20. Determination of the chemical composition of human renal stones with MDCT: influence of the surrounding media

    NASA Astrophysics Data System (ADS)

    Grosjean, Romain; Sauer, Benoît; Guerra, Rui; Kermarrec, Isabelle; Ponvianne, Yannick; Winninger, Daniel; Daudon, Michel; Blum, Alain; Felblinger, Jacques; Hubert, Jacques

    2007-03-01

    The selection of the optimal treatment method for urinary stones diseases depends on the chemical composition of the stone and its corresponding fragility. MDCT has become the most used modality to determine rapidly and accurately the presence of stones when evaluating urinary lithiasis treatment. That is why several studies have tempted to determine the chemical composition of the stones based on the stone X-ray attenuation in-vitro and invivo. However, in-vitro studies did not reproduce the normal abdominal wall and fat, making uncertain the standardization of the obtained values. The aim of this study is to obtain X-ray attenuation values (in Hounsfield Units) of the six more frequent types of human renal stones (n=217) and to analyze the influence of the surrounding media on these values. The stones were first placed in a jelly, which X-ray attenuation is similar to that of the human kidney (30 HU at 120 kV). They were then stuck on a grid, scanned in a water tank and finally scanned in the air. Significant differences in CT-attenuation values were obtained with the three different surrounding media (jelly, water, air). Furthermore there was an influence of the surrounding media and consequently discrepancies in determination of the chemical composition of the renal stones. Consequently, CT-attenuation values found in in-vitro studies cannot really be considered as a reference for the determination of the chemical composition except if the used phantom is an anthropomorphic one.

  1. Dust accretion under stone pavements: A complementary environmental archive in arid environments

    NASA Astrophysics Data System (ADS)

    Dietze, Michael; Fuchs, Markus; Kleber, Arno

    2014-05-01

    Stone pavements are widespread surface covers in arid environments. They form predominantly by the trapping of aeolian dust, which trickles below the surficial clast layer, where it forms a continuous layer of fine-grained material with a prominent foamy structure: the vesicular horizon (Av). Successive accretion of dust leads to a thickening of the aeolian mantle and detaches clasts from bedrock. Since this process is dependent on environmental conditions, stone pavement-covered accretionary sections can be used as palaeoenvironmental archive. In the eastern Mojave Desert, correlation of six sediment sections on a 560 ka old basalt flow yield a standard section, comprising at least three distinct units of pulsed aeolian sediment input, interrupted by phases of stone pavement formation, their burial and subsequent pedogenetic alteration. Formation and subsequent burial of stone pavements requires lateral re-formation processes. Two such processes - clast drag by unconcentrated overland flow and clast creep by air release from the soil - are presented, along with their environmental boundary conditions. The different sedimentary units under stone pavements in the eastern Mojave Desert must be interpreted in the light of both, the prominent climatic changes during the Pleistocene/Holocene and the young drainage system in this region. Accretionary dust sections under stone pavements receive their sediment predominantly from modern playas. However, they typically start trapping sediment and thus environmental information when the lake level drops and the lacustrine archive deceases. Hence, they appear to be complementary archives with a the potential to fill the stratigraphic gaps in lacustrine records.

  2. From stones to rocks

    NASA Astrophysics Data System (ADS)

    Mortier, Marie-Astrid; Jean-Leroux, Kathleen; Cirio, Raymond

    2013-04-01

    With the Aquila earthquake in 2009, earthquake prediction is more and more necessary nowadays, and people are waiting for even more accurate data. Earthquake accuracy has increased in recent times mainly thanks to the understanding of how oceanic expansion works and significant development of numerical seismic prediction models. Despite the improvements, the location and the magnitude can't be as accurate as citizen and authorities would like. The basis of anticipating earthquakes requires the understanding of: - The composition of the earth, - The structure of the earth, - The relations and movements between the different parts of the surface of the earth. In order to answer these questions, the Alps are an interesting field for students. This study combines natural curiosity about understanding the predictable part of natural hazard in geology and scientific skills on site: observing and drawing landscape, choosing and reading a representative core drilling, replacing the facts chronologically and considering the age, the length of time and the strength needed. This experience requires students to have an approach of time and space radically different than the one they can consider in a classroom. It also limits their imagination, in a positive way, because they realize that prediction is based on real data and some of former theories have become present paradigms thanks to geologists. On each location the analyzed data include landscape, core drilling and the relation established between them by students. The data is used by the students to understand the meaning, so that the history of the formation of the rocks tells by the rocks can be explained. Until this year, the CBGA's perspective regarding the study of the Alps ground allowed students to build the story of the creation and disappearance of the ocean, which was a concept required by French educational authorities. But not long ago, the authorities changed their scientific expectations. To meet the requirements of educational authorities, the reflection of the president and vice president of the association and some other high school teachers will help with the evolution and progression of Wegener's theory. I will present to you how the examination of clues found in different areas of the Alps will be taken by the students to reconstitute the evolution of research begun by Wegener in the early 1900s for the understanding of the oceanic expansion. Moreover this experience reinforces the scientific mindset of the class, as well as, what they see originally as an ordinary rock will become a precious rock of scientific significance.

  3. Method and apparatus for production of subsea hydrocarbon formations

    DOEpatents

    Blandford, Joseph W.

    1995-01-01

    A system for controlling, separating, processing and exporting well fluids produced from subsea hydrocarbon formations is disclosed. The subsea well tender system includes a surface buoy supporting one or more decks above the water surface for accommodating equipment to process oil, gas and water recovered from the subsea hydrocarbon formation. The surface buoy includes a surface-piercing central flotation column connected to one or more external floatation tanks located below the water surface. The surface buoy is secured to the seabed by one or more tendons which are anchored to a foundation with piles imbedded in the seabed. The system accommodates multiple versions on the surface buoy configuration.

  4. Method and apparatus for production of subsea hydrocarbon formations

    DOEpatents

    Blandford, J.W.

    1995-01-17

    A system for controlling, separating, processing and exporting well fluids produced from subsea hydrocarbon formations is disclosed. The subsea well tender system includes a surface buoy supporting one or more decks above the water surface for accommodating equipment to process oil, gas and water recovered from the subsea hydrocarbon formation. The surface buoy includes a surface-piercing central flotation column connected to one or more external flotation tanks located below the water surface. The surface buoy is secured to the sea bed by one or more tendons which are anchored to a foundation with piles imbedded in the sea bed. The system accommodates multiple versions on the surface buoy configuration. 20 figures.

  5. Method for reducing carbon formation in a thermal cracking process

    SciTech Connect

    Kukes, S.; Harris, J.R.; Porter, R.A.; Reed, L.E.

    1983-10-18

    The formation of carbon on metals exposed to hydrocarbons in a thermal cracking process is reduced by contacting such metals with a halogen containing silicon compound selected from the group consisting of halogen containing silanes, halogen containing disilanes, and halogen containing siloxanes. After the metals are contacted with the halogen containing silicon compound, the halogen containing silicon compound is converted to silicon dioxide to form a protective coating on the metals. This protective coating substantially reduces the formation of carbon on metals exposed to hydrocarbons in a thermal cracking process.

  6. Investigations of stone consolidants by neutron imaging

    NASA Astrophysics Data System (ADS)

    Hameed, F.; Schillinger, B.; Rohatsch, A.; Zawisky, M.; Rauch, H.

    2009-06-01

    The chemical preservation and structural reintegration of natural stones applied in historical buildings is carried out by the use of different stone strengtheners. As these agents contain hydrogen, they offer good properties for neutron imaging. The main interest in the restoration process is the development of a suitable stone consolidant. In cooperation with the St. Stephans Cathedral and the geologists at Vienna University of Technology, we are investigating the penetration depth and distribution of different stone consolidants. These studies are being carried out with different stone samples, mostly porous natural building stones, limestones and sandstones. The two strengtheners used in this study are ethyl silicate ester (Wacker OH100) and dissolved polymethylmetacrylate (PMMA, Paraloid B72). Neutron radiography and neutron tomography can be used successfully to visualize the distribution of consolidants both in two and three dimensions.

  7. Prevalence of Coronal Pulp Stones and Its Relation with Systemic Disorders in Northern Indian Central Punjabi Population

    PubMed Central

    Bains, Sandeep Kumar; Bhatia, Archana; Singh, Harkanwal Preet; Biswal, Swati Swagatika; Kanth, Shashi; Nalla, Srinivas

    2014-01-01

    Aim. To estimate the prevalence of coronal pulp stones in the molar teeth of dental outpatients of Sunam, Sangrur district, Punjab, India, to report any association between occurrence of pulp stones with age, gender, dental arch, side, and dental status and to find out correlation between pulp stones with dental and systemic diseases. Materials and Methods. 500 routine dental outpatients within age group of 18–67 years were involved in the study. Molar bitewing of left and right side of each patient was taken with XCP bitewing instrument and size 2 film. The presence or absence of pulp stones was recorded. Chi-square analysis was used to record the prevalence of pulp stones and to compare it with demographic and systemic factors. Results. Overall prevalence of pulp stones was 41.8%. Pulp stones were significantly higher in maxilla (11.59%) than mandible (6.54%), left side than right side, and first molar than other molars. Higher numbers of pulp stones were recorded in patients with cardiovascular disease (38.89%) than with cholelithiasis and renal lithiasis. Conclusion. Pulp stones were higher in maxillary arch than mandibular arch and in females than males. Cardiovascular patients had higher number of pulp stones than other groups. PMID:24944821

  8. Novel grinding stone used for polishing 3D plastic replica with rapid prototyping technology

    NASA Astrophysics Data System (ADS)

    Feng, Wang; Niikura, Yoshihiro; Sato, Toshio; Kawashima, Norimichi

    2006-01-01

    Rapid prototyping (RP) apparatus accepts a specific format translated from CAD data (patient's CT) and "slices" it into two-dimensional cross sections for laser photo curing. Surgeon can conduct safer surgery by reappearing on an actual model using 3D plastic replica in the preoperative. Polishing has to be used to eliminate the marks after removal of supports and the build layer pitches. Complicated and narrow areas of the 3D replica are difficult to be polished with the conventional grinding stone. This study proposes a novel grinding stone and introduces its producing process and characteristics. The novel grinding stone has many advantages as follows; (1) Preparation is possible of grinding stone that follows the complicated shape. (2) Grinding stone with uniformly dispersed abrasive grains can be prepared using magnetic particles and magnetic field. (3) Reshaping of grinding stone by heating is possible since the binder is made of a thermoplastic resin. (4) Every process can easily be carried out. We could polish to eliminate the marks after removal of supports and the build layer pitches on 3D plastic replica surface with the grinding stone.

  9. Method for describing fractures in subterranean earth formations

    DOEpatents

    Shuck, Lowell Z.

    1977-01-01

    The configuration and directional orientation of natural or induced fractures in subterranean earth formations are described by introducing a liquid explosive into the fracture, detonating the explosive, and then monitoring the resulting acoustic emissions with strategically placed acoustic sensors as the explosion propagates through the fracture at a known rate.

  10. Expectant Management of Ureter Stones: Outcome and Clinical Factors of Spontaneous Passage in a Single Institution's Experience

    PubMed Central

    Tchey, Dong-Un; Ha, Yun Sok; Kim, Won Tae; Yun, Seok Joong; Kim, Wun Jae

    2011-01-01

    Purpose The aim of this study was to evaluate the outcome of ureter stones with expectant management and the clinical factors associated with stone passage in Koreans. Materials and Methods We reviewed the charts of patients who visited the emergency room or urological office of our institution with acute renal colic between 2001 and 2008. A total of 656 ureter stone formers were enrolled in this study who had decided to be treated by expectant management. Clinical data such as gender, age, size and location of the stone, body mass index, and previous stone history were analyzed to find the factors related to spontaneous passage of ureter stones. Results Of the 656 ureter stones, 566 stones (86.3%) were spontaneously expelled. Mean duration of follow-up was 17.5 days (range, 1 to 100 days). Mean time to stone passage was 6.8 days for stones less than 2 mm in size, 12.6 days for stones 2 to 4 mm, 14.8 days for stones 4 to 6 mm, and 21.8 days for stones 6 to 8 mm (p<0.001). The cumulative spontaneous passage rate was 55.3% in 7 days, 73.7% in 14 days, 88.5% in 28 days, and 97.7% in 60 days after the first attack. A total of 90 patients (13.7%) required interventions because of symptom relapse or renal deterioration that was related to the location and size of the stone (each, p<0.001). The more proximal the location and the larger the stone was than 6 mm, the less the chance of spontaneous passage (each, p<0.001). Conclusions Size and location of ureter stones are the most important factors for predicting the spontaneous passage of the stone. If a patient has a distal ureter stone of less than 6 mm in size, it is acceptable for the urologist to observe for spontaneous passage for 2 months. PMID:22216398

  11. Temporal Trends in the Incidence of Kidney Stones among Children: A 25-Year Population-Based Study

    PubMed Central

    Dwyer, Moira E.; Krambeck, Amy E.; Bergstralh, Eric J.; Milliner, Dawn S.; Lieske, John C.; Rule, Andrew D.

    2012-01-01

    PURPOSE We conducted a population-based pediatric study to determine the incidence of symptomatic kidney stones over a 25-year period and to identify factors related to variation in stone incidence during this time period. MATERIALS AND METHODS The Rochester Epidemiology Project was used to identify all children (ages <18 years) diagnosed with kidney stones in Olmsted County, Minnesota from 1984–2008. Medical records were reviewed to validate first time symptomatic stone-formers with identification of age-appropriate symptoms plus stone confirmation by imaging or passage. The incidence of symptomatic stones by age, gender, and time period was compared. Clinical characteristics of incident stone-formers were described. RESULTS There were 207 children who received a diagnostic code for kidney stones, 84 (41%) of whom were validated as incident stone-formers. The incidence rate increased 4% per calendar year (p=0.01) throughout the 25-year period. This was due to a 6% per year rise of incidence in children aged 12–17 years (p=0.02 for age x calendar year interaction) with an increase from 13 per 100,000 person-years in 1984–1990 to 36 per 100,000 person-years in 2003–2008. Computed tomography (CT) identified the stone in 6% (1/18) of adolescent stone-formers from 1984–1996 versus 76% (34/45) from 1997–2008. The incidence of spontaneous stone passage in adolescents did not increase significantly between these two time periods (16 versus 18 per 100,000 person-years, p=0.30) CONCLUSIONS The incidence of kidney stones increased dramatically among adolescents in the general population over a 25-year period. The exact cause of this finding remains to be determined. PMID:22595060

  12. Shock wave lithotripsy outcomes for lower pole and non-lower pole stones from a university teaching hospital: Parallel group comparison during the same time period

    PubMed Central

    Geraghty, Robert; Burr, Jacob; Simmonds, Nick; Somani, Bhaskar K.

    2015-01-01

    Introduction: Shock wave lithotripsy (SWL) is a treatment option for all locations of renal and ureteric stones. We compared the results of SWL for lower pole renal stones with all other non-lower pole renal and ureteric stones during the same time period. Material and Methods: All SWL procedures were carried out as day case procedures by a mobile lithotripter from January 2012 to August 2013. The follow-up imaging was a combination of KUB X-ray or USS. Following SWL treatment, the stone free rate (SFR) was defined as ≤3 mm fragments. Results: A total of 148 patients with a mean age of 62 years underwent 201 procedures. Of the 201 procedures, 93 (46%) were for lower pole stones. The non-lower pole stones included upper pole (n = 36), mid pole (n = 40), renal pelvis (n = 10), PUJ (n = 8), mid ureter (n = 3), upper ureter (n = 5) and a combination of upper, middle and/or lower pole (n = 6). The mean stone size for lower pole stones (7.4 mm; range: 4-16 mm) was slightly smaller than non-lower pole stones (8 mm; range: 4-17 mm). The stone fragmentation was successful in 124 (62%) of patients. However, the SFR was statistically significantly better (P = 0.023) for non-lower pole stones 43 (40%) compared to lower pole stones 23 (25%). There were 9 (4%) minor complications and this was not significantly different in the two groups. Conclusions: Although SWL achieves a moderately high stone fragmentation rate with a low complication rate, the SFR is variable depending on the location of stone and the definition of SFR, with lower pole stones fairing significantly worse than stones in all other locations. PMID:25657543

  13. Method and apparatus for production of subsea hydrocarbon formations

    DOEpatents

    Blandford, Joseph W.

    1994-01-01

    A well tender system for controlling, separating, storing and offloading well fluids produced from subsea hydrocarbon formations. The system comprises a vertically aligned series of tethered cylindrical tanks which are torsionally stabilized by flexible catenary production riser and export riser bundles, and serviced by separate catenary pipe bundles. Piles are secured to the seabed, each pile assembly being pivotally connected to a lower rigid tendon, which is in turn connected to tendons arranged about the periphery of the interconnected cylindrical tanks.

  14. Method and apparatus for production of subsea hydrocarbon formations

    DOEpatents

    Blandford, Joseph W.

    1992-01-01

    A well tender system for controlling, separating, storing and offloading well fluids produced from subsea hydrocarbon formations. The system comprises a vertically aligned series of tethered cylindrical tanks which are torsionally stabilized by flexible catenary production riser and expert riser bundles, and serviced by separate catenary pipe bundles. Piles are secured to the seabed, each pile assembly being pivotally connected to a lower rigid tendon, which is in turn connected to tendons arranged about the periphery of the interconnected cylindrical tanks.

  15. Downhole burner systems and methods for heating subsurface formations

    DOEpatents

    Farmayan, Walter Farman (Houston, TX); Giles, Steven Paul (Damon, TX); Brignac, Jr., Joseph Phillip (Katy, TX); Munshi, Abdul Wahid (Houston, TX); Abbasi, Faraz (Sugarland, TX); Clomburg, Lloyd Anthony (Houston, TX); Anderson, Karl Gregory (Missouri City, TX); Tsai, Kuochen (Katy, TX); Siddoway, Mark Alan (Katy, TX)

    2011-05-31

    A gas burner assembly for heating a subsurface formation includes an oxidant conduit, a fuel conduit, and a plurality of oxidizers coupled to the oxidant conduit. At least one of the oxidizers includes a mix chamber for mixing fuel from the fuel conduit with oxidant from the oxidant conduit, an igniter, and a shield. The shield includes a plurality of openings in communication with the oxidant conduit. At least one flame stabilizer is coupled to the shield.

  16. Method for selectively orienting induced fractures in subterranean earth formations

    DOEpatents

    Shuck, Lowell Z.

    1977-02-01

    The orientation of hydraulically-induced fractures in relatively deep subterranean earth formations is normally confined to vertical projections along a plane parallel to the maximum naturally occurring (tectonic) compressive stress field. It was found that this plane of maximum compressive stress may be negated and, in effect, re-oriented in a plane projecting generally orthogonal to the original tectonic stress plane by injecting liquid at a sufficiently high pressure into a wellbore fracture oriented in a plane parallel to the plane of tectonic stress for the purpose of stressing the surrounding earth formation in a plane generally orthogonal to the plane of tectonic stress. With the plane of maximum compressive stress re-oriented due to the presence of the induced compressive stress, liquid under pressure is injected into a second wellbore disposed within the zone influenced by the induced compressive stress but at a location in the earth formation laterally spaced from the fracture in the first wellbore for effecting a fracture in the second wellbore along a plane generally orthogonal to the fracture in the first wellbore.

  17. Cast Stone Formulation At Higher Sodium Concentrations

    SciTech Connect

    Fox, K. M.; Roberts, K. A.; Edwards, T. B.

    2014-02-28

    A low temperature waste form known as Cast Stone is being considered to provide supplemental Low Activity Waste (LAW) immobilization capacity for the Hanford site. Formulation of Cast Stone at high sodium concentrations is of interest since a significant reduction in the necessary volume of Cast Stone and subsequent disposal costs could be achieved if an acceptable waste form can be produced with a high sodium molarity salt solution combined with a high water to premix (or dry blend) ratio. The objectives of this study were to evaluate the factors involved with increasing the sodium concentration in Cast Stone, including production and performance properties and the retention and release of specific components of interest. Three factors were identified for the experimental matrix: the concentration of sodium in the simulated salt solution, the water to premix ratio, and the blast furnace slag portion of the premix. The salt solution simulants used in this study were formulated to represent the overall average waste composition. The cement, blast furnace slag, and fly ash were sourced from a supplier in the Hanford area in order to be representative. The test mixes were prepared in the laboratory and fresh properties were measured. Fresh density increased with increasing sodium molarity and with decreasing water to premix ratio, as expected given the individual densities of these components. Rheology measurements showed that all of the test mixes produced very fluid slurries. The fresh density and rheology data are of potential value in designing a future Cast Stone production facility. Standing water and density gradient testing showed that settling is not of particular concern for the high sodium compositions studied. Heat of hydration measurements may provide some insight into the reactions that occur within the test mixes, which may in turn be related to the properties and performance of the waste form. These measurements showed that increased sodium concentration in the salt solution reduced the time to peak heat flow, and reducing the amount of slag in the premix increased the time to peak heat flow. These observations may help to describe some of the cured properties of the samples, in particular the differences in compressive strength observed after 28 and 90 days of curing. Samples were cured for at least 28 days at ambient temperature in the laboratory prior to cured properties analyses. The low activity waste form for disposal at the Hanford Site is required to have a compressive strength of at least 500 psi. After 28 days of curing, several of the test mixes had mean compressive strengths that were below the 500 psi requirement. Higher sodium concentrations and higher water to premix ratios led to reduced compressive strength. Higher fly ash concentrations decreased the compressive strength after 28 days of curing. This may be explained in that the cementitious phases matured more quickly in the mixes with higher concentrations of slag, as evidenced by the data for the time to peak heat generation. All of the test mixes exhibited higher mean compressive strengths after 90 days of curing, with only one composition having a mean compressive strength of less than 500 psi. Leachability indices were determined for the test mixes for contaminants of interest. The leaching performance of the mixes evaluated in this study was not particularly sensitive to the factors used in the experimental design. This may be beneficial in demonstrating that the performance of the waste form is robust with respect to changes in the mix composition. The results of this study demonstrate the potential to achieve significantly higher waste loadings in Cast Stone and other low temperature, cementitious waste forms. Additional work is needed to elucidate the hydration mechanisms occurring in Cast Stone formulated with highly concentrated salt solutions since these reactions are responsible for determining the performance of the cured waste form. The thermal analyses completed in this study provide some preliminary insight, although the limited range of the factors in the test matrix hindered the identification of individual component effects. Future work should involve broader factor ranges to identify the roles played by each of the components in the mix via thermal analyses, analytical microscopy, and characterization of phase formation.

  18. Cast Stone Formulation At Higher Sodium Concentrations

    SciTech Connect

    Fox, K. M.; Edwards, T. A.; Roberts, K. B.

    2013-10-02

    A low temperature waste form known as Cast Stone is being considered to provide supplemental Low Activity Waste (LAW) immobilization capacity for the Hanford site. Formulation of Cast Stone at high sodium concentrations is of interest since a significant reduction in the necessary volume of Cast Stone and subsequent disposal costs could be achieved if an acceptable waste form can be produced with a high sodium molarity salt solution combined with a high water to premix (or dry blend) ratio. The objectives of this study were to evaluate the factors involved with increasing the sodium concentration in Cast Stone, including production and performance properties and the retention and release of specific components of interest. Three factors were identified for the experimental matrix: the concentration of sodium in the simulated salt solution, the water to premix ratio, and the blast furnace slag portion of the premix. The salt solution simulants used in this study were formulated to represent the overall average waste composition. The cement, blast furnace slag, and fly ash were sourced from a supplier in the Hanford area in order to be representative. The test mixes were prepared in the laboratory and fresh properties were measured. Fresh density increased with increasing sodium molarity and with decreasing water to premix ratio, as expected given the individual densities of these components. Rheology measurements showed that all of the test mixes produced very fluid slurries. The fresh density and rheology data are of potential value in designing a future Cast Stone production facility. Standing water and density gradient testing showed that settling is not of particular concern for the high sodium compositions studied. Heat of hydration measurements may provide some insight into the reactions that occur within the test mixes, which may in turn be related to the properties and performance of the waste form. These measurements showed that increased sodium concentration in the salt solution reduced the time to peak heat flow, and reducing the amount of slag in the premix increased the time to peak heat flow. These observations may help to describe some of the cured properties of the samples, in particular the differences in compressive strength observed after 28 and 90 days of curing. Samples were cured for at least 28 days at ambient temperature in the laboratory prior to cured properties analyses. The low activity waste form for disposal at the Hanford Site is required to have a compressive strength of at least 500 psi. After 28 days of curing, several of the test mixes had mean compressive strengths that were below the 500 psi requirement. Higher sodium concentrations and higher water to premix ratios led to reduced compressive strength. Higher fly ash concentrations decreased the compressive strength after 28 days of curing. This may be explained in that the cementitious phases matured more quickly in the mixes with higher concentrations of slag, as evidenced by the data for the time to peak heat generation. All of the test mixes exhibited higher mean compressive strengths after 90 days of curing, with only one composition having a mean compressive strength of less than 500 psi. Leach indices were determined for the test mixes for contaminants of interest. The leaching performance of the mixes evaluated in this study was not particularly sensitive to the factors used in the experimental design. This may be beneficial in demonstrating that the performance of the waste form is robust with respect to changes in the mix composition. The results of this study demonstrate the potential to achieve significantly higher waste loadings in Cast Stone and other low temperature, cementitious waste forms. Additional work is needed to elucidate the hydration mechanisms occurring in Cast Stone formulated with highly concentrated salt solutions since these reactions are responsible for determining the performance of the cured waste form. The thermal analyses completed in this study provide some preliminary insight, although the limited range of the factors in the test matrix hindered the identification of individual component effects. Future work should involve broader factor ranges to identify the roles played by each of the components in the mix via thermal analyses, analytical microscopy, and characterization of phase formation.

  19. Cast Stone Formulation At Higher Sodium Concentrations

    SciTech Connect

    Fox, K. M.; Roberts, K. A.; Edwards, T. B.

    2013-09-17

    A low temperature waste form known as Cast Stone is being considered to provide supplemental Low Activity Waste (LAW) immobilization capacity for the Hanford site. Formulation of Cast Stone at high sodium concentrations is of interest since a significant reduction in the necessary volume of Cast Stone and subsequent disposal costs could be achieved if an acceptable waste form can be produced with a high sodium molarity salt solution combined with a high water to premix (or dry blend) ratio. The objectives of this study were to evaluate the factors involved with increasing the sodium concentration in Cast Stone, including production and performance properties and the retention and release of specific components of interest. Three factors were identified for the experimental matrix: the concentration of sodium in the simulated salt solution, the water to premix ratio, and the blast furnace slag portion of the premix. The salt solution simulants used in this study were formulated to represent the overall average waste composition. The cement, blast furnace slag, and fly ash were sourced from a supplier in the Hanford area in order to be representative. The test mixes were prepared in the laboratory and fresh properties were measured. Fresh density increased with increasing sodium molarity and with decreasing water to premix ratio, as expected given the individual densities of these components. Rheology measurements showed that all of the test mixes produced very fluid slurries. The fresh density and rheology data are of potential value in designing a future Cast Stone production facility. Standing water and density gradient testing showed that settling is not of particular concern for the high sodium compositions studied. Heat of hydration measurements may provide some insight into the reactions that occur within the test mixes, which may in turn be related to the properties and performance of the waste form. These measurements showed that increased sodium concentration in the salt solution reduced the time to peak heat flow, and reducing the amount of slag in the premix increased the time to peak heat flow. These observations may help to describe some of the cured properties of the samples, in particular the differences in compressive strength observed after 28 and 90 days of curing. Samples were cured for at least 28 days at ambient temperature in the laboratory prior to cured properties analyses. The low activity waste form for disposal at the Hanford Site is required to have a compressive strength of at least 500 psi. After 28 days of curing, several of the test mixes had mean compressive strengths that were below the 500 psi requirement. Higher sodium concentrations and higher water to premix ratios led to reduced compressive strength. Higher fly ash concentrations decreased the compressive strength after 28 days of curing. This may be explained in that the cementitious phases matured more quickly in the mixes with higher concentrations of slag, as evidenced by the data for the time to peak heat generation. All of the test mixes exhibited higher mean compressive strengths after 90 days of curing, with only one composition having a mean compressive strength of less than 500 psi. Leach indices were determined for the test mixes for contaminants of interest. The leaching performance of the mixes evaluated in this study was not particularly sensitive to the factors used in the experimental design. This may be beneficial in demonstrating that the performance of the waste form is robust with respect to changes in the mix composition. The results of this study demonstrate the potential to achieve significantly higher waste loadings in Cast Stone and other low temperature, cementitious waste forms. Additional work is needed to elucidate the hydration mechanisms occurring in Cast Stone formulated with highly concentrated salt solutions since these reactions are responsible for determining the performance of the cured waste form. The thermal analyses completed in this study provide some preliminary insight, although the limited range of the factors in the test matrix hindered the identification of individual component effects. Future work should involve broader factor ranges to identify the roles played by each of the components in the mix via thermal analyses, analytical microscopy, and characterization of phase formation.

  20. Methods and systems for the formation of cyclic carbonates

    DOEpatents

    Hatton, Trevor Alan; Jamison, Timothy F; Kozak, Jennifer Aiden; Simeon, Fritz; Wu, Jie

    2014-12-30

    Described herein are inventive methods for synthesis of cyclic carbonates from CO.sub.2 and epoxide. In some embodiments, the methods are carried out in the presence of a catalyst comprising an electrophilic halogen. In some embodiments, the methods are carried out in a flow reactor.

  1. The Prevalence of Pulp stones in Adult Patients of Shiraz Dental School, a Radiographic Assessment

    PubMed Central

    Ravanshad, Shohreh; Khayat, Shideh; Freidonpour, Najmeh

    2015-01-01

    Statement of the Problem Pulp stones are calcifications found in the pulp chamber or pulp canals of the teeth. Its different prevalence in different population is a matter of concern. Purpose This study aimed to assess the prevalence of pulp stones in a sample of Iranian population and to report its occurrence regarding gender, dental arch, tooth type and dental status. Materials and Methods Dental records of patients who attended Shiraz Dental School were selected randomly. Only bitewing and periapical radiographs of maxillary and mandibular permanent posterior teeth were studied. Teeth were classified in the case of presence or absence of pulp stones, and the prevalence was analyzed in different gender, tooth types, dental arch, and dental status (intact, carious, or restored) groups. Statistical analysis was performed using X2 test. Results Of the 652examined subjects, 306 (46.9%) had one or more teeth with pulp stones. Of the 8244 posterior teeth examined, 928 (11.25%) had pulp stones in the pulp chamber. These pulp stones were detected in 76(37.6%) of males and 230 (51%) of females. The frequency of pulp stones among different teeth between maxillary and mandibular arches had almost a similar pattern. Among teeth demonstrating the condition, first molars were the most prevalent, followed by second molars. In maxillary molars the frequency of occurrence (26%) was higher than mandibular molars (18.7%). No Significant difference was found between dental status and pulp stones occurrence. Conclusion The occurrence of pulp stones noted in this study was significantly higher in female, molar teeth than premolar and 1st maxillary molar than mandibular. There was no significant association between pulp stone and condition of the crown. PMID:26636125

  2. Evaluation of Extracorporeal Shock Wave Lithotripsy (ESWL): Efficacy in Treatment of Urinary System Stones

    PubMed Central

    Junuzovic, Dzelaludin; Prstojevic, Jelena Kovacevic; Hasanbegovic, Munira; Lepara, Zahid

    2014-01-01

    ABSTRACT Introduction: Elimination of stone is determined by size and its localization. Stone from the ureter in 80% of cases can be eliminated spontaneously. If the stone by its characteristics is not spontaneously eliminated, taken are further steps and therapeutic protocols to solve this problem. Material and methods: The study was prospective, open and comparative. It was conducted at the Urology Clinic Clinical Center of Sarajevo University in the period from 2007 to 2013. The study included 404 patients with urinary tract lithiasis treated by ESWL. ESWL treatment is performed on the machine Siemens Model Lithostar Multiline, which has a combined ultrasonographic and fluoroscopic display, large energy density in order to obtain optimum focus (without damaging surrounding tissue) and minimal pain that on rare occasions requires for mild sedation-sedation. Results: From a total of 404 patients included in the study there were 234 (57.92%) male and 170 (42.08%) female patients. The most common type of stone both in female and male patients was calcium type. From a total of 262 calcium stones, 105 of them (40.07%) was present in female patients and 157 (59.92%) in male. Share of infectious type of stone in female patients was 63 (49.60%) and 64 among males (50.39%). Other stones were less abundant in both the gender groups and their total number was only 17. In women their frequency was 2 (13.33%) and 13 among males (86.67%). There was a significant difference in the frequency of different types of stones by gender (x2 = 11.47, p = 0.009). Conclusion: There was no statistically significant correlation between the number of treatments and localization of stones in the ureter, as well as a statistically significant correlation between the size of the stone and the localization of calculus in the ureter. PMID:25568579

  3. Detection and Measurement of Stones With Ultrasound Strain Elastography: A Phantom Study.

    PubMed

    Li, Qian; Chen, Lei; Halpern, Elkan F; Samir, Anthony E

    2015-12-01

    The sonoelastographic appearances of stones in a phantom were evaluated in this study. Ten stones were embedded into a tissue-mimicking meat phantom. The stone axial (vertical) and transverse (horizontal) dimensions measured by an electronic digital caliper, gray-scale ultrasound, and strain elastography (SE) were compared in 5 groups with stones embedded at different depths. In this study, physically measured axial and transverse stone dimensions were 1.17 to 6.86 and 1.30 to 11.15 mm, respectively. Strain elastography showed a characteristic 3-layer pattern associated with stones, comprising a superficial transition region, a hard region, and a deep transition region. As SE data were available in group 5, only data of groups 1 to 4 were analyzed. Compared with physical measurements, measurement mean errors of SE horizontal and SE vertical dimensions ranged from -0.20 to 0.42 mm and from -1.28 to -0.05 mm, respectively, in the 4 groups. Paired t testing demonstrated a significant horizontal dimension measurement error difference between B mode and SE method in group 4 (0.44 vs -0.20 mm, P < 0.05; F = 1.18, P > 0.05), but not in the other groups. Strain elastography horizontal dimension measurement error was not statistically correlated with stone size in the 4 groups. Strain elastography vertical dimension measurement error significantly correlated with stone size only in group 4 (P < 0.05). Preliminary results indicate that stone horizontal and vertical dimensions can be measured using SE in a soft tissue phantom, including when shadowing precludes measurement of vertical dimension on conventional 2-dimensional ultrasound. These results provide substantial motivation to further investigate SE as a modality to image stones in clinical practice. PMID:26656990

  4. Optimal Management of Lower Polar Calyceal Stone 15 to 20 mm

    PubMed Central

    Haroon, Naveed; Nazim, Syed M

    2013-01-01

    Purpose To compare the stone clearance rate, efficiency quotient (EQ), and early complications of shock wave lithotripsy (SWL) and percutaneous nephrolithotomy (PCNL) for solitary lower-pole renal stones measuring 15 to 20 mm. Materials and Methods This was a retrospective matched-pair analysis of 142 patients (78 in the SWL and 64 in the PCNL group). Preoperative imaging was done by use of noncontrast computed tomography (CT kidney, ureter, and bladder [KUB]), intravenous urogram, or plain X-ray and ultrasound KUB to assess the largest dimension of the stones. Only patients with radiopaque stones were included. The stone-free rates were assessed with plain X-ray and ultrasound at 4 weeks. Data were analyzed by use of SPSS ver. 19. Results The patients' demographic profiles (age, body mass index) and the stone sizes were comparable in the two groups. The mean stone size was 17.4±2.12 in the PCNL group compared with 17.67±2.04 in the SWL group (p=0.45). At 4 weeks, 83% of patients undergoing PCNL were stone-free compared with 51% in the SWL group (p<0.001). The EQ for the PCNL group was 76% compared with 44% for the SWL group (p<0.001). Ancillary procedures were required by 9% of patients in the PCNL group compared with 15% in the SWL group. The complication rate was 19% in both groups. The SWL complications were minor. Conclusions Stone clearance from the lower pole of solitary stones sized 15 to 20 mm at the greatest diameter following SWL is poorer. These calculi can be better managed with percutaneous surgery owing to its higher efficacy and acceptably low morbidity. PMID:23614064

  5. A Lion of a Stone

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This approximate true-color image of the rock called 'Lion Stone' was acquired by the Mars Exploration Rover Opportunity's panoramic camera on sol 104 (May 9, 2004). The rock stands about 10 centimeters tall (about 4 inches) and is about 30 centimeters long (12 inches). Plans for the coming sols include investigating the rock with the spectrometers on the rover's instrument arm.

    This image was generated using the camera's L2 (750-nanometer), L5 (530-nanometer) and L6 (480-nanometer) filters.

  6. Determination of minor and trace elements concentration in kidney stones using elemental analysis techniques

    NASA Astrophysics Data System (ADS)

    Srivastava, Anjali

    The determination of accurate material composition of a kidney stone is crucial for understanding the formation of the kidney stone as well as for preventive therapeutic strategies. Radiations probing instrumental activation analysis techniques are excellent tools for identification of involved materials present in the kidney stone. The X-ray fluorescence (XRF) and neutron activation analysis (NAA) experiments were performed and different kidney stones were analyzed. The interactions of X-ray photons and neutrons with matter are complementary in nature, resulting in distinctly different materials detection. This is the first approach to utilize combined X-ray fluorescence and neutron activation analysis for a comprehensive analysis of the kideny stones. Presently, experimental studies in conjunction with analytical techniques were used to determine the exact composition of the kidney stone. The use of open source program Python Multi-Channel Analyzer was utilized to unfold the XRF spectrum. A new type of experimental set-up was developed and utilized for XRF and NAA analysis of the kidney stone. To verify the experimental results with analytical calculation, several sets of kidney stones were analyzed using XRF and NAA technique. The elements which were identified from XRF technique are Br, Cu, Ga, Ge, Mo, Nb, Ni, Rb, Se, Sr, Y, Zr. And, by using Neutron Activation Analysis (NAA) are Au, Br, Ca, Er, Hg, I, K, Na, Pm, Sb, Sc, Sm, Tb, Yb, Zn. This thesis presents a new approach for exact detection of accurate material composition of kidney stone materials using XRF and NAA instrumental activation analysis techniques.

  7. Method of producing drive fluid in situ in tar sands formations

    SciTech Connect

    Mudunuri, Ramesh Raju; Jaiswal, Namit; Vinegar, Harold J.; Karanikas, John Michael

    2010-03-23

    Methods of treating a tar sands formation are described herein. Methods for treating a tar sands may include providing heat to at least part of a hydrocarbon layer in the formation from one or more heaters located in the formation. The heat may be allowed to transfer from the heaters to at least a portion of the formation such that a drive fluid is produced in situ in the formation. The drive fluid may move at least some mobilized, visbroken, and/or pyrolyzed hydrocarbons from a first portion of the formation to a second portion of the formation. At least some of the mobilized, visbroken, and/or pyrolyzed hydrocarbons may be produced from the formation.

  8. High precision mapping of kidney stones using μ-IR spectroscopy to determine urinary lithogenesis.

    PubMed

    Blanco, Francisco; Ortiz-Alías, Pilar; López-Mesas, Montserrat; Valiente, Manuel

    2015-06-01

    Evolution of urinary lithiasis is determined by the metabolism and life-style of the related patient. The appropriate classification of the stone is mandatory for the identification of the lithogenic process. In this study, cros-sections from a single stone of each of the most frequent urolithiasis types (calcium oxalate mono and dihydrate and carbonate apatite) have been selected and imaged using IR microspectroscopy. Moreover, the use of high definition sFTIR (synchrotron source) has revealed hidden information to the conventional FTIR. This work has demonstrated that minor components become key factors on the description of the stages of stone formation. Intensity map for COM (1630 cm(-1) peak). The high spatial definition achieved is key for the precise description of the kidney stone history. PMID:25091212

  9. Environmental history recorded in aeolian deposits under stone pavements, Mojave Desert, USA

    NASA Astrophysics Data System (ADS)

    Dietze, Michael; Dietze, Elisabeth; Lomax, Johanna; Fuchs, Markus; Kleber, Arno; Wells, Stephen G.

    2016-01-01

    Reconstructing the evolution of arid landscapes is challenged by limited availability of appropriate environmental archives. A widespread surface feature - stone pavement - traps aeolian fines and forms a special accretionary archive. Seven stone pavement-covered sections on basalt flows in the eastern Mojave Desert are condensed into a composite section, comprising five sedimentological units supported by an OSL-based chronology. Three of the units are of accretionary nature and each is covered by a stone pavement. They were deposited > 50.9-36.6 ka, < 36.6-14.2 ka and < 14.2 ka, and they are intimately coupled with the history of nearby Lake Mojave, which advances the current understanding of regional aeolian activity. End-member modeling analysis of grain-size distributions yielded seven sediment transport regimes. The accretionary system operates in two modes: A) episodic formation of a stone pavement by lateral processes once a vesicular horizon has formed on a barren surface; and B) accretion of dust and eventual burial of the clast layer. These findings improve current concepts about stone pavement evolution and their environmental proxy function in arid landscapes. Stone pavement-covered accretionary deposits are a new key archive that allows quantifying the relative importance of dust accretion, slope processes, soil formation and vegetation cover.

  10. Chemical dissolution of common bile duct stones.

    PubMed

    Leuschner, U; Baumgärtel, H

    1984-01-01

    Dissolution of bile duct calculi is complicated by the facts that about 30-40% of them are pigment stones and the stone cannot be unambiguously identified by radiography before the start of therapy. Thus it does not appear logical only to infuse irrigation media that dissolve cholesterol (cholate, Capmul) but to use solutions that also dissolve calcium bilirubinate. Calcium bilirubinate is the most important compound in primary pigment stones in the bile duct. Thin sections of calcium bilirubinate stones can be dissolved in EDTA 4Na. The rate is determined by the temperature, the pH, and the surface tension of the solution. In vitro experiments showed that cholesterol stones and composition stones can be dissolved more rapidly by alternating therapy with an EDTA solution and a Capmul preparation than by monotherapy with glycerol octanoate, and that bovine pigment stones can also be disaggregated. Since calcium bilirubinate stones consist up to 20-60% of an organic matrix, a mixture of glycerol octanoate and EDTA was prepared containing SH-activated papain. It was possible, by using this mixture, to disaggregate human calcium bilirubinate stones. The process of dissolution is complex and is not yet understood in detail. It is supposed that the important steps are the extraction of calcium, the chemical solution and molecular dispersion of bilirubin and cholesterol, and the disaggregation of the structure of the stone by surface-active substances. The irrigation media have but little effect on black pigment stones. Toxicity studies have shown that cholate, glycerol octanoate, and glycerol octanoate preparations are locally toxic and can lead to cholangitis and cholecystitis in animals. EDTA solutions bring about lesser changes. In humans, it has not been possible to distinguish these inflammatory changes unambiguously from those found in untreated gallstone patients. PMID:6433355

  11. Crystal aggregation in kidney stones; a polymer aggregation problem?

    NASA Astrophysics Data System (ADS)

    Wesson, J.; Beshensky, A.; Viswanathan, P.; Zachowicz, W.; Kleinman, J.

    2008-03-01

    Kidney stones most frequently form as aggregates of calcium oxalate monohydrate (COM) crystals with organic layers between them, and the organic layers contain principally proteins. The pathway leading to the formation of these crystal aggregates in affected people has not been identified, but stone forming patients are thought to have a defect in the structure or distribution of urinary proteins, which normally protect against stone formation. We have developed two polyelectrolyte models that will induce COM crystal aggregation in vitro, and both are consistent with possible urinary protein compositions. The first model was based on mixing polyanionic and polycationic proteins, in portions such that the combined protein charge is near zero. The second model was based on reducing the charge density on partially charged polyanionic proteins, specifically Tamm-Horsfall protein, the second most abundant protein in urine. Both models demonstrated polymer phase separation at solution conditions where COM crystal aggregation was observed. Correlation with data from other bulk crystallization measurements suggest that the anionic side chains form critical binding interactions with COM surfaces that are necessary along with the phase separation process to induce COM crystal aggregation.

  12. Formation of magnetoconvection by photoabsorptive methods in ferrofluid layers

    NASA Astrophysics Data System (ADS)

    Zablotsky, Dmitry; Mezulis, Ansis; Blums, Elmars

    2013-04-01

    A periodic concentration grating was induced in a layer of ferrofluid by photoabsorption and thermophoresis under the action of the applied uniform magnetic field. The application of the external field causes the appearance of an internal demagnetizing field within the layer and of magnetic forces due to the non-uniform distribution of concentration. The induced magnetic forces cause the appearance of parasitic microconvection within the layer. The experimental observations of the formation stage of the grating are interpreted to explain magnetoconvection, making use of numerical simulations.

  13. Silicosis among Stone- Cutter Workers: A Cross-Sectional Study

    PubMed Central

    Naserbakht, Ali; Naserbakht, Morteza; Attari, Ghavamedin

    2012-01-01

    Background Production process of most factory-made products is harmful to our health and environment. Silica is the most important stone used in stone cutting factories. Numerous researches have reported respiratory diseases due to the inhalation of these particles in various occupations. Silicosis is a disease with typical radiographic pattern caused as the result of inhalation of silica particles. According to the intensity of exposures and onset of initiation of clinical symptoms silicosis is classified into three groups of acute, chronic and accelerated forms. The present study evaluated silicosis among stone cutter workers. Materials and Methods This cross sectional study was performed on stone cutter workers in Malayer city (Azandarian) between 2008 and 2009. Respiratory data of our study participants were collected with a respiratory questionnaire and performing spirometry tests and chest radiography. Results Among our participants, 16 silicosis cases were diagnosed by radiographic changes. Among them, 10 workers had exposure for more than three years and 6 workers were smokers. Eleven workers had an abnormal radiographic pattern on their chest x-rays. Seven workers had obstructive and 4 workers had restrictive spirometric patterns. Conclusion Prevalence of silicosis was high among our understudy workers and preventive strategies are required to control it. PMID:25191413

  14. Weathering Grade Classification of Granite Stone Monument Using Reflectance Spectroscopy

    NASA Astrophysics Data System (ADS)

    Hyun, C.; Roh, T.; Choi, M.; Park, H.

    2009-05-01

    Stone monument has been placed in field and exposed to rain and wind. This outdoor environment and air pollution induced weathering of stone monument. Weathering grade classification is necessary to manage and conserve stone monuments. Visual interpretation by geologist and laboratory experiments using specimens fallen off from the monument to avoid damage on the monument have been applied to classify weathering grade conventionally. Rocks and minerals absorb some particular wavelength ranges of electromagnetic energy by electronic process and vibrational process of composing elements and these phenomena produce intrinsic diagnostic spectral reflectance curve. Non-destructive technique for weathering degree assessment measures those diagnostic absorption features of weathering products and converts the depths of features related to abundance of the materials to relative weathering degree. We selected granite outcrop to apply conventional six folded weathering grade classification method using Schmidt hammer rebound teste. The correlations between Schmidt hammer rebound values and absorption depths of iron oxides such as ferric oxide in the vicinity of 0.9 micrometer wavelength and clay minerals such as illite and kaolinite in the vicinity of 2.2 micrometer wavelength, representative weathering products of granite, were analyzed. The Schmidt hammer rebound value decreased according to increase of absorption depths induced from those weathering products. Weathering grade classification on the granite stone monument was conducted by using absorption depths of weathering products This research is supported from National Research Institute of Cultural Heritage and we appreciate for this.

  15. Mass spectroscopic characteristics of low molecular weight proteins extracted from calcium oxalate stones: preliminary study.

    PubMed

    Chen, Wen-Chi; Lai, Chien-Chen; Lai, Chein-Cheng; Tsai, Yuhsin; Tsai, Yu-Hsin; Lin, Wei-Yong; Tsai, Fuu-Jen

    2008-01-01

    It is believed that boundary compositions of matrix proteins might play a role in stone formation; however, few proteomic studies concerning matrix proteins in urinary stones have been conducted. In this study, we extracted low molecular weight proteins from calcium oxalate stones and measured their characteristic patterns by mass spectroscopy. A total of 10 stones were surgically removed from patients with urolithiasis. Proteins were extracted from the stones and identified by one-dimensional electrophoresis (sodium dodecyl sulfate buffer [SDS]-polyacrylamide gel electrophoresis [SDS-PAGE]). After in-gel digest, samples were analyzed by the surface-enhanced laser desorption ionization-time of flight (SELDI-TOF) technique. The peptide sequences were analyzed from the data of mass spectroscopy. Proteins were identified from Database Search (SwissProt Protein Database; Swiss Institute of Bioinformatics; http://www.expasy.org/sprot) on a MASCOT server (Matrix Science Ltd.; http://www.matrixscience.com). A total of three bands of proteins (27, 18, and 14 kDa) were identified from SDS-PAGE in each stone sample. A database search (SwissProt) on a MASCOT server revealed that the most frequently seen proteins from band 1 (27 kDa) were leukocyte elastase precursor, cathepsin G precursor, azurocidin precursor, and myeloblastin precursor (EC 3.4.21.76) (leukocyte proteinase 3); band 2 (18 kDa) comprised calgranulin B, eosinophil cationic protein precursor, and lysozyme C precursor; band 3 (14 kDa) showed neutrophil defensin 3 precursor, calgranulin A, calgranulin C, and histone H4. The modifications and deamidations found from the mass pattern of these proteins may provide information for the study of matrix proteins. Various lower molecular weight proteins can be extracted from calcium oxalate stones. The characteristic patterns and their functions of those proteins should be further tested to investigate their roles in stone formation. PMID:18200570

  16. Effect of Potassium Citrate on Calcium Phosphate Stones in a Model of Hypercalciuria.

    PubMed

    Krieger, Nancy S; Asplin, John R; Frick, Kevin K; Granja, Ignacio; Culbertson, Christopher D; Ng, Adeline; Grynpas, Marc D; Bushinsky, David A

    2015-12-01

    Potassium citrate is prescribed to decrease stone recurrence in patients with calcium nephrolithiasis. Citrate binds intestinal and urine calcium and increases urine pH. Citrate, metabolized to bicarbonate, should decrease calcium excretion by reducing bone resorption and increasing renal calcium reabsorption. However, citrate binding to intestinal calcium may increase absorption and renal excretion of both phosphate and oxalate. Thus, the effect of potassium citrate on urine calcium oxalate and calcium phosphate supersaturation and stone formation is complex and difficult to predict. To study the effects of potassium citrate on urine supersaturation and stone formation, we utilized 95th-generation inbred genetic hypercalciuric stone-forming rats. Rats were fed a fixed amount of a normal calcium (1.2%) diet supplemented with potassium citrate or potassium chloride (each 4 mmol/d) for 18 weeks. Urine was collected at 6, 12, and 18 weeks. At 18 weeks, stone formation was visualized by radiography. Urine citrate, phosphate, oxalate, and pH levels were higher and urine calcium level was lower in rats fed potassium citrate. Furthermore, calcium oxalate and calcium phosphate supersaturation were higher with potassium citrate; however, uric acid supersaturation was lower. Both groups had similar numbers of exclusively calcium phosphate stones. Thus, potassium citrate effectively raises urine citrate levels and lowers urine calcium levels; however, the increases in urine pH, oxalate, and phosphate levels lead to increased calcium oxalate and calcium phosphate supersaturation. Potassium citrate induces complex changes in urine chemistries and resultant supersaturation, which may not be beneficial in preventing calcium phosphate stone formation. PMID:25855777

  17. Armenian Khatchkar (Stone Cross) Carved in 1308.

    ERIC Educational Resources Information Center

    Hacobian, Mossik

    This booklet introduces students to a unique form of stone sculpture made by Armenian artists for over twelve centuries, the khatchkar, or stone cross. The document is part of a series of seven instructional materials dealing with the history and culture of Armenian Americans. It contains a reading on khatchkars as symbols of faith for eternity, a…

  18. The Stone Center: A Visitor's Perspective.

    ERIC Educational Resources Information Center

    Liddle, Shirley M.

    1991-01-01

    Author describes her perspective on the Stone Center for Developmental Services and Studies, integral part of Wellesley College established in 1981 and dedicated to prevention of emotional problems, primarily among women. Describes Education, Research, and Counseling divisions of the Stone Center and the basic tenets that drive the center's…

  19. Ventricular candidiasis in stone curlews (Burhinus oedicnemus).

    PubMed

    Caliendo, Valentina; Bull, Andrew

    2011-09-01

    Ventricular candidiasis is consistently one of the most prominent pathologic conditions diagnosed in stone curlews (Burhinus oedicnemus) in the United Arab Emirates, predominately affecting the captive population. Predisposing factors are a humid environment, stress, immunosuppression, inadequate nutrition, and an extended use of oral antibiotics. In this report, we describe the clinical signs, diagnosis, and pathologic result in stone curlews with ventricular candidiasis. PMID:22017057

  20. Elemental Content of Calcium Oxalate Stones from a Canine Model of Urinary Stone Disease

    PubMed Central

    Killilea, David W.; Westropp, Jodi L.; Shiraki, Ryoji; Mellema, Matthew; Larsen, Jennifer; Kahn, Arnold J.; Kapahi, Pankaj; Chi, Thomas; Stoller, Marshall L.

    2015-01-01

    One of the most common types of urinary stones formed in humans and some other mammals is composed of calcium oxalate in ordered hydrated crystals. Many studies have reported a range of metals other than calcium in human stones, but few have looked at stones from animal models such as the dog. Therefore, we determined the elemental profile of canine calcium oxalate urinary stones and compared it to reported values from human stones. The content of 19 elements spanning 7-orders of magnitude was quantified in calcium oxalate stones from 53 dogs. The elemental profile of the canine stones was highly overlapping with human stones, indicating similar inorganic composition. Correlation and cluster analysis was then performed on the elemental profile from canine stones to evaluate associations between the elements and test for potential subgrouping based on elemental content. No correlations were observed with the most abundant metal calcium. However, magnesium and sulfur content correlated with the mineral hydration form, while phosphorous and zinc content correlated with the neuter status of the dog. Inter-elemental correlation analysis indicated strong associations between barium, phosphorous, and zinc content. Additionally, cluster analysis revealed subgroups within the stones that were also based primarily on barium, phosphorous, and zinc. These data support the use of the dog as a model to study the effects of trace metal homeostasis in urinary stone disease. PMID:26066810

  1. Method for formation of thin film transistors on plastic substrates

    DOEpatents

    Carey, Paul G.; Smith, Patrick M.; Sigmon, Thomas W.; Aceves, Randy C.

    1998-10-06

    A process for formation of thin film transistors (TFTs) on plastic substrates replaces standard thin film transistor fabrication techniques, and uses sufficiently lower processing temperatures so that inexpensive plastic substrates may be used in place of standard glass, quartz, and silicon wafer-based substrates. The process relies on techniques for depositing semiconductors, dielectrics, and metals at low temperatures; crystallizing and doping semiconductor layers in the TFT with a pulsed energy source; and creating top-gate self-aligned as well as back-gate TFT structures. The process enables the fabrication of amorphous and polycrystalline channel silicon TFTs at temperatures sufficiently low to prevent damage to plastic substrates. The process has use in large area low cost electronics, such as flat panel displays and portable electronics.

  2. Method for formation of thin film transistors on plastic substrates

    DOEpatents

    Carey, P.G.; Smith, P.M.; Sigmon, T.W.; Aceves, R.C.

    1998-10-06

    A process for formation of thin film transistors (TFTs) on plastic substrates replaces standard thin film transistor fabrication techniques, and uses sufficiently lower processing temperatures so that inexpensive plastic substrates may be used in place of standard glass, quartz, and silicon wafer-based substrates. The process relies on techniques for depositing semiconductors, dielectrics, and metals at low temperatures; crystallizing and doping semiconductor layers in the TFT with a pulsed energy source; and creating top-gate self-aligned as well as back-gate TFT structures. The process enables the fabrication of amorphous and polycrystalline channel silicon TFTs at temperatures sufficiently low to prevent damage to plastic substrates. The process has use in large area low cost electronics, such as flat panel displays and portable electronics. 5 figs.

  3. Kidney stone risk following modern bariatric surgery.

    PubMed

    Gonzalez, Ricardo D; Canales, Benjamin K

    2014-05-01

    Over the past 10 years, a variety of reports have linked bariatric surgery to metabolic changes that alter kidney stone risk. Most of these studies were retrospective, lacked appropriate controls, or involved bariatric patients with a variety of inclusion criteria. Despite these limitations, recent clinical and experimental research has contributed to our understanding of the pathophysiology of stone disease in this high-risk population. This review summarizes the urinary chemistry profiles that may be responsible for the increased kidney stone incidence seen in contemporary epidemiological bariatric studies, outlines the mechanisms of hyperoxaluria and potential therapies through a newly described experimental bariatric animal model, and provides a focused appraisal of recommendations for reducing stone risk in bariatric stone formers. PMID:24658828

  4. [Asymptomatic kidney stones: active surveillance vs. treatment].

    PubMed

    Neisius, A; Thomas, C; Roos, F C; Hampel, C; Fritsche, H-M; Bach, T; Thüroff, J W; Knoll, T

    2015-09-01

    The prevalence of kidney stones is increasing worldwide. Asymptomatic non-obstructing kidney stones are increasingly detected as an incidental finding on radiologic imaging, which has been performed more frequently over the last decades. Beside the current interventional treatment modalities such as extracorporeal shockwave lithotripsy (ESWL), ureterorenoscopy (URS) and percutaneous nephrolithotomy (PNL), active surveillance of asymptomatic kidney stones has been a focus of discussion lately, not only for attending physicians, but even more so for patients. The current German and European guidelines recommend active surveillance for patients with asymptomatic kidney stones if no interventional therapy is mandatory because of pain or medical factors. Herein we review the current literature on risks and benefits of active surveillance of asymptomatic non-obstructing kidney stones. PMID:26378390

  5. Method for determining formation quality factor from seismic data

    DOEpatents

    Taner, M. Turhan; Treitel, Sven

    2005-08-16

    A method is disclosed for calculating the quality factor Q from a seismic data trace. The method includes calculating a first and a second minimum phase inverse wavelet at a first and a second time interval along the seismic data trace, synthetically dividing the first wavelet by the second wavelet, Fourier transforming the result of the synthetic division, calculating the logarithm of this quotient of Fourier transforms and determining the slope of a best fit line to the logarithm of the quotient.

  6. From crystalluria to kidney stones, some physicochemical aspects of calcium nephrolithiasis

    PubMed Central

    Baumann, Johannes M; Affolter, Beat

    2014-01-01

    Nephrolithiasis seems to be the result of crystal formation, aggregation and retention in the kidney during crystalluria. These processes have to occur within the short urinary transit time through the kidney being in the order of few minutes. Recently much work was done on rather qualitative aspects of nephrolithiasis like genetics, metabolism and morphology. In this review we try to provide some quantitative information on urinary supersaturation with respect to stone minerals, especially Ca oxalate (CaOx), on the formation and aggregation of CaOx crystals and on crystal retention in the kidney. The paper is centered on idiopathic Ca nephrolithiasis being the most frequent stone disease with only partially known pathogenesis. New aspects of the role of urinary macromolecules in stone formation and of the mechanism of crystal aggregation are provided. PMID:25374820

  7. A new use of hydroxyapatite-based consolidant: cleaning and consolidation of stones in one step by reaction with gypsum crust

    NASA Astrophysics Data System (ADS)

    Molina Piernas, Eduardo; Rueda Quero, Lucia; Cultrone, Giuseppe; Ruiz Agudo, Encarnación

    2015-04-01

    The reaction between diammonium hydrogen phosphate (DAP) and calcite in the stone to form hydroxyapatite (HAP) had provided a new product to consolidate limestone or Ca-rich stones, for example sandstones with carbonatic cement. However, what does it happen with the stones without Ca-bearing compounds? Obviously, HAP cannot form. In the other hand, recent research about consolidation with DAP show a good interaction between carbonatic stones and HAP, improving their mechanical properties. For these reasons, we propose a new method for the consolidation of building stone capable of cleaning the gypsum crust and consolidating stones at the same time, based in the Ferroni-Dini method [1] and using DAP. Based on this method, we aim at obtaining a consolidating component reacting DAP (instead of ammonium carbonate) and the gypsum contained in the crust of weathered stones in polluted environments. As an advantage, we do not need to use barium hydroxide (the second step required in the Ferroni-Dini method), thereby reducing the time necessary to carry out the consolidation. Here, we report different tests to evaluate this new procedure. In a first set of experiments, a DAP solution was poured on a gypsum (dihydrate calcium sulphate) saturated solution and by monitoring the free calcium content of the solution using an ion-selective electrode we have evaluated the fluctuations in the content in calcium of the solution and the speed of the reaction. Once the reaction finished, we analyzed the solids formed to verify the formation of hydroxyapatite by FTIR and microRAMAN. The second test consisted in the alteration of limestone blocks with sulfuric acid to obtain a crust of gypsum and, after that, the samples were consolidated by means of cellulose compress soaked in DAP 3M during different reaction times (30 minutes, 1 hour and 4 hours, at controlled temperature -20 °C- and relative humidity -40% HR-). The samples were then analyzed by XRD, FTIR, microRAMAN and SEM-EDX to verify the formation of hydroxyapatite and the elimination of gypsum by transformation into ammonium sulphate (highly soluble). Our preliminary results show that the reaction occurs at room temperature in a short period of time. The amount of gypsum decreases with reaction time, while the amount of HAP significantly increases, with the gypsum being almost completely removed after 4 hours of reaction. We can conclude that this procedure is an optimal solution to remove the gypsum contained in the crust of the weathered stones and to consolidate them, independently of the mineralogical composition of the stone. Acknowledgements: This study was financially supported by Research Group RNM179 of the Junta de Andalucía and by the Research Project MAT2012-34473. [1] M. Matteini, "In review: An assessment of Florentine Methods of Wall Painting Conservation Based on the Use of Mineral Treatments", in "The Conservation of Wall Paintings: Proceedings of a Symposium organized by the Courtauld Institute of Art and the Getty Conservation Institute", London, 1987, pp. 137-146.

  8. Archaeomagnetic studies of Maori Hangi Stones from New Zealand

    NASA Astrophysics Data System (ADS)

    Kinger, R.; Turner, G. M.; McFadgen, B.

    2014-12-01

    Global palaeosecular variation models still suffer from a paucity of high quality data from the SW Pacific region. Over the past two years we have worked to fill this gap with archaeomagnetic data - directions and palaeointensities - by studying the thermoremanent magnetization of Maori hangi cooking stones. Used as heat retainers, these stones are heated, frequently above the Curie temperatures of constituent magnetic minerals, before being buried in earth ovens. After removal of the food, hangi sites are often abandoned with the stones still in situ, carrying a record of the magnetic field in which they were last cooled. We have sampled a range of archaeological hangi sites throughout New Zealand, dating to early prehistoric times (ca 700 BP). The stones vary in lithology from andesites, originating from the central North Island volcanoes, favoured by Maori for their durability and with NRM intensities up to 30 A/m, to greywackes and schists from the main axial ranges, with NRMs as weak as 10-4A/m. In all cases, we have independently oriented and retrieved several stones, and we have made several specimens from each stone, either by drilling (standard cylindrical specimens) or sawing (pseudo-cubes) in the laboratory. We have calculated site mean palaeomagnetic directions from principal component analysis of thermal demagnetization data, discarding the data of stones that show evidence of disturbance. We have carried out palaeointensity experiments using a Coe/Thellier method with pTRM and tail checks, and with selection criteria modified to the situation. Rock magnetic experiments contribute to our understanding of the mineralogy, domain state and blocking temperature spectra. The palaeodirections fall between declinations of 348o and 24.5o, and inclinations of -46.4o and -72.4o, with palaeointensities between 43.7±1.4 and 81.3±6.1 mT. Most fall within the expected range of secular variation for New Zealand. However the palaeointensity of 81.34±6.08mT, from an archaeological site at Opihi in the south of the South Island, dated at 382±20 BP, is unexpectedly high. We present our data against model records for New Zealand calculated using the ARCH3k model of Korte et al (2009), and suggest that the addition of our new data will improve the model for the most recent period of time.

  9. The Effect of Tamsulosin in the Medical Treatment of Distal Ureteral Stones

    PubMed Central

    Alizadeh, M.; Magsudi, M.

    2014-01-01

    Introduction: Renal stones are common disorders that affect approximately 5% to 10% of the population and the incidence of renal stones is rising. Treatment of ureteral stones is an important part of urologists and minimally invasive procedures such as ESWL and ureteroscopy effectiveness has been proven in various studies. However, these methods are not completely safe and are expensive and can be complicated. Purpose of this study is to evaluate the effectiveness of tamsulosin in the medical treatment of distal ureteral stones. Patients and methods: A total of 96 patients with distal ureteral stones or UVj are randomly divided into two study group (50 patients) and control group (46 patients). Patients in the control group allowed to freely consuming fluids (hydration) and indomethacin 100 mg PRN. Study group in addition to indomethacin and daily analgesic 0.4 mg tamsulosin was administered. All subjects in terms of analgesic dose, duration of expulsion and expulsion were studied. Results: Spontaneous expulsion of stone was occurred in 62.5% (30 patients out of 46) of control group patients and 82% (41 patients out of 50) that there was no significant difference (P>0.05). Average time to fix the stone in control group 4.7±8.03 days (range 2 to 28 days) and in the study group, 3.7±5.70 days (range 1 to 23 days) is significantly different (P>0.05). The average amount of analgesic consumption in the control group was 2.3±4.31and in the study group was 1.48±2.15 that showed significant differences (P<0.05). Conclusions: In this study, although the addition of tamsulosin to conservative treatment of distal ureteral stones in the distal ureteral stone expulsion showed no significant difference between the two groups, but the reduction in the duration of expulsion, reduce pain and reduce the need for analgesic has been beneficial. PMID:25363178

  10. Method predicts frae gradient for abnormally pressured formations

    SciTech Connect

    Constant, W.D.; Bourgoyne, A.T.

    1986-01-01

    When drilling offshore wells with abnormally pressured zones, the prediction of fracture pressure gradients is essential from both an economic and safety standpoint. In wildcat areas, high reliance must be placed on fracture gradient correlations. The following method, an extension of Eaton's approach, fits stress ratio to depth exponentially and calculates variable overburden stress with depth, based on the exponential trend of average porosity from bulk density logging methods. The Poisson's ratio trend, taken from Eaton's data, may not be the same for all geographical areas, but field data can be fitted by the same method. Then, for a given well or area, plots can be made for rapid prediction of fracture pressure gradients. The working equations, and the Basic computer program which employs them, allows calculation of fracture pressure gradients for a given area, with pore pressure, sediment depth, air gap, and water depth being the only variables. The technique is ideally suited for implementation in the field.

  11. Metabolic disturbances and renal stone promotion on treatment with topiramate: a systematic review

    PubMed Central

    Dell'Orto, Valentina G; Belotti, Eva A; Goeggel-Simonetti, Barbara; Simonetti, Giacomo D; Ramelli, Gian Paolo; Bianchetti, Mario G; Lava, Sebastiano A G

    2014-01-01

    Aims The use of topiramate, which is prescribed for the management of epilepsy, for migraine headache prophylaxis and as a weight-loss agent, has been associated with the development of metabolic acidosis, hypokalaemia and renal stone disease. We systematically reviewed all the literature. Methods The systematic review of the literature was realized using the principles underlying the UK Economic and Social Research Council guidance on the conduct of narrative synthesis and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Results Fourty-seven reports published between 1996 and 2013 were retained for the final analysis. Five case–control studies and six longitudinal studies addressed the effect of topiramate on acid–base and potassium balance. A significant tendency towards mild-to-moderate hyperchloraemic metabolic acidosis (with bicarbonate ≤21.0 mmol l−1 in approximately every third case) and mild hypokalaemia (with potassium ≤3.5 mmol l−1 in 10% of the cases) was noted on treatment with topiramate, which was similar in children and adults. A single study observed that topiramate causes mild hyperuricaemia in male adults. A tendency towards hypocitraturia, a recognized promoter of renal stone formation, was noted in all patients on topiramate. Conclusions Increasing evidence supports the use of topiramate. Topiramate is generally well tolerated, and serious adverse events are rare. Nonetheless, the present systematic review of the literature indicates that its use is linked with the development of acidosis, hypokalaemia, hyperuricaemia and hypocitraturia. PMID:24219102

  12. Electromagnetic wave method for mapping subterranean earth formations

    DOEpatents

    Shuck, Lowell Z.; Fasching, George E.; Balanis, Constantine A.

    1977-01-01

    The present invention is directed to a method for remotely mapping subterranean coal beds prior to and during in situ gasification operations. This method is achieved by emplacing highly directional electromagnetic wave transmitters and receivers in bore holes penetrating the coal beds and then mapping the anomalies surrounding each bore hole by selectively rotating and vertically displacing the directional transmitter in a transmitting mode within the bore hole, and thereafter, initiating the gasification of the coal at bore holes separate from those containing the transmitters and receivers and then utilizing the latter for monitoring the burn front as it progresses toward the transmitters and receivers.

  13. Beamforming and holography image formation methods: an analytic study.

    PubMed

    Solimene, Raffaele; Cuccaro, Antonio; Ruvio, Giuseppe; Tapia, Daniel Flores; O'Halloran, Martin

    2016-04-18

    Beamforming and holographic imaging procedures are widely used in many applications such as radar sensing, sonar, and in the area of microwave medical imaging. Nevertheless, an analytical comparison of the methods has not been done. In this paper, the Point Spread Functions pertaining to the two methods are analytically determined. This allows a formal comparison of the two techniques, and to easily highlight how the performance depends on the configuration parameters, including frequency range, number of scatterers, and data discretization. It is demonstrated that the beamforming and holography basically achieve the same resolution but beamforming requires a cheaper (less sensors) configuration.. PMID:27137336

  14. Silodosin vs tamsulosin in the management of distal ureteric stones: A prospective randomised study

    PubMed Central

    Elgalaly, Hazem; Sakr, Ahmed; Fawzi, Amr; Salem, Emad A.; Desoky, Esam; Shahin, Ashraf; Kamel, Mostafa

    2015-01-01

    Objectives To compare the efficacy of silodosin (8 mg) vs tamsulosin (0.4 mg), as a medical expulsive therapy, in the management of distal ureteric stones (DUS) in terms of stone clearance rate and stone expulsion time. Patients and methods A prospective randomised study was conducted on 115 patients, aged 21–55 years, who had unilateral DUS of ⩽10 mm. Patients were divided into two groups. Group 1 received silodosin (8 mg) and Group 2 received tamsulosin (0.4 mg) daily for 1 month. The patients were followed-up by ultrasonography, plain abdominal radiograph of the kidneys, ureters and bladder, and computed tomography (in some cases). Results There was a significantly higher stone clearance rate of 83% in Group 1 vs 57% in Group 2 (P = 0.007). Group 1 also showed a significant advantage for stone expulsion time and analgesic use. Four patients, two in each group, discontinued the treatment in first few days due to side-effects (orthostatic hypotension). No severe complications were recorded during the treatment period. Retrograde ejaculation was recorded in nine and three patients in Groups 1 and 2, respectively. Conclusion Our data show that silodosin is more effective than tamsulosin in the management of DUS for stone clearance rates and stone expulsion times. A multicentre study on larger scale is needed to confirm the efficacy and safety of silodosin. PMID:26966587

  15. Non-invasive Differentiation of Kidney Stone Types using X-ray Dark-Field Radiography

    PubMed Central

    Scherer, Kai; Braig, Eva; Willer, Konstantin; Willner, Marian; Fingerle, Alexander A.; Chabior, Michael; Herzen, Julia; Eiber, Matthias; Haller, Bernhard; Straub, Michael; Schneider, Heike; Rummeny, Ernst J.; Noël, Peter B.; Pfeiffer, Franz

    2015-01-01

    Treatment of renal calculi is highly dependent on the chemical composition of the stone in question, which is difficult to determine using standard imaging techniques. The objective of this study is to evaluate the potential of scatter-sensitive X-ray dark-field radiography to differentiate between the most common types of kidney stones in clinical practice. Here, we examine the absorption-to-scattering ratio of 118 extracted kidney stones with a laboratory Talbot-Lau Interferometer. Depending on their chemical composition, microscopic growth structure and morphology the various types of kidney stones show strongly varying, partially opposite contrasts in absorption and dark-field imaging. By assessing the microscopic calculi morphology with high resolution micro-computed tomography measurements, we illustrate the dependence of dark-field signal strength on the respective stone type. Finally, we utilize X-ray dark-field radiography as a non-invasive, highly sensitive (100%) and specific (97%) tool for the differentiation of calcium oxalate, uric acid and mixed types of stones, while additionally improving the detectability of radio-lucent calculi. We prove clinical feasibility of the here proposed method by accurately classifying renal stones, embedded within a fresh pig kidney, using dose-compatible measurements and a quick and simple visual inspection. PMID:25873414

  16. Clinical Features and Outcomes of Endoscopic Treatment for Stones in Stemware-Shaped Common Bile Ducts: A Multicenter Data Analysis

    PubMed Central

    Han, Jee Young; Lee, Don Haeng; Jeong, Seok; Choi, Hyun Jong; Moon, Jong Ho; Han, Joung-Ho; Kwon, Chang-Il; Lee, Tae Hoon; Hyun, Jong Jin; Hwang, Jae Chul; Koh, Dong Hee

    2015-01-01

    Background/Aims Various anatomical features of the biliary tree affect ability to remove difficult common bile duct (CBD) stones. In this study, we evaluated the clinical characteristics and outcomes of the endoscopic treatment of stones in stemware-shaped CBDs. Methods Thirty-four patients with a stone and a stemware-shaped CBD who were treated at different tertiary referral centers from January 2008 to December 2012 were studied retrospectively. When stone removal failed, percutaneous or direct peroral cholangioscopic lithotripsy, endoscopic retrograde biliary drainage, or surgery was performed as a second-line procedure. Results The overall success rate of the first-line procedure was 41.2%. Five of the 34 patients (14.7%) experienced procedure-related complications. No procedure-related mortality occurred. Mechanical lithotripsy was required to completely remove stones in 13 patients (38.2%). Conversion to a second-line procedure was required in 20 patients (58.8%). Mechanical lithotripsy was needed in 75% and 66.7% of those with a stone size of <1 cm or ≥1 cm, respectively. Stone recurrence occurred in two patients (9.1%) after 6 months and 27 months, respectively. Conclusions The endoscopic treatment of stones in a stemware-shaped CBD is challenging. The careful assessment of difficult CBD stones is required before endoscopic procedures. PMID:26087795

  17. AB208. Can bladder irrigation reduce the morbidity of bladder stones in patients with spinal cord injury?

    PubMed Central

    Chen, H; Xie, KJ; Jiang, CH; Zeng, JW; Huang, MP; Liu, QL; Huang, JB; Huang, TH; Li, YF

    2016-01-01

    Objective To assess the safety and efficacy of bladder irrigation for reducing the morbidity of bladder stones in spinal cord injury (SCI) patients. Methods From December 2011 to July 2013, SCI patients were prospectively randomized and assigned to either a bladder irrigation group or a no bladder irrigation group. Bladder irrigations were performed twice a week by urologists. The primary outcomes were incidences of bladder stones and Incontinence-Specific Quality-of-Life Instrument (I-QoL). Secondary outcomes were related adverse events. Results A total of 80 eligible patients participated and 78 (97.5%) patients (bladder irrigation, n=39; no bladder irrigation, n=39) completed 24 weeks of follow-up. Out of the 78 patients, 19 (24.3%) developed bladder stones. All occurred in no bladder irrigation group. In 8 of the 19 patients (42.1%), stones were only detected by cystoscopy .The bladder stones were mostly thin with an eggshell appearance (78.95% for diameter of stone <5 mm, 84.21% for volume of bladder stone<0.2 cm3). Bladder stones were removed by vigorous bladder irrigation guided by ultrasound (73.68%) or endoscopic lithotripsy (26.32%). The I-QOL was significantly better in the bladder irrigation group than in no bladder irrigation group at weeks 6, 12, 18, and 24 of follow-up. Conclusions Bladder irrigation may be more effective and safer than no bladder irrigation for reducing the morbidity of bladder stone in SCI patients.

  18. New methods and materials for molding and casting ice formations

    NASA Technical Reports Server (NTRS)

    Reehorst, Andrew L.; Richter, G. Paul

    1987-01-01

    This study was designed to find improved materials and techniques for molding and casting natural or simulated ice shapes that could replace the wax and plaster method. By utilizing modern molding and casting materials and techniques, a new methodology was developed that provides excellent reproduction, low-temperature capability, and reasonable turnaround time. The resulting casts are accurate and tough.

  19. An association between urinary cadmium and urinary stone disease in persons living in cadmium-contaminated villages in northwestern Thailand: A population study

    SciTech Connect

    Swaddiwudhipong, Witaya; Mahasakpan, Pranee; Limpatanachote, Pisit; Krintratun, Somyot

    2011-05-15

    Excessive urinary calcium excretion is the major risk of urinary stone formation. Very few population studies have been performed to determine the relationship between environmental cadmium exposure and urinary stone disease. This population-based study examined an association between urinary cadmium excretion, a good biomarker of long-term cadmium exposure, and prevalence of urinary stones in persons aged 15 years and older, who lived in the 12 cadmium-contaminated villages in the Mae Sot District, Tak Province, northwestern Thailand. A total of 6748 persons were interviewed and screened for urinary cadmium and urinary stone disease in 2009. To test a correlation between urinary excretion of cadmium and calcium, we measured urinary calcium content in 1492 persons, who lived in 3 villages randomly selected from the 12 contaminated villages. The rate of urinary stones significantly increased from 4.3% among persons in the lowest quartile of urinary cadmium to 11.3% in the highest quartile. An increase in stone prevalence with increasing urinary cadmium levels was similarly observed in both genders. Multiple logistic regression analysis revealed a positive association between urinary cadmium levels and stone prevalence, after adjusting for other co-variables. The urinary calcium excretion significantly increased with increasing urinary cadmium levels in both genders, after adjusting for other co-variables. Elevated calciuria induced by cadmium might increase the risk of urinary stone formation in this environmentally exposed population. - Research highlights: {yields} Excessive calciuria is the major risk of urinary stone formation. {yields} We examine cadmium-exposed persons for urinary cadmium, calcium, and stones. {yields} The rate of urinary stones increases with increasing urinary cadmium. {yields} Urinary calcium excretion increases with increasing urinary cadmium. {yields} Elevated calciuria induced by cadmium may increase the risk of urinary stones.

  20. Method of junction formation for CIGS photovoltaic devices

    DOEpatents

    Delahoy, Alan E.

    2010-01-26

    Sulfur is used to improve the performance of CIGS devices prepared by the evaporation of a single source ZIS type compound to form a buffer layer on the CIGS. The sulfur may be evaporated, or contained in the ZIS type material, or both. Vacuum evaporation apparatus of many types useful in the practice of the invention are known in the art. Other methods of delivery, such as sputtering, or application of a thiourea solution, may be substituted for evaporation.

  1. Method of junction formation for CIGS photovoltaic devices

    DOEpatents

    Delahoy, Alan E.

    2006-03-28

    Sulfur is used to improve the performance of CIGS devices prepared by the evaporation of a single source ZIS type compound to form a buffer layer on the CIGS. The sulfur may be evaporated, or contained in the ZIS type material, or both. Vacuum evaporation apparatus of many types useful in the practice of the invention are known in the art. Other methods of delivery, such as sputtering, or application of a thiourea solution, may be substituted for evaporation.

  2. Characterisation of urinary stones in the presence of iodinated contrast medium using dual-energy CT: a phantom study

    PubMed Central

    Wang, Jia; Qu, Mingliang; Duan, Xinhui; Takahashi, Naoki; Kawashima, Akira; Leng, Shuai; McCollough, Cynthia H.

    2014-01-01

    Objective To develop a dual-energy CT (DECT) method for differentiating uric acid (UA) from non-UA stones in the presence of iodinated contrast medium. Methods Thirty UA and 45 non-UA stones were selected after infra-red spectroscopic analysis and independently placed in a 1.5-ml vial, which was filled first with saline and then with increasing concentrations of iodine. For each condition, tubes were put in a 35-cm water phantom and examined using a dual-source CT system at 100 and 140 kV. Virtual unenhanced images created from CT data sets of the stones in iodine-containing solutions provided position and volume information. This map was used to calculate a CT number ratio to differentiate stone type. A region-growing method was developed to improve the ability to differentiate between UA and non-UA stones with iodinated contrast medium. Results The sensitivity for detecting UA stones was 100 % for unenhanced images but fell to 18 % with 20 mgI/ml iodine solution and 0 % for higher concentrations. With region growing, the sensitivity for detecting UA stones was increased to 100 %, 82 %, 57 %, 50 % and 21 % for iodine solutions of 20, 40, 60, 80 and 100 mgI/ml. Conclusion The region-growing method improves differentiation of UA from non-UA stones on contrast-enhanced DECT urograms. PMID:22865225

  3. Formation of optical microlens by laser polymerization method

    NASA Astrophysics Data System (ADS)

    Suzuki, Kaoru

    2001-11-01

    Optical lens of micrometer order diameter for coupling between optical fiber and laser diode were formed by argon ion laser polymerization method at visible light cured resin. Test resin materials consisted of triethylene glycol dimethacrylate for main resin, camphorquinon for photo initiator of visible light area, hydroquinon for inhibitor, and N,N-dimethylmethacrylate for reducing agent. In order to obtain the micro lens of short focal length and small spherical aberration, the use of this technique makes it possible to simultaneously form the polymerized aria on glass plate at the argon ion laser beam irradiation zone. The polmerized aria made a high quality micro lens without using molding pattern. We have verified our claims with visual inspection, ray trajectory calculations for measurement of side long spherical aberration (transverse aberration), Fourier transform infrared spectroscopy for degree of conversion analysis of polymerized resin area, and Duc de Chaulnes method for measurement of lens shape. The lens has a diameter of 300micrometers or more, a focal length of 500micrometers or more with an NA of 0.5, and transverse aberration plot of about 100% of the within the limits of +/- 25micrometers . This method can be applied for producing circular, non-circular, linear, and array micro lenses by scanning or patterning of argon ion laser beam.

  4. Apparatus for disintegrating kidney stones

    NASA Technical Reports Server (NTRS)

    Angulo, E. D. (Inventor)

    1984-01-01

    The useful life of the wire probe in an ultrasonic kidney stone disintegration instrument is enhanced and prolonged by attaching the wire of the wire probe to the tip of an ultrasonic transducer by means of a clamping arrangement. Additionally, damping material is applied to the wire probe in the form of a damper tube through which the wire probe passes in the region adjacent the transducer tip. The damper tube extends outwardly from the transducer tip a predetermined distance, terminating in a resilient soft rubber joint. Also, the damper tube is supported intermediate its length by a support member. The damper system thus acts to inhibit lateral vibrations of the wire in the region of the transducer tip while providing little or no damping to the linear vibrations imparted to the wire by the transducer.

  5. Cosmogenic radionuclides in stone meteorites

    NASA Technical Reports Server (NTRS)

    Cressy, P. J., Jr.

    1976-01-01

    This document presents the techniques and compilation of results of cosmogenic Al-26 measurements at Goddard Space Flight Center on 91 samples of 76 stone meteorites. Short-lived radionuclides, including Na-22, Sc-46, Mn-54, and Co-60, were measured in 13 of these meteorites. About one-third of these data has not previously been published. The results are discussed briefly in terms of (1) depletion of Al-26 and natural potassium due to weathering, (2) possible exposure of several chondrites to an unusually high cosmic-ray flux, (3) comparison of Al-26, Na-22, Sc-46, and Mn5-54 in chondrites with the spallation Ne-22/Ne-21 ratio as a shielding indicator, and (4) comparison of (Al-26)-(Ne-22)/Ne-21 data for achondrite classes with the chondrite trend.

  6. Stone orientation affects the mechanism of failure in artificial kidney stones subject to shock waves

    NASA Astrophysics Data System (ADS)

    van Cauwelaert, Javier; Cleveland, Robin O.

    2003-10-01

    Micro computed tomography (CT) imaging was used to follow the progressive development of cracks in artificial kidney stones. The artificial stones were made from U30 cement with a cylindrical shape (6.5 mm diameter and 8.5 mm long). The stones were held within a polypropylene vial in one of three orientations: vertical, horizontal, and angled at 45 deg. The stones were treated with an electromagnetic lithotripter and the initiation and growth of cracks was observed using microCT. The images show that the orientation of the stones with respect to the shock changes the dominant mechanism for fragmentation. Vertical stones developed a spall-like crack near the distal surface, which propagated from the surface to the interior of the stone. Initiation of a secondary spall-like crack was observed proximal to the first crack. Little surface damage was observed. Horizontal stones presented pitting in the proximal surface and erosion in lateral faces, indicating the action of cavitation. Angled stones presented both spall-like fracture in either the leading or the distal corners and surface damage (pitting) in the proximal surface. Experiments are being performed to follow the development of cracks in human kidney stones. [Work supported by the Whitaker Foundation.

  7. Correlation of volume, position of stone, and hydronephrosis with microhematuria in patients with solitary urolithiasis

    PubMed Central

    Inci, Mehmet Fatih; Ozkan, Fuat; Bozkurt, Selim; Sucakli, Mustafa Haki; Altunoluk, Bulent; Okumus, Mehmet

    2013-01-01

    Background The aim of this study was to determine the relationship between hematuria and volume, position of stone, and hydronephrosis in patients with a solitary stone, using unenhanced multidetector computed tomography (MDCT). Material/Methods This retrospective study evaluated the clinical and radiological records of 83 patients undergoing MDCT for the evaluation of acute flank pain and suspected renal colic, who also underwent a microscopic urinalysis at the emergency department of our hospital during a 1-year period. Inclusion criteria of the MDCT study were solitary urolithiasis and cumulative stone diameter under 1 cm. Results A total of 83 patients were included in the study, with a mean age of 42.1±14.4 years; 48 (57.8%) were females and 35 (42.2%) were males. Detection of 5 or more red cells on urinalysis was regarded as microscopic hematuria, and was positive in 46 patients (55.4%). There was a positive correlation between the position of the stone (especially upper two-thirds ureteral stones) and microhematuria rate (r: 0.28, p=0.009). There was a statistically significant difference in presence of hydronephrosis between the microhematuria (36 patients, 78%) and non-microhematuria (12 patients, 32%) groups (p<0.001). The median stone volume between the microhematuria and non-microhematuria groups were not statistically different, 37.5 mm3 (range 5–425) and 28 mm3 (range 4–412), respectively (p=0.39). Conclusions Although stone volume is one of the best indicators of stone burden, it was not correlated with microhematuria. However, in patients with renal colic, microhematuria requires ultrasound examination whether hydronephrosis and ureteral stones are present or not. Further studies with larger sample sizes are warranted. PMID:23612123

  8. Usefulness of hounsfield unit and density in the assessment and treatment of urinary stones

    PubMed Central

    Gücük, Adnan; Üyetürk, Uğur

    2014-01-01

    Computed tomography (CT) is widely used to examine stones in the urinary system. In addition to the size and location of the stone and the overall health of the kidney, CT can also assess the density of the stone in Hounsfield units (HU). The HU, or Hounsfield density, measured by CT, is related to the density of the tissue or stone. A number of studies have assessed the use of HU in urology. HUs have been used to predict the type and opacity of stones during diagnosis, and the efficacy has been assessed using methods including extracorporeal shock wave lithotripsy (ESWL), percutaneous nephrolithotomy (PCNL), ureterorenoscopic ureterolithotripsy (URSL), and medical expulsive treatment (MET). Previous studies have focused on the success rate of HU for predicting the type of stone and of ESWL treatment. Understanding the composition of the stone plays a key role in determining the most appropriate treatment modality. The most recent reports have suggested that the HU value and its variants facilitate prediction of stone composition. However, the inclusion of data regarding urine, such as pH and presence of crystals, increases the predictive accuracy. HUs, which now form part of the clinical guidelines, allow us to predict the success of ESWL; therefore, they should be taken into account when ESWL is considered as a treatment option. However, there are currently insufficient data available regarding the value of HU for assessing the efficacy of PCNL, URSL, and MET. Studies performed to date suggest that these values would make a significant contribution to the diagnosis and treatment of urinary system stones. However, more data are required to assess this further. PMID:25374823

  9. Percutaneous Transhepatic Removal of Bile Duct Stones: Results of 261 Patients

    SciTech Connect

    Ozcan, Nevzat Kahriman, Guven Mavili, Ertugrul

    2012-06-15

    Purpose: To determine the effectiveness of percutaneous transhepatic removal of bile duct stones when the procedure of endoscopic therapy fails for reasons of anatomical anomalies or is rejected by the patient. Methods: Between April 2001 and May 2010, 261 patients (138 male patients and 123 female patients; age range, 14-92 years; mean age, 64.6 years) with bile duct stones (common bile duct [CBD] stones = 248 patients and hepatolithiasis = 13 patients) were included in the study. First, percutaneous transhepatic cholangiography was performed and stones were identified. Percutaneous transhepatic balloon dilation of the papilla of Vater was performed. Then stones were pushed out into the duodenum with a Fogarty balloon catheter. If the stone diameter was larger than 15 mm, then basket lithotripsy was performed before balloon dilation. Results: Overall success rate was 95.7%. The procedure was successful in 97.5% of patients with CBD stones and in 61.5% of patients with hepatolithiasis. A total of 18 (6.8%) major complications, including cholangitis (n = 7), subcapsular biloma (n = 4), subcapsular hematoma (n = 1), subcapsular abscess (n = 1), bile peritonitis (n = 1), duodenal perforation (n = 1), CBD perforation (n = 1), gastroduodenal artery pseudoaneurysm (n = 1), and right hepatic artery transection (n = 1), were seen after the procedure. There was no mortality. Conclusion: Our experience suggests that percutaneous transhepatic stone expulsion into the duodenum through the papilla is an effective and safe approach in the nonoperative management of the bile duct stones. It is a feasible alternative to surgery when endoscopic extraction fails or is rejected by the patient.

  10. Percutaneous Transhepatic Removal of Bile Duct Stones: Results of 261 Patients

    SciTech Connect

    Ozcan, Nevzat Kahriman, Guven Mavili, Ertugrul

    2012-08-15

    Purpose: To determine the effectiveness of percutaneous transhepatic removal of bile duct stones when the procedure of endoscopic therapy fails for reasons of anatomical anomalies or is rejected by the patient. Methods: Between April 2001 and May 2010, 261 patients (138 male patients and 123 female patients; age range, 14-92 years; mean age, 64.6 years) with bile duct stones (common bile duct [CBD] stones = 248 patients and hepatolithiasis = 13 patients) were included in the study. Percutaneous transhepatic cholangiography was performed, and stones were identified. Percutaneous transhepatic balloon dilation of the papilla of Vater was performed. Then stones were pushed out into the duodenum with a Fogarty balloon catheter. If the stone diameter was larger than 15 mm, then basket lithotripsy was performed before balloon dilation. Results: Overall success rate was 95.7%. The procedure was successful in 97.5% of patients with CBD stones and in 61.5% of patients with hepatolithiasis. A total of 18 major complications (6.8%), including cholangitis (n = 7), subcapsular biloma (n = 4), subcapsular hematoma (n = 1), subcapsular abscess (n = 1), bile peritonitis (n = 1), duodenal perforation (n = 1), CBD perforation (n = 1), gastroduodenal artery pseudoaneurysm (n = 1), and right hepatic artery transection (n = 1), were observed after the procedure. There was no mortality. Conclusion: Our experience suggests that percutaneous transhepatic stone expulsion into the duodenum through the papilla is an effective and safe approach in the nonoperative management of the bile duct stones. It is a feasible alternative to surgery when endoscopic extraction fails or is rejected by the patient.

  11. Pathophysiology of the Hypercalciuria in the Genetic Hypercalciuric Stone-Forming Rats

    NASA Astrophysics Data System (ADS)

    Bushinsky, David A.

    2007-04-01

    Given evidence for a genetic cause of hypercalciuria, we screened adult male and female Sprague-Dawley (SD) rats for hypercalciuria and used those with the highest urinary calcium excretion to breed the next generation, followed by subsequent selection and inbreeding of their most hypercalciuric progeny. By the 30th generation, and continuing to the present, the GHS rats (for Genetic Hypercalciuric Stone-forming rats) excrete 8-10 times as much calcium as simultaneously studied control rats The GHS rats were found to have defects in calcium transport in the intestine, kidneys and bone, similar to abnormalities found in many patients with idiopathic hypercalciuria. The GHS rats also form kidney stones. By the conclusion of an 18 wk study, all of the GHS rats formed stones, while there was no stone formation in similarly treated SD controls. The GHS rats, when fed a standard 1.2% calcium diet, form only poorly crystalline apatite stones. However, when 5% hydroxyproline is added to the diet of the GHS rats, they form only calcium oxalate stones.

  12. Method for in situ heating of hydrocarbonaceous formations

    SciTech Connect

    Little, W.E.; Mc Lendon, T.R.

    1987-11-10

    A method for extracting valuable constituents from underground hydrocarbonaceous deposits such as oil shale comprising the steps of: drilling a hole into but not beyond a stratum which contains a rich deposit of valuable constituents; hydraulically fracturing the stratum which contains the deposit to form a single horizontally extending fracture plane located at the bottom of the hole; injecting a liquid and conducting proppant into the fracture plane to form a horizontal liquid plate; introducing electrical excitations to the stratum adjacent the liquid plate; continuing the electrical excitation to retort the stratum along the liquid plate; and recovering valuable constituents from the stratum adjacent the liquid plate.

  13. Characterization of Technetium Speciation in Cast Stone

    SciTech Connect

    Um, Wooyong; Jung, Hun Bok; Wang, Guohui; Westsik, Joseph H.; Peterson, Reid A.

    2013-11-11

    This report describes the results from laboratory tests performed at Pacific Northwest National Laboratory (PNNL) for the U.S. Department of Energy (DOE) EM-31 Support Program (EMSP) subtask, “Production and Long-Term Performance of Low Temperature Waste Forms” to provide additional information on technetium (Tc) speciation characterization in the Cast Stone waste form. To support the use of Cast Stone as an alternative to vitrification for solidifying low-activity waste (LAW) and as the current baseline waste form for secondary waste streams at the Hanford Site, additional understanding of Tc speciation in Cast Stone is needed to predict the long-term Tc leachability from Cast Stone and to meet the regulatory disposal-facility performance requirements for the Integrated Disposal Facility (IDF). Characterizations of the Tc speciation within the Cast Stone after leaching under various conditions provide insights into how the Tc is retained and released. The data generated by the laboratory tests described in this report provide both empirical and more scientific information to increase our understanding of Tc speciation in Cast Stone and its release mechanism under relevant leaching processes for the purpose of filling data gaps and to support the long-term risk and performance assessments of Cast Stone in the IDF at the Hanford Site.

  14. How Should Biliary Stones be Managed?

    PubMed Central

    2010-01-01

    Minimally invasive therapy is currently invaluable for the treatment of biliary stones. Clinicians should be familiar with the various endoscopic modalities that have been evolving. I reviewed the treatment of biliary stones from the common practice to pioneering procedures, and here I also briefly summarize the results of many related studies. Lithotripsy involves procedures that fragment large stones, and they can be roughly classified into two groups: intracorporeal modalities and extracorporeal shock-wave lithotripsy (ESWL). Intracorporeal modalities are further divided into mechanical lithotripsy (ML), electrohydraulic lithotripsy, and laser lithotripsy. ESWL can break stones by focusing high-pressure shock-wave energy at a designated target point. Balloon dilation after minimal endoscopic sphincterotomy (EST) is effective for retrieving large biliary stones without the use of ML. Peroral cholangioscopy provides direct visualization of the bile duct and permits diagnostic procedures or therapeutic interventions. Biliary stenting below an impacted stone is sometimes worth considering as an alternative treatment in elderly patients. This article focuses on specialized issues such as lithotripsy rather than simple EST with stone removal in order to provide important information on state-of-the-art procedures. PMID:20559517

  15. Segmental Bile Duct-Targeted Liver Resection for Right-Sided Intrahepatic Stones

    PubMed Central

    Li, Shao-Qiang; Hua, Yun-Peng; Shen, Shun-Li; Hu, Wen-Jie; Peng, Bao-Gang; Liang, Li-Jian

    2015-01-01

    Abstract Hepatectomy is a safe and effective treatment for intrahepatic stones (IHSs). However, the resection plane for right-sided stones distributed within 2 segments is obstacle because of atrophy-hypertrophy complex formation of the liver and difficult dissection of segmental pedicle within the Glissonean plate by conventional approach. Thus, we devised segmental bile duct-targeted liver resection (SBDLR) for IHS, which aimed at completely resection of diseased bile ducts. This study aimed to evaluate the outcomes of SBDLR for right-sided IHSs. From January 2009 to December 2013, 107 patients with IHS treated by SBDLR in our center were reviewed in a prospective database. Patients’ intermediate and long-term outcomes after SBDLR were analyzed. A total of 40 (37.4%) patients with localized right-sided stone and 67 (62.7%) patients with bilateral stones underwent SBDLR alone and SBDLR combined with left-sided hepatectomy, respectively. There was no hospital mortality of this cohort of patients. The postoperative morbidity was 35.5%. The mean intraoperative blood loss was 414 mL (range: 100–2500). Twenty-one (19.6%) patients needed red blood cells transfusion. The intermediate stone clearance rate was 94.4%; the final clearance rate reached 100% after subsequent postoperative cholangioscopic lithotomy. Only 2.8% patients developed stone recurrence in a median follow-up period of 38.3 months. SBDLR is a safe and effective treatment for right-sided IHS distributed within 2 segments. It is especially suitable for a subgroup of patients with bilateral stones whose right-sided stones are within 2 segments and bilateral liver resection is needed. PMID:26181559

  16. Managing acute and chronic renal stone disease.

    PubMed

    Moran, Conor P; Courtney, Aisling E

    2016-02-01

    Nephrolithiasis, or renal stone disease, is common and the incidence is increasing globally. In the UK the lifetime risk is estimated to be 8-10%. On a population level, the increase in stone incidence, erosion of gender disparity, and younger age of onset is likely to reflect increasing prevalence of obesity and a Western diet with a high intake of animal protein and salt. Stones can be detected by a variety of imaging techniques. The gold standard is a non-contrast CT of kidneys, ureters and bladder (CT KUB) which can identify > 99% of stones. CT KUB should be the primary mode of imaging for all patients with colic unless contraindicated. In such instances, or if a CT KUB is not available, an ultrasound KUB is an alternative. This has advantages in terms of radiation exposure and cost, but is limited in sensitivity, particularly for ureteric stones. Once diagnosed, a plain film KUB can be used for follow-up of radiopaque stones. For most patients diclofenac is a reasonable first choice of analgesia, e.g. 50-100 mg rectally, or 75 mg IM. Opioid medication can worsen nausea and be less effective, but should be used if there is a contraindication to NSAIDs. A combination of diclofenac, paracetamol, and/or codeine regularly can provide adequate pain control in many cases. Failure of this analgesic combination should prompt consideration of secondary care support. If a ureteric stone < 5 mm in diameter is identified, the expectation is that this will pass without intervention. Initially medical management is still useful for stones between 5 and 10mm in diameter, but urology input is more likely to be necessary as up to 50% of these may require intervention. Stones that are >10 mm in diameter should be discussed with the urology service as they are unlikely to pass spontaneously. PMID:27032222

  17. Renovascular acute renal failure precipitated by extracorporeal shock wave lithotripsy for pancreatic stones.

    PubMed

    Cecere, Nicolas; Goffette, Pierre; Deprez, Pierre; Jadoul, Michel; Morelle, Johann

    2015-08-01

    Extracorporeal shock wave lithotripsy (ESWL) for pancreatic stones is considered a safe and efficient method to facilitate fragmentation and stone removal. We describe the case of a 73-year-old woman with a solitary functioning kidney who presented an acute-onset anuria and renovascular renal failure the day after ESWL. We speculate that vascular calcifications in the area targeted by shock waves played a critical role in renal artery obstruction in the present case. PMID:26251710

  18. Mild Catalytic methods for Alkyl-Alkyl Bond Formation

    SciTech Connect

    Vicic, David A

    2009-08-10

    Overview of Research Goals and Accomplishments for the Period 07/01/06 – 06/30/07: Our overall research goal is to transform the rapidly emerging synthetic chemistry involving alkyl-alkyl cross-couplings into more of a mechanism-based field so that that new, rationally-designed catalysts can be performed under energy efficient conditions. Our specific objectives for the previous year were 1) to obtain a proper electronic description of an active catalyst for alkyl-alkyl cross-coupling reactions and 2) to determine the effect of ligand structure on the rate, scope, selectivity, and functional group compatibility of C(sp3)-C(sp3) cross-coupling catalysis. We have completed both of these initial objectives and established a firm base for further studies. The specific significant achievements of the current grant period include: 1) we have performed magnetic and computational studies on (terpyridine)NiMe, an active catalyst for alkyl-alkyl cross couplings, and have discovered that the unpaired electron resides heavily on the terpyridine ligand and that the proper electronic description of this nickel complex is a Ni(II)-methyl cation bound to a reduced terpyridine ligand; 2) we have for the first time shown that alkyl halide reduction by terpyridyl nickel catalysts is substantially ligand based; 3) we have shown by isotopic labeling studies that the active catalyst (terpyridine)NiMe is not produced via a mechanism that involves the formation of methyl radicals when (TMEDA)NiMe2 is used as the catalyst precursor; 4) we have performed an extensive ligand survey for the alkyl-alkyl cross-coupling reactions and have found that electronic factors only moderately influence reactivity in the terpyridine-based catalysis and that the most dramatic effects arise from steric and solubility factors; 5) we have found that the use of bis(dialkylphosphino)methanes as ligands for nickel does not produce active catalysts for cross-coupling but rather leads to bridging hydride complexes of varying geometries; 6) we have determined that the geometry of aforementioned bridging hydride complexes is largely determined by external forces such as hydrogen bonding interactions and crystal packing forces; 7) we have found that the rate of reductive elimination of alkane from a (pyridyl-2-pyrrolide)AuMe2 complex is severely inhibited due to the rigid geometry of the pyridyl-2-pyrrolide ligand; 8) we have prepared, structurally characterized, and explored the reactivity of 1-adamantylzinc reagents as model nucleophiles for sterically challenging alkyl-alkyl cross-coupling reactions. The continued success of this work will lead to alkyl-alkyl cross-coupling catalysts with broad scope and selectivities. The work has potential to significantly impact science and technologies of interest to the DOE as the chemistry is focused on developing useful reactions using reagents that can be directly prepared from petroleum and natural gas feedstocks. Moreover, the developing synthetic chemistry can profoundly affect the way materials, fine chemicals, and drugs are made. Since the methodology we are developing can shorten existing synthetic protocols, proceed at room temperature, and operate under environmentally benign conditions, it can greatly reduce energy expenditures, especially considering the contribution of the chemical manufacturing field to the gross domestic product.

  19. Calculation methods for rotor wake formation in forward flight

    NASA Technical Reports Server (NTRS)

    Drela, Mark

    1993-01-01

    The primary focus of this research centered on improving the vorticity-capturing properties of Eulerian flow solvers in convection-dominated flows. The work was motivated by the fact that excessive numerical diffusion observed in current Euler solvers on grids of feasible size is a major obstacle to accurately computing the flow about helicopter rotors, especially in the forward flight case. The work was originally supported by NASA Grant NAG2-421 for two years. The research then continued for four more years under an ONR contract. The research goal of reduction of numerical diffusion in Euler solvers remained the same, although the target application was now the prediction of internal vortical secondary flows. This was part of a larger ONR-sponsored research program at MIT aimed at reducing the noise of turbopumps. The research work culminated in the PhD thesis titled 'A Coupled Eulerian/Lagrangian Method for the Solution of Three-Dimensional Vortical Flows'.

  20. Method for in situ heating hydrocarbonaceous formations. [Radio frequency heating

    SciTech Connect

    Little, W.E.; McLendon, T.R.

    1986-05-27

    A method for extracting valuable constituents from underground hydrocarbonaceous deposits such as heavy crude, tar sands and oil shale is disclosed. Initially, a stratum containing a rich deposit is hydraulically fractured to form a horizontally extending fracture plane. A conducting liquid and proppant are then injected into the fracture plane to form a conducting plate. Electrical excitations are then introduced into the stratum adjacent the conducting plate to retort the rich stratum along the conducting plate. The valuable constituents from the stratum adjacent the conducting plate are then recovered. Subsequently, the remainder of the deposit is also combustion retorted to further recover valuable constituents from the deposit. Various rf heating systems are also disclosed for use in the present invention. 5 figs.

  1. Method for in situ heating of hydrocarbonaceous formations

    DOEpatents

    Little, William E.; McLendon, Thomas R.

    1987-01-01

    A method for extracting valuable constituents from underground hydrocarbonaceous deposits such as heavy crude tar sands and oil shale is disclosed. Initially, a stratum containing a rich deposit is hydraulically fractured to form a horizontally extending fracture plane. A conducting liquid and proppant is then injected into the fracture plane to form a conducting plane. Electrical excitations are then introduced into the stratum adjacent the conducting plate to retort the rich stratum along the conducting plane. The valuable constituents from the stratum adjacent the conducting plate are then recovered. Subsequently, the remainder of the deposit is also combustion retorted to further recover valuable constituents from the deposit. Various R.F. heating systems are also disclosed for use in the present invention.

  2. Method and apparatus for the formation of a spheromak plasma

    DOEpatents

    Yamada, Masaaki; Furth, Harold P.; Stix, Thomas H.; Todd, Alan M. M.

    1982-01-01

    A method and apparatus for forming a detached, compact toroidally shaped spheromak plasma by an inductive mechanism. A generally spheroidal vacuum vessel (1) houses a toroidally shaped flux ring or core (2) which contains poloidal and toroidal field generating coils. A plasma discharge occurs with the pulsing of the toroidal field coil, and the plasma is caused to expand away from the core (2) and toward the center of the vacuum vessel (1). When the plasma is in an expanded state, a portion of it is pinched off in order to form a separate, detached spheromak plasma configuration. The detached plasma is supported by a magnetic field generated by externally arranged equilibrium field coils (5).

  3. Method and apparatus for the formation of a spheromak plasma

    DOEpatents

    Jardin, Stephen C.; Yamada, Masaaki; Furth, Harold P.; Okabayashi, Mitcheo

    1984-01-01

    An inductive method and apparatus for forming detached spheromak plasma using a thin-walled metal toroidal ring, with external current leads and internal poloidal and toroidal field coils located inside a vacuum chamber filled with low density hydrogen gas and an external axial field generating coil. The presence of a current in the poloidal field coils, and an externally generated axial field sets up the initial poloidal field configuration in which the field is strongest toward the major axis of the toroid. The internal toroidal-field-generating coil is then pulsed on, ionizing the gas and inducing poloidal current and toroidal magnetic field into the plasma region in the sleeve exterior to and adjacent to the ring and causing the plasma to expand away from the ring and toward the major axis. Next the current in the poloidal field coils in the ring is reversed. This induces toroidal current into the plasma and causes the poloidal magnetic field lines to reconnect. The reconnection continues until substantially all of the plasma is formed in a separated spheromak configuration held in equilibrium by the initial external field.

  4. Geomorphology's role in the study of weathering of cultural stone

    NASA Astrophysics Data System (ADS)

    Pope, Gregory A.; Meierding, Thomas C.; Paradise, Thomas R.

    2002-10-01

    Great monumental places—Petra, Giza, Angkor, Stonehenge, Tikal, Macchu Picchu, Rapa Nui, to name a few—are links to our cultural past. They evoke a sense of wonderment for their aesthetic fascination if not for their seeming permanence over both cultural and physical landscapes. However, as with natural landforms, human constructs are subject to weathering and erosion. Indeed, many of our cultural resources suffer from serious deterioration, some natural, some enhanced by human impact. Groups from the United Nations to local civic and tourism assemblies are deeply interested in maintaining and preserving such cultural resources, from simple rock art to great temples. Geomorphologists trained in interacting systems, process and response to thresholds, rates of change over time, and spatial variation of weathering processes and effects are able to offer insight into how deterioration occurs and what can be done to ameliorate the impact. Review of recent literature and case studies presented here demonstrate methodological and theoretical advances that have resulted from the study of cultural stone weathering. Because the stone was carved at a known date to a "baseline" or zero-datum level, some of the simplest methods (e.g., assessing surface weathering features or measuring surface recession in the field) provide useful data on weathering rates and processes. Such data are difficult or impossible to obtain in "natural" settings. Cultural stone weathering studies demonstrate the importance of biotic and saline weathering agents and the significance of weathering factors such as exposure (microclimate) and human impact. More sophisticated methods confirm these observations, but also reveal discrepancies between field and laboratory studies. This brings up two important caveats for conservators and geomorphologists. For the conservator, are laboratory and natural setting studies really analogous and useful for assessing stone damage? For the geomorphologist, does cultural stone data have any real relevance to the natural environment? These are questions for future research and debate. In any event, cultural stone weathering studies have been productive for both geomorphologists and conservators. Continued collaboration and communication between the geomorphic, historic preservation, archaeological, and engineering research communities are encouraged.

  5. The complexon-renal stone interaction: solubility and electronic microscopy studies.

    PubMed

    Kustov, Andrey V; Berezin, Boris D; Trostin, Vyacheslav N

    2009-07-16

    We have studied how complex formation between calcium and ethylenediaminetetraacetate or citrate ions influences the surface texture and the size of passed oxalate-phosphate renal stones. The four hour concrement treatment by sodium citrate or ethylenediaminetetraacetate aqueous solutions strongly affects the stone texture and provides a mass loss of 6-15%. We have found a significant decrease of the calcium and phosphor content on a concrement surface and formation of appreciable cracks. Our results do indicate that the Ca-complexon interaction can be effectively applied for disrupting some types of renal stones and, especially, residual concrements, which frequently occurs after a surgical operation or an extracorporeal shock-wave lithotripsy. This study provides an additional quantitative physicochemical basis for this slightly invasive therapy. PMID:19537693

  6. Efficiency of heating methods for polymer fibers with formation of adhesion compounds

    SciTech Connect

    Markova, L.V.; Markov, E.M.; Pinchuk, I.S.

    1995-12-01

    Efficiency of contact and contactless methods of heating of a fiber polymer material upon formation of adhesion compounds between its layers is analyzed. The advisability of contact heating in the preliminary stage and contactless heating in the final stage of formation of compounds is shown.

  7. Method of preparing and using and composition for acidizing subterranean formations

    SciTech Connect

    Dill, W.R.

    1984-08-21

    A composition and method of acidizing or fracturing a subterranean formation comprises contacting the formation with a composition comprising an acid, urea, and a selected gelling agent. The urea is present in an amount sufficient to extend the viscous stability of the gelled acid composition in comparison to the acid and gelling agent alone.

  8. Knowledge, attitudes, and practice patterns of recurrent urinary stones prevention in Saudi Arabia.

    PubMed

    Binsaleh, Saleh; Habous, Mohamad; Madbouly, Khaled

    2016-04-01

    The purpose of this study is to assess the knowledge, attitudes, and practice patterns of urologists in Saudi Arabia regarding prevention of recurrent stone formation and how much they follow preventive stone disease management guidelines. A questionnaire about knowledge, attitudes, and practice patterns of urologists in Saudi Arabia regarding prevention of recurrent stone formation was used. The survey comprised three domains: knowledge, attitudes, and practice patterns. Data about gender, duration of experience and health care sector were also collected. Individual responses were recorded, tabulated and compared using descriptive statistics. The overall response rate was 38.8 %. All respondents were male urologists. Most of them (62, 71.3 %) had an experience of 5-20 years in management of stone disease patients and the majority (74, 85.1 %) belonged to the governmental health care sector. A total of 51 % of the respondents answered in concordance with the best practice guidelines in at least half of the questions and 40 % in all of the questions. Overall, practice patterns of 58 % of the respondents were in concordance with the best practice guidelines in all the questions except for the question of practices regarding stone analysis. As regards to attitude domain, a total of 58.7 % respondents expressed their agreement or strong agreement with the questions. Urologists' knowledge of stone recurrence preventive programs is suboptimal. They do not apply effectively the best stone prevention practice guidelines in their daily practice as well. Efforts to increase knowledge and enforce its application in daily practice are strongly warranted. PMID:26296383

  9. Prophylactic effects of quercetin and hyperoside in a calcium oxalate stone forming rat model.

    PubMed

    Zhu, Wei; Xu, Yun-fei; Feng, Yuan; Peng, Bo; Che, Jian-ping; Liu, Min; Zheng, Jun-hua

    2014-12-01

    Quercetin and hyperoside (QH) are the two main constituents of the total flavone glycosides of Flos Abelmoschus manihot, which has been prescribed for treating chronic kidney disease for decades. This study aimed to investigate the effect of QH on calcium oxalate (CaOx) formation in ethylene glycol (EG)-fed rats. Rats were divided into three groups: an untreated stone-forming group, a QH-treated stone-forming group (20 mg/kg/day) and a potassium citrate-treated stone-forming group (potassium citrate was a worldwide-recognized calculi-prophylactic medicine). Ethylene glycol (0.5 %) was administered to the rats during the last week, and vitamin D3 was force-fed to induce hyperoxaluria and kidney calcium oxalate crystal deposition. 24 h urine samples were collected before and after inducing crystal deposits. Rats were killed and both kidneys were harvested after 3 weeks. Bisected kidneys were examined under a polarized light microscope for semi-quantification of the crystal-formation. The renal tissue superoxide dismutase and catalase levels were measured by Western blot. QH and potassium citrate have the ability to alkalinize urine. The number of crystal deposits decreased significantly in the QH-treated stone-forming group as compared to the other groups. Superoxide dismutase and catalase levels also increased significantly in the QH-treated stone-forming group, as compared with the untreated stone-forming group. QH administration has an inhibitory effect on the deposition of CaOx crystal in EG-fed rats and may be effective for preventing stone-forming disease. PMID:25085199

  10. Analysis of Light Transport Features in Stone Fruits Using Monte Carlo Simulation

    PubMed Central

    Ding, Chizhu; Shi, Shuning; Chen, Jianjun; Wei, Wei; Tan, Zuojun

    2015-01-01

    The propagation of light in stone fruit tissue was modeled using the Monte Carlo (MC) method. Peaches were used as the representative model of stone fruits. The effects of the fruit core and the skin on light transport features in the peaches were assessed. It is suggested that the skin, flesh and core should be separately considered with different parameters to accurately simulate light propagation in intact stone fruit. The detection efficiency was evaluated by the percentage of effective photons and the detection sensitivity of the flesh tissue. The fruit skin decreases the detection efficiency, especially in the region close to the incident point. The choices of the source-detector distance, detection angle and source intensity were discussed. Accurate MC simulations may result in better insight into light propagation in stone fruit and aid in achieving the optimal fruit quality inspection without extensive experimental measurements. PMID:26469695

  11. Effect of urinary stone disease and its treatment on renal function

    PubMed Central

    Mehmet, Necmettin Mercimek; Ender, Ozden

    2015-01-01

    Urolithiasis is a common disease that affects urinary tract in all age groups. Both in adults and in children, stone size, location, renal anatomy, and other factors, can influence the success of treatment modalities. Recently, there has been a great advancement in technology for minimally invasive management of urinary stones. The epoch of open treatment modalities has passed and currently there are much less invasive treatment approaches, such as percutaneous nephrolithotomy, ureteroscopy, shockwave lithotripsy, and retrograde internal Surgery. Furthermore, advancement in imaging technics ensures substantial knowledge that permit physician to decide the most convenient treatment method for the patient. Thus, effective and rapid treatment of urinary tract stones is substantial for the preservation of the renal function. In this review, the effects of the treatment options for urinary stones on renal function have been reviewed. PMID:25949941

  12. Portugues Marbles as Stone Heritage

    NASA Astrophysics Data System (ADS)

    Lopes, Luis; Martins, Ruben

    2013-04-01

    The main objective of this paper is to present and justify the reasons for the worldwide recognition of Portuguese Marbles as Stone Heritage. These marbles are also known as "Estremoz Marble" since was the first county were exploited. In the Estremoz Anticline marbles occupy an intermediate stratigraphic position being part of a volcano-sedimentary sequence of Cambrian age. The anticlinal structure has a Precambrian core and the younger rocks aged Devonian Period. This sequence has deformed by the Variscan Orogeny, which performed twice with different intensities both in ductile and brittle tension fields. The early Alpine Cycle also acts in the region and cause more fracturing of the marble. Practically in all the quarries is possible to perceive the spatial-temporal continuity of the deformation where one can describe a complete Wilson Cycle. Together all these geological features imprint the marbles beautiful aesthetic patterns that can be highlighted when used as dimension stone. Nowadays most of the quarries are placed in the counties of Borba and mainly in Vila Viçosa. This last city claims for itself the "Capital of the Marble" title and named the marble as "White Gold". In fact, according to the historical record, the marbles were quarried in Portuguese Alentejo's Province since the fourth century BC. Locally these geological materials are available easily accessible. Exhibit physical properties that allow the fabrication of structural and decorative elements and so were used since humans settled in the region and developed a structured Society. In the Roman period, the pieces of art made with Estremoz Marbles were exported abroad and today are represented in Museums and Archaeological Sites throughout Europe and North Africa countries. The Portuguese Marbles and Limestones, transformed into altars, stairways, columns, statues and pieces of wall cladding, were carried as ballast in the holds of ships. At the destination the Portuguese People had built numerous churches which today can be found in Brazil but also along the South American and African coasts. Currently the global market of Modern Dimension Stones Industry allows Portuguese Marbles to be present in buildings, architectural pieces and works of arts all over the World. Despite almost continuous mining activity in the region it's notice that there was no depletion of raw material, in fact almost every varieties of marble have enough reserves to sustain the mining activity is several hundreds of years. The Alentejo whitewashed houses are a hallmark of the unique landscape that can only have been developed by the availability of marbles to produce quicklime. In cities and villages, the built heritage based on the marble is very rich and is always present, meanwhile the surrounding countryside is marked by intense mining activity living side by side with rural industries, namely wheatfields, groves, orchards and vineyards; therefore the region has unique characteristics allowing the development of integrated industrial tourism routes. The Portuguese Marbles are a key factor for local sustainable development and it's leading the region to new opportunities of industrial, scientific and technological culture, pointing to a successful future.

  13. Fluoroscopically guided laser lithotripsy versus extracorporeal shock wave lithotripsy for retained bile duct stones: a prospective randomised study.

    PubMed Central

    Jakobs, R; Adamek, H E; Maier, M; Krömer, M; Benz, C; Martin, W R; Riemann, J F

    1997-01-01

    BACKGROUND AND AIMS: To compare extracorporeal shock wave lithotripsy (ESWL) and laser induced shock wave lithotripsy (LISL) of retained bile duct stones to stone free rate, number of therapeutic sessions, and costs. PATIENTS: Thirty four patients were randomly assigned to either ESWL or LISL therapy. The main reasons for failure of standard endoscopy were due to stone impaction (n = 12), biliary stricture (n = 8), or large stone diameter (n = 14). METHODS: An extracorporeal piezoelectic lithotripter with ultrasonic guidance and a rhodamine 6G laser with an integrated stone tissue detection system were used. LISL was performed exclusively under radiological control. RESULTS: Using the initial methods complete stone fragmentation was achieved in nine of 17 patients (52.4%) of the ESWL group and in 14 of 17 patients (82.4%) in the LISL group, or combined with additional fragmentation techniques 31 of the 34 patients (91.2%) were stone free at the end of treatment. In comparison LISL tended to be more efficient in clearing the bile ducts (p = 0.07, NS). Significantly less fragmentation sessions (1.29 v 2.82; p = 0.0001) and less additional endoscopic sessions (0.65 v 1.6; p = 0.002) were necessary in the LISL group. There were no major complications in either procedure. CONCLUSIONS: Compared with ESWL, fluoroscopically guided LISL achieves stone disintegration more rapidly and with significantly less treatment sessions, which leads to a significant reduction in cost. PMID:9203950

  14. [A case of ammonium urate urinary stone].

    PubMed

    Hara, Noboru; Koike, Hiroshi

    2004-05-01

    An 18-year-old female, who had undergone antireflux surgery for bilateral vesicoureteral reflux 5 years ago, was admitted to our department with complaints of fever and left-sided back pain. Bilateral renal stones and pyelonephritis were diagnosed after roentgenography, ultrasonography and urinalysis. Pyelonephritis was successfully treated with antibiotics and the left renal stone was completely disintegrated with extracorporeal shock wave lithotripsy. Spectrophotometric analysis revealed that the stone was composed of pure ammonium urate (AU). The patient had not experienced any episodes of urinary tract infection from the antireflux surgery until the present event, but had lost 20 kg in body weight during the last year due to a low-caloric diet and laxative abuse. AU urinary stones have been infrequently reported in Japan, and they are supposed to be associated with a low-caloric diet, laxative abuse, and anorexia nervosa. PMID:15237492

  15. Clinical and biochemical profile of patients with "pure" uric acid nephrolithiasis compared with "pure" calcium oxalate stone formers.

    PubMed

    Negri, Armando Luis; Spivacow, Rodolfo; Del Valle, Elisa; Pinduli, Irene; Marino, Alicia; Fradinger, Erich; Zanchetta, Jose Ruben

    2007-10-01

    The purpose of the present study was to compare the clinical characteristics of "pure" uric acid (UA) stone formers with that of "pure" calcium oxalate (CaOx) stone formers and to determine whether renal handling of UA, urinary pH, and urinary excretion of promoters and inhibitors of stone formation were different between the two groups. Study subjects comprised 59 patients identified by records of stone analysis: 30 of them had "pure" UA stones and 29 had "pure" CaOx nephrolithiasis. Both groups underwent full outpatient evaluation of stone risk analysis that included renal handling of UA and urinary pH. Compared to CaOx stone formers, UA stone formers were older (53.3 +/- 11.8 years vs. 44.5 +/- 10.0 years; P = 0.003); they had higher mean weight (88.6 +/- 12.5 kg vs. 78.0 +/- 11.0 kg; P = 0.001) and body mass index (29.5 +/- 4.2 kg/m(2) vs. 26.3 +/- 3.5 kg/m(2); P = 0.002) with a greater proportion of obese subjects (43.3% vs. 16.1%; P = 0.01). Patients with "pure" UA lithiasis had significantly lower UA clearance, UA fractional excretion, and UA/creatinine ratio, with significantly higher serum UA. The mean urinary pH was significantly lower in UA stone formers compared to CaOx stone formers (5.17 +/- 0.20 vs. 5.93 +/- 0.42; P < 0.0001). Patients with CaOx stones were a decade younger, having higher 24-h urinary calcium excretion (218.5 +/- 56.3 mg/24 h vs. 181.3 +/- 57.1 mg/24 h; P = 0.01) and a higher activity product index for CaOx [AP (CaOx) index]. Overweight/obesity and older age associated with low urine pH were the principal characteristic of "pure" UA stone formers. Impairment in urate excretion associated with increased serum UA was also another characteristic of UA stone formers that resembles patients with primary gout. Patients with pure CaOx stones were younger; they had a low proportion of obese subjects, a higher urinary calcium excretion, and a higher AP index for CaOx. PMID:17786420

  16. Method of temporarily plagging portions of a subterranean formation using a diverting agent

    SciTech Connect

    Dill, W. R.; Gdanski, R. D.

    1985-07-09

    A method of temporarily plugging a subterranean formation using a diverting material comprising an aqueous carrier liquid and a diverting agent comprising a solid azo compound having an azo component and a methylenic component.

  17. Stone Composition as a Function of Age and Sex

    PubMed Central

    Rule, Andrew D.; Krambeck, Amy E.; Williams, James C.; Bergstralh, Eric J.; Mehta, Ramila A.; Moyer, Thomas P.

    2014-01-01

    Background and objectives Kidney stones are heterogeneous but often grouped together. The potential effects of patient demographics and calendar month (season) on stone composition are not widely appreciated. Design, setting, participants, & measurements The first stone submitted by patients for analysis to the Mayo Clinic Metals Laboratory during 2010 was studied (n=43,545). Stones were classified in the following order: any struvite, any cystine, any uric acid, any brushite, majority (?50%) calcium oxalate, or majority (?50%) hydroxyapatite. Results Calcium oxalate (67%) was the most common followed by hydroxyapatite (16%), uric acid (8%), struvite (3%), brushite (0.9%), and cystine (0.35%). Men accounted for more stone submissions (58%) than women. However, women submitted more stones than men between the ages of 1019 (63%) and 2029 (62%) years. Women submitted the majority of hydroxyapatite (65%) and struvite (65%) stones, whereas men submitted the majority of calcium oxalate (64%) and uric acid (72%) stones (P<0.001). Although calcium oxalate stones were the most common type of stone overall, hydroxyapatite stones were the second most common before age 55 years, whereas uric acid stones were the second most common after age 55 years. More calcium oxalate and uric acid stones were submitted in the summer months (July and August; P<0.001), whereas the season did not influence other stone types. Conclusions It is well known that calcium oxalate stones are the most common stone type. However, age and sex have a marked influence on the type of stone formed. The higher number of stones submitted by women compared with men between the ages of 10 and 29 years old and the change in composition among the elderly favoring uric acid have not been widely appreciated. These data also suggest increases in stone risk during the summer, although this is restricted to calcium oxalate and uric acid stones. PMID:25278549

  18. Assessing applicants to the NASA flight program for their renal stone-forming potential.

    PubMed

    Pak, C Y; Hill, K; Cintron, N M; Huntoon, C

    1989-02-01

    Spaceflight could provoke formation of kidney stones, in part by causing hypercalciuria and hyperphosphaturia. Applicants for spaceflight who have metabolic or environmental derangements to begin with might be particularly susceptible to stone formation in space. We, therefore, analyzed 24-h urine samples for stone-forming risk factors in 104 male applicants before their selection into the astronaut-mission specialist corps. The urinary environment was abnormally supersaturated with calcium oxalate in 25.0% of applicants, brushite in 36.5%, and monosodium urate in 66.3%, predisposing these applicants to crystallization of stone-forming calcium salts. This high level of supersaturation was caused by both "metabolic" and environmental disturbances. Thus, hypercalciuria was found in 11.5% of applicants, hyperoxaluria in 2.9%, hyperuricosuria in 18.3% and hypocitraturia in 5.8%. Environmental derangements were generally more prominent, as indicated by low urine volume of less than 2 L.d-1 in 84.6%, high urinary phosphate in 24.4%, and high urinary sodium in 10.6% of applicants. The results suggest that most of the abnormal stone risk factors disclosed among applicants for spaceflight programs were environmental in origin. PMID:2930428

  19. The risk of kidney stones following bariatric surgery: a systematic review and meta-analysis.

    PubMed

    Thongprayoon, Charat; Cheungpasitporn, Wisit; Vijayvargiya, Priya; Anthanont, Pimjai; Erickson, Stephen B

    2016-04-01

    Background With rising prevalence of morbid obesity, the number of bariatric surgeries performed each year has been increasing worldwide. The objective of this meta-analysis was to assess the risk of kidney stones following bariatric surgery. Methods A literature search was performed using MEDLINE, EMBASE, and Cochrane Database of Systematic Reviews from inception through July 2015. Only studies reporting relative risks, odd ratios or hazard ratios (HRs) to compare risk of kidney stones in patients who underwent bariatric surgery versus no surgery were included. Pooled risk ratios (RR) and 95% confidence interval (CI) were calculated using a random-effect, generic inverse variance method. Results Four studies (One randomized controlled trial and three cohort studies) with 11,348 patients were included in analysis to assess the risk of kidney stones following bariatric surgery. The pooled RR of kidney stones in patients undergoing bariatric surgery was 1.22 (95% CI, 0.63-2.35). The type of bariatric surgery subgroup analysis demonstrated an increased risk of kidney stones in patients following Roux-en-Y gastric bypass (RYGB) with the pooled RR of 1.73 (95% CI, 1.30-2.30) and a decreased risk of kidney stones in patients following restrictive procedures including laparoscopic banding or sleeve gastrectomy with the pooled RR of 0.37 (95% CI, 0.16-0.85). Conclusions Our meta-analysis demonstrates an association between RYGB and increased risk of kidney stones. Restrictive bariatric surgery, on the other hand, may decrease kidney stone risk. Future study with long-term follow-up data is needed to confirm this potential benefit of restrictive bariatric surgery. PMID:26803902

  20. Meridian Stones: for Form or for Function?

    NASA Astrophysics Data System (ADS)

    Amory, L.; Boyce, P.; diCurcio, R.; Strelnitski, V.

    2002-12-01

    The goal of this investigation was to reveal the original intent and purpose of the creator of the ``Nantucket Meridian Stones'' - self taught astronomer and surveyor William Mitchell (the father of the first American female astronomer, Maria Mitchell). Throughout time, these two enigmatic stone obelisks in downtown Nantucket have been cloaked in controversial legends. We did not find any mention of these stones in the original diaries and journals of William Mitchell, or in the town's public documents (except for the written decision of the 1840 town meeting to allot money for the stones' erection). However, amongst several controversial articles on the stones in the local newspaper published during the 20th century, we found one (dated 1921) which gives the most plausible explanation: the meridian line defined by the stones was used by the local surveyors to keep track of the variation in the magnetic declination, the angle between the directions to the magnetic North and the true (geographical) North. This hypothesis will be compared with the existing information on the purpose and use of other historical meridian markers, both in America and Europe. This project was supported by Vassar College and the Nantucket Maria Mitchell Association.

  1. Famous Stone Patients and Their Disease

    NASA Astrophysics Data System (ADS)

    Moran, Michael E.

    2007-04-01

    The fact that stone patients have endured much throughout the ages and that prior to our current era, when the ultimate horror, "being cut for the stone" was the only alternative to the repeated episodes of colic, should be recalled from time to time. Urolithiasis has affected humanity throughout the ages and has been indiscriminate to those lives it touched. A full accounting of those who have suffered and recorded their agonies is beyond the scope of this investigation; however, even a partial accounting is valuable for present day physicians who care for those with stone disease. For the present work, the historical accounts of stone disease literature were scrutinized for individual sufferers who could be cross-referenced from other sources as legitimately afflicted by stones. Only those patients that could be documented and were (or are) well known were included, because the internet is now a verdant repository of thousands of "not so well knowns." Reliable historical data was found for a variety of persons from the pre-Christian era to the present, including those remembered as philosophers and scientists, physicians, clergy, leaders and rulers, entertainers, athletes and fictitious/Hollywood-type individuals. Verified accounts of famous stone formers were chosen for this paper, and are presented in chronological order. The list of urolithiasis sufferers presented here is undoubtedly incomplete, but it is not through lack of trying that they are missing. Most often, the suffering do so silently, and that is always allowed.

  2. Development of a biofilm formation method for waste forms stability evaluation.

    PubMed

    Idachaba, M A; Nyavor, K; Egiebor, N O; Rogers, R D

    2000-10-01

    The development of an accurate assessment protocol is critical for the prediction of long-term performance of waste disposal systems under field conditions. In this study, the development of a biofilm formation method for the evaluation of waste forms stability to microbially induced degradation (MID) is reported. The development process involved significant modifications to the existing Nuclear Regulatory Commission (NRC) approach. In the biofilm formation method, the control media and fermenter broths are designed to be of similar pH to avoid overestimation of the microbe's capability to degrade the waste forms. In the NRC approach, the pH values are different. The existing one-stage process of the NRC approach is also replaced with a two-stage process in the biofilm formation method. This is to ensure full evaluation of the microbe's involvement in waste forms degradation. The first stage of the two-stage process is for biofilm formation and the second is for biofilm evaluation. The use of a two-stage process eliminates the possibility of substrate limitation, resulting in values of degradation indices that are about two times higher than those obtained using the single-stage NRC approach. Two waste forms (100% Tuskegee cement and 21% cobalt chloride/79% cement) were used in the development of the biofilm formation method. Both waste forms showed evidence of biofilm formation. The formation of biofilm on the cobalt-containing waste form indicates a lack of anti-microbial capability of cobalt. PMID:10946124

  3. Correlates of kidney stone disease differ by race in a multi-ethnic middle aged population: The ARIC Study

    PubMed Central

    Akoudad, Saloua; Szklo, Moyses; McAdams, Mara A.; Fulop, Tibor; Anderson, Cheryl A.M.; Coresh, Josef; Köttgen, Anna

    2010-01-01

    Objective To identify correlates of kidney stone disease in white and African American men and women in a population-based longitudinal study starting in four US communities, and to assess differences in correlates across racial groups. Methods 12,161 middle-aged participants of the ARIC Study provided information on history of kidney stone disease between 1993–1995. Information on incident kidney stone-related hospitalizations was obtained from ICD-codes on hospital discharge records. Results Kidney stone disease was reported by 12.0% of men and 4.8% of women. After multivariable adjustment, prevalent kidney stone disease was significantly (p<0.05) associated with male gender (PR=2.50), increased serum triglycerides (PR=1.07 per SD increase), diabetes (PR=1.27), gallstone disease (PR=1.54), white race (PR= 1.67), and region of residence. Male gender (HR=1.70), diabetes (HR=1.98) and hypertension (HR=1.69) were significantly associated (p<0.05) with incident kidney stone-related hospitalizations (n=94). Race-stratified analyses showed stronger associations of prevalent kidney stone disease with increased triglycerides, older age, and gallstone disease in African Americans compared to whites, whereas male gender showed stronger association in whites (all p-interaction<0.05). Conclusion We identified novel correlates of kidney stone disease (triglycerides, gallstone disease) and risk factor interactions by race (age, male gender, triglycerides, gallstone disease). PMID:20801154

  4. Urinary stone differentiation in patients with large body size using dual-energy dual-source computed tomography

    PubMed Central

    Qu, Mingliang; Jaramillo-Alvarez, Giselle; Ramirez Giraldo, Juan C.; Liu, Yu; Duan, Xinhui; Wang, Jia; Vrtiska, Terri J; Krambeck, Amy E.; Lieske, John; McCollough, Cynthia H

    2013-01-01

    Objective To evaluate the ability of 100/Sn140 kV (Sn, tin filter) dual-energy CT to differentiate urinary stone types in a patient cohort with a wide range of body sizes. Methods 80 human urinary stones were categorised into four groups (uric acid; cystine; struvite, oxalate and brushite together; and apatite) and imaged in 30–50-cm wide water tanks using clinical 100/Sn140 kV protocols. The CT number ratio (CTR) between the low- and high-energy images was calculated. Thresholds for differentiating between stone groups were determined using ROC analysis. Additionally, 86 stones from 66 patients were characterised using the size-adaptive CTR thresholds determined in the phantom study. Results In phantoms, the area under the ROC curve for differentiating between stone groups ranged from 0.71 to 1.00, depending on phantom size. In patients, body width ranged from 28.5 to 50.0 cm, and 79.1% of stones were correctly characterised. Sensitivity and specificity for correctly identifying the stone category were 100% and 100% (group 1), 100% and 95.3% (group 2), 85.7% and 60.9% (group 3), and 52.6% and 92.5% (group 4). Conclusion Dual-energy CT can provide in vivo urinary stone characterisation for patients over a wide range of body sizes. PMID:23263603

  5. Determination of chemical composition of gall bladder stones: Basis for treatment strategies in patients from Yaounde, Cameroon

    PubMed Central

    III, Fru F. Angwafo; Takongmo, Samuel; Griffith, Donald

    2004-01-01

    AIM: Gallstone disease is increasing in sub-saharan Africa (SSA). In the west, the majority of stones can be dissolved with bile salts, since the major component is cholesterol. This medical therapy is expensive and not readily accessible to poor populations of SSA. It was therefore necessary to analyze the chemical composition of biliary stones in a group of patients, so as to make the case for introducing bile salt therapy in SSA. METHODS: All patients with symptomatic gallstones were recruited in the study. All stones removed during cholecystectomy were sent to Houston for x-ray diffraction analysis. Data on age, sex, serum cholesterol, and the percentage by weight of cholesterol, calcium carbonate, and amorphous material in each stone was entered into a pre-established proforma. Frequencies of the major components of the stones were determined. RESULTS: Sixteen women and ten men aged between 27 and 73 (mean 44.9) years provided stones for the study. The majority of patients (65.38%) had stones with less than 25% of cholesterol. Amorphous material made up more than 50% and 100% of stones from 16 (61.53%) and 9 (34.61%) patients respectively. CONCLUSION: Cholesterol is present in small amounts in a minority of gallstones in Yaounde. Dissolution of gallstones with bile salts is unlikely to be successful. PMID:14716845

  6. Comparison of methods for geologic storage of carbon dioxide in saline formations

    SciTech Connect

    Goodman, Angela L.; Bromhal, Grant S.; Strazisar, Brian; Rodosta, Traci D.; Guthrie, William J.; Allen, Douglas E.; Guthrie, George D.

    2013-01-01

    Preliminary estimates of CO{sub 2} storage potential in geologic formations provide critical information related to Carbon Capture, Utilization, and Storage (CCUS) technologies to mitigate CO{sub 2} emissions. Currently multiple methods to estimate CO{sub 2} storage and multiple storage estimates for saline formations have been published, leading to potential uncertainty when comparing estimates from different studies. In this work, carbon dioxide storage estimates are compared by applying several commonly used methods to general saline formation data sets to assess the impact that the choice of method has on the results. Specifically, six CO{sub 2} storage methods were applied to thirteen saline formation data sets which were based on formations across the United States with adaptations to provide the geologic inputs required by each method. Methods applied include those by (1) international efforts the Carbon Sequestration Leadership Forum (Bachu et al., 2007); (2) United States government agencies U.S. Department of Energy National Energy Technology Laboratory (US-DOE-NETL, 2012) and United States Geological Survey (Brennan et al., 2010); and (3) the peer-reviewed scientific community Szulczewski et al. (2012) and Zhou et al. (2008). A statistical analysis of the estimates generated by multiple methods revealed that assessments of CO{sub 2} storage potential made at the prospective level were often statistically indistinguishable from each other, implying that the differences in methodologies are small with respect to the uncertainties in the geologic properties of storage rock in the absence of detailed site-specific characterization.

  7. Introductory Overview of Stone Heritages in Japan

    NASA Astrophysics Data System (ADS)

    Kato, Hirokazu; Oikawa, Teruki; Fujita, Masayo; Yokoyama, Shunji

    2013-04-01

    As one contribution to 'Global Heritage Stone Resources' (GHSR), some stone heritages in Japan, which are nominated in the interim list, are briefly introduced. The geology of Japanese Islands where are the one of the most active areas in the history of the Earth, is very complicated. Therefore Japanese Islands consist of various kinds of minerals and rocks. Some of them were used to make stone implements and accessories. Japanese people also used to the best possible advantage to built tombstone, gate, pavement ,and the basement and wall of the large building such as temples, shrines, castles and modern buildings. 1. Stone Heritages of Pre-historical age: In the late Pleistocene and the early Holocene, ancient Japanese used obsidian cooled rapidly from rhyolitic magma.to make small implements and accessories. For example, Shirataki, Hokkaido (north island) is the largest place producing obsidian in Japan where Paleolithic people made arrowhead, knives and so on. Another example, Jade yielded in Itoigawa City, Japan Sea coast of central Japan, was made in the metamorphic rock about five hundred million years ago. Itoigawa area is only one place where jade is abundantly produced in Japan. Ancient people had been already collected and processed to ornaments although it is very hard and traded in wide area more than several thousand years ago. 2. Stone Heritages of Historical age: 2.1 Archaeological remains: In the Kofun (old mound) period (250 to 538 AD), stone burial chambers were used for old mounds to preserve against the putrefaction and to protect from the theft. For example, Ishibutai Kofun ("ishi" means "stone" and "butai" means "stage") in Nara old capital city, southwest Japan, is the largest known megalithic structure made of granite in Japan. 2.2 Stone walls of some typical castles Stones used is because of not only the rich reserves of rocks but also restriction of transportation. Osaka (second biggest city) castle, are composed of Cretaceous granite exceeding over 500,000 in number and the largest block is 108 ton in weight. Stoens of Hikone Castle came from Paleogene Koto Rhyolite. Edo (old Tokyo, biggest city, central Japan) castle ,Imperial Palace at present, Stones are late Quaternary andesite of Hakone Volcanic Products whose quarrying places are more than 100km far from Edo.They were transported by ships and manpower on land .

  8. Bone metabolism and renal stone risk during International Space Station missions.

    PubMed

    Smith, Scott M; Heer, Martina; Shackelford, Linda C; Sibonga, Jean D; Spatz, Jordan; Pietrzyk, Robert A; Hudson, Edgar K; Zwart, Sara R

    2015-12-01

    Bone loss and renal stone risk are longstanding concerns for astronauts. Bone resorption brought on by spaceflight elevates urinary calcium and the risk of renal stone formation. Loss of bone calcium leads to concerns about fracture risk and increased long-term risk of osteoporosis. Bone metabolism involves many factors and is interconnected with muscle metabolism and diet. We report here bone biochemistry and renal stone risk data from astronauts on 4- to 6-month International Space Station missions. All had access to a type of resistive exercise countermeasure hardware, either the Advanced Resistance Exercise Device (ARED) or the Interim Resistance Exercise Device (iRED). A subset of the ARED group also tested the bisphosphonate alendronate as a potential anti-resorptive countermeasure (Bis+ARED). While some of the basic bone marker data have been published, we provide here a more comprehensive evaluation of bone biochemistry with a larger group of astronauts. Regardless of exercise, the risk of renal stone formation increased during spaceflight. A key factor in this increase was urine volume, which was lower during flight in all groups at all time points. Thus, the easiest way to mitigate renal stone risk is to increase fluid consumption. ARED use increased bone formation without changing bone resorption, and mitigated a drop in parathyroid hormone in iRED astronauts. Sclerostin, an osteocyte-derived negative regulator of bone formation, increased 10-15% in both groups of astronauts who used the ARED (p<0.06). IGF-1, which regulates bone growth and formation, increased during flight in all 3 groups (p<0.001). Our results are consistent with the growing body of literature showing that the hyper-resorptive state of bone that is brought on by spaceflight can be countered pharmacologically or mitigated through an exercise-induced increase in bone formation, with nutritional support. Key questions remain about the effect of exercise-induced alterations in bone metabolism on bone strength and fracture risk. PMID:26456109

  9. Percutaneous nephrolithotomy versus open surgery for treatment of staghorn stones in pediatric patients

    PubMed Central

    El-Nahas, Ahmed R.; Shokeir, Ahmed A.; Shoma, Ahmed M.; Eraky, Ibrahim; Sarhan, Osama M.; Hafez, Ashraf T.; Dawaba, Mohamed S.; Elshal, Ahmed M.; Ghali, Ahmed M.; El-Kenawy, Mahmoud R.

    2014-01-01

    Introduction: We compare percutaneous nephrolithotomy (PCNL) and open surgery in the treatment of staghorn stones in children. Methods: We retrospectively reviewed the electronic records of children who underwent treatment for staghorn stones between September 2000 and August 2013. They were divided between Group 1 (patients who underwent PCNL) and Group 2 (patients who underwent open surgery). We compared stone-free and complications rates, need for multiple procedures, and hospital stay. Results: The study included 41 patients (35 boys and 6 girls), with mean age 7.4 ± 3.1 years (range: 2–15). Of these 41 patients, 26 had unilateral renal stone and 15 had bilateral renal stones. The total number of treated renal units was 56: 28 underwent PCNL and 28 underwent open surgery. The complication rate was comparable for both groups (32% for open surgery vs. 28.6%, p = 0.771). Multiple procedures were more needed in PCNL group (60.7% vs. 32% in open surgery, p = 0.032). The stone-free rate was 71.4% after PCNL and 78.6% after open surgery (p = 0.537). A significant difference was observed in shorter hospital stay after PCNL (5 vs. 8.8 days, p < 0.001). Our study’s limitations include its retrospective design and relatively small sample size. Conclusions: For the treatment of staghorn stones in children, PCNL was comparable to open surgery in complication and stone-free rates. PCNL had the advantage of a shorter hospital stay and open surgery showed a decreased need for multiple procedures. PMID:25553164

  10. Body Mass Index and Kidney Stones: A Cohort Study of Japanese Men

    PubMed Central

    Yoshimura, Eiichi; Sawada, Susumu S.; Lee, I-Min; Gando, Yuko; Kamada, Masamitsu; Matsushita, Munehiro; Kawakami, Ryoko; Ando, Ryosuke; Okamoto, Takashi; Tsukamoto, Koji; Miyachi, Motohiko; Blair, Steven N.

    2016-01-01

    Background In Japan, the incidence of kidney stones has increased markedly in recent decades. Major causes of kidney stones remain unclear, and limited data are available on the relationship between overweight/obesity and the incidence of kidney stones. We therefore evaluated body mass index (BMI) and the incidence of kidney stones in Japanese men. Methods Of the workers at a gas company, 5984 males aged 20–40 years underwent a medical examination in 1985 (baseline). This study includes 4074 of the men, who were free of kidney stones at baseline and underwent a second medical examination performed between April 2004 and March 2005. BMI was calculated from measured height and weight in 1985, and men were categorized into tertiles. The development of kidney stones during follow-up was based on self-reports from questionnaires at the second medical examination. Results The average duration of follow-up was 19 years, with 258 participants developing kidney stones during this period. Using the lowest BMI (1st tertile) group as a reference, the hazard ratios (95% confidence intervals [CIs]) for the 2nd and 3rd BMI tertiles were: 1.26 (95% CI, 0.92–1.73) and 1.44 (95% CI, 1.06–1.96), respectively (P for trend = 0.019). After additionally adjusting for potential confounders, such as age, systolic blood pressure, cardiorespiratory fitness, cigarette smoking, and alcohol consumption, the hazard ratios were 1.28 (95% CI, 0.93–1.76) and 1.41 (95% CI, 1.02–1.97), respectively (P for trend = 0.041). Conclusions These results suggest that increased BMI is a risk factor for kidney stones in Japanese men. PMID:26616396

  11. Outcomes of ureteroscopy for patients with stones in a solitary kidney: evidence from a systematic review

    PubMed Central

    Rai, Bhavan Prasad; Somani, Bhaskar K.

    2016-01-01

    Introduction Management of urolithiasis in a solitary functioning kidney can be clinically challenging. The aim of this article was to review the outcomes of URS for patients with stone disease in a solitary kidney and critically appraise the existing evidence and outcome reporting standards. Material and methods We conducted a systematic review in line with PRISMA checklist and Cochrane guidelines between January 1980 and February 2015. Our inclusion criteria were all English language articles reporting on a minimum of 10 patients with a solitary kidney undergoing ureteroscopy for stone disease. Results A total of 116 patients (mean age 50 years) underwent URS for stones in solitary kidney. For a mean stone size of 16.8 mm (range: 5–60 mm) and 1.23 procedures/patient, the mean stone free rate was 87%. No significant change in renal function was recorded in any of the studies although a transient elevation in creatinine was reported in 10 (8.6%) patients. A total of 33 (28%) complications were recorded a majority (n = 21) of which were Clavien grade I. The Clavien grade II/III complications as reported by authors were urosepsis, steinstrasse and renal colic. None of the procedures required conversion to open surgery with no cases of renal haematoma or ureteric perforation. Conclusions This contemporary review highlights URS as a viable treatment option for stone disease in patients with a solitary kidney. It is associated with superior clearance rates to SWL and fewer high-risk complications compared to PCNL. PMID:27123332

  12. Retroperitoneal laparoscopic technique in treatment of complex renal stones: 75 cases

    PubMed Central

    2014-01-01

    Background In most hospitals, several options for the management of renal stones are available: shockwave lithotripsy, endourologic treatment, or surgery. Choice of treatment is based on the anatomic characteristics of the patient, and the location and size of the stones. In this study we assessed a retroperitoneal laparoscopic technique for treatment of complex renal stones. Methods Seventy-five patients, including 53 men and 22 women with a mean age of 47.8 years (range 18–74 y), underwent retroperitoneal laparoscopy for the treatment of complex renal stones between July 2006 and November 2012 in our hospital. Results The retroperitoneal laparoscopic procedures for treatment of complex renal stones were completely successful in 73 cases, while 2 cases converted to open surgery. The operative time was 85–190 min with a mean of 96 min. The estimated blood lost was 20–400 mL with a mean of 80 mL. After the operation 7 patients experienced urinary leakage. Ultrasonography, x-ray of the kidney, ureter and bladder, and intravenous urography were reviewed at post-procedural follow-up at 6–82 months. No hydronephrosis aggravation was found, and there was no calculus recurrence. Conclusion The merits of retroperitoneal laparoscopy for the treatment of complex renal stones include sparing the nephron, less bleeding, short hospitalization, quick postoperative recovery, and controllable procedure after training Success depends on the experience of surgeons and judicious selection of cases. PMID:24491207

  13. Analysis of urinary stone based on a spectrum absorption FTIR-ATR

    NASA Astrophysics Data System (ADS)

    Asyana, V.; Haryanto, F.; Fitri, L. A.; Ridwan, T.; Anwary, F.; Soekersi, H.

    2016-03-01

    This research analysed the urinary stone by measuring samples using Fourier transform infrared-attenuated total reflection spectroscopy and black box analysis. The main objective of this study is to find kinds of urinary stone and determine a total spectrum, which is a simple model of the chemical and mineral composition urinary stone through black box analysis using convolution method. The measurements result showed that kinds of urinary stone were pure calcium oxalate monohydrate, ion amino acid calcium oxalate monohydrate, a mixture of calcium oxalate monohydrate with calcium phosphate, a mixture of ion amino acid calcium oxalate monohydrate and calcium phosphate,pure uric acid, ion amino acid uric acid, and a mixture of calcium oxalate monohydrate with ion amino acid uric acid. The results of analysis of black box showed characteristics as the most accurate and precise to confirm the type of urinary stones based on theregion absorption peak on a graph, the results of the convolution, and the shape of the total spectrum on each urinary stones.

  14. Retrograde Intrarenal Surgery in Patients Who Previously Underwent Open Renal Stone Surgery

    PubMed Central

    Alkan, Erdal; Saribacak, Ali; Ozkanli, Ahmet Oguz; Başar, Mehmet Murad; Acar, Oguz; Balbay, Mevlana Derya

    2015-01-01

    Purpose. To ascertain whether retrograde intrarenal surgery (RIRS) is as effective in patients treated previously with open renal stone surgery (ORSS) on the same kidney as in patients with no previous ORSS. Methods. There were 32 patients with renal stones who had previous ORSS and were treated with RIRS in the study group (Group 1). A total of 38 patients with renal stones who had no previous ORSS and were treated with RIRS were selected as the control group (Group 2). Recorded data regarding preoperative characteristics of the patients, stone properties, surgical parameters, outcomes, SFRs (no fragments or small fragments <4 mm), and complications between groups were compared. Results. Mean age, mean BMI, mean hospital stay, and mean operative time were not statistically different between groups. Mean stone size (10.1 ± 5.6 versus 10.3 ± 4.2; p = 0.551) and mean stone burden (25.4 ± 14.7 versus 23.5 ± 9.9; p = 0.504) were also similar between groups. After the second procedures, SFRs were 100% and 95% in groups 1 and 2, respectively (p = 0.496). No major perioperative complications were seen. Conclusion. RIRS can be safely and effectively performed with acceptable complication rates in patients treated previously with ORSS as in patients with no previous ORSS. PMID:26357570

  15. Surgical versus endoscopic management of common bile duct stones.

    PubMed Central

    Miller, B M; Kozarek, R A; Ryan, J A; Ball, T J; Traverso, L W

    1988-01-01

    The charts of all patients with common bile duct (CBD) stones admitted to Virginia Mason Medical Center between January 1, 1981 and July 31, 1986 were reviewed to define current methods of management and results of operative versus endoscopic therapy. Two hundred thirty-seven patients with CBD stones were treated. One hundred thirty patients had intact gallbladders. Of these patients, 76 (59%) underwent cholecystectomy and common bile duct exploration (CBDE) while 54 (41%) underwent endoscopic papillotomy (EP) only. Of the 107 patients admitted with recurrent stones after cholecystectomy, all but five were treated with EP. The overall mortality rate was 3.0%. Complications, success, and death rates were all similar for CBDE and EP, but the complications of EP were often serious and directly related to the procedure (GI hemorrhage, 6; duodenal perforation, 5; biliary sepsis, 4; pancreatitis, 1). Patients undergoing EP required significantly shorter hospitalization than those undergoing CBDE. Multivariate analysis showed that age greater than 70 years, technical failure, and complications increased the risk of death, regardless of procedure performed. Twenty-one per cent of those undergoing EP with gallbladders intact eventually required cholecystectomy. The conclusion is that the results of EP and CBDE are similar, and the use of EP has not reduced the mortality rates of this disease. PMID:3341812

  16. Surgical Management of Stone Disease in Patient with Primary Hyperoxaluria

    PubMed Central

    Carrasco, Alonso; Granberg, Candace F.; Gettman, Matthew T.; Milliner, Dawn S.; Krambeck, Amy E.

    2015-01-01

    Objectives To present our experience with surgical management of nephrolithiasis in patients with primary hyperoxaluria (PH). Methods A retrospective chart review from 1994–2012 was perform to identify patients with diagnosis of PH. Results A total of 14 patients with PH were identified with median follow-up of 18.6 years (range: 0.9–51). Median age at initial symptom and subsequent diagnosis were 6.7 years (range: 1.1–35.5) and 0.42 years (range: 0–33.25), respectively. Patients underwent a total of 54 procedures at our institution including: ureteroscopy 27 (50%), percutaneous nephrolithotomy 15 (28%), shock wave lithotripsy 8 (15%), and combined procedures 4 (7%). Overall non-intraparenchymal stone free rate after first, second, and third procedure(s) were 59%, 76%, and 78%, respectively. On average 1.6 procedures (range: 1–4) were required to rid patients of symptomatic stones, which subsequently afforded them a mean of 3.62 years (range: 0.25–21.5) without the need of additional intervention. There were 6 Clavien grade ≥ III complications in 4 patients, including immediate postoperative ESRD in 3. Conclusions Despite optimal medical and surgical management, patients experience recurrent acute stone events requiring multiple urologic interventions. Significant complications such as ESRD can occur secondary to surgical intervention. PMID:25733260

  17. John's Stone: A possible fragment of the 1908 Tunguska meteorite

    NASA Astrophysics Data System (ADS)

    Anfinogenov, John; Budaeva, Larisa; Kuznetsov, Dmitry; Anfinogenova, Yana

    2014-11-01

    The aim of this study was to discover remnants of the 1908 Tunguska meteorite. Field studies identified exotic rocks, furrows, and penetration funnels reported by the first eyewitnesses. Main methods included decoding of aerial survey photographs, systematic survey of epicenter area of the Tunguska explosion, exploratory excavations, reconstruction studies of the exotic rocks, mineralogical and spectral analysis of specimens, and experimental attempt of plasma-induced reproduction of fusion crust. The authors report the discovery of funnel-like structures and of an exotic boulder known as John's Stone (JS) in the epicentral area. The article provides detailed description of JS, fresh furrows in the permafrost, multiple shear-fractured splinters, splinters with glassy coatings, evidence of high-speed impact of JS in the ground, and clear consistency in the geometry of spacial arrangements of all splinters, furrows, and cleaved pebbles. Pattern of permafrost destruction suggested about high-speed entry and lateral ricochet of JS in the ground with further deceleration and breakage. Calculated landing velocity of JS was at least 547 m/s. John's Stone is composed of highly silicified gravelite sandstone (98.5% SiO2) with grain size of 0.5-1.5 cm. Outer surface of several splinters showed continuous glassy coating similar to shiny fusion crust reminiscent of freshly applied enamel. Plasma-induced heating of John's Stone specimen led to its explosive disintegration; residue presented with light-colored semi-transparent pumice-like grains and irregularly shaped fused particles. Overall, our data suggest that John's Stone may be a fragment of the 1908 Tunguska meteorite and may represent a new type of meteorite.

  18. Pattern of ocular injuries in stone pelters in Kashmir valley☆

    PubMed Central

    Khan, Shabana; Maqbool, Akifa; Abdullah, Nowsheen; Keng, Manzoor Q.

    2012-01-01

    Purpose To describe the pattern and types of ocular injuries in stone pelters in Kashmir valley during recent turmoil. Design Cross sectional study. Methods Sixty patients with different types of eye injuries were assessed between June–September 2010 and initial visual acuity was recorded. The injuries were classified according to Systems for Classifying Ocular Injuries (OTCS) and Ocular Trauma Score (OTS) was calculated in order to estimate the probability of follow-up visual acuity range. Results Most of the victims (75%) were young boys between 16–26 years with a mean age of 20.95, 95% of cases were males. The main cause of injury was stones (48.3%) and pellets (30%) besides rubber bullets, sling shots and tear gas shells. Most of the open-globe injuries due to stones were of Type B and A, Grade E, Zone II and III with Afferent Pupillary Defect (APD) in 30% of the cases. Closed-globe injuries were mostly of Type A, Grade C and D and Zone II and III. Most of the open-globe injuries due to pellets were of Type D, Grade D, Zone II and APD in 33.3%. Pellets Intra Ocular Foreign Body (IOFB) was in 41.6%. Most of the closed-globe injuries were of Type A, Grade D and E and of Zone III. Overall OTS of 1 was calculated in 16.6% and 3 in 53.3% of the cases. Conclusion In stone pelting demonstrations eye injuries can result in visually significant trauma. Injuries due to pellets are mostly perforating and pellet IOFB, and both tend to have a very poor prognosis. OTS can be used to estimate visual prognosis. PMID:23961014

  19. High-speed photography during laser-based gall bladder stone lithotripsy

    NASA Astrophysics Data System (ADS)

    Kokaj, Jahja O.

    2001-04-01

    Shadowgraphy of gall bladder stone, which is held by a basket and immersed in a civete is performed. The exposure time is determined by the time of a N-Dye laser pulse used as a lightening source for photography. The shadowgram is projected in the objective of a camera which is connected to a microscope. The light coming from the laser, illuminates the civete collecting optical information of the stone and physical phenomena appearing above the stone. On top of the stone a tip of optical fiber is fixed, which is used for transmitting Ho:Yag laser power to the stone. Using a computer and time delay the laser pulses used for destruction and illumination are synchronized. Since the N-Dye laser pulse is pico-second range and the Ho:Yag laser pulse is in the range of micro-second, many image frames are obtained within the time of one pulse applied during the destruction. It is known that in the process of stone destruction several phenomena like plume, plasma, shock wave and bubble formation take place. However, the physical mechanism of the stone destruction is not yet completely understood. From the obtained results the above phenomena are studied which gives new information and clue for understanding some of the mentioned phenomena. The laser power which is guided by an optical fiber into the gall bladder or kidney of the human body can damage the living tissue and cause some serious health problems. For this reason the fiber needs to be oriented properly during the action of the laser power.

  20. Novel method for Ag colloidal cluster formation by laser ablation at the air-liquid interface

    NASA Astrophysics Data System (ADS)

    Nishi, Teppei; Akimoto, Yusuke; Takahashi, Naoko; Kitazumi, Kosuke; Kajiya, Shuji; Watanabe, Yoshihide

    2015-09-01

    We report a novel method for formation of sub-nanoclusters by laser ablation at the air-liquid interface. The density of plasma induced by laser ablation at the air-liquid interface should be lower than that produced by laser ablation in liquid. In the lower density plasma, the produced clusters rarely grow or aggregate into larger clusters because the collision probability is low, resulting in the formation of small clusters. Ag sub-nanoclusters were observed by electrospray ionization mass spectrometry (ESI-MS) and X-ray photoelectron spectroscopy (XPS). These results show that low-density plasma can be applied to small-cluster formation and that laser ablation at the air-liquid interface produces a good reactive field for the formation of sub-nanoclusters. Our results highlight the importance of low-density plasma induced at the air-liquid interface for sub-nanocluster formation.

  1. A Simple Method for the Consecutive Determination of Protonation Constants through Evaluation of Formation Curves

    ERIC Educational Resources Information Center

    Hurek, Jozef; Nackiewicz, Joanna

    2013-01-01

    A simple method is presented for the consecutive determination of protonation constants of polyprotic acids based on their formation curves. The procedure is based on generally known equations that describe dissociation equilibria. It has been demonstrated through simulation that the values obtained through the proposed method are sufficiently…

  2. METHOD OF SUPPRESSING UAl$sub 4$ FORMATION IN U-Al ALLOYS

    DOEpatents

    Picklesimer, M.L.; Thurber, W.C.

    1960-08-23

    A method is given for suppressing the formation of UAl/sub 4/ in uranium- - aluminum alloys, thereby rendering these alloys more easily workable. The method comprises incorporating in the base alloy a Group Four element selected from the group consisting of Si, Ti, Ge, Zr, and Sn, the addition preferably being within the range of 0.5to20at.%.

  3. An Extension of Four IRT Linking Methods for Mixed-Format Tests

    ERIC Educational Resources Information Center

    Kim, Seonghoon; Lee, Won-Chan

    2006-01-01

    Under item response theory (IRT), linking proficiency scales from separate calibrations of multiple forms of a test to achieve a common scale is required in many applications. Four IRT linking methods including the mean/mean, mean/sigma, Haebara, and Stocking-Lord methods have been presented for use with single-format tests. This study extends the…

  4. Managing Small Ureteral Stones: A Retrospective Study on Follow-Up, Clinical Outcomes and Cost-Effectiveness of Conservative Management vs. Early Surgery

    PubMed Central

    Alevizopoulos, Aristeidis; Zosimas, Dimitrios; Piha, Lamprini; Hanna, Milad; Charitopoulos, Konstantinos

    2016-01-01

    Introduction The management of ureteral calculi has evolved over the past decades with the advent of new surgical and medical treatments. The current guidelines support conservative management as a possible approach for ureteral stones sized = 10 mm. Objectives We purport to follow the natural history of ureteral stones managed conservatively in this retrospective study, and attempt to ascribe an estimated health-care and cost-effectiveness, from presentation to time of being stone-free. Materials and methods 192 male and female patients with a single ureteral stone sized = 10 mm were included in this study. The clinical and cost-related outcome was analyzed for different stone sizes (0-4, 4-6 and 6-10 mm). The effectiveness of selected follow-up (FU) scans was also analyzed. Results Stone size was found to be related to the degree of hydronephrosis and to the likelihood of need for a surgical management. Conservative management was found to be clinically effective, as 88% of the patients did not require surgery for their stone. 96.1% of the patients with a stone 0-4mm managed to expel their ureteral stone. Bigger ureteral stones were found to be more costly. The cost-effectiveness of the single FU scans was found to be related to their efficiency, while the global cost-effectiveness of conservative management vs. early surgery was higher for smaller stones (26.8 vs. 17.32% for stones 0-4 vs. 6-10 mm). Conclusion Conservative management is clinically effective with a significant cost-benefit, particularly for the subgroup of stones sized 0-4 mm, where a need for FU scans is in dispute. PMID:26989370

  5. The effect of climate variability on urinary stone attacks: increased incidence associated with temperature over 18 °C: a population-based study.

    PubMed

    Park, Hyoung Keun; Bae, Sang Rak; Kim, Satbyul E; Choi, Woo Suk; Paick, Sung Hyun; Ho, Kim; Kim, Hyeong Gon; Lho, Yong Soo

    2015-02-01

    The aim of this study was to evaluate the effect of seasonal variation and climate parameters on urinary tract stone attack and investigate whether stone attack is increased sharply at a specific point. Nationwide data of total urinary tract stone attack numbers per month between January 2006 and December 2010 were obtained from the Korean Health Insurance Review and Assessment Service. The effects of climatic factors on monthly urinary stone attack were assessed using auto-regressive integrated moving average (ARIMA) regression method. A total of 1,702,913 stone attack cases were identified. Mean monthly and monthly average daily urinary stone attack cases were 28,382 ± 2,760 and 933 ± 85, respectively. The stone attack showed seasonal trends of sharp incline in June, a peak plateau from July to September, and a sharp decline after September. The correlation analysis showed that ambient temperature (r = 0.557, p < 0.001) and relative humidity (r = 0.513, p < 0.001) were significantly associated with urinary stone attack cases. However, after adjustment for trends and seasonality, ambient temperature was the only climate factor associated with the stone attack cases in ARIMA regression test (p = 0.04). Threshold temperature was estimated as 18.4 °C. Risk of urinary stone attack significantly increases 1.71% (1.02-2.41 %, 95% confidence intervals) with a 1 °C increase of ambient temperature above the threshold point. In conclusion, monthly urinary stone attack cases were changed according to seasonal variation. Among the climates variables, only temperature had consistent association with stone attack and when the temperature is over 18.4 °C, urinary stone attack would be increased sharply. PMID:25407800

  6. Experimental models of renal calcium stones in rodents

    PubMed Central

    Bilbault, Héloïse; Haymann, Jean-Philippe

    2016-01-01

    In human nephrolithiasis, most stones are containing calcium and are located within urinary cavities; they may contain monohydrate calcium oxalate, dihydrate calcium oxalate and/or calcium phosphates in various proportion. Nephrolithiasis may also be associated with nephrocalcinosis, i.e., crystal depositions in tubular lumen and/or interstitium, an entity which suggests specific pathological processes. Several rodents models have been developed in order to study the pathophysiology of intrarenal crystal formation. We review here calcium rodent models classified upon the presence of nephrolithiasis and/or nephrocalcinosis. As rodents are not prone to nephrolithiasis, models require the induction of a long standing hypercalciuria or hyperoxaluria (thus explaining the very few studies reported), conversely to nephrocalcinosis which may occur within hours or days. Whereas a nephrotoxicity leading to tubular injury and regeneration appears as a critical event for crystal retention in nephrocalcinosis models, surprisingly very little is known about the physiopathology of crystal attachment to urothelium in nephrolithiasis. Creating new models of nephrolithiasis especially in different genetic mice strains appears an important challenge in order to unravel the early mechanisms of urinary stone formation in papilla and fornices. PMID:26981444

  7. Experimental models of renal calcium stones in rodents.

    PubMed

    Bilbault, Héloïse; Haymann, Jean-Philippe

    2016-03-01

    In human nephrolithiasis, most stones are containing calcium and are located within urinary cavities; they may contain monohydrate calcium oxalate, dihydrate calcium oxalate and/or calcium phosphates in various proportion. Nephrolithiasis may also be associated with nephrocalcinosis, i.e., crystal depositions in tubular lumen and/or interstitium, an entity which suggests specific pathological processes. Several rodents models have been developed in order to study the pathophysiology of intrarenal crystal formation. We review here calcium rodent models classified upon the presence of nephrolithiasis and/or nephrocalcinosis. As rodents are not prone to nephrolithiasis, models require the induction of a long standing hypercalciuria or hyperoxaluria (thus explaining the very few studies reported), conversely to nephrocalcinosis which may occur within hours or days. Whereas a nephrotoxicity leading to tubular injury and regeneration appears as a critical event for crystal retention in nephrocalcinosis models, surprisingly very little is known about the physiopathology of crystal attachment to urothelium in nephrolithiasis. Creating new models of nephrolithiasis especially in different genetic mice strains appears an important challenge in order to unravel the early mechanisms of urinary stone formation in papilla and fornices. PMID:26981444

  8. Percutaneous management of renal caliceal diverticular stones: Ten-year experience of a tertiary care center with different techniques to deal with diverticula after stone extraction

    PubMed Central

    Srivastava, Aneesh; Chipde, Saurabh Sudhir; Mandhani, Anil; Kapoor, Rakesh; Ansari, Mohammad S.

    2013-01-01

    Introduction: Caliceal diverticulae are a frequent surgical problem. We present our experience with caliceal diverticular stones (CDS) managed with percutaneous nephrolithotomy (PCNL) and describe the two different techniques to deal with diverticula after stone retrieval. Materials and Methods: We retrospectively analyzed 10-year data of 44 consecutive patients who underwent PCNL for CDS. During PCNL, if the guide wire could be negoted through the neck of the diverticula, we dilated and stented it. If we couldnot find the neck, we fulgurated the diverticular walls. Follow-up included intravenous urogram at 3 months and annual plain films thereafter. We analyzed the outcome, complications, and recurrence rate. Results: Total stone clearance was obtained in 40 (90.90%) patients. We dilated and stented the diverticula in 35 (79.5%) patients and fulgurated the walls in nine (20.5%) patients. Complications occurred in three patients. The postoperative intravenous urogram showed obliteration of diverticula in seven patients and the improved drainage in 37 patients. At the average follow-up of 2 years, 41 (93.18%) patients were asymptomatic and two (4.5%) patients showed the recurrence of stone. Conclusions: PCNL can clear calculi from caliceal diverticula in most cases with minimal morbidity. After stone retrieval, the diverticula may be drained into the pyelocaliceal system, if the neck is negotiable and fulgurated if the neck cannot be dilated. PMID:24235786

  9. "Sydney sandstone": Heritage Stone from Australia

    NASA Astrophysics Data System (ADS)

    Cooper, Barry; Kramar, Sabina

    2014-05-01

    Sydney is Australia's oldest city being founded in 1788. The city was fortunate to be established on an extensive and a relatively undeformed layer of lithified quartz sandstone of Triassic age that has proved to be an ideal building stone. The stone has been long identified by geologists as the Hawkesbury Sandstone. On the other hand the term "Sydney sandstone" has also been widely used over a long period, even to the extent of being utilised as the title of published books, so its formal designation as a heritage stone will immediately formalise this term. The oldest international usage is believed to be its use in the construction of the Stone Store at Kerikeri, New Zealand (1832-1836). In the late 19th century, public buildings such as hospitals, court houses as well as the prominent Sydney Town Hall, Sydney General Post Office, Art Gallery of New South Wales, State Library of New South Wales as well as numerous schools, churches, office building buildings, University, hotels, houses, retaining walls were all constructed using Sydney sandstone. Innumerable sculptures utilising the gold-coloured stone also embellished the city ranging from decorative friezes and capitals on building to significant monuments. Also in the late 19th and early 20th century, Sydney sandstone was used for major construction in most other major Australian cities especially Melbourne, Adelaide and Brisbane to the extent that complaints were expressed that suitable local stone materials were being neglected. Quarrying of Sydney sandstone continues today. In 2000 it was recorded noted that there were 33 significant operating Sydney sandstone quarries including aggregate and dimension stone operations. In addition sandstone continues to be sourced today from construction sites across the city area. Today major dimension stone producers (eg Gosford Quarries) sell Sydney sandstone not only into the Sydney market but also on national and international markets as cladding and paving products as well as block. Recent international projects by Gosford Quarries include Mishima Golf Club in Japan, Al Awadi Tower in Kuwait, New World Resort in China and a Hard Rock Café in Florida, USA. Arguably Sydney sandstone is Australia's most prominent potential Global Heritage Stone Resource and details are readily available in existing publications to make the nomination.

  10. Discerning total salt contents and surface humidity on building stone with a portable moisture meter (Protimeter) in the region of Petra (Jordan)

    NASA Astrophysics Data System (ADS)

    Gomez-Heras, M.; Wedekind, W.; Lopez-Arce, P.

    2012-04-01

    Water and moisture are some of the main decay agents of building stone and, in general of any stone structure. Several non-invasive methods are used to quantify moisture in building stone, many of them based on the fact that moist stone presents different electrical properties than dry stone. This is the case of resistance-based sensing equipment, such as "Protimeter" portable moisture meters. Although originally designed to measure moisture contents in wood, this sensing equipment is commonly used to measure the so-called "Wood Moisture Equivalent" (WME) in other building materials, such stone and mortar. However, this type of resistance-based sensors pose a degree of uncertainty, as there are other factors that modify electrical properties, such as porosity and salt content. When assessing the overall state of decay of a structure, it might not be crucial, in some cases, to discern between salt and water content: both high moisture levels and high salt content give high WME values, and both are usually related to areas with overall poor state of conservation and/or more prone to decay. However, discerning these two factors is crucial when trying to understand the dynamics of how some decay patterns are formed. This is the case of surface runoff in vertical façades and how it leads to the formation of alveoli and tafoni through salt weathering. Surface runoff and associated salt weathering are among the main decay processes found at the archaeological site of Petra (Jordan) and its understanding is of paramount importance for the conservation of this site. Some "Protimeter" sensors include a capacitance sensor in addition to the usual resistance sensing pins, which allows to measure sub-surface electrical properties. This paper presents results on how the combination of these two measurement modes could be used to discern if high WME values are caused by high surface humidity or by high salt contents in the context of Surface runoff and associated salt weathering. Research funded by AECID (PCI A/032184/10)

  11. Medical and dietary therapy for kidney stone prevention.

    PubMed

    Gul, Zeynep; Monga, Manoj

    2014-12-01

    The prevalence of kidney stone disease is increasing, and newer research is finding that stones are associated with several serious morbidities. These facts suggest that emphasis needs to be placed not only on stone treatment but also stone prevention. However, there is a relative dearth of information on dietary and medical therapies to treat and avoid nephrolithiasis. In addition, studies have shown that there are many misconceptions among both the general community and physicians about how stones should be managed. This article is meant to serve as a review of the current literature on dietary and drug therapies for stone prevention. PMID:25512810

  12. Medical and Dietary Therapy for Kidney Stone Prevention

    PubMed Central

    Gul, Zeynep

    2014-01-01

    The prevalence of kidney stone disease is increasing, and newer research is finding that stones are associated with several serious morbidities. These facts suggest that emphasis needs to be placed not only on stone treatment but also stone prevention. However, there is a relative dearth of information on dietary and medical therapies to treat and avoid nephrolithiasis. In addition, studies have shown that there are many misconceptions among both the general community and physicians about how stones should be managed. This article is meant to serve as a review of the current literature on dietary and drug therapies for stone prevention. PMID:25512810

  13. Retrograde upper-pole calyceal access for percutaneous nephrolithotripsy of stones in the lower-pole calyx

    PubMed Central

    Al-Otaibi, Khalid M.

    2012-01-01

    Objective To present the results of upper calyceal access during percutaneous nephrolithotripsy (PCNL) for stones in the lower calyx, as PCNL is considered the most effective minimally invasive surgery for managing lower calyceal stones, with percutaneous access either directly to the lower calyx or through an upper or middle calyx. Patients and methods The study included 76 patients with single (51) and multiple (25) stones in the lower calyx, and stones in the lower calyx plus renal pelvis (six) and associated pelvi-ureteric junction obstruction (PUJO, five). They were managed by PCNL using retrograde access through the upper-pole calyx in addition to laser endopyelotomy for the PUJO. Results The mean duration required for establishing the retrograde nephrostomy tract was 14.4 min, and for completing the procedure was 40 min. The mean fluoroscopy exposure time was 3.2 min. Access from the upper calyx allowed easy and rapid advancement of the nephroscope to the lower calyx. The stones varied in size, at 10–25 mm. Stones were cleared completely in 70 of the 76 patients (92%); the stone-free rate was 100%. The residual stone fragments (2–4 mm) in the remaining six patients (8%) were considered insignificant. Complications were minor in four patients (5%), and included pleural effusion in two, bleeding in one and an arteriovenous fistula in one. Conclusions Upper-pole calyceal access for PCNL provides easy and effective clearance of stones in the lower calyx. This access should be considered for PCNL of single or multiple stones in the lower calyx. PMID:26558049

  14. Cumulative Sum Analysis for Experiences of a Single-Session Retrograde Intrarenal Stone Surgery and Analysis of Predictors for Stone-Free Status

    PubMed Central

    Cho, Sung Yong; Choo, Min Soo; Jung, Jae Hyun; Jeong, Chang Wook; Oh, Sohee; Lee, Seung Bae; Son, Hwancheol; Jeong, Hyeon

    2014-01-01

    Introduction This study investigated the learning curve of a single-session retrograde intrarenal surgery (RIRS) in patients with mid-sized stones. Competence and trainee proficiency for RIRS was assessed using cumulative sum analysis (CUSUM). Materials and Methods The study design and the use of patients' information stored in the hospital database were approved by the Institutional