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Sample records for stone formation methods

  1. Simplified methods for the evaluation of the risk of forming renal stones and the follow-up of stone-forming propensity during the preventive treatment of stone-formation.

    PubMed

    Grases, Flix; Costa-Bauz, Antonia

    2016-02-01

    Renal lithiasis is a complex multifactorial disease in which recurrence is common. Thus, simple and reliable procedures are needed to evaluate patients with previous kidney stones to determine the risk of recurrence. In this paper we review simple biochemical procedures that can be used to determine the risk for renal stone formation when the stone is available or unavailable for analysis. Our present knowledge of renal lithiasis indicates that renal stones form due to several well-defined factors. Analysis of the renal stone itself can provide important information about clinical factors that require further investigation. When the stone is unavailable, it is necessary to perform a general evaluation of main urinary risk factors associated to renal stone formation, but this study should be complemented considering information related to direct familial antecedents, recidivant degree, radiological images, medical history, and life style habits. Finally, tools for patient follow-up of stone-forming propensity during the preventive treatment are discussed . PMID:26614111

  2. 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

  3. 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.

  4. 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

  5. Determinants of Brushite Stone Formation: A Case-Control Study

    PubMed Central

    Siener, Roswitha; Netzer, Linda; Hesse, Albrecht

    2013-01-01

    Purpose The occurrence of brushite stones has increased during recent years. However, the pathogenic factors driving the development of brushite stones remain unclear. Methods Twenty-eight brushite stone formers and 28 age-, sex- and BMI-matched healthy individuals were enrolled in this case-control study. Anthropometric, clinical, 24 h urinary parameters and dietary intake from 7-day weighed food records were assessed. Results Pure brushite stones were present in 46% of patients, while calcium oxalate was the major secondary stone component. Urinary pH and oxalate excretion were significantly higher, whereas urinary citrate was lower in patients as compared to healthy controls. Despite lower dietary intake, urinary calcium excretion was significantly higher in brushite stone patients. Binary logistic regression analysis revealed pH>6.50 (OR 7.296; p?=?0.035), calcium>6.40 mmol/24 h (OR 25.213; p?=?0.001) and citrate excretion <2.600 mmol/24 h (OR 15.352; p?=?0.005) as urinary risk factors for brushite stone formation. A total of 56% of patients exhibited distal renal tubular acidosis (dRTA). Urinary pH, calcium and citrate excretion did not significantly differ between patients with or without dRTA. Conclusions Hypercalciuria, a diminished citrate excretion and an elevated pH turned out to be the major urinary determinants of brushite stone formation. Interestingly, urinary phosphate was not associated with urolithiasis. The increased urinary oxalate excretion, possibly due to decreased calcium intake, promotes the risk of mixed stone formation with calcium oxalate. Neither dietary factors nor dRTA can account as cause for hypercalciuria, higher urinary pH and diminished citrate excretion. Further research is needed to define the role of dRTA in brushite stone formation and to evaluate the hypothesis of an acquired acidification defect. PMID:24265740

  6. 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

  7. 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.

  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. Proteome of melamine urinary bladder stones and implication for stone formation.

    PubMed

    Liu, Jian-dong; Liu, Jian-jun; Yuan, Jian-hui; Tao, Gong-hua; Wu, De-sheng; Yang, Xi-fei; Yang, Lin-qing; Huang, Hai-yan; Zhou, Li; Xu, Xin-yun; Hu, Jun-jie; Zhuang, Zhi-xiong

    2012-08-01

    Melamine can cause urinary stones related to nephropathy of the kidney and hyperplasia or carcinoma of the bladder, but the mechanism of stone formation is not well understood. In this study, male rats were administered melamine for thirteen weeks to establish melamine bladder stone models and the stones were analysed by Fourier transform infrared (FTIR) spectroscopy, powder X-ray diffraction (XRD), energy dispersive X-ray (EDX) spectroscopy, sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE), liquid chromatography/mass spectrometry/mass spectrometry (LC-MS/MS) and western blot, respectively, for the composition and proteome, and to explore the implication of proteins for stone formation. The results showed bladder stones were composed of predominant melamine and a few amount of proteins. The proteins had a wide range of molecular weights and 1051 proteins were identified. Gene Ontology (GO) classification of the identified proteins showed most proteins were from injured cells, involved in various metabolic processes and had binding functions. Of the identified proteins, there were a few inflammatory proteins and urinary proteins. Physicochemical characteristics of the identified proteins showed that 67.1% proteins' isoelectric points (pI) value was below 7.0, 91.1% proteins' grand average of hydropathicity (GRAVY) scores were below 0 and nearly half of the proteins were stable. Our data indicated proteins might play an important role in melamine bladder stone formation. PMID:22688180

  10. Triamterene and renal stone formation: the influence of triamterene and triamterene stones on calcium oxalate crystallization.

    PubMed

    White, D J; Nancollas, G H

    1987-02-01

    A constant composition method has been used to compare the effects of triamterene renal stone material, synthetic triamterene precipitates, and soluble triamterene on the nucleation and crystallization kinetics of calcium oxalate in aqueous solution in vitro. Crystallization studies have been carried out with the concentrations of calcium and oxalate ions maintained constant by the potentiometrically controlled addition of concentrated reagent solutions containing these ions. Triamterene renal stones were found to be much less effective than synthetic triamterene towards promoting the nucleation and crystallization of calcium oxalate from supersaturated solution. Renal stones composed of triamterene and matrix did not significantly enhance the deposition of calcium oxalate compared to nonseeded controls. The triamterene stones were also found to be ineffective in promoting calcium oxalate crystallization compared to other precipitates thought to be involved in the etiology of stone disease such as calcium hydroxyapatite. For stones of mixed triamterene/calcium oxalate composition, the enhancement of the nucleation and crystallization of calcium oxalate was directly related to the calcium oxalate content of the stone seed material. The presence of soluble triamterene or its metabolites in solution did not influence the crystallization kinetics of pure calcium oxalate seed materials. The results of this study indicate that triamterene in stones does not significantly contribute to further stone development through the enhancement of calcium oxalate crystallization processes. PMID:3105837

  11. 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.

  12. 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.

  13. The role of Randall plaques on kidney stone formation

    PubMed Central

    2014-01-01

    Randalls plaque is microscopically a plaque of calcium deposited in the interstitial tissue of the renal papilla. These plaques are thought to serve as a nidus for urinary stone formation. Large amounts of Randalls plaque are unique to idiopathic calcium oxalate stone formers. Although Randalls plaques can be found in other stone formers, only in idiopathic calcium oxalate stone formers, the detailed mechanism of stone overgrow on plaque was thoroughly studied. Calcification is invariably located in the basement membrane of the loops of Henle and from there plaques spread through the interstitium toward urothelium. Within the basement membrane, mineral deposits are individual laminated particles in which zones of crystal and organic matrix overlay each other. In the interstitium, the particles appear to fuse on the collagen bundles to form a syncytium of crystal islands in an organic sea. By loss of integrity of urothelium, regions of plaque are exposed to urine. The exposed surface will touch and be covered by molecules of urine origin, including osteopontin, Tamm Horsfall protein, and crystals formed under urine supersaturations, resulting in a ribbon of alternating matrix and crystal. Eventually crystallization escapes from matrix modulation and crystals extend outward into the space of urine and begin to form a calcium oxalate stone proper. Randalls plaque plays an important role and is prerequisite of kidney stone formation in idiopathic calcium oxalate stone formers. PMID:26816774

  14. 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.

  15. 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.

  16. Molecular mechanisms of pancreatic stone formation in chronic pancreatitis.

    PubMed

    Ko, Shigeru B H; Azuma, Sakiko; Yoshikawa, Toshiyuki; Yamamoto, Akiko; Kyokane, Kazuhiro; Ko, Minoru S H; Ishiguro, Hiroshi

    2012-01-01

    Chronic pancreatitis (CP) is a progressive inflammatory disease in which the pancreatic secretory parenchyma is destroyed and replaced by fibrosis. The presence of intraductal pancreatic stone(s) is important for the diagnosis of CP; however, the precise molecular mechanisms of pancreatic stone formation in CP were left largely unknown. Cystic fibrosis transmembrane conductance regulator (CFTR) is a chloride channel expressed in the apical plasma membrane of pancreatic duct cells and plays a central role in [Formula: see text] secretion. In previous studies, we have found that CFTR is largely mislocalized to the cytoplasm of pancreatic duct cells in all forms of CP and corticosteroids normalizes the localization of CFTR to the proper apical membrane at least in autoimmune pancreatitis. From these observations, we could conclude that the mislocalization of CFTR is a cause of protein plug formation in CP, subsequently resulting in pancreatic stone formation. Considering our observation that the mislocalization of CFTR also occurs in alcoholic or idiopathic CP, it is very likely that these pathological conditions can also be treated by corticosteroids, thereby preventing pancreatic stone formation in these patients. Further studies are definitely required to clarify these fundamental issues. PMID:23133422

  17. 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

  18. 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

  19. 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

  20. Constraining the age and formation of stone runs in the Falkland Islands using Optically Stimulated Luminescence

    NASA Astrophysics Data System (ADS)

    Hansom, James D.; Evans, David J. A.; Sanderson, David C. W.; Bingham, Robert G.; Bentley, Michael J.

    2008-02-01

    The stone runs of the Falkland Islands are thought to be periglacial blockfields but their age and detailed origin remain enigmatic. We examine the fine sediments that underlie two stone runs in order to establish whether Optically Stimulated Luminescence (OSL) dating is an appropriate technique to constrain the date of emplacement of the fine sediments and, hence, the stone runs. Six samples were collected from two accessible sections during the Scotia Centenary Antarctic expedition in 2003. All samples were used to explore the main luminescence characteristics of the sediment, followed by quartz SAR dating procedures on four of the samples. Age estimates range from in excess of 54 ka to 16 ka, suggesting that the overlying stone runs remained active until 16 ka or later. Saturation of luminescence from quartz limits age estimates for the oldest samples in the sequences, however these are not critical to define the upper limit to the emplacement age for the overlying stone runs. The sediments also contain feldspars and initial results suggest that these may be useful in extending the timescale further, but require further samples to be obtained from other parts of the sequence. Extending the method to other stone runs in the Port Stanley Formation may allow estimates of the age of stabilisation of the stone runs to be extended into the 1-250 ka timescale. Luminescence dating of the underlying sediments, used in conjunction with cosmogenic isotope dating of the surface boulders from a range of locations along the stone runs, appears to offer a useful route towards decoding the depositional history of these impressive deposits.

  1. Potential etiologic role of brushite in the formation of calcium (renal) stones

    NASA Astrophysics Data System (ADS)

    Pak, Charles Y. C.

    1981-05-01

    Brushite may play an important regulatory role in the formation of calcium -containing renal stones. The urinary environment from patients with hypercalciuric nephrolithiasis is typically supersaturated and shows an increased propensity for the spontaneous nucleation of brushite. Brushite has been identified in "stone-forming" urine and in stones. This crystalline phase may undergo phase transformation to hydroxyapatite or cause heterogeneous nucleation or epitaxial growth of calcium oxalate. Thus, brushite may also participate in the formation of stones of hydroxypatite or calcium oxalate.

  2. 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

  3. [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

  4. 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.

  5. 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.

  6. 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.

  7. 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

  8. Dual roles of brushite crystals in calcium oxalate crystallization provide physicochemical mechanisms underlying renal stone formation.

    PubMed

    Tang, R; Nancollas, G H; Giocondi, J L; Hoyer, J R; Orme, C A

    2006-07-01

    Calcium oxalate monohydrate (COM) crystals are the major mineral component of most kidney stones, and thus have an important role in chronic human disease. However, the physicochemical mechanisms leading to calcium oxalate (CaOx) stone disease are only partially defined. As spontaneous precipitation of CaOx is rare under renal conditions, an alternative pathway for CaOx crystallization seems necessary to resolve this central issue. We performed kinetic studies using the dual constant composition method to simultaneously analyze the crystallization of COM and brushite, the form of calcium phosphate that is most readily formed in the typical slightly acidic urinary milieu. These studies were supported by parallel analysis by scanning electron and atomic force microscopy. In these studies, mineralization of a thermodynamically stable phase (COM) was induced by the presence of brushite, a more readily precipitated inorganic phase. Furthermore, once formed, the COM crystals grew at the expense of brushite crystals causing the dissolution of the brushite crystals. These studies show that brushite may play crucial roles in the formation of COM crystals. The definition of these two roles for brushite thereby provides physicochemical explanations for the initiation of COM crystallization and also for the relative paucity of calcium phosphate detected in the majority of CaOx renal stones. PMID:16641926

  9. 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.

  10. 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

  11. 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.

  12. The Systematic Classification of Gallbladder Stones

    PubMed Central

    Qiao, Tie; Ma, Rui-hong; Luo, Xiao-bing; Yang, Liu-qing; Luo, Zhen-liang; Zheng, Pei-ming

    2013-01-01

    Background To develop a method for systematic classification of gallbladder stones, analyze the clinical characteristics of each type of stone and provide a theoretical basis for the study of the formation mechanism of different types of gallbladder stones. Methodology A total of 807 consecutive patients with gallbladder stones were enrolled and their gallstones were studied. The material composition of gallbladder stones was analyzed using Fourier Transform Infrared spectroscopy and the distribution and microstructure of material components was observed with Scanning Electron Microscopy. The composition and distribution of elements were analyzed by an X-ray energy spectrometer. Gallbladder stones were classified accordingly, and then, gender, age, medical history and BMI of patients with each type of stone were analyzed. Principal Findings Gallbladder stones were classified into 8 types and more than ten subtypes, including cholesterol stones (297), pigment stones (217), calcium carbonate stones (139), phosphate stones (12), calcium stearate stones (9), protein stones (3), cystine stones (1) and mixed stones (129). Mixed stones were those stones with two or more than two kinds of material components and the content of each component was similar. A total of 11 subtypes of mixed stones were found in this study. Patients with cholesterol stones were mainly female between the ages of 30 and 50, with higher BMI and shorter medical history than patients with pigment stones (P<0.05), however, patients with pigment, calcium carbonate, phosphate stones were mainly male between the ages of 40 and 60. Conclusion The systematic classification of gallbladder stones indicates that different types of stones have different characteristics in terms of the microstructure, elemental composition and distribution, providing an important basis for the mechanistic study of gallbladder stones. PMID:24124459

  13. 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

  14. The preventive effect of sodium pentosan polysulfate against renal stone formation in hyperoxaluric rats.

    PubMed

    Nakatani, Tatsuya; Ishii, Keiichi; Yoneda, Yukio; Kamikawa, Sadanori; Kanazawa, Toshinao; Sugimoto, Toshikado; Osswald, Hartmut

    2002-10-01

    Sodium pentosan polysulfate (SPP), a semi-synthetic glycosaminoglycan, was administered to rats with hyperoxaluria, induced by a vitamin B6 deficient diet, as a model of calcium oxalate stone formation. We studied the preventive effects of SPP on stone formation as well as its inhibitory effects on stone growth by autoradiography and radioluminography after intravenous injection of (14)C-oxalate. The rats were divided into non-treated and SPP-treated groups. The non-treated rats were divided into three groups: one group was fed a regular diet, while the other two groups were fed a vitamin B6 deficient diet for 2 and 4 weeks, respectively. The SPP-treated rats were divided into two groups: one group was intravenously injected with SPP from the start of the vitamin B6 deficient diet for a total of 4 weeks and the other group was injected with the same amount of SPP after 2 weeks of the diet for 2 weeks. (14)C-oxalate renal macroautoradiograms were prepared, and calcium oxalate deposits in the renal tissues were compared between the non-treated and SPP-treated groups. The preventive effects on calcium oxalate stone formation were clearly observed in the group injected with SPP for 4 weeks. Even in the other SPP-treated group, in which the administration of SPP was started at 2 weeks after the start of the diet when calcium oxalate stone formation was already observed, the size of the calcium oxalate deposits observed after 4 weeks was smaller than that in the non-treated group fed a vitamin B6 deficient diet for 4 weeks. In conclusion, our results show that SPP has not only preventive effects on calcium oxalate stone formation but also growth inhibitory effects on stones in hyperoxaluric rats. PMID:12389123

  15. 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

  16. X-ray microanalysis of urinary stones, a comparison with other methods

    SciTech Connect

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

    1985-01-01

    A previous study of urinary stones by a combined electron microscopy demonstrated the potential of scanning electron microscopy and X-ray analysis as an analytic tool for urinary stones. Electron diffraction was chosen for the final confirmation of crystals in the study. Although electron diffraction is highly accurate for this purpose, it is desirable to establish the sensitivity of X-ray analysis for the identification of stone components relative to the more commonly used methods. Eighty six consecutive urinary stones were analyzed by X-ray analysis and the findings were compared with those of X-ray diffraction, infrared spectrometry and chemical analysis. The results indicate that X-ray analysis exceeds X-ray diffraction and infrared spectroscopy in its sensitivity for the identification of stone components several fold. This was largely due to the inability of the latter methods to detect apatite in more than half of the apatite containing stones. The findings in X-ray analysis had the best correlation with chemical analysis, which was applied mainly to the detection of apatite. X-ray analysis is particularly suited for the detection of rare and minor inorganic components of urinary stones such as silica and gypsum, and is obviously one of the most powerful tools for the analysis of urinary stones. Further application of X-ray analysis to urinary stone is likely to discern rare inorganic components of urinary stones overlooked by other methods. 42 references.

  17. Does Potassium Citrate Medical Therapy Increase the Risk of Calcium Phosphate Stone Formation?

    NASA Astrophysics Data System (ADS)

    Leitao, Victor; Haleblian, George E.; Robinson, Marnie R.; Pierre, Sean A.; Sur, Roger L.; Preminger, Glenn M.

    2007-04-01

    Potassium citrate has been extensively used in the treatment of recurrent nephrolithiasis. Recent evidence suggests that it may contribute to increasing urinary pH and, as such, increase the risk of calcium phosphate stone formation. We performed a retrospective review of our patients to further investigate this phenomenon.

  18. EVALUATION OF HYDRODYNAMIC FORCE ON SOLIDLY CONNECTED NATURAL STONE AND PROPOSAL OF ITS DESIGN METHOD

    NASA Astrophysics Data System (ADS)

    Kaseguma, Kimiko; Maeno, Shiro; Tamagawa, Katsuya; Yamamura, Akira

    In recent years, it has become necessary to develop suitable methods for restoring natural rivers. The authors have examined more nature-friendly hydraulic structures made of connected natural stones. Although such structures are excellent in environmental aspects, design standards for such structures have not been established yet because the structures comprise natural stones with various shapes. Furthermore, the design flow velocity is not clarified when the proposed connected natural stones were used as a groin and other hydraulic structures. At present, 1.2-1.5 times large velocity of the representative mean velocity is used as the design velocity. Therefore, in this study, the hydrodynamic force for solidly connected natural stones, and the velocity field around such structures were examined experimentally. Experimental results clarified not only the hydraulic characteristics of the flow around the groin, but also the drag and lift coefficients of the connected stone. An efficient design method for the solidly connected stone was proposed.

  19. [Components of Urinary Nanocrystals and Their Influence on Formation of Calcium Oxalate Stones].

    PubMed

    Li, Yu-bao; Wen, Xiao-ling; Xue, Jun-fa; Ouyang, Jian-ming

    2015-08-01

    High-resolution transmission electron microscopy, X-ray diffraction, selected area electron diffraction (SAED), and energy dispersive spectroscopy (EDS) were accurately performed to analyze the components of nanocrystals in the urine of patients with calcium oxalate (CaOx) stones. XRD, SAED and FFT detected the presence of calcium oxalate monohydrate (COM), uric acid (UA), and calcium phosphate (CaP). EDS detected the elements of C, O, Ca, with a small amount of N and P. These results showed that the main components of urinary nanocrystals were COM, with a small amount UA and phosphate. HRTEM observation showed that the particle size of urinary nanocrystals was dozens of nanometers. The result was consistent with the calculation by Debye-Scherrer equation. When the urine was filtered through a microporous membrane of 0.45, 1.2, and 3 ?m, respectively, the number of diffraction peaks of the obtained urine crystallites increased with the increased pore size, indicating the increase of urinary crystallite species. Crystal nucleation, growth, aggregation, and adhesion of crystals to the renal epithelial cells are important processes for CaOx stone formation. The presence of a large amount of COM crystals in patients' urine is a critical factor for CaOx stones formation. Nano UA and CaP crystallite can induce the CaOx stone formation as central nidus. PMID:26672305

  20. 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

  1. 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.

  2. 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.

  3. 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.

  4. [Formation of organic acids by fungi isolated from the surface of stone monuments].

    PubMed

    Sazanova, K V; Shchiparev, S M; Vlasov, D Iu

    2014-01-01

    Capacity of the fungi isolated from the surface of stone monuments for acid formation was studied in cultures under various carbon sources and cultivation conditions. The composition of organic nutrients was adjusted according to the results of investigation of the surface layers from the monuments in urban environment. The primary soil formed at the surface of the stone monuments under urban conditions was shown to contain a variety of carbon and nitrogen sources and is a rich substrate for fungal growth. Oxalic acid was produced by fungi grown on media with various concentrations of sugars, sugar alcohols, and organic acids. Malic, citric, fumaric, and succinic acids were identified only at elevated carbohydrate concentrations, mostly in liquid cultures. Oxalic acid was the dominant among the acids produced by Aspergillus niger at all experimental setups. Unlike A. niger, the relative content of oxalic acid produced by Penicillium citrinum decreased at high carbohydrate concentrations. PMID:25844464

  5. Intracorporeal electrohydraulic lithotripsy for intrahepatic bile duct stone formation after choledochal cyst excision.

    PubMed

    Shima, Hideki; Yamataka, Atsuyuki; Yanai, Toshihiro; Kobayashi, Hiroyuki; Miyano, Takeshi

    2004-01-01

    An 18-year-old girl who had undergone excision of a choledochal cyst and Roux-en-Y hepatico-jejunostomy at another hospital when 23 months old was referred to our department because of recurrent cholangitis. Radiological investigations showed stones lying in minimally dilated, right posterior intrahepatic bile ducts (IHBD). At laparotomy, the hepatico-jejunostomy site was incised, and a flexible endoscope inserted into the IHBD. Multiple stones packed in the IHBD were easily fragmented using an electro-hydraulic lithotripsy (EHL) device inserted through the endoscope, and removed. There were no EHL-related complications, and her postoperative progress was uneventful. She is currently well with no episodes of cholangitis after a follow-up period of 3 years. EHL is a simple, effective alternative method for removing IHBD stones after choledochal cyst excision. To the best of our knowledge, this is the first report of EHL being used to remove stones that developed in the IHBD after choledochal cyst excision. PMID:14758497

  6. The measurement of surface roughness to determine the suitability of different methods for stone cleaning

    NASA Astrophysics Data System (ADS)

    Vazquez-Calvo, Carmen; Alvarez de Buergo, Monica; Fort, Rafael; Varas-Muriel, Maria Jose

    2012-08-01

    The roughness of stone surface was measured, before and after bead blasting-based cleaning methods, to select the most efficient one to be used in masonry and stonework of specific areas of the Cathedral of Segovia (Spain). These types of cleaning methods can, besides the removal of soiling and surface deposits, leave a rougher surface, which would mean higher and more rapid water retention and deposit accumulation due to a specific surface increase, therefore accelerating stone decay. Or, in contrast, the cleaning method can be so aggressive that it can smooth the surface by reducing its roughness, a fact that usually corresponds to excessive material removalsoot and deposits--but also part of the stone substrate. Roughness results were complemented with scanning electron microscopy observations and analyses and colour measurements. Finally, it was possible to select the best cleaning method among the six that were analysed, for different areas and different stone materials. Therefore, this study confirms the measurement of surface roughness as a reliable test to determine the suitability of stone cleaning methods; it is a non-destructive technique, portable and friendly to use, which can help us to rapidly assesstogether with other techniquesthe efficacy and aggressiveness of the stone cleaning method.

  7. In vitro studies on the role of glycosaminoglycans in crystallization intensity during infectious urinary stones formation.

    PubMed

    Torzewska, Agnieszka; R?alski, Antoni

    2014-06-01

    Proteus mirabilis cause urinary tract infections which are recurrent and can lead to formation of urinary calculi. Both bacterial and the host factors are involved in the development of urolithiasis. To determine the impact of glycosaminoglycans (GAGs) in the formation of P. mirabilis-induced urinary stones, we investigated the in vitro crystallization, aggregation and adhesion of crystals in the presence of GAGs naturally appearing in urine. Crystallization experiments were performed in synthetic urine infected with P. mirabilis in the presence of: hyaluronic acid (HA), heparan sulfate (HS), chondroitin sulfate A, B and C (ChSA, ChSB, ChSC). The intensity of crystallization and aggregation were established by counting particles and phase-contrast microscopy. To analyze the adhesion of crystals, we used normal urothelium and (45)Ca isotope-labeled crystals. In the presence of ChSC, both the size of the crystals formed and their number were higher compared with the control. GAGs increased crystals adhesion to the cells, but only for ChSA this effect was significant. Chondroitin sulfates, which accelerate the first stages of infection-induced stones formation, may play an important role in the pathogenesis of infectious urolithiasis. PMID:24164670

  8. 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.

  9. 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.

  10. 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

  11. 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.

  12. 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

  13. 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

  14. [A case of stone formation in the Mainz pouch using appendix as the efferent limb: a case report].

    PubMed

    Kurizaki, Yoshiki; Fujiwara, Masayo; Nakazawa, Masaki; Yoneyama, Takehisa

    2002-05-01

    A large calculus (6.0 x 4.5 x 7.0 cm sized) in the continent urinary pouch was detected incidentally by computed tomography in a 7-year-old man with a gall bladder stone. He underwent a total cystectomy and Mainz pouch formation using appendix as the efferent limb for bladder cancer 7 years ago. Urine culture showed Proteus mirabilis and Escherichia coli, and urine pH was 8.5. The stone was removed successfully through a pouchotomy and composed mainly of struvite. The stone analysis was MAP; 88% and CaCO3; 12%. Convalescence was uneventful. This is the first case of in Mainz pouch using appendix as the efferent limb. PMID:12056043

  15. 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

  16. 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.

  17. 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

  18. Efficient extraction of olive pulp and stone proteins by using an enzyme-assisted method.

    PubMed

    Vergara-Barbern, Mara; Lerma-Garca, Mara Jess; Herrero-Martnez, Jos Manuel; Sim-Alfonso, Ernesto Francisco

    2014-07-01

    An efficient protein extraction protocol for proteins from olive pulp and stone by using enzymes was developed. For this purpose, different parameters that affect the extraction process, such as enzyme type and content, pH, and extraction temperature and time, were tested. The influence of these factors on protein recovery was examined using the standard Bradford assay, while the extracted proteins were characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The best extraction conditions were achieved at pH 7.0 and 5% (v/v) Palatase 20000 L (lipase) for pulp and Lecitase Ultra (phospholipase) for stone proteins. The optimal extraction temperature and time were 30 and 40 C for 15 min for pulp and stone tissues, respectively. Under these conditions, several protein extracts coming from olive fruits of different genetic variety were analyzed, their profiles being compared by SDS-PAGE. The developed enzyme-assisted extraction method showed faster extraction, higher recovery, and reduced solvent usage than the nonenzymatic methods previously described in the literature. In the case of stone proteins, different electrophoretic profiles and band intensities were obtained that could be helpful to distinguish samples according to their genetic variety. PMID:24894067

  19. The preventive treatment of recurrent stone-formation: how can we improve compliance in the treatment of patients with recurrent stone disease?

    PubMed

    Kok, Dirk Jan

    2016-02-01

    Whether prevention of Urolithiasis is worthwhile is the outcome of the balance between efficacy of prevention and costs and efforts related of respectively prevention and treatment of a new stone. Well controlled trials demonstrate that effective prevention of new stone formation is possible using medical treatment and lifestyle interventions. In long-term general practice the results obtained with preventive interventions is disappointing. Low and diminishing long-term compliance to the intervention is a major cause for this. Both the long-term aspect and the natural resistance to lifestyle changes contribute to this low compliance. From an analysis of the existing data on trials of preventive interventions and from experiences obtained in other patient groups where lifestyle changes are applied I will make the case that self-empowerment of the patient using m-health lifestyle coaching (a smart phone application) can considerably enhance the level of prevention that is obtained in general practice. In conclusion, I will describe what features will improve usage and efficacy of such an app. PMID:26667826

  20. The effect of verapamil and thiazide in the prevention of renal stone formation.

    PubMed

    Halabe, A; Wong, N L; Sutton, R A

    1990-01-01

    The effect of the calcium antagonist verapamil, and of thiazide, a well accepted treatment in the prevention of calcium oxalate renal stones, were examined in an experimental renal stone model. Calcium oxalate stones were induced by the synthetic metabolite of vitamin D3, the alpha-OH-vitamin D3 plus ethylene glycol fed rats. A significant decrease in urinary calcium and oxalate was observed following verapamil treatment. Thiazide significantly decreased urinary calcium, but unlike verapamil, did not decrease urinary oxalate. However, no differences in the radiological findings or in the calcium or magnesium content of the kidneys were observed. Although several animal models have been described for the study of calcium oxalate stones, none has yet been proven useful for the evaluation of stone therapy. PMID:2339485

  1. Kidney stones

    MedlinePLUS

    ... Calcium stones can also form from combining with phosphate or carbonate. Other types of stones include: Cystine ... uric acid stones) Antibiotics (for struvite stones) Diuretics Phosphate solutions Sodium bicarbonate or sodium citrate Water pills ( ...

  2. Face-specific molecular adhesion and binding to calcium oxalate monohydrate: Implication for kidney stone formation

    NASA Astrophysics Data System (ADS)

    Sheng, Xiaoxia

    This thesis focuses on the face-specific molecular adhesion to calcium oxalate monohydrate (COM) crystals, the principal crystalline in kidney stones. The primary technique used is atomic force microscopy (AFM), which allows visualizing the structure and growth of crystals, measuring the adhesion force between functional groups and crystal faces, and examining adhesion and binding of the molecules to crystals. The microscopic events associated with crystal growth on the {100}, {12-1}, and {010} faces have been investigated. Each face exhibits hillocks with step sites that can be assigned to specific crystal planes, enabling direct determination of growth rates along specific crystallographic directions. The growth rates are found to depend on the degree of supersaturation. The addition of macromolecules with anionic side chains results in inhibition of hillock growth. The magnitude of this effect depends on the macromolecule structure & concentration, and the identity of the step site. The different profiles observed for three synthetic macromolecules, which have similar backbones but different side chains, argues that local binding of anionic side chains to crystal surface sites governs growth inhibition rather than any secondary polymer structure. The dependence of adhesion force on the functional group-COM crystal face combinations has been identified. Tip-immobilized carboxylate and amidinium groups display the largest adhesion forces among all the functional groups examined, and the adhesive strength decreases as (100) > (12-1) > (010). The more adherent surface of COM, compared with its dihydrate form COD, corroborates the critical role of COM in stone formation. The influence of small molecules, synthetic polymers and native proteins on adhesion was examined. The introduction of these molecular additives, except osteopontin, result in a reduction in the adhesion force measured for all three faces. The extent of suppression, however, varies for molecule-crystal face combination. Curiously, osteopontin exhibits a unique behavior as it increased the adhesion force between the carboxylate tip and the (100) crystal face. Collectively, the force measurements demonstrate that adhesion of functional groups and binding of soluble additives, including urinary macromolecules, to COM crystal surfaces are highly specific in nature.

  3. 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.

  4. Evaluation of the Various Drying Methods on Surface Hardness of Type IV Dental Stone

    PubMed Central

    Sudhakar, A; Srivatsa, G; Shetty, Rohit; Rajeswari, C L; Manvi, Supriya

    2015-01-01

    Background: Studies regarding the effect of various methods to increase the surface hardness of Type IV dental stone are not conclusive. Therefore, this study was carried out to evaluate the effect of air drying, micro oven drying and die hardener on surface hardness of Type IV dental stone. Materials and Methods: A standard metal die was fabricated; polyvinyl siloxane impression material was used to make the molds of metal die. A total of 120 specimens were obtained from two different die stones and were grouped as Group A (kalrock) and Group B (pearl stone), and were subjected to air drying for 24 h, micro oven drying and application of die hardener. These models were then subjected to surface hardness testing using the knoop hardness instrument. The obtained data were subjected to statistical analysis. Results: The hardness of Group A specimens was 64 0.54 Knoop hardness number (KHN) after application of die hardener, 60.47 0.41 KHN after 24 h air drying, 58.2 0.88 after microwave oven drying and 24.6 0.4 after 1 h air drying. The hardness of Group B specimens was 45.59 0.63 KHN after application of die hardener, 40.2 0.63 KHN after 24 h air drying, 38.28 0.55 KHN after microwave oven drying and 19.91 0.64 KHN after 1 h air drying. Conclusion: Group A showed better results than Group B at all times. Application of the die hardener showed highest hardness values followed in the order by 24 h air drying, microwave oven drying and 1 h air drying in both groups. The study showed that air drying the dies for 24 h followed by application of a single layer of the die hardener produced the best surface hardness and is recommended to be followed in practice. PMID:26124610

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. OBSERVATIONS ON SOME CAUSES OF GALL STONE FORMATION : III. THE RELATION OF THE REACTION OF THE BILE TO EXPERIMENTAL CHOLELITHIASIS.

    PubMed

    Drury, D R; McMaster, P D; Rous, P

    1924-02-29

    As previous papers from our laboratory have shown, there exists a well defined tendency for calcium carbonate to come out of solution in the normal liver bile of the dog, and for it to be deposited on certain nuclei not infrequent in the secretion under pathological circumstances. Gall stones that had arisen in this fashion were a frequent occurrence in the intubated animals we studied. The present paper is concerned with the reasons for the absence of such stones from dogs with an intact biliary tract. The solubility of calcium carbonate is known to be markedly affected by the reaction of the fluid in which it is contained. The normal liver bile, out of which it tends to precipitate, is alkaline, with an average pH of 8.20 but in the gall bladder where conditions might otherwise seem especially favorable to precipitation, the secretion undergoes a change toward the acid side, becoming on long sojourn there, strongly acid to litmus (pH 5.18 to 6.00). From bile as thus altered, no carbonate precipitation takes place, even when it becomes greatly concentrated as in fasting animals or after obstruction of the common duct. Furthermore, carbonate which has precipitated out of liver bile on standing dissolves again in it when the fluid is rendered slightly acid in vitro, or, in some cases merely neutral to litmus. There are several obvious reasons for the absence of carbonate stones from the normal ducts under ordinary conditions,-notably the motility of these latter, the flushing that they undergo from an intermittently quickened bile stream, and the cleansing and possibly antagonistic action of the secretion elaborated by the duct mucosa. In the fasting animal, one at least of these influences is almost done away with, the rate of bile flow is so greatly cut down; while furthermore the calcium concentration of the secretion undergoes a considerable increase. But pari passu with these changes there occurs one in the bile reaction, a diminution in alkalinity so great that the pH often approximates that of the neutral point for litmus. That this change is not a direct consequence of the increase in calcium, may be inferred from the findings with stasis bile, the calcium content and reaction of which were observed to vary independently, if in general in the same direction. These adjustments within the organism, some of which may be thought to exhibit an element of the purposeful, when considered with the test-tube experiments, strongly suggest that the reaction of the bile plays a critical part in determining the occurrence of carbonate stones, as furthermore that their absence from the normal gall bladder is a consequence of the changes in the bile reaction there occurring. The changes come about through a functional activity of the bladder. This being the case, one might suppose that the failure to act would be followed by a formation of carbonate stones. There is sufficient evidence available in the literature to indicate that this happens, in rabbits at least. It is important to know whether changes in the bile reaction play any part in determining the cholelithiasis of man. To determine the matter will require a large material. But this much we have shown, that carbonate spheroliths not infrequently serve in human beings as centers in a formation of secondary stones of carbonate and cholesterol, as further that cholesterol precipitation out of human bladder bile can be induced or prevented by slightly altering the reaction of the fluid toward the alkaline and acid sides, respectively. The possibility that cholelithiasis may be a consequence of sins of omission on the part of the biliary channels and reservoir deserves to be considered. PMID:19868854

  10. 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.

  11. 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

  12. 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

  13. 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

  14. 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

  15. 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 ...

  16. 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.

  17. 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.

  18. 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

  19. 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.

  20. 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

  1. Hydrogen Atom Mediated Stone-Wales Rearrangement of Pyracyclene: A Model for Annealing in Fullerene Formation

    SciTech Connect

    Nimlos, M. R.; Filley, J.; McKinnon, J. T.

    2005-01-01

    We have investigated the Stone-Wales (SW) rearrangement of pyracyclene (C{sub 14}H{sub 12}) using quantum mechanical molecular modeling. Of particular interest in this study is the effect of an added hydrogen atom on the barriers to SW rearrangement. Hydrogen atoms are found in high abundance during combustion, and their effect upon isomerization of aromatic compounds to more stable species may play an important role in the combustion synthesis of fullerenes. We have calculated the barriers for the SW rearrangement in pyracyclene using density functional theory B3LYP/6-31G(d) and B3LYP/6-311G(d,p). Two mechanisms have been investigated: (i) a mechanism with two identical transition states of C{sub 1} symmetry and a cyclobutyl intermediate and (ii) a mechanism with one transition state containing an sp{sup 3} carbon (J. Am. Chem. Soc. 2003, 125, 5572?5580; Nature 1993, 366, 665?667). We find that the barriers for these mechanisms are 120.0 kcal mol{sup -1} for the cyclobutyl mechanism and 130.1 kcal mol{sup -1} for the sp{sup 3} mechanism. Adding a hydrogen atom to the internal bridge carbon atoms of pyracyclene reduces the barrier of the cyclobutyl mechanisms to 67.0 kcal mol{sup -1} and the sp{sup 3} mechanism to 73.1 kcal mol{sup -1}. The bonding of carbon atoms in pyracyclene is similar to those found in isomers of C{sub 60}, and the barriers are low enough so that these reactions can become significant during fullerene synthesis in flames. Adding hydrogen atoms to the external bridge atoms on pyracyclene produces a smaller reduction in the SW barrier and adding hydrogen atoms to nonbridge external carbon atoms results in no reduction of the barrier.

  2. 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

  3. Biomimetic Randalls Plaque as an In Vitro Model System for Studying the Role of Acidic Biopolymers in Idiopathic Stone Formation

    PubMed Central

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

    2014-01-01

    Randalls 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 for 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 in order 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. In order 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

  4. 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.

  5. 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

  6. 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.

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

    PubMed

    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) (I(COM)), 1473 cm(-1) (I(COD)), 961 cm(-1) (I(HAP)) and 1282 cm(-1) (I(UA)) were used. PMID:23816485

  8. 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

  9. Does the use of chitosan contribute to oxalate kidney stone formation?

    PubMed

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

    2015-01-01

    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

  10. Adenoid Stones Adenoliths

    PubMed Central

    Sakano, Hitomi; Thaker, Ameet I.; Davis, Greg E.

    2015-01-01

    Stones made of bacterial aggregates can be found in chronically inflamed lymphoid tissue such as hypertrophied tonsils. Although it is common to find tonsilloliths in cryptic tonsils, it is rare to find stones in adenoid tissue. Here we present an interesting case of a patient who underwent adenoidectomy for adenoid hypertrophy, recurrent malaise and upper respiratory infections. Intraoperatively we found numerous bright green stones in the crypts of the adenoid tissue, reminiscent of tonsilloliths in tonsillar crypts. Pathology revealed polymicrobial bacterial aggregates surrounded by neutrophils. Our findings suggest that the pathophysiology is similar to that of tonsillolith formation. Thus, we should at least consider the presence of adenoid stones and consider adenoidectomy for symptoms often attributed to tonsilloliths. We have coined the term adenoliths to describe this interesting finding and present it as a potential source of recurrent infection. PMID:26798664

  11. Laser beam pulse formatting method

    DOEpatents

    Daly, T.P.; Moses, E.I.; Patterson, R.W.; Sawicki, R.H.

    1994-08-09

    A method for formatting a laser beam pulse using one or more delay loops is disclosed. The delay loops have a partially reflective beam splitter and a plurality of highly reflective mirrors arranged such that the laser beam pulse enters into the delay loop through the beam splitter and circulates therein along a delay loop length defined by the mirrors. As the laser beam pulse circulates within the delay loop a portion thereof is emitted upon each completed circuit when the laser beam pulse strikes the beam splitter. The laser beam pulse is thereby formatted into a plurality of sub-pulses. The delay loops are used in combination to produce complex waveforms by combining the sub-pulses using additive waveform synthesis. 8 figs.

  12. Laser beam pulse formatting method

    DOEpatents

    Daly, Thomas P. (Livermore, CA); Moses, Edward I. (Livermore, CA); Patterson, Ralph W. (Livermore, CA); Sawicki, Richard H. (Danville, CA)

    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.

  13. 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...

  14. 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.

  15. Terrestrial weathering of Antarctic stone meteorites - Formation of Mg-carbonates on ordinary chondrites

    NASA Technical Reports Server (NTRS)

    Velbel, Michael A.; Long, David T.; Gooding, James L.

    1991-01-01

    Results are presented on the mineralogy, chemistry, and origin of white efflorescences on the surface of Lewis Cliff (Antarctica) 85320 (H5) chondrite (LEW 85320). Particular attention is given to determining the sources of the cations and anions of the evaporite, in order to establish the relative importance of the meteoritic element distribution and terrestrial contamination in the evaporite formation during the weathering process. The data on Na, K, Ca, and Rb abundances in efflorescence from LEW 85320 suggest that cations in evaporite minerals on Antarctic meteorites are not the products of contamination by terrestrial (marine) salts. It is suggested that the Mg in efflorescence on LEW 85320 originated from weathering of meteoritic olivine.

  16. 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.

  17. 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.

  18. 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.

  19. 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

  20. 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

  1. 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.

  2. Functional dissection of a eukaryotic dicistronic gene: transgenic stonedB, but not stonedA, restores normal synaptic properties to Drosophila stoned mutants.

    PubMed Central

    Estes, Patricia S; Jackson, Taryn C; Stimson, Daniel T; Sanyal, Subhabrata; Kelly, Leonard E; Ramaswami, Mani

    2003-01-01

    The dicistronic Drosophila stoned mRNA produces two proteins, stonedA and stonedB, that are localized at nerve terminals. While the stoned locus is required for synaptic-vesicle cycling in neurons, distinct or overlapping synaptic functions of stonedA and stonedB have not been clearly identified. Potential functions of stoned products in nonneuronal cells remain entirely unexplored in vivo. Transgene-based analyses presented here demonstrate that exclusively neuronal expression of a dicistronic stoned cDNA is sufficient for rescue of defects observed in lethal and viable stoned mutants. Significantly, expression of a monocistronic stonedB trangene is sufficient for rescuing various phenotypic deficits of stoned mutants, including those in organismal viability, evoked transmitter release, and synaptotagmin retrieval from the plasma membrane. In contrast, a stonedA transgene does not alleviate any stoned mutant phenotype. Novel phenotypic analyses demonstrate that, in addition to regulation of presynaptic function, stoned is required for regulating normal growth and morphology of the motor terminal; however, this developmental function is also provided by a stonedB transgene. Our data, although most consistent with a hypothesis in which stonedA is a dispensable protein, are limited by the absence of a true null allele for stoned due to partial restoration of presynaptic stonedA by transgenically provided stonedB. Careful analysis of the effects of the monocistronic transgenes together and in isolation clearly reveals that the presence of presynaptic stonedA is dependent on stonedB. Together, our findings improve understanding of the functional relationship between stonedA and stonedB and elaborate significantly on the in vivo functions of stonins, recently discovered phylogenetically conserved stonedB homologs that represent a new family of "orphan" medium (mu) chains of adaptor complexes involved in vesicle formation. Data presented here also provide new insight into potential mechanisms that underlie translation and evolution of the dicistronic stoned mRNA. PMID:14504226

  3. Clonorcis sinensis eggs are associated with calcium carbonate gallbladder stones.

    PubMed

    Qiao, Tie; Ma, Rui-hong; Luo, Zhen-liang; Yang, Liu-qing; Luo, Xiao-bing; Zheng, Pei-ming

    2014-10-01

    Calcium carbonate gallbladder stones were easily neglected because they were previously reported as a rare stone type in adults. The aim of this study was to investigate the relationship between calcium carbonate stones and Clonorchis sinensis infection. A total of 598 gallbladder stones were studied. The stone types were identified by FTIR spectroscopy. The C. sinensis eggs and DNA were detected by microscopic examination and real-time fluorescent PCR respectively. And then, some egg-positive stones were randomly selected for further SEM examination. Corresponding clinical characteristics of patients with different types of stones were also statistically analyzed. The detection rate of C. sinensis eggs in calcium carbonate stone, pigment stone, mixed stone and cholesterol stone types, as well as other stone types was 60%, 44%, 36%, 6% and 30%, respectively, which was highest in calcium carbonate stone yet lowest in cholesterol stone. A total of 182 stones were egg-positive, 67 (37%) of which were calcium carbonate stones. The C. sinensis eggs were found adherent to calcium carbonate crystals by both light microscopy and scanning electron microscopy. Patients with calcium carbonate stones were mainly male between the ages of 30 and 60, the CO2 combining power of patients with calcium carbonate stones were higher than those with cholesterol stones. Calcium carbonate gallbladder stones are not rare, the formation of which may be associated with C. sinensis infection. PMID:24945791

  4. Recent management of urinary stone disease in a pediatric population.

    PubMed

    Aydogdu, Ozgu; Karakose, Ayhan; Celik, Orcun; Atesci, Yusuf Ziya

    2014-02-01

    The incidence of stone disease has been increasing and the risk of recurrent stone formation is high in a pediatric population. It is crucial to use the most effective method with the primary goal of complete stone removal to prevent recurrence from residual fragments. While extracorporeal shock wave lithotripsy (ESWL) is still considered first line therapy in many clinics for urinary tract stones in children, endoscopic techniques are widely preferred due to miniaturization of instruments and evolution of surgical techniques. The standard procedures to treat urinary stone disease in children are the same as those used in an adult population. These include ESWL, ureterorenoscopy, percutaneous nephrolithotomy (standard PCNL or mini-perc), laparoscopic and open surgery. ESWL is currently the procedure of choice for treating most upper urinary tract calculi in a pediatric population. In recent years, endourological management of pediatric urinary stone disease is preferred in many centers with increasing experience in endourological techniques and decreasing sizes of surgical equipment. The management of pediatric stone disease has evolved with improvements in the technique and a decrease in the size of surgical instruments. Recently, endoscopic methods have been safely and effectively used in children with minor complications. In this review, we aim to summarize the recent management of urolithiasis in children. PMID:25254178

  5. Recent management of urinary stone disease in a pediatric population

    PubMed Central

    Aydogdu, Ozgu; Karakose, Ayhan; Celik, Orcun; Atesci, Yusuf Ziya

    2014-01-01

    The incidence of stone disease has been increasing and the risk of recurrent stone formation is high in a pediatric population. It is crucial to use the most effective method with the primary goal of complete stone removal to prevent recurrence from residual fragments. While extracorporeal shock wave lithotripsy (ESWL) is still considered first line therapy in many clinics for urinary tract stones in children, endoscopic techniques are widely preferred due to miniaturization of instruments and evolution of surgical techniques. The standard procedures to treat urinary stone disease in children are the same as those used in an adult population. These include ESWL, ureterorenoscopy, percutaneous nephrolithotomy (standard PCNL or mini-perc), laparoscopic and open surgery. ESWL is currently the procedure of choice for treating most upper urinary tract calculi in a pediatric population. In recent years, endourological management of pediatric urinary stone disease is preferred in many centers with increasing experience in endourological techniques and decreasing sizes of surgical equipment. The management of pediatric stone disease has evolved with improvements in the technique and a decrease in the size of surgical instruments. Recently, endoscopic methods have been safely and effectively used in children with minor complications. In this review, we aim to summarize the recent management of urolithiasis in children. PMID:25254178

  6. 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).

  7. 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.

  8. 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

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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

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

    PubMed

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

    2015-07-01

    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

  15. 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. Randalls 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

  16. 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 168.9392.5 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

  17. 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

  18. Systemic implications of urinary stone disease

    PubMed Central

    Kovshilovskaya, Bogdana; Miller, Joe; Stoller, Marshall L.

    2012-01-01

    Urinary stone disease is the third most common condition affecting the urinary tract. It contributes to a great deal of morbidity for both men and women, and cost the United States (US) over 5.3 billion dollars in 2000 alone. Moreover, it is associated with systemic diseases such as hypertension, diabetes, and other components of the metabolic syndrome. Reciprocally, these systemic diseases may be contributing to the rising incidence in urinary stone disease. Previously described mechanisms of stone formation attribute stone development and growth to the urinary milieu. While this may partly influence the process, it cannot account for the associations between systemic diseases and stones observed in large community-based studies. Here we present a review of the evidence demonstrating a link between urinary stone disease and components of the metabolic syndrome. We believe a vascular etiology for the initiation of urinary stones may tie these processes together. PMID:26816692

  19. Discrimination between urinary tract tissue and urinary stones by fiber-optic-pulsed photothermal radiometry method in vivo

    NASA Astrophysics Data System (ADS)

    Daidoh, Yuichiro; Arai, Tsunenori; Suda, Akira; Kikuchi, Makoto; Komine, Yukikuni; Murai, Masaru; Nakamura, Hiroshi

    1991-07-01

    To minimize urotherial tissue injuries by false laser irradiation during the laser stones fragmentation, a novel fiber-optic analytical system was developed which was able to distinguish urotherial tissues from urinary stones in vivo. This system was composed of the fiber-optic pulsed photo-thermal radiometry (PPTR) system together with a thin-fiber endoscope. The ultraviolet Ar laser was employed as the excitation light source. The catheter of this system was 6F in diameter and consisted of SiO2 glass fiber (400 micrometers (phi) ) as an excitation line, an As-S glass fiber (400 micrometers (phi) ) as a detection line, and a thin-fiber endoscope (610 micrometers (phi) ). A urinary stone was introduced into the canine ureter uneter under general anesthesia. The catheter system was inserted through an opening of the ureter distal to the stone. The e-folding decay time of the PPTR waveform of which optical and/or thermal properties of the tissues and stones were characterized was measured in vivo. The e-folding decay times were significantly different between urinary stones and the canine ureter. These results suggest that the fiber-optic PPTR analysis might be significantly useful procedure to prevent urotherial tissue from false irradiation injuries in clinical laser stone fragmentation.

  20. 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

  1. 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.

  2. A Case of Recurrent Renal Aluminum Hydroxide Stone

    PubMed Central

    Cak?roglu, 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

  3. Methods for forming wellbores in heated formations

    DOEpatents

    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.

  4. Kidney Stones (For Parents)

    MedlinePLUS

    ... can develop in the urinary tract . Also called calculi or nephrolithiasis, kidney stones form when salts and ... form a stone. Struvite stones: Also called staghorn calculi because they look like a stag's antlers, these ...

  5. 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 m and 1 m, respectively for the coarse-grained limestone (Bretigny) and the finest one (Mign). 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.

  6. 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.

  7. 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

  8. Outcome of ureteroscopy for stone disease in patients with horseshoe kidney: Review of world literature

    PubMed Central

    Ishii, Hiro; Rai, Bhavan; Traxer, Olivier; Kata, Slawomir G.; Somani, Bhaskar K.

    2015-01-01

    Introduction and Objectives: The management of urolithiasis in patients with horseshoe kidney (HSK) is difficult. Stone formation occurred in 1:5 patients with HSK due to impaired urinary drainage and infections. Percutaneous nephrolithotomy and shock wave lithotripsy can be technically challenging due to altered anatomy. Materials and Methods: We conducted a systematic review of the literature to look at the role of ureteroscopy for stone management in these patients. We searched MEDLINE, PubMed and the Cochrane Library from January 1990 to April 2013 for results of ureteroscopy and stone treatment in HSK patients. Inclusion criteria were all English language articles reporting on ureteroscopy in patients with HSK. Data were extracted on the outcomes and complications. Results: A total of 3 studies was identified during this period. Forty-one patients with HSK underwent flexible ureteroscopy and stone treatment. The mean age was 42 with a male:female ratio nearly 3:1. The mean stone size was 16 mm (range: 3-35 mm). The mean operating time was 86 min with multiple stones seen in 15 patients. All 41 patients had a ureteral access sheath used and flexible ureteroscopy and holmium laser fragmentation done. Thirty-two (78%) patients were stone-free with a mean hospital stay of 1-day. Minor complications (Clavien I or II) were seen in 13 (32%) of which 6 had stent discomfort, 3 needed intravenous antibiotics for <24 h, 3 had hematuria of which 2 needed blood transfusion and one had pyelonephritis needing re-admission and antibiotics. There were no major complications found in the review. Conclusions: Retrograde stone treatment using ureteroscopy and lasertripsy in HSK patients can be performed with good stone clearance rate, but with a slightly higher complication rate. This procedure should, therefore, be done in high volume stone center with an experienced stone surgeon/team. PMID:26692667

  9. Pyrophosphate Transport and Stones

    NASA Astrophysics Data System (ADS)

    Sayer, John A.; Carr, Georgina; Moochhala, Shabbir H.; Simmons, Nicholas L.

    2008-09-01

    Since the 1960's, inorganic pyrophosphate (PPi) has been known to inhibit apatite precipitation. Recent findings suggest that PPi plays a central role in the control of normal bone mineralization. Knockout mice have established the functional importance of PPi transmembrane transport, via the pyrophosphate transporter ANKH. The molecular nature and transport function of ANKH are reviewed. PPi is present in urine and ANKH is expressed in the cortical collecting duct where PPi transport to both the tubular lumen and renal interstitium may occur. Arginine vasopressin stimulation of cortical collecting duct cells grown on semi-permeable supports appears to upregulate apical ANKH expression, which we postulate may be a mechanism of stone inhibition during urinary concentration and supersaturation of calcium salts. Hypopyrophosphaturia may be a forgotten metabolic risk factor for stone formation and polymorphisms of the ANKH gene may underlie this defect. The physiological importance and clinical significance of PPi generation and transport in preventing idiopathic renal stone disease and nephrocalcinosis now needs to be established.

  10. 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

  11. Pulsed Thrust Method for Hover Formation Flying

    NASA Technical Reports Server (NTRS)

    Hope, Alan; Trask, Aaron

    2003-01-01

    A non-continuous thrust method for hover type formation flying has been developed. This method differs from a true hover which requires constant range and bearing from a reference vehicle. The new method uses a pulsed loop, or pogo, maneuver sequence that keeps the follower spacecraft within a defined box in a near hover situation. Equations are developed for the hover maintenance maneuvers. The constraints on the hover location, pulse interval, and maximum/minimum ranges are discussed.

  12. 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.

  13. 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

  14. Marble tombstone in national cemeteries as indicators of stone damage: general methods

    SciTech Connect

    Baer, N.S.; Berman, S.M.

    1983-01-01

    The role of acid deposition in damage to materials exposed to the environment is a matter of national concern. Marble tombstones are an example of widely distributed materials of uniform composition which have known times of exposure. A study of marble tombstones in 23 national cemeteries and soldiers lots in private cemeteries identified the marble source, the method of cutting, historical data, and physical measurements. The results show that fine-grained Vermont marble should be used as a standard in short-term exposure studies because it weathers more rapidly. A comparison of the weathering rates for rural, suburban, and urban cemeteries with comparable climates with high annual precipitation levels indicates that the urban environment causes significant damage beyond that observed in rural environments and that local sources dominate the deposition of damaging pollutants. 16 references, 6 figures, 4 tables.

  15. Calcium intake and urinary stone disease

    PubMed Central

    2014-01-01

    Calcium homeostasis is a complicated and incompletely understood process that is primarily regulated through an interaction between the intestines, kidneys, and bones. Intestinal calcium absorption is determined by many factors including the amount of regular calcium intake, as well as vitamin D and parathyroid hormone levels. Intestinal calcium absorption is likely different between stone formers and non-stone formers, with higher levels of calcium absorption in those with a history of stones independent of their calcium intake. We no longer recommend dietary calcium restriction as this may lead to bone demineralization and an increase in stone formation. Practitioners need to continue to educate patients to maintain moderate dietary calcium intake. The effect of calcium supplementation on stone formation is currently controversial. It is likely that large doses of supplemental calcium, especially if taken separate from a meal, may lead to stone formation. When necessary, stone forming patients should be encouraged to take their calcium supplements with a meal and their stone disease should be monitored. PMID:26816771

  16. 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

  17. Urine citrate and renal stone disease.

    PubMed Central

    Goldberg, H; Grass, L; Vogl, R; Rapoport, A; Oreopoulos, D G

    1989-01-01

    Calcium stone disease is attributable to supersaturation of the urine with calcium and other salts, the presence of substances that promote crystallization and a deficiency of inhibitors of crystallization. Citrate is a potent inhibitor of calcium oxalate and calcium phosphate stone formation whose excretion is diminished in some patients with stone disease owing to idiopathic causes or secondary factors such as bowel disease and use of thiazides. The pH within the proximal tubule cells is an important determinant of citrate excretion. Multivariate analysis has shown that the urine concentrations of calcium and citrate are the most important factors in stone formation. In uncontrolled studies potassium citrate, which increases urinary citrate excretion, appears to be promising as a therapeutic agent for patients with stone disease and hypocitraturia refractory to other treatment. On the other hand, there are potential drawbacks to sodium alkali therapy, such as the precipitation of calcium phosphates. PMID:2665909

  18. 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.

  19. 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

  20. 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.

  1. Management of stone disease in infants.

    PubMed

    Azili, Mujdem Nur; Ozturk, Fatma; Inozu, Mihriban; ayci, Fatma ?emsa; 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

  2. Utility and Limitation of Cumulative Stone Diameter in Predicting Urinary Stone Burden at Flexible Ureteroscopy with Holmium Laser Lithotripsy: A Single-Center Experience

    PubMed Central

    Ito, Hiroki; Kawahara, Takashi; Terao, Hideyuki; Ogawa, Takehiko; Yao, Masahiro; Kubota, Yoshinobu; Matsuzaki, Junichi

    2013-01-01

    Purpose To retrospectively assess the clinical utility in ureteroscopy (URS) planning of cumulative stone diameter (CSD), which does not account for stone width or depth, as a predictor of URS outcome and compare it with stone volume. Materials and Methods Patients with renal stones treated at a single institute by flexible URS were retrospectively evaluated. To assess the clinical utility of CSD, relationships between stone-free (SF) status and stone burden (CSD and volume) were analyzed using the area under the receiver operating characteristics (AUROC) curve. To identify stone number impact on CSD, the AUROC of CSD divided by stone number was evaluated. Correlation coefficients of CSD and stone volume were also calculated for groups by stone number. Results In cases with CSD <20.0 mm, CSD and stone volume revealed equal ability to predict SF status. In cases with CSD ?20.0 mm, stone volume showed higher predictive ability. The ROC curves for cases with ?4 stones showed that CSD was less predictive of SF status than stone volume. The correlation coefficients of CSD and stone volume by stone number were 0.922 for 1 stone, 0.900 for 23 stones, and 0.661 for ?4 stones. Conclusions In cases with CSD ?20.0 mm or ?4 stones, we should evaluate stone volume for a more predictive stone burden, and pretreatment non-contrast CT seems sufficient. In cases with CSD <20.0 mm or 13 stones, CSD was as valid a predictor of preoperative stone burden as stone volume, so preoperative kidney-ureter-bladder (KUB) films may be sufficient. PMID:23750229

  3. 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

  4. Method For Screening Microcrystallizations For Crystal Formation

    DOEpatents

    Santarsiero, Bernard D. (Chicago, IL), Stevens, Raymond C. (La Jolla, CA), Schultz, Peter G. (La Jolla, CA), Jaklevic, Joseph M. (Lafayette, CA), Yegian, Derek T. (Oakland, CA), Cornell, Earl W. (Antioch, CA), Nordmeyer, Robert A. (San Leandro, CA)

    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.

  5. Treatment and prevention of kidney stones: an update.

    PubMed

    Frassetto, Lynda; Kohlstadt, Ingrid

    2011-12-01

    The incidence of nephrolithiasis (kidney stones) is rising worldwide, especially in women and with increasing age. Kidney stones are associated with chronic kidney disease. Preventing recurrence is largely specific to the type of stone (e.g., calcium oxalate, calcium phosphate, cystine, struvite [magnesium ammonium phosphate]), and uric acid stones); however, even when the stone cannot be retrieved, urine pH and 24-hour urine assessment provide information about stone-forming factors that can guide prevention. Medications, such as protease inhibitors, antibiotics, and some diuretics, increase the risk of some types of kidney stones, and patients should be counseled about the risks of using these medications. Managing diet, medication use, and nutrient intake can help prevent the formation of kidney stones. Obesity increases the risk of kidney stones. However, weight loss could undermine prevention of kidney stones if associated with a high animal protein intake, laxative abuse, rapid loss of lean tissue, or poor hydration. For prevention of calcium oxalate, cystine, and uric acid stones, urine should be alkalinized by eating a diet high in fruits and vegetables, taking supplemental or prescription citrate, or drinking alkaline mineral waters. For prevention of calcium phosphate and struvite stones, urine should be acidified; cranberry juice or betaine can lower urine pH. Antispasmodic medications, ureteroscopy, and metabolic testing are increasingly being used to augment fluid and pain medications in the acute management of kidney stones. PMID:22150656

  6. Kidney Stones in Adults

    MedlinePLUS

    ... people than in non-Hispanic black people and Mexican Americans. Overweight and obese people are more likely ... more struvite stones. Cystine stones result from a genetic disorder that causes cystine to leak through the ...

  7. 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

  8. Relevance of dietary protein concentration and quality as risk factors for the formation of calcium oxalate stones in cats.

    PubMed

    Palack, Nadine; Burmeier, Hannes; Brenten, Thomas; Neumann, Konrad; Zentek, Jrgen

    2014-01-01

    The role of dietary protein for the development of feline calcium oxalate (CaOx) uroliths has not been conclusively clarified. The present study evaluated the effects of a varying dietary protein concentration and quality on critical indices for the formation of CaOx uroliths. Three diets with a high protein quality (10-11 % greaves meal/diet) and a varying crude protein (CP) concentration (35, 44 and 57 % in DM) were compared. Additionally, the 57 % CP diet was compared with a fourth diet that had a similar CP concentration (55 % in DM), but a lower protein quality (34 % greaves meal/diet). The Ca and oxalate (Ox) concentrations were similar in all diets. A group of eight cats received the same diet at the same time. Each feeding period was divided into a 21 d adaptation period and a 7 d sampling period to collect urine. There were increases in urinary volume, urinary Ca concentrations, renal Ca and Ox excretion and urinary relative supersaturation (RSS) with CaOx with increasing dietary protein concentrations. Urinary pH ranged between 634 and 666 among all groups, with no unidirectional effect of dietary protein. Lower renal Ca excretion was observed when feeding the diet with the lower protein quality, however, the underlying mechanism needs further evaluation. In conclusion, although the observed higher urinary volume is beneficial, the increase in urinary Ca concentrations, renal Ca and Ox excretion and urinary RSS CaOx associated with a high-protein diet may be critical for the development of CaOx uroliths in cats. PMID:26101619

  9. 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

  10. 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

  11. 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 647 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

  12. Effectiveness of Flexible Ureteroscopic Stone Removal for Treating Ureteral and Ipsilateral Renal Stones: A Single-Center Experience

    PubMed Central

    Lee, Sang Hyup; Kim, Tae-Hyoung; Myung, Soon Chul; Moon, Young Tae; Kim, Kyung Do; Kim, Jung Hoon; Kwon, Jong Kyou

    2013-01-01

    Purpose The aim of this study was to evaluate the effectiveness of simultaneous flexible ureteroscopic removal of stones (URS) for ureteral and ipsilateral renal stones and to analyze the predictive factors for renal stone-free status. Materials and Methods We retrospectively reviewed the records of patients who underwent simultaneous flexible URS of ureteral and ipsilateral renal stones from January 2010 to May 2012. All operations used a flexible ureteroscope. We identified 74 cases of retrograde intrarenal surgery and 74 ureteral stones (74 patients). Stone-free status was respectively defined as no visible stones and clinically insignificant residual stones <3 mm on a postoperative image study. Predictive factors for stone-free status were evaluated. Results The immediate postoperative renal stone-free rate was 70%, which increased to 83% at 1 month after surgery. The immediate postoperative ureteral stone-free rate was 100%. Among all renal stones, 15 (20.3%) were separately located in the renal pelvis, 11 (14.8%) in the upper calyx, 15 (20.3%) in the mid calyx, and 33 (44.6%) in the lower calyx. The mean cumulative stone burden was 92.22105.75 mm2. In a multivariate analysis, cumulative stone burden <100 mm2 was a significant predictive factor for postoperative renal stone-free status after 1 month (p<0.01). Conclusions Flexible URS can be considered simultaneously for both ureteral and renal stones in selected patients. Flexible URS is a favorable option that promises high stone-free status without significant complications for patients with a stone burden <100 mm2. PMID:23789046

  13. 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

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. OBSERVATIONS ON SOME CAUSES OF GALL STONE FORMATION : I. EXPERIMENTAL CHOLELITHIASIS IN THE ABSENCE OF STASIS, INFECTION, AND GALL BLADDER INFLUENCES.

    PubMed

    Rous, P; McMaster, P D; Drury, D R

    1924-01-01

    Gall stones frequently form in dogs intubated for the collection of bile under sterile conditions, in the absence of stasis and of gall bladder influence. The stones consist almost entirely of two substances-calcium carbonate and calcium bilirubinate-and they are remarkably uniform in character, as would follow from the limiting conditions of their development. They are not the result of bile loss, for similar ones may be recovered from the wall of glass tubes interpolated in ducts with intestinal connection undisturbed. The study of them has brought out evidence on the general problem of cholelithiasis. Some factors in their causation and that of gall stones as a class will be considered in succeeding papers. PMID:19868836

  6. Kinetic analysis on the non-isothermal degradation of plum stone waste by thermogravimetric analysis and integral master-plots method.

    PubMed

    Ceylan, Selim

    2015-04-01

    In this study, pyrolysis of plum stone was investigated by thermogravimetric analysis in a nitrogen atmosphere at heating rates of 5, 10, 20 and 40?C?min(-1). Pyrolysis characteristics and the thermal-decomposition rate were significantly affected by variation in the heating rate. However, the heating rate slightly affected the total yield of the volatile matters. Activation energy of the pyrolysis reaction was evaluated by model-free methods, Friedman and Kissingere-Akahirae-Sunose. Results of the Master-Plots method indicated that the most probable reaction model function was the nth order reaction model function as f(x) = (1-x) (3.11), A = 8.02x10(12) under a mean activation energy of 150.61?kJ?mol(-1). Proximate and ultimate analysis showed that plum stone can be considered as a favourable source for energy production owing to its low moisture and ash content, and high volatile matter ratio and moderate heating value. PMID:25784691

  7. Extracorporeal Shockwave Lithotripsy of Primary Intrahepatic Stones

    PubMed Central

    Kim, Myung Hwan; Lee, Sung Koo; Min, Young Il; Lee, Mun Gyu; Sung, Kyu Bo; Cho, Kyung Sik; Lee, Sung Gyu; Min, Pyung Chul

    1992-01-01

    Extracorporeal shockwave lithothripsy (ESWL) was performed in intrahepatic stone patients (n = 18) by Dornier MPL 9,000 with ultrasound guidance. The patients had T-tube (n = 9) or percutaneous transhepatic biliary drainge tube (n = 9). Average treatment session was four and shock-wave numbers were in the range of 3,064 to 12,000 (average 6,288 shocks). Intrahepatic stones were removed completely in 16 patients over a 3 month period by ESWL and combined stone extraction maneuver such as cholangioscopic or interventional radiologic method. Extracorporeal shockwave lithothripsy was very helpful in facilitating extraction of stones in unfavorable locations or located above the severe stricture. In summary, extracorporeal Shockwave lithotripsy, followed by percutaneous stone extraction, will provide an improvement in the success rate and duration of treatment required for complete removal of primary hepatolithiasis. PMID:1477027

  8. Glucose metabolism in renal stone patients.

    PubMed

    Iguchi, M; Umekawa, T; Takamura, C; Sugihara, I; Nakamura, K; Kohri, K; Kurita, T

    1993-01-01

    The calciuric response and the changes of plasma glucose and insulin produced by a 75-gram oral glucose tolerance test were determined in 27 male patients with idiopathic calcium renal stones (6 with dietary hypercalciuria, 5 with nondietary hypercalciuria and 16 with normocalciuria) and 22 healthy male subjects. The subjects were classified as obese (> or = 120% ideal weight) and nonobese. The incidence of an abnormal response to glucose loading was similar in the stone patients and the healthy subjects. In addition, the plasma glucose and insulin levels after oral glucose load did not differ between the stone patients and control subjects and were affected by the individual degree of obesity. Urinary calcium excretion increased significantly after glucose ingestion in both the stone patients and the control subjects. Urinary calcium excretion was greater in the stone patients than in the control subjects due to the presence of patients with nondietary hypercalciuria, and the increment in urinary calcium excretion in the dietary hypercalciuric and normocalciuric stone patients was indistinguishable from that in the control subjects. The degree of obesity did not affect the increment in urinary calcium excretion. These results suggest that overconsumption of refined carbohydrates such as sugar-sweetened soft drinks, soda and cakes may be a risk factor for stone formation, especially in the patients with nondietary hypercalciuria. PMID:8266608

  9. 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

  10. 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.

  11. Can stone density on plain radiography predict the outcome of extracorporeal shockwave lithotripsy for ureteral stones?

    PubMed Central

    Lim, Ki Hong; Jung, Jin-Hee; Kwon, Jae Hyun; Lee, Yong Seok; Bae, Jungbum; Cho, Min Chul; Lee, Kwang Soo

    2015-01-01

    Purpose The objective was to determine whether stone density on plain radiography (kidney-ureter-bladder, KUB) could predict the outcome of extracorporeal shockwave lithotripsy (ESWL) for ureteral stones. Materials and Methods A total of 223 patients treated by ESWL for radio-opaque ureteral stones of 5 to 20 mm were included in this retrospective study. All patients underwent routine blood and urine analyses, plain radiography (KUB), and noncontrast computed tomography (NCCT) before ESWL. Demographic, stone, and radiological characteristics on KUB and NCCT were analyzed. The patients were categorized into two groups: lower-density (LD) group (radiodensity less than or equal to that of the 12th rib, n=163) and higher-density (HD) group (radiodensity greater than that of the 12th rib, n=60). Stone-free status was assessed by KUB every week after ESWL. A successful outcome was defined as stone free within 1 month after ESWL. Results Mean stone size in the LD group was significantly smaller than that in the HD group (7.51.4 mm compared with 9.92.9 mm, p=0.002). The overall success rates in the LD and HD groups were 82.1% and 60.0%, respectively (p=0.007). The mean duration of stone-free status and average number of SWL sessions required for success in the two groups were 21.7 compared with 39.2 days and 1.8 compared with 2.3, respectively (p<0.05). On multivariate logistic analysis, stone size and time to ESWL since colic and radiodensity of the stone on KUB were independent predictors of successful ESWL. Conclusions Our data suggest that larger stone size, longer time to ESWL, and ureteral stones with a radiodensity greater than that of the 12th rib may be at a relatively higher risk of ESWL failure 1 month after the procedure. PMID:25598937

  12. 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.

  13. 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

  14. 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 authors collection of proceedings of urolithiasis conferences: The keywords included economics, cost, urolithiasis, nephrolithiasis, renal stone disease, metaphylaxis, recurrence) during 19992011. 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

  15. Urinary infection stones caused by Ureaplasma urealyticum: a review.

    PubMed

    Grenabo, L; Hedelin, H; Pettersson, S

    1988-01-01

    Experimental and clinical studies have been performed to determine whether Ureaplasma urealyticum has an etiological role in the development of infection stones in the urinary tract. Incubation of synthetic urine in vitro with U. urealyticum caused alkalinization of the urine and crystallization of struvite and calcium phosphate. Inoculation of U. urealyticum into rat bladders resulted in the formation of struvite stones in 84% of the rats. Furthermore, infection with U. urealyticum markedly increased the adherence of urease-induced crystals to the bladder epithelium compared to normal rat bladders, probably due to elimination of the mucous coat which covers the normal urothelium. Clinically, U. urealyticum has been cultured from voided urine and from the stone in patients operated on for renal stones. U. urealyticum was cultured in voided urine in 31 of 247 patients (13%) with metabolic stones, compared to 43 of 145 patients (30%) with infection stones (p less than 0.001). In the patients where stone cultures were performed, U. urealyticum was found in 2 of 125 patients (2%) with metabolic stones, compared to 10 of 64 patients (16%) with infection stones (p less than 0.001). These observations strongly suggest that U. urealyticum is linked to the formation of infection stones in the urinary tract. PMID:3047857

  16. 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.

  17. Kidney Stones (For Parents)

    MedlinePLUS

    ... in urine (pee) become extra concentrated and form crystals. Over a few weeks or months, the crystals can build up and become stones. Kidney stones ... changes the level of a substance in it, crystals can begin to form. The crystals can become ...

  18. 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

  19. Old Stone Field Marker

    USGS Multimedia Gallery

    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...

  20. 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...

  1. 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

  2. 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.

  3. 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.

  4. Method and compositions for fracturing subterranean formations

    SciTech Connect

    Almond, S. W.

    1984-10-16

    An aqueous gel containing a retarded crosslinking composition comprising a zirconium salt or chelate and a polyhydroxyl-containing compound and optionally including an aqueous fluid or an alkanol. The gel is useful for fracturing and placing propping agents within a subterranean formation. The del has a high viscosity in the formation and has pumping characteristics in turbulent flow similar to those of the base gel.

  5. 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.

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

    PubMed Central

    zgr, Faruk; Kktopcu, Onur; ?im?ek, Abdulmuttalip; Sar?lar, mer; Binbay, Murat; Grbz, Gkhan

    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

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

    PubMed

    Tamoaityt?, Sandra; Hendrixson, Vaiva; elvys, Ar?nas; Tyla, Ram?nas; Ku?inskien?, Zita A; Jankevi?ius, Feliksas; Pu?etait?, Milda; Jablonskien?, Valerija; ablinskas, 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. PMID:23429795

  8. 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

  9. 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

  10. 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

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. Kidney Stones in Children

    MedlinePLUS

    ... Nephrology American Kidney Fund National Kidney Foundation MedlinePlus Kidney and Urologic Disease Organizations Many organizations provide support ... Disease Organizations​​ . (PDF, 345 KB) Alternate Language URL Kidney Stones in Children Page Content On this page: ...

  18. 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

  19. 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.

  20. Safety and efficacy of using the stone cone and an entrapment and extraction device in ureteroscopic lithotripsy for ureteric stones

    PubMed Central

    Shabana, Waleed; Teleb, Mohamed; Dawod, Tamer

    2015-01-01

    Objective To assess the safety and efficacy of using a stone cone and an entrapment and extraction device (N-Trap, Cook Urological, Bloomington, IN, USA) to avoid stone retropulsion during ureteroscopic lithotripsy for ureteric stones. Patients and methods This retrospective comparative study included 436 patients treated with ureteroscopic lithotripsy for a single ureteric stone from February 2011 to January 2014. The diagnosis of a stone was confirmed by plain spiral computed tomography in all cases. Patients were divided according to the ureteric occlusion device applied to avoid stone retropulsion during pneumatic lithotripsy into three groups; group 1 (156) had no instruments used, group 2 (140) in whom the stone cone was applied, and group 3 (140) in whom the N-Trap was used. Patient demographics, stone criteria, operative duration and complications, and success rates (complete stone disintegration with no upward migration) were reported and analysed statistically. Results The stone was in the lower ureter in >55% of patients in all groups. The mean (SD) of maximum stone length was 9.8 (2.5), 10.4 (2.8) and 9.7 (2.9) in groups 13, respectively. The use of the stone cone or N-Trap did not significantly increase the operative duration (P=0.13) or complication rates (P=0.67). There was a statistically significant difference (P<0.001) favouring groups 2 and 3 for retropulsion and success rates, being 83.3% in group 1, 97.1% in group 2 and 95.7% in group 3. Conclusion The stone cone and N-Trap gave high success rates in preventing stone retropulsion during ureteric pneumatic lithotripsy. Both devices caused no increase in operative duration or complications when used cautiously. PMID:26413324

  1. 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.

  2. 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

  3. 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.

  4. Impact of urinary stone volume on computed tomography stone attenuations measured in Hounsfield units in a large group of Austrian patients with urolithiasis

    PubMed Central

    Patzak, Johanna; Lutfi, Andre; Pummer, Karl; Augustin, Herbert

    2014-01-01

    Introduction To investigate retrospectively the impact of urinary stone volume on computed tomography stone attenuations measured in Hounsfield units in 253 patients with urolithiasis. Material and methods CT scans were performed in 253 patients with suspected urinary stone disease from 2008 to 2010 using CTScanner Siemens, SOMATOM, Sensation 64. One experienced radiologist (A.L) who was blinded to the chemical composition of the stones retrospectively reviewed images and analyzed data to determine the composition of the stones. The results were compared with the biochemical analysis results obtained by infrared spectroscopy (100 FTIR, PerkinElmer). Results 253 consecutive patients from 2008 to 2010 were included into analysis: 189 males, and 64 females. Mean age was 51.2. According to stone volume, stones were divided into 2 groups: 126 stones with volume of 4.3 mm or more, 127 stones with volume less than 4.3 mm. There was a significant relationship between stone volume and its CT attenuation only in stones with a volume 4.3 mm or more (p <0.05). Conclusions We failed to show a significant relationship between stone volume and its attenuations in Hounsfield units. We could not distinguish uric acid stones from non uric acid stones. PMID:25247090

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

    DOEpatents

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

  6. 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

  7. 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.

  8. The role of open stone surgery

    PubMed Central

    El-Husseiny, Tamer; Buchholz, Noor

    2012-01-01

    Objective To highlight the role of open stone surgery in the management of urolithiasis in the current era of minimally invasive therapies. The introduction and continuous development of extracorporeal shockwave lithotripsy (ESWL), ureterorenoscopy and percutaneous nephrolithotomy (PCNL) over the past 30years have led to a significant change in the current management of urolithiasis, where the indications for open stone surgery have been narrowed significantly, making it a second- or third-line treatment option. Methods We reviewed the most recent guidelines published by the European Association of Urology and the American Urological Association, and reviewed reports through a MEDLINE search to identify the indications and current role of open stone surgery. Results From the MEDLINE search, it was obvious that the number of papers published on open renal stone surgery has decreased during the last three decades, soon after the introduction of ESWL and PCNL. Conclusion Although currently most patients with stones can be managed by minimally invasive therapy, we believe that open surgery still has a role, and therefore it is of great importance to recognise that a small group of patients with complex stone disease, and those with anatomical and physiological anomalies, will benefit from this treatment option. PMID:26558038

  9. 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

  10. Damage of Stone Baskets by Endourologic Lithotripters: A Laboratory Study of 5 Lithotripters and 4 Basket Types

    PubMed Central

    Brinkmann, Ralf; Jocham, Dieter

    2013-01-01

    Background. In some cases, the ureteral stone is simultaneously stabilized by a stone basket when endourologic lithotripsy is performed. This stabilization can be either on purpose or by accident. By accident means that an impaction in the ureter occurs by an extraction of a stone with a basket. A stabilization on purpose means to avoid a retropulsion of the stone into the kidney during lithotripsy. At this part of the operation, stone baskets have been frequently damaged. This severing of wires can lead to ureteral trauma because of hook formation. Material and Methods. In a laboratory setting, the time and the pulse numbers were measured until breaking the wires from four different nitinol stone baskets by using five different lithotripsy devices. The endpoint was gross visibledamage to the wire and loss of electric conduction. Results. The Ho:YAG laser and the ultrasonic device were able to destroy almost all the wires. The ballistic devices and the electrohydraulic device were able to destroy thin wires. Conclusion. The operating surgeon should know the risk of damagefor every lithotripter. The Ho:YAG-laser and the ultrasonic device should be classified as dangerous for the basket wire with all adverse effects to the patient. PMID:24288527

  11. Are stone analysis results different with repeated sampling?

    PubMed Central

    Lee, Terence T. N.; Elkoushy, Mohamed A.; Andonian, Sero

    2014-01-01

    Introduction: We assessed differences in results of stone analyses on subsequent sampling. Methods: A retrospective review of patients with stone analyses at a tertiary stone centre between March 2006 and July 2012 was performed. All stones were analyzed at a centralized laboratory using infrared spectroscopy. Patients were grouped according to the first predominant stone type on record, as defined by the predominant stone component of at least 60%. Stone groups included calcium oxalate (CaOx), calcium phosphate (CaP), uric acid (UA), cystine, struvite, mixed CaOx-CaP and mixed CaOx-UA. All patients had a full metabolic stone workup. Results: Of the 303 patients with stone analyses, 118 (38.9%) patients had multiple stone analyses. The mean age was 53.4 15.1 years, and 87 (73.7%) were males. Of the 118, the initial stone analysis showed 43 CaOx, 38 CaP, 21 UA, 4 CaOx-CaP, 2 CaOx-UA, 6 cystine, and 4 struvite. There was a different stone composition in 25 (21.2%) patients with a median time delay of 64.5 days. Different compositions were found in 7 CaOx (to 3 CaP, 2 CaOx-CaP, and 2 UA), 5 CaP (to 3 CaOx and 2 CaOx-CaP), 3 UA (to 3 CaOx), 4 CaOx-CaP (to 2CaOx, 1 UA and 1 CaP), 2 CaOx-UA (to 2 CaOx) and 4 struvite (to 3 CaP and 1 UA). Conclusions: Stone composition was different in 21.2% of patients on subsequent analyses. PMID:24940457

  12. [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

  13. Kidney Stones 2012: Pathogenesis, Diagnosis, and Management

    PubMed Central

    Maalouf, Naim M.; Sinnott, Bridget

    2012-01-01

    Context: The pathogenetic mechanisms of kidney stone formation are complex and involve both metabolic and environmental risk factors. Over the past decade, major advances have been made in the understanding of the pathogenesis, diagnosis, and treatment of kidney stone disease. Evidence Acquisition and Synthesis: Both original and review articles were found via PubMed search reporting on pathophysiology, diagnosis, and management of kidney stones. These resources were integrated with the authors' knowledge of the field. Conclusion: Nephrolithiasis remains a major economic and health burden worldwide. Nephrolithiasis is considered a systemic disorder associated with chronic kidney disease, bone loss and fractures, increased risk of coronary artery disease, hypertension, type 2 diabetes mellitus, and the metabolic syndrome. Further understanding of the pathophysiological link between nephrolithiasis and these systemic disorders is necessary for the development of new therapeutic options. PMID:22466339

  14. Analysis of urinary stone components by x-ray coherent scatter: characterizing composition beyond laboratory x-ray diffractometry

    NASA Astrophysics Data System (ADS)

    Davidson, Melanie T. M.; Batchelar, Deidre L.; Velupillai, Sujeevan; Denstedt, John D.; Cunningham, Ian A.

    2005-08-01

    Monoenergetic x-ray diffraction (XRD) analysis is an established standard for the assessment of urinary stone composition. The inherent low energy of x-rays used (8 keV), however, restricts penetration depth and imposes a requirement for small powdered samples. A technique capable of producing detailed information regarding component structural arrangements in calculi non-destructively would provide clearer insights into causes of formation and subsequent growth and allow the selection of more appropriate courses of therapy. We describe a new method based on the detection of coherent scatter (CS) in stone components using polyenergetic x-rays (70 kVp) from diagnostic equipment. While the higher energy allows the analysis of intact calculi, the polyenergetic source causes an angular broadening of measured CS patterns. We show that it is possible to relate the polyenergetic (CS) and monoenergetic (XRD) measurements through a superposition integral of the monoenergetic XRD cross-section with a function representative of the polyenergetic spectrum used in CS. Experimentally acquired diffractometry cross-sections of the seven major urinary stone components were subjected to this operation, revealing good agreement of diffraction features with CS. Therefore, our CS analysis is sensitive to stone component structure, similar to conventional XRD analysis. This indicates that CS analysis can be used as a basis to classify urinary calculi by composition. The potential of identifying stone components non-destructively was demonstrated from a tomographic CS analysis of a stone-mimicking phantom. Tomographic composition maps were generated from CS patterns, showing the structural arrangement of multiple stone components within the phantom. CS analysis has the ability to detect components in the presence of many others. The ability to perform CS measurements in intact calculi would allow for the identification of stone structures critical to patient metaprophylaxis.

  15. 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.

  16. 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.

  17. Diet for Kidney Stone Prevention

    MedlinePLUS

    ... may also help prevent kidney stones, such as citrus drinks. Recommendations based on the specific type of ... do to prevent kidney stones. Some studies suggest citrus drinks like lemonade and orange juice protect against ...

  18. 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 ...

  19. KIDNEY STONES: AN UPDATE ON CURRENT PHARMACOLOGICAL MANAGEMENT AND FUTURE DIRECTIONS

    PubMed Central

    Xu, Hongshi; Zisman, Anna L.; Coe, Fredric L.; Worcester, Elaine M.

    2013-01-01

    Introduction Kidney stones are a common problem worldwide with substantial morbidities and economic costs. Medical therapy reduces stone recurrence significantly. Much progress has been made in the last several decades in improving therapy of stone disease. Areas covered 1) effect of medical expulsive therapy on spontaneous stone passage, 2) pharmacotherapy in the prevention of stone recurrence, 3) future directions in the treatment of kidney stone disease. Expert Opinion fluid intake to promote urine volume of at least 2.5L each day is essential to prevent stone formation. Dietary recommendations should be adjusted based on individual metabolic abnormalities. Properly dosed thiazide treatment is the standard therapy for calcium stone formers with idiopathic hypercalciuria. Potassium alkali therapy is considered for hypocitraturia, but caution should be taken to prevent potential risk of calcium phosphate stone formation. For absorptive hyperoxaluria, low oxalate diet and increased dietary calcium intake are recommended. Pyridoxine has been shown effective in some cases of primary hyperoxaluria type I. Allopurinol is used in calcium oxalate stone formers with hyperuricosuria. Treatment of cystine stones remains challenging. Tiopronin can be used if urinary alkalinization and adequate fluid intake are insufficient. For struvite stones, complete surgical removal coupled with appropriate antibiotic therapy is necessary. PMID:23438422

  20. 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

  1. 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.

  2. 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.

  3. Management of lower ureteric stones: a prospective study

    PubMed Central

    Morsi, Gamal A.M.; Beshir, Mansour S.M.; Soliman, Sheri S.; Galal, Hussein A.; OrtizVanderdys, 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 stonefree 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 stonefree 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 stonefree 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 stonefree 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 stonefree results, morbidity and retreatment rates for each therapy. PMID:24757544

  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. Solution mining systems and methods for treating hydrocarbon containing formations

    DOEpatents

    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.

  6. Ureteral stricture formation after ureteroscope treatment of impacted calculi: A prospective study

    PubMed Central

    Singam, Praveen; Ho, Christopher Chee Kong; Sridharan, Radhika; Hod, Rozita; Bahadzor, Badrulhisham; Goh, Eng Hong; Tan, Guan Hee; Zainuddin, Zulkifli

    2015-01-01

    Purpose Urinary calculi is a familiar disease. A well-known complication of endourological treatment for impacted ureteral stones is the formation of ureteral strictures, which has been reported to occur in 14.2% to 24% of cases. Materials and Methods This was a prospective study. Ureterotripsy treatment was used on patients with impacted ureteral stones. Then, after 3 months and 6 months, the condition of these patients was assessed by means of a kidney-ureter-bladder (KUB) ultrasound. If the KUB ultrasound indicated moderate to serious hydronephrosis, the patient was further assessed by means of a computed tomography intravenous urogram or retrograde pyelogram to confirm the occurrence of ureteral strictures. Results Of the 77 patients who participated in the study, 5 developed ureteral strictures. Thus, the stricture rate was 7.8%. An analysis of the intraoperative risk factors including perforation of the ureter, damage to the mucous membrane, and residual stone impacted within the ureter mucosa revealed that none of these factors contributed significantly to the formation of the ureteric strictures. The stone-related risk factors that were taken into consideration were stone size, stone impaction site, and duration of impaction. These stone factors also did not contribute significantly to the formation of the ureteral strictures. Conclusions This prospective study failed to identify any predictable factors for ureteral stricture formation. It is proposed that all patients undergo a simple postoperative KUB ultrasound screening 3 months after undergoing endoscopic treatment for impacted ureteral stones. PMID:25598938

  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. 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…

  9. Stone composition and metabolic status.

    PubMed

    Bibilash, B S; Vijay, Adarsh; Fazil Marickar, Y M

    2010-06-01

    This paper aims to study the correlation between biochemical risk factors of the stone former and the type of oxalate stone formed, namely calcium oxalate monohydrate (COM) and calcium oxalate dehydrate (COD). A retrospective study of 487 patients who had been attending the urinary stone clinic, Trivandrum during 1998-2007 was conducted. The stones retrieved from them were subjected to chemical analysis and FTIR spectrographic analysis. They were categorized into COM, COD, mixed COM+COD and others. Of 142 pure calcium oxalate stone patients, 87 were predominantly COM stone formers and 55 COD stone formers. Their metabolic status of 24 h urine and serum was assessed. The values of urine calcium, phosphorus, uric acid, magnesium, creatinine, oxalate, citric acid, sodium and potassium, serum values of calcium, phosphorus, uric acid, magnesium and creatinine and calculated values of creatinine clearance, tubular reabsorption of phosphate, calcium magnesium ratio and calcium oxalate ratio were recorded. Comparison was made between the COM stone group and the COD stone group. Patients forming COM stones had significantly higher mean values for urine calcium (P < 0.05), oxalate (P < 0.01) and magnesium (P < 0.05) levels and significantly lower level of urine calcium-oxalate ratio (P < 0.01) and urine calcium-magnesium ratio (P < 0.01) compared to COD stone forming patients. All other values failed to show significant difference. Patients, with higher urine oxalate, formed COM stones. Those with low magnesium (which is an inhibitor) formed more of COD stones. Urine calcium was high in both groups without showing significant variation from the mean. In patients with high calcium-oxalate and calcium-magnesium ratios, there is higher chance of forming a COD stone than COM. Identification of the crystallization pattern of the calcium stone will help in selecting treatment modalities. PMID:19921167

  10. In vitro anti-lithogenic activity of lime powder regimen (LPR) and the effect of LPR on urinary risk factors for kidney stone formation in healthy volunteers.

    PubMed

    Chariyavilaskul, Pajaree; Poungpairoj, Poonsin; Chaisawadi, Suchada; Boonla, Chanchai; Dissayabutra, Thasinas; Prapunwattana, Phisit; Tosukhowong, Piyaratana

    2015-04-01

    Hypocitraturia, hypokaliuria, and increased oxidative stress are common lithogenic risk factors found in nephrolithiasis patients, especially in Thailand. We previously developed lime powder regimen (LPR), and demonstrated that LPR delivered citraturic, alkalinizing, and antioxidative effects in kidney stone patients. In this study, in vitro anti-lithogenic activity, in vivo acute toxicity, and crossover-designed phase 1 trial (in 13 healthy volunteers) of LPR were investigated. LPR inhibited the growth of calcium oxalate monohydrate (COM) crystals in dose-dependent manner, and inhibited the intracellular production of reactive oxygen species (ROS) in COM-treated HK-2 cells. LPR did not significantly alter viability of HK-2 cells. No acute toxicity was detected in mice orally fed with LPR (10 g/kg). No adverse effect and complaint of LPR ingestion (5 g/dose) were observed in the tested volunteers. Plasma citrate was elevated at 30 min after LPR load, which was higher than the water load control. Plasma potassium was significantly elevated at 30 min after LPR load and remained high for 2 h, and at 2 h, it was significantly higher than the water load. Urinary citrate was significantly increased at 1 h after LPR load and remained high for 2 h, and at 2 h, it was significantly higher than the water load. Urinary potassium was significantly increased at 1 h after LPR load and remained high for 3 h, and its levels at 1, 2, and 3 h were significantly higher than the water load. Urinary total antioxidant status was significantly increased at 2 h after LPR load. In conclusion, LPR had an inhibitory effect on COM growth and exerted as antioxidant to attenuate ROS production in the COM-treated renal tubular cells. LPR provided citraturic, kaliuric, and antioxidative responses in healthy individuals without any adverse events. This suggests that LPR is well tolerated and safe for daily consumption. PMID:25588323

  11. CONTRASTING HISTOPATHOLOGY AND CRYSTAL DEPOSITS IN KIDNEYS OF IDIOPATHIC STONE FORMERS WHO PRODUCE HYDROXY APATITE, BRUSHITE, OR CALCIUM OXALATE STONES

    PubMed Central

    Evan, Andrew P; Lingeman, James E; Worcester, Elaine M; Sommer, Andre J; Phillips, Carrie L; Williams, James C; Coe, Fredric L

    2014-01-01

    Our previous work has shown that stone formers who form calcium phosphate (CaP) stones that contain any brushite (BRSF) have a distinctive renal histopathology and surgical anatomy when compared to idiopathic calcium oxalate stone formers (ICSF). Here we report on another group of idiopathic CaP stone formers, those forming stone containing primarily hydroxyapatite, in order to clarify in what ways their pathology differs from BRSF and ICSF. Eleven hydroxyapatite stone formers (HASF) (2 males, 9 females) were studied using intra-operative digital photography and biopsy of papillary and cortical regions to measure tissue changes associated with stone formation. Our main finding is that HASF and BRSF differ significantly from each other and that both differ greatly from ICSF. Both BRSF and ICSF patients have significant levels of Randalls plaque compared to HASF. Intra-tubular deposit number is greater in HASF than BRSF and non-existent in ICSF while deposit size is smaller in HASF than BRSF. Cortical pathology is distinctly greater in BRSF than HASF. Four attached stones were observed in HASF, three in 25 BRSF and 510 per ICSF patient. HASF and BRSF differ clinically in that both have higher average urine pH, supersaturation of CaP, and calcium excretion than ICSF. Our work suggests that HASF and BRSF are two distinct and separate diseases and both differ greatly from ICSF. PMID:24478243

  12. 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

  13. Economic impact of urinary stones

    PubMed Central

    Hyams, Elias S.

    2014-01-01

    Kidney stones have been rising in prevalence in the United States and worldwide, and represent a significant cost burden. Cost effectiveness research in this area may enable improvements in treatment efficiency that can benefit patients, providers and the healthcare system. There has been limited research in the cost effectiveness of surgical interventions for stone disease, despite the diverse treatment approaches that are available. Medical expulsive therapy (MET) has been shown to improve rates of stone passage for ureteral stones, and there is evidence that this practice should be liberalized from the standpoint of both clinical and cost effectiveness. While conservative treatment following a primary stone event appears to be cost effective, the economic impact of medical therapy for recurrent stone formers requires clarification despite its clinical efficacy. Future study regarding the cost effectiveness of prevention and interventions for stone disease are likely to improve both the quality and efficiency of care. PMID:26816777

  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 Central

    WANG, SHUO; XU, QINGQUAN; HUANG, XIAOBO; LIN, JINGXING; WANG, JINXING; WANG, XIAOFENG

    2013-01-01

    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. 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

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

    DOEpatents

    Hampikian, Janet M (Decatur, GA); Hunt, Eden M (Atlanta, GA)

    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.

  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. 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.

  20. Buried stone lines in deserts - What can they tell us about landscape evolution?

    NASA Astrophysics Data System (ADS)

    Dietze, M.; Kleber, A.

    2009-04-01

    Stone pavements are typical features of climate-sensitive arid environments. They allow formation of cumulic soils, protected from erosion, which may be used as archives that recorded past geomorphologic and pedologic processes. Stone lines within the soil column resulted from buried stone pavements. These stone lines, situated between compound soil horizons were affected by postdepositional processes that may be attributed to specific palaeoenvironmental conditions. From Cima Volcanic Field, eastern Mojave Desert, California, we present detailed alignment measurements of buried stone stratae. Soils in the study area were developed on basalt flows of middle Pleistocene age and consist mainly of aeolian dust which was overprinted by several phases of soil formation and stone pavement development. Stones that were arranged in specific depth intervals between compound soil horizons showed prominent orientation patterns that may be attributed to geomorphic processes that created, distorted or reworked at least two ancient stone pavements, now covered by sediment and the modern pavement. We suggest fluvial (re-)orientation of surficial stones prior to burial. Furthermore, a lateral displacement of clasts within the sediment matrix is recorded. The stratigraphic position of realigned stone lines within soil horizons presumably formed, both, under humid and arid environmental conditions allows the description of geomorphic processes for discrete climatic frameworks. Buried stone pavements are thus a unique opportunity for investigating past landscape dynamics, not recorded in other archives.

  1. Effect of blind treatment on stone disease.

    PubMed

    Fazil Marickar, Y M; Salim, Abiya; Vijay, Adarsh

    2010-06-01

    Most of the drugs administered to stone patients appear to be inappropriate and doing more harm than good to the patients. The objective of this paper is to identify the prevalence of blind chemotherapy among the stone patients and find out the real indication for the drugs administered. Patients who attended the stone clinic for the first time were interviewed to find out what drugs they had been taking before the attendance at the stone clinic. 350 patients consuming specific drugs relevant to stone formation at least for a period of 15 days were selected for a detailed assessment. The type of drug consumed, the dose, the duration, the side effects, compliance rate and effect on stone disease were assessed. The biochemical profile of the patients was assessed to identify the role of the therapeutic modalities utilised. Conclusions regarding the utility of drugs in the process of stone formation were made. The values were compared with those of patients not on medication and considering laboratory standards. Of the 350 patients studied, 96 patients were consuming potassium citrate in different doses, 50 were consuming allopurinol, 44 cystone, 27 potassium citrate + magnesium, 25 calcury, 24 rowatinex, 21 ayurvedic drugs, 17 dystone, 17 homeopathic medicines and 17 other drugs. The longest duration of compliance was for cystone-2.5 years. All other drugs were stopped by the patients themselves due to recurrence of symptoms. As much as 93% of the patients did not feel that there was any significant relief of symptoms. The side effects which prompted the patients to stop medicine were gastro intestinal upset, particularly with potassium citrate, rowatinex and potassium citrate + magnesium combination. The relevant biochemical changes noted were increased urinary citrate levels in patients consuming potassium citrate alone or in combination with magnesium. Serum uric acid was within normal limits in patients consuming allopurinol. Urine uric acid levels were also lower in patients on allopurinol. It is concluded that most of the drugs administered blindly were neither indicated nor beneficial for the patients. Metabolic correction has to be based on proper metabolic assessment. PMID:19997722

  2. 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

  3. 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.

  4. 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.

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

    DOEpatents

    Sisemore, Clyde J. (Livermore, CA)

    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.

  6. 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.

  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. [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

  9. 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

  10. DISPOSAL METHODS: LANDFILLS, GEOLOGIC FORMATIONS, CHEMICAL STABILIZATION, AND CHEMICAL TREATMENT

    EPA Science Inventory

    The section will deal with four hazardous waste disposal options, i.e., landfills, geologic formations, chemical stabilization, and chemical treatment. Landfilling has been the traditional method of disposing of hazardous waste. Improper land disposal has led to numerous cases of...

  11. 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…

  12. Method for inhibiting gum formation in liquid hydrocarbon mediums

    SciTech Connect

    Reid, D.K.

    1990-07-17

    This patent describes a method of inhibiting the formation of gum and sediment in a liquid hydrocarbonaceous medium. It comprises: adding to the medium an inhibiting amount of an alkyl 1,2-dihydroquinoline or polymerized alkyl 1,2-dihydroquinoline.

  13. 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.

  14. 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.

  15. 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.

  16. Lunar Tractive Forces and Renal Stone Incidence

    PubMed Central

    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

  17. 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

  18. A new method for measuring osteoclast formation by electrical impedance.

    PubMed

    Emori, Haruka; Iwai, Shinichi; Ryu, Kakei; Amano, Hitoshi; Sambe, Takehiko; Kobayashi, Takahiro; Oguchi, Tatsunori; Ohura, Kiyoshi; Oguchi, Katsuji

    2015-06-01

    Osteoclasts are important target cells for osteoporosis treatment. Recently, a real-time cell analysis (RTCA) system was developed to observe cell morphology and adhesion; however, the use of RTCA to study osteoclastogenesis has not been reported. Here, we investigated whether osteoclast formation could be monitored in real-time using RTCA. The cell index determined via electrical impedance using RTCA, and the number of osteoclasts exhibited a significant positive correlation. RTCA was useful for determining the effect of (-)-epigallocatechin-3-gallate on the inhibition of bone resorption. We established a new method of measuring osteoclast formation in real-time using RTCA. PMID:26032840

  19. 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

  20. 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.

  1. Olive stone an attractive source of bioactive and valuable compounds.

    PubMed

    Rodrguez, Guillermo; Lama, Antonio; Rodrguez, Roco; Jimnez, Ana; Guilln, Rafael; Fernndez-Bolaos, Juan

    2008-09-01

    The olive stone and seed are an important byproduct generated in the olive oil extraction and pitted table olive industries. As a lignocellulosic material, the hemicellulose, cellulose and lignin are the main components of olive stone as wells as protein, fat, phenols, free sugars and poliols composition. The main use of this biomass is as combustion to produce electric energy or heat. Other uses such as activated carbon, furfural production, plastic filled, abrasive and cosmetic or other potential uses such as biosorbent, animal feed or resin formation have been cited. In this article, an overview of the characterization and main uses of olive stone and seed are described for the first time. Also, this review discusses the potential use of this material based on each component. In this way, a new approach to the olive stone and seed by pretreating with a steam explosion followed by chemical fractionation is described. PMID:18160280

  2. Efficacy of surgical techniques and factors affecting residual stone rate in the treatment of kidney stones

    PubMed Central

    Aydemir, Hseyin; Budak, Salih; Kumsar, ?kr; Kse, Osman; Sa?lam, Hasan Salih; Adsan, ztu?

    2014-01-01

    Objective: In this study, we aimed to evaluate, the efficacy of surgical methods and the factors affecting the residual stone rate by scrutinizing retrospectively the patients who had undergone renal stone surgery. Material and methods: Records of 109 cases of kidney stones who had been surgically treated between January 2010, and July 2013 were reviewed. Patients were divided into three groups in terms of surgical treatment; open stone surgery, percutaneous nephrolithotomy (PNL) and retrograde intrarenal surgery (RIRS). Patients history, physical examination, biochemical and radiological images and operative and postoperative data were recorded. Results: The patients had undergone PNL (n=74; 67.9%), RIRS (n=22;20.2%), and open renal surgery (n=13; 11.9%). The mean and median ages of the patients were 469, 41 (2175) and, 42 (2367) years, respectively. The mean stone burden was 2.60.7 cm2 in the PNL, 1.40.1 cm2 in the RIRS, and 3.10.9 cm2 in the open surgery groups. The mean operative times were 12624 min in the PNL group, 7212 min in the RIRS group and 8222 min in the open surgery group. The duration of hospitalisation was 3.10.2 days, 1.20.3 days and 3.41.1 days respectively. While the RIRS group did not need blood transfusion, in the PNL group blood transfusions were given in the PNL (n=18), and open surgery (n=2) groups. Residual stones were detected in the PNL (n=22), open surgery (n=2), and RIRS (n=5) groups. Conclusion: PNL and RIRS have been seen as safe and effective methods in our self application too. However, it should not be forgotten that as a basical method, open surgery may be needed in cases of necessity. PMID:26328168

  3. 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).

  4. 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).

  5. Endolithic phototrophs in built and natural stone.

    PubMed

    Gaylarde, Christine C; Gaylarde, Peter M; Neilan, Brett A

    2012-08-01

    Lichens, algae and cyanobacteria have been detected growing endolithically in natural rock and in stone buildings in various countries of Australasia, Europe and Latin America. Previously these organisms had mainly been described in natural carbonaceous rocks in aquatic environments, with some reports in siliceous rocks, principally from extremophilic regions. Using various culture and microscopy methods, we have detected endoliths in siliceous stone, both natural and cut, in humid temperate and subtropical climates. Such endolithic growth leads to degradation of the stone structure, not only by mechanical means, but also by metabolites liberated by the cells. Using in vitro culture, transmission, optical and fluorescence microscopy, and confocal laser scanning microscopy, both coccoid and filamentous cyanobacteria and algae, including Cyanidiales, have been identified growing endolithically in the facades of historic buildings built from limestone, sandstone, granite, basalt and soapstone, as well as in some natural rocks. Numerically, the most abundant are small, single-celled, colonial cyanobacteria. These small phototrophs are difficult to detect by standard microscope techniques and some of these species have not been previously reported within stone. PMID:22614098

  6. 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

  7. Galaxy formation with local photoionization feedback - I. Methods

    NASA Astrophysics Data System (ADS)

    Kannan, R.; Stinson, G. S.; Macci, A. V.; Hennawi, J. F.; Woods, R.; Wadsley, J.; Shen, S.; Robitaille, T.; Cantalupo, S.; Quinn, T. R.; Christensen, C.

    2014-01-01

    We present a first study of the effect of local photoionizing radiation on gas cooling in smoothed particle hydrodynamics simulations of galaxy formation. We explore the combined effect of ionizing radiation from young and old stellar populations. The method computes the effect of multiple radiative sources using the same tree algorithm as used for gravity, so it is computationally efficient and well resolved. The method foregoes calculating absorption and scattering in favour of a constant escape fraction for young stars to keep the calculation efficient enough to simulate the entire evolution of a galaxy in a cosmological context to the present day. This allows us to quantify the effect of the local photoionization feedback through the whole history of a galaxy's formation. The simulation of a Milky Way-like galaxy using the local photoionization model forms 40 per cent less stars than a simulation that only includes a standard uniform background UV field. The local photoionization model decreases star formation by increasing the cooling time of the gas in the halo and increasing the equilibrium temperature of dense gas in the disc. Coupling the local radiation field to gas cooling from the halo provides a preventive feedback mechanism which keeps the central disc light and produces slowly rising rotation curves without resorting to extreme feedback mechanisms. These preliminary results indicate that the effect of local photoionizing sources is significant and should not be ignored in models of galaxy formation.

  8. 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.

  9. 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.

  10. 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.

  11. Treatment of urinary tract stones.

    PubMed Central

    Wickham, J E

    1993-01-01

    Replacement of open surgery with minimally invasive techniques for treating stones in the renal tract has greatly reduced patients' morbidity and mortality and the period of hospitalisation and convalescence. Extracorporeal shockwave lithotripsy does not require anaesthesia and requires little analgesia so that treatment can be given on an outpatient basis, and there is no wound to heal. Only a small puncture site is needed for percutaneous endoscopic lithotomy, and with the advent of prophylactic antibiotics there are few complications. Of renal stones, about 85% can now be successfully treated by extracorporeal lithotripsy alone, and almost all of the stones too large or hard for lithotripsy can be treated endoscopically, with ultrasonic or electrohydraulic probes being used to fragment the stone. Stones in the upper and lower thirds of the ureter can be treated by extracorporeal lithotripsy, but stones in the middle third, which cannot normally be visualised to allow focusing of the shockwaves, usually require ureteroscopy. Nearly all bladder stones can be treated by transurethral endoscopy with an electrohydraulic probe. Only the largest renal tract stones still require open surgery. Images FIG 10 p1415-a p1415-b p1416-a p1416-b p1417-a PMID:8274898

  12. 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.

  13. Formation spectra of pionic atoms in the Green's function method

    NASA Astrophysics Data System (ADS)

    Ikeno, Natsumi; Yamagata-Sekihara, Junko; Nagahiro, Hideko; Hirenzaki, Satoru

    2015-03-01

    We study the formation spectra of deeply bound pionic atoms in the (d, ^3He) reactions using the Green's function method, stimulated by recent developments in experimental techniques. The Green's function method is considered to be a better theoretical formalism than the effective number approach to evaluate the formation rate of unstable systems. We compare the calculated results by the Green's function method with those by the effective number approach in various cases. We find that the differences between the results obtained by both methods are reasonably small and we can reaffirm that the effective number approach is a good theoretical method for the analyses of the previous experimental data with typical binding-energy errors of ? B.E. ? 20keV for the deeply bound pionic atoms. On the other hand, we think that theoretical results using the Green's function method will be necessary in the near future to deduce precise information on the pion properties in nuclei from analyses of the pionic atom data with better accuracy than before.

  14. 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

  15. 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 19902011). 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

  16. Analysis of renal stones by capillary isotachophoresis.

    PubMed

    Jarolmov, Zde?ka; Lubal, P?emysl; Kanick, Viktor

    2012-08-30

    An analytical method for the determination of the composition of renal stones by capillary isotachophoresis with conductometric detection was developed. Using different leading/terminating electrolyte systems, the qualitative and quantitative analysis of organic compounds (urate, xanthate, oxalate) and inorganic ions (phosphate, Ca(2+), Mg(2+), Na(+), NH(4)(+)) species commonly present in mixed renal stones in three separate steps can be carried out with limits of detection about 10 ?mol/L. The developed method was validated by the analysis of real samples and can be used for urinary calculi classification. In addition, it was verified that this method can also be employed for the determination of the above mentioned analytes in some other samples (bones, teeth) concerning apatite biominerals (fluoro-, carbonate-, chloro-apatite). PMID:22939127

  17. 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

  18. Residual gallbladder stones after cholecystectomy: A literature review

    PubMed Central

    Chowbey, Pradeep; Sharma, Anil; Goswami, Amit; Afaque, Yusuf; Najma, Khoobsurat; Baijal, Manish; Soni, Vandana; Khullar, Rajesh

    2015-01-01

    BACKGROUND: Incomplete gallbladder removal following open and laparoscopic techniques leads to residual gallbladder stones. The commonest presentation is abdominal pain, dyspepsia and jaundice. We reviewed the literature to report diagnostic modalities, management options and outcomes in patients with residual gallbladder stones after cholecystectomy. MATERIALS AND METHODS: Medline, Google and Cochrane library between 1993 and 2013 were reviewed using search terms residual gallstones, post-cholecystectomy syndrome, retained gallbladder stones, gallbladder remnant, cystic duct remnant and subtotal cholecystectomy. Bibliographical references from selected articles were also analyzed. The parameters that were assessed include demographics, time of detection, clinical presentation, mode of diagnosis, nature of intervention, site of stone, surgical findings, procedure performed, complete stone clearance, sequelae and follow-up. RESULTS: Out of 83 articles that were retrieved between 1993 and 2013, 22 met the inclusion criteria. In most series, primary diagnosis was established by ultrasound/computed tomography scan. Localization of calculi and delineation of biliary tract was performed using magnetic resonance imaging/magnetic resonance cholangiopancreatography and endoscopic retrograde cholangiopancreatography. In few series, diagnosis was established by endoscopic ultrasound, intraoperative cholangiogram and percutaneous transhepatic cholangiography. Laparoscopic surgery, endoscopic techniques and open surgery were the most common treatment modalities. The most common sites of residual gallstones were gallbladder remnant, cystic duct remnant and common bile duct. CONCLUSION: Residual gallbladder stones following incomplete gallbladder removal is an important sequelae after cholecystectomy. Completion cholecystectomy (open or laparoscopic) is the most common treatment modality reported in the literature for the management of residual gallbladder stones. PMID:26622110

  19. Clearance of refractory bile duct stones with extracorporeal shockwave lithotripsy

    PubMed Central

    Ellis, R; Jenkins, A; Thompson, R; Ede, R

    2000-01-01

    BACKGROUNDExtracorporeal shockwave lithotripsy (ESWL) has been used since the mid-1980s to fragment bile duct stones which cannot be removed endoscopically. Early machines required general anaesthesia and immersion in a waterbath.?AIMSTo investigate the effectiveness of the third generation Storz Modulith SL20 lithotriptor in fragmenting bile duct stones that could not be cleared by mechanical lithotripsy.?METHODSEighty three patients with retained bile duct stones were treated. All patients received intravenous benzodiazepine sedation and pethidine analgesia. Stones were targeted by fluoroscopy following injection of contrast via a nasobiliary drain or T tube. Residual fragments were cleared at endoscopic retrograde cholangiopancreatography.?RESULTSComplete stone clearance was achieved in 69(83%) patients and in 18of 24patients (75%) who required more than one ESWL treatment. Stone clearance was achieved in all nine patients (100%) with intrahepatic stones and also in nine patients (100%) referred following surgical exploration of the bile duct. Complications included six cases of cholangitis and one perinephric haematoma which resolved spontaneously.?CONCLUSIONUsing the Storz Modulith, 83% of refractory bile duct calculi were cleared with a low rate of complications. These results confirm that ESWL is an excellent alternative to surgery in those patients in whom endoscopic techniques have failed.???Keywords: lithotripsy; bile duct calculi; extracorporeal lithotripsy PMID:11034593

  20. The comparative survey of Hounsfield units of stone composition in urolithiasis patients

    PubMed Central

    Shahnani, Parisa Sotoodeh; Karami, Mehdi; Astane, Bahman; Janghorbani, Mohsen

    2014-01-01

    Background: Non-contrast computed tomography (NCCT) is the diagnostic choice for renal stone disease. Knowing the composition of a stone before passage can help to choose a better management. We sought to determine whether the Hounsfield unit (HU) measured by NCCT can predict the composition. Materials and Methods: 180 urinary stones from patients seen at Shariati, Kashani and Alzahra CT centers, were submitted to stone analysis, 2012. All scans had been interpreted for HU. Primitive statistical findings showed an effect of size on the HU. To avoid confounding bias, Hounsfield Density (HD: HU/largest transverse diameter) was calculated. Statistical comparisons were performed between composition with HU and HD. Results: Calcium stones had specific ranges for HD and HU. No non-calcium stone had HU more than 448 and HD greater than 50 HU/mm. Conclusion: NCCT can differentiate just Calcium from non-calcium stones. PMID:25364366

  1. 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.

  2. 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

  3. Effectiveness of Flexible Ureterorenoscopy and Laser Lithotripsy for Multiple Unilateral Intrarenal Stones Smaller Than 2?cm

    PubMed Central

    Alkan, Erdal; Ozkanli, Oguz; Avci, Egemen; Turan, Mirac; Ba?ar, M. Murad; Acar, Oguz; Balbay, M. Derya

    2014-01-01

    Purpose. To evaluate the safety and efficacy of RIRS for the treatment of multiple unilateral intrarenal stones smaller than 20?mm. Methods. Between March 2007 and April 2013, patients with multiple intrarenal stones smaller than 20?mm were treated with RIRS and evaluated retrospectively. Each patient was evaluated for stone number, stone burden (cumulative stone length), operative time, SFRs, and complications. Results. 173 intrarenal stones in 48 patients were included. Mean age, mean number of stones per patient, mean stone burden, and mean operative time were 40.2 10.9 years (2363), 3.6 3.0 (218), 22.2 8.4?mm (1245), and 60.3 22.0 minutes (30130), respectively. The overall SFR was 91.7%. SFRs for patients with a stone burden less and greater than 20?mm were 100% (23/23) and 84% (21/25), respectively (?2 = 26.022, P < 0.001). Complications occurred in six (12.5%6/48) patients, including urinary tract infection or high-grade fever >38.5C in three cases, prolonged hematuria in two cases, and ureteral perforation in one case, all of whom were treated conservatively. No major complications occurred. Conclusions. RIRS is an effective treatment option in patients with multiple unilateral intrarenal stones especially when the total stone burden is less than 20?mm. PMID:25024702

  4. Low-dose unenhanced computed tomography for diagnosing stone disease in obese patients

    PubMed Central

    Abou El-Ghar, Mohamed E.; Shokeir, Ahmed A.; Refaie, Huda F.; El-Nahas, Ahmed R.

    2012-01-01

    Objective To evaluate the detectability, size, location and density of urinary stones with unenhanced computed tomography (CT), using the half-radiation (low) dose (LDCT) technique, compared with the standard-dose CT (SDCT), in obese patients. Patients and methods The study included 50 patients with a body mass index of >30kg/m2 and bilateral renal stones diagnosed with SDCT, and managed on one side. All the patients had LDCT during the follow-up and SDCT was used as a reference for comparison. Results Of the 50 patients, the right side was affected in 27 and the left side in 23. In all, 35 patients had a single stone while the remaining 15 had multiple stones. With SDCT, 95 stones were detected; there were 45 of ?5mm, 46 of 615mm and only four of >15mm. LDCT barely detected three stones of <3mm, compared with SDCT, while larger stones had the same appearance at both scans. The site of stone in the kidney or the ureter did not affect its detection on LDCT vs. SDCT. The mean stone diameter was identical in both techniques. At LDCT, all stones were detected with no difference in their number, location or density vs. SDCT. However, the tube current and radiation dose were significantly lower with LDCT. Conclusions In obese patients with stone disease, LDCT is as accurate as SDCT, while avoiding exposure of the patient to high-dose radiation. PMID:26558037

  5. 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

  6. 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.

  7. Ranging methods for developing wellbores in subsurface formations

    DOEpatents

    MacDonald, Duncan (Houston, TX)

    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.

  8. 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.

  9. 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.

  10. Alterations in renal stone risk factors after space flight.

    PubMed

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

    1993-09-01

    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. PMID:8345588

  11. Method for formation of subsurface barriers using viscous colloids

    DOEpatents

    Apps, John A. (Lafayette, CA); Persoff, Peter (Piedmont, CA); Moridis, George (Oakland, CA); Pruess, Karsten (Berkeley, CA)

    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.

  12. 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.

  13. 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

  14. 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

  15. Stone runs in the Falkland Islands: Periglacial or tropical?

    NASA Astrophysics Data System (ADS)

    Andr, Marie-Franoise; Hall, Kevin; Bertran, Pascal; Arocena, Joselito

    2008-03-01

    "Stone runs" is the Falklands vernacular term for openwork boulder accumulations, which include extensive blockstreams like the famous Darwin "stone-river" and associated features such as stone stripes. Since the early 20th century, they have been interpreted as the product of a suite of periglacial processes, including frost-wedging, gelifluction, frost heave, frost-sorting and snowmelt runoff. Following a literature review, the results of recent field investigations of the valley-floor blockstreams of East Falkland are presented. Access to the internal structure of these forms provides evidence for the existence of a three-fold profile, with clear vertical size gradation presenting striking similarities with an inverted weathering profile. Micromorphological analyses, SEM, XRD, thin sections and grain-size analyses lead to the hypothesis of an alternative model of stone run formation. It is suggested that the material forming the stone run profile lato sensu (including the superficial pavement) is not of periglacial origin, but derives directly from the stripping and accumulation downslope of a regolith, possibly Tertiary in age and formed under subtropical or temperate conditions. The valley-floor stone runs should, therefore, be considered as complex polygenetic landforms that may have formed according to a six-stage scenario, including in situ chemical weathering, regolith stripping by mass movements, soil formation, further regolith stripping, downslope accumulation and matrix washing-out (all phases possibly achieved by the Early Quaternary). Periglacial reworking of the stone run material would have operated at a "final" stage, i.e. during Quaternary cold stages, with boulder bioweathering and limonite-staining operating during the temperate intervals including the present one. The suggested antiquity of the Falklands blockstreams is in accordance with Caine's pioneer interpretation of Tasmania blockfields and with recent analyses and cosmogenic datings of blockfields from Scandinavia and North America.

  16. 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 25.422.0 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

  17. Influence of Ureteral Stone Components on the Outcomes of Electrohydraulic Lithotripsy

    PubMed Central

    Song, Hyeong Cheol; Jung, Ha Bum; Lee, Yong Seong; Lee, Young Goo; Kim, Ki Kyung

    2012-01-01

    Purpose We evaluated the influence of urinary stone components on the outcomes of ureteroscopic removal of stones (URS) by electrohydraulic lithotripsy (EHL) in patients with distal ureteral stones. Materials and Methods Patients with a single distal ureteral stone with a stone size of 0.5 to 2.0 cm that was completely removed by use of EHL were included in the study. Operating time was defined as the time interval between ureteroscope insertion and complete removal of ureteral stones. Ureteral stones were classified into 5 categories on the basis of their main component (that accounting for 50% or more of the stone content) as follows: calcium oxalate monohydrate (COM), calcium oxalate dihydrate, carbonate apatite (CAP), uric acid (UA), and struvite (ST). Results A total of 193 patients (131 males and 62 females) underwent EHL. The mean operating time was 25.18.2 minutes and the mean stone size was 1.150.44 cm. Calcium oxalate stones accounted for 64.8% of all ureteral stones, followed by UA (19.7%), CAP (8.3%), and ST (7.2%) stones. The mean operating time was significantly longer in the UA group (28.68.3 minutes) than in the COM group (24.07.8 minutes, p=0.04). In multivariate analyses, the stone size was negatively associated with the odds ratio (OR) for successful fragmentation. UA as a main component (OR, 0.42; 95% confidence interval, 0.20 to 0.89; p=0.023) was also found to be significantly important as a negative predictive factor of successful fragmentation after adjustment for stone size. Conclusions The results of the present study suggest that successful fragmentation by URS with EHL could be associated with the proportion of the UA component. PMID:23301129

  18. 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

  19. Value of preoperative stone scoring systems in predicting the results of percutaneous nephrolithotomy

    PubMed Central

    Aydemir, Hseyin; Halis, Fikret; Kse, Osman; Gke, Ahmet; Adsan, Oztug

    2015-01-01

    Introduction Guy's Stone Score and S.T.O.N.E. Nephrolithometry nomograms have been introduced for systematic and quantitative assessment of kidney stones. The aim of this study was to reveal the value of two scorings systems, Guy and S.T.O.N.E, most frequently used for predicting postoperative stone-free status prior to Percutaneous Nephrolithotomy (PCNL), in the prediction of postoperative results of PCNL. Material and methods We retrospectively examined patients who underwent PCNL. Preoperative abdominopelvic computerized tomography images of these patients were reviewed and scored according to the Guy and S.T.O.N.E. systems. The relationship between the Guy and S.T.O.N.E. scores, and their postoperative stone-free status, complications based on Clavien system, operation time, fluoroscopy time and period of hospitalization was compared. Results We identified a total of 102 patients who underwent PCNL between 2010 and 2014, having met the inclusion criteria. The relationships between the total S.T.O.N.E score and Clavien score (p <0.001); time of operation (p = 0.012) and stone-free status (p <0.001); Guy stone score and Clavien score (p <0.001); and period of hospitalization (p <0.001) and time of operation (p <0.001) were found to be statistically significant. There was no statistically significant relationship between Guy score and stone-free status and no statistically significant relationship was found between fluoroscopy time and both stone scoring systems. Conclusions Guy and S.T.O.N.E. scoring systems may be used as effective instruments particularly for predicting postoperative complications. PMID:26568881

  20. Treatment of patients with uric acid stones.

    PubMed

    Heilberg, Ita Pfeferman

    2016-02-01

    Uric acid nephrolithiasis and unduly acidic urinary pH are both considered a renal manifestation of insulin resistance but the underlying mechanisms for the development of low urinary pH and the propensity for uric acid stone formation are not completely elucidated. Nevertheless, excessive dietary acid intake, increased endogenous acid production and/or defective NH4+ excretion play an important role, among other factors. The main principles of therapy for uric acid nephrolithiasis are aimed at urinary alkalinization through diet modification or pharmacologic agents, increase of urinary volume, and less importantly at the reduction of uric acid excretion. PMID:26645868

  1. 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.

  2. Improved ureteral stone fragmentation catheter

    NASA Technical Reports Server (NTRS)

    Gammell, P. M.

    1981-01-01

    Catheter includes fiber optic viewer, more reliable ultrasonic probe, and better contact sensor. It is guided by four steering wires, and irrigation fluid is supplied through lumen to remove stone fragments.

  3. Formation of spatial thinking skills through different training methods.

    PubMed

    Kornkasem, Sorachai; Black, John B

    2015-09-01

    Spatial training can be durable and transferable if the training involves cognitive process-based tasks. The current study explored different spatial training methods and investigated the sequences of process-based mental simulation that was facilitated by various structures of external spatial representation, 3D technology, spatial cues, and/or technical languages. A total of 115 Columbia University's students were conducted through three experiments using a between-subjects design to examine the effects of spatial training methods on spatial ability performance. The conditions for training environments included 3D-virtual and 3D-physical interactions with abstract (nonsense-geometric) and concrete (everyday-object) contents. Overall, learners in the treatment conditions improved in their spatial skills significantly more than those in the control conditions. Particularly, 3D-direct-manipulation conditions in the third experiment added promising results about the specific sequences during spatial thinking formation processes. PMID:26224268

  4. 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

  5. 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.

  6. 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.

  7. 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.

  8. Renal struvite stones--pathogenesis, microbiology, and management strategies.

    PubMed

    Flannigan, Ryan; Choy, Wai Ho; Chew, Ben; Lange, Dirk

    2014-06-01

    Infection stones-which account for 10-15% of all urinary calculi-are thought to form in the presence of urease-producing bacteria. These calculi can cause significant morbidity and mortality if left untreated or treated inadequately; optimal treatment involves complete stone eradication in conjunction with antibiotic therapy. The three key principles of treating struvite stones are: removal of all stone fragments, the use of antibiotics to treat the infection, and prevention of recurrence. Several methods to remove stone fragments have been described in the literature, including the use of urease inhibitors, acidification therapy, dissolution therapy, extracorporeal shockwave lithotripsy, ureteroscopy, percutaneous nephrolithotomy (PCNL), and anatrophic nephrolithotomy. PCNL is considered to be the gold-standard approach to treating struvite calculi, but adjuncts might be used when deemed necessary. When selecting antibiotics to treat infection, it is necessary to acquire a stone culture or, at the very least, urine culture from the renal pelvis at time of surgery, as midstream urine cultures do not always reflect the causative organism. PMID:24818849

  9. Economic Outcomes of Treatment for Ureteral and Renal Stones: A Systematic Literature Review

    PubMed Central

    Matlaga, Brian R.; Jansen, Jeroen P.; Meckley, Lisa M.; Byrne, Thomas W.; Lingeman, James E.

    2013-01-01

    Purpose We evaluated the cost-effectiveness of ureteral/renal stone treatment by comparing ureteroscopy, extracorporeal shock wave lithotripsy and percutaneous nephrolithotomy. Materials and Methods We performed a systematic literature search to identify studies of treatment for adults with ureteral and renal stones that were published between 1995 and 2010. For inclusion in analysis studies had to provide the stone-free rate and the cost of at least 2 therapies. Results Ten studies were identified, including 8 with an observational design and 2 that synthesized data using decision modeling techniques. Five of 6 studies, including 1 of 2 from the United States, compared ureteroscopy vs shock wave lithotripsy for proximal stones and showed a higher stone-free rate and lower cost for ureteroscopy. Four of the 5 studies, including the only American study, compared ureteroscopy vs shock wave lithotripsy for distal ureteral stones and also showed such an economically dominant result. Studies of shock wave lithotripsy vs percutaneous nephrolithotomy and ureteroscopy vs percutaneous nephrolithotomy for renal stones demonstrated higher cost and a higher stone-free rate for percutaneous nephrolithotomy. Conclusions Despite the great heterogeneity and limited quality of available cost-effectiveness evaluations most studies demonstrated that ureteroscopy was more favorable than shock wave lithotripsy for ureteral stones in stone-free rate and cost. PMID:22698623

  10. 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.

  11. 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.

  12. 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.

  13. Chemical decomposition of urinary stones during holmium-laser lithotripsy: II. Evidence for photothermal breakdown

    NASA Astrophysics Data System (ADS)

    Glickman, Randolph D.; Teichman, Joel M. H.; Vassar, George J.; Weintraub, Susan T.; Chan, Kin Foong; Pfefer, T. Joshua; Welch, Ashley J.

    1999-06-01

    Because of the greater than or equal to 250 microsecond pulsewidth emitted by the Ho:YAG laser used in clinical lithotripsy, it is unlikely that stress confinement occurs within the irradiated stones. Experimental data supports a thermal mechanism for Ho:YAG laser stone ablation. Stone fragmentation occurs soon after the onset of the laser pulse, is uncorrelated to cavitation bubble formation or collapse, and is associated with low pressures (cf. part I). The mass- loss of desiccated calcium oxalate monohydrate (COM) stones exposed to 150 J from the Ho:YAG laser in air was 40 plus or minus 12 mg (mean plus or minus 1 s.d.); for hydrated stones in air was 25 plus or minus 9 mg; and for hydrated stones in water was 17 plus or minus 3 mg, p less than .001. These differences indicate that direct absorption of the laser radiation by the stone is required for the most efficient ablation. Lowering the initial temperature of COM or cystine stones also reduced the stone mass-loss following 20 J of delivered laser energy: 2.2 plus or minus 1.1 mg vs 5.2 plus or minus 1.6 mg for COM stones (-80 vs 23 degrees Celsius), and 0.8 plus or minus 0.4 mg vs 2.2 plus or minus 1.1 mg for cystine stones (-80 vs 23 degrees Celsius), p less than or equal to .05. Finally, chemical analysis of the laser-induced stone fragments revealed the presence of thermal breakdown products: CaCO3 from COM; free sulfur and cysteine from cystine; Ca2O7P2 from calcium hydorgen phosphate dihydrate, and cyanide from uric acid.

  14. 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

  15. Current approach for urinary system stone disease in pregnant women.

    PubMed

    Celik, Orcun; Trk, Hakan; Cakmak, Ozgur; Ekin, Rahmi Gokhan; Keskin, Mehmet Zeynel; Yildiz, Guner; Ilbey, Yusuf Ozlem

    2016-01-01

    Urinary system stones can be classified according to size, location, X-ray characteristics, aetiology of formation, composition, and risk of recurrence. Especially urolithiasis during pregnancy is a diagnostic and therapeutic challenge. In most cases, it becomes symptomatic in the second or third trimester. Diagnostic options in pregnant women are limited due to the possible teratogenic, carcinogenic, and mutagenic risk of foetal radiation exposure. Clinical management of a pregnant urolithiasis patient is complex and demands close collaboration between patient, obstetrician and urologist. We would like to review current diagnosis and treatment modalities of stone disease of pregnant woman. PMID:26766798

  16. 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.

  17. Efficacy of extracorporeal shockwave lithotripsy using Dornier SII in different levels of ureteral stones

    PubMed Central

    Elkholy, Mohamed M.; Ismail, Hassan; Abdelkhalek, Mohamed A.; Badr, Mohamad M.; Elfeky, Mohamed M.

    2014-01-01

    Objective: The objective of this study was to evaluate the efficacy and safety of the Dornier lithotripter S II system in the treatment of ureteral calculi. Patients and Methods: A total of 97 cases which consists of 54 males and 43 females with ureteral stones were treated by extracorporeal shock wave lithotripsy (ESWL). Mean age was 42.6 years. Inclusion criteria were solitary radiopaque ureteral stones of radiological stone size of ?1 cm. The stones were not impacted, with normal kidney functions. Procedure time, number of shocks, energy used, number of sessions and complications were reported. The outcome of ESWL was also recorded. Results: Stones were in the abdominal (upper ureter) in 50% of patients, in pelvic (middle ureter) in 47% of patients. All patients had unilateral stones and the mean stone size in maximum length was) 10 mm). Good dye excretion passing the stone was noted in all patients. Mild hydronephrosis was found in 85% of cases. A total of 49 cases were treated by a single session, while in 35% of cases two sessions were enough and 16% received three sessions. The average number of shocks per session was 3125. The average number of shocks per patient was 5962.5 shocks and average energy was 204.3 Joules. The overall stone-free rate 3 months after lithotripsy was 94%. After a single session of lithotripsy, 49 patients (49%) became stone-free. Stone free rates after ESWL for upper, middle ureteral stones were 94%, 95.7% respectively. Additional procedures were needed in only 6 cases (6%) to render patients stone-free after lithotripsy. No serious complications occurred. Conclusion: The Dornier lithotripter S II is very effective in the treatment of ureteral calculi with no major complications. PMID:25371614

  18. 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

  19. [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

  20. 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

  1. Optimal Compression Methods for Floating-point Format Images

    NASA Technical Reports Server (NTRS)

    Pence, W. D.; White, R. L.; Seaman, R.

    2009-01-01

    We report on the results of a comparison study of different techniques for compressing FITS images that have floating-point (real*4) pixel values. Standard file compression methods like GZIP are generally ineffective in this case (with compression ratios only in the range 1.2 - 1.6), so instead we use a technique of converting the floating-point values into quantized scaled integers which are compressed using the Rice algorithm. The compressed data stream is stored in FITS format using the tiled-image compression convention. This is technically a lossy compression method, since the pixel values are not exactly reproduced, however all the significant photometric and astrometric information content of the image can be preserved while still achieving file compression ratios in the range of 4 to 8. We also show that introducing dithering, or randomization, when assigning the quantized pixel-values can significantly improve the photometric and astrometric precision in the stellar images in the compressed file without adding additional noise. We quantify our results by comparing the stellar magnitudes and positions as measured in the original uncompressed image to those derived from the same image after applying successively greater amounts of compression.

  2. 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

  3. 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

  4. Kidney Stones in Children and Teens

    MedlinePLUS

    ... Email Print Share Kidney Stones in Children and Teens Page Content Article Body ​Kidney stones are hard ... age, even in premature infants , most occur in teens , with teen girls having the highest incidence. Types ...

  5. Keep Your Kidneys Clear: Kicking Kidney Stones

    MedlinePLUS

    ... made of the mineral calcium, combined with either oxalate or phosphate. Less common types of stones are ... drinks. For example, people prone to forming calcium oxalate stones should avoid spinach, peanuts and chocolate. People ...

  6. "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)

  7. Kidney stones - what to ask your doctor

    MedlinePLUS

    A kidney stone is a solid piece of material that forms in your kidney. The kidney stone may be stuck in your ureter (the tube that carries urine from your kidneys to your bladder). It also may be stuck ...

  8. 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

  9. 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.

  10. 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.

  11. 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.

  12. 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

  13. 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

  14. Minimally invasive surgical treatment for large impacted upper ureteral stones: Ureteroscopic lithotripsy or percutaneous nephrolithotomy?

    PubMed Central

    Bozkurt, Ibrahim Halil; Yonguc, Tarik; Arslan, Burak; Degirmenci, Tansu; Gunlusoy, Bulent; Aydogdu, Ozgu; Koras, Omer

    2015-01-01

    Introduction: The management of patients with large impacted upper ureteral stones is difficult; there is no standard treatment. We compared the outcomes of percutaneous nephrolithotomy (PCNL) and ureteroscopic lithotripsy (UL) to treat large (?1.5 cm), impacted, upper ureteral stones. Methods: In total, 86 patients with large impacted upper ureteral stones were included in this study. Of these patients 41 underwent UL and 45 underwent PCNL. The inclusion criteria were: longest diameter of stone ?1.5 cm, the localization of stone between the lower border of L4 spine and ureteropelvic junction and impacted stone. Results: In the UL group, we were unable to reach the stone in 3 patients because of ureteral stricture and edema despite balloon dilation. Of these 3 patients, we were unable to optimally visualize the stone in 2 patients due to bleeding and mucosal injury following balloon dilation. The stricture was too firm and could not be passed in the third patient. Also in the UL group, 15 patients had stones or big fragments which migrated into the renal collecting system. In the PCNL group, 21 patients had concurrent renal stones <1 cm and stones were successfully removed in all patients. No statistically significant difference was found between groups in terms of operation time. Mean hospital stay was significantly shorter in the UL group. Success rates were 82.3% in the UL group and 97.6% in the PCNL group (p = 0.001). Conclusion: The recent study confirms that PCNL is a safe and effective minimally invasive procedure with acceptable complication rates in the treatment of patients with large, impacted upper ureteral stones. PMID:25844097

  15. Composition of gall bladder stones associated with octreotide: response to oral ursodeoxycholic acid.

    PubMed Central

    Hussaini, S H; Pereira, S P; Murphy, G M; Kennedy, C; Wass, J A; Besser, G M; Dowling, R H

    1995-01-01

    Octreotide, an effective treatment for acromegaly, induces gall bladder stones in 13-60% of patients. Because knowledge of stone composition is essential for studies of their pathogenesis, treatment, and prevention, this was investigated by direct and indirect methods in 14 octreotide treated acromegalic patients with gall stones. Chemical analysis of gall stones retrieved at cholecystectomy from two patients, showed that they contained 71% and 87% cholesterol by weight. In the remaining 12 patients, localised computed tomography of the gall bladder showed that eight had stones with maximum attenuation scores of < 100 Hounsfield units (values of < 100 HU predict cholesterol rich, dissolvable stones). Gall bladder bile was obtained by ultrasound guided, fine needle puncture from six patients. All six patients had supersaturated bile (mean (SEM) cholesterol saturation index of 1.19 (0.08) (range 1.01-1.53)) and all had abnormally rapid cholesterol microcrystal nucleation times (< 4 days (range 1-4)), whilst in four, the bile contained cholesterol microcrystals immediately after sampling. Of the 12 patients considered for oral ursodeoxycholic acid (UDCA) treatment, two had a blocked cystic duct and were not started on UDCA while one was lost to follow up. After one year of treatment, five of the remaining nine patients showed either partial (n = 3) or complete (n = 2) gall stone dissolution, suggesting that their stones were cholesterol rich. This corresponds, by actuarial (life table) analysis, to a combined gall stone dissolution rate of 58.3 (15.9%). In conclusion, octreotide induced gall stones are generally small, multiple, and cholesterol rich although, in common with spontaneous gall stone disease, at presentation some patients will have a blocked cystic duct and some gall stones containing calcium. Images Figure 1 PMID:7890216

  16. Thiazide Diuretic Prophylaxis for Kidney Stones and the Risk of Diabetes Mellitus

    PubMed Central

    Singh, Prince; Knoedler, John J.; Krambeck, Amy E.; Lieske, John C.; Bergstralh, Eric J.; Rule, Andrew D.

    2014-01-01

    Purpose Thiazide diuretics used to treat hypertension are associated with a modest risk of diabetes mellitus. It is unknown if there is a similar risk with kidney stone prevention. Materials and Methods We identified and validated incident stone formers in Olmsted County, Minnesota from 1984 to 2011 with manual review of medical records using the Rochester Epidemiology Project. The risk of diabetes mellitus after thiazide therapy was evaluated with and without multivariate adjustment for hypertension, age, gender, race, family history of stones, body mass index and number of stone events. Results Among 2,350 incident stone formers with a median followup of 10 years, 332 (14%) were treated with thiazide diuretics at some point after the first stone event and 84 (3.6%) received the thiazide diuretic only for kidney stone prevention. Stone formers who received thiazide diuretics were more likely to be older, have hypertension, have higher body mass index and have more stone events. The incidence of diabetes mellitus at 10 years after the first stone event was 9.2% in the group that received thiazide diuretics vs 4.2% in those who did not (HR 2.91; 95% CI 2.02, 4.20). After multivariate adjustment the risk of diabetes mellitus was attenuated (HR 1.20; 95% CI 0.78, 1.83). The risk of diabetes mellitus among those receiving thiazide diuretics solely for kidney stones was further attenuated (multivariate adjusted HR 0.80; 95% CI 0.28, 2.23). Conclusions Thiazide diuretic use for kidney stone prophylaxis was not associated with a high risk of diabetes mellitus. Larger studies are needed to determine if there is a modest risk of diabetes mellitus with thiazide diuretics. PMID:24992333

  17. Distribution of ureteral stones and factors affecting their location and expulsion in patients with renal colic

    PubMed Central

    Moon, Young Joon; Kim, Hong-Wook; Kim, Jin Bum; Chang, Young-Seop

    2015-01-01

    Purpose To evaluate the distribution of ureteral stones and to determine their characteristics and expulsion rate based on their location. Materials and Methods We retrospectively reviewed computed tomography (CT) findings of 246 patients who visited our Emergency Department (ED) for renal colic caused by unilateral ureteral stones between January 2013 and April 2014. Histograms were constructed to plot the distribution of stones based on initial CT findings. Data from 144 of the 246 patients who underwent medical expulsive therapy (MET) for 2 weeks were analyzed to evaluate the factors responsible for the stone distribution and expulsion. Results The upper ureter and ureterovesical junction (UVJ) were 2 peak locations at which stones initially lodged. Stones lodged at the upper ureter and ureteropelvic junction (group A) had a larger longitudinal diameter (4.21 mm vs. 3.56 mm, p=0.004) compared to those lodged at the lower ureter and UVJ (group B). The expulsion rate was 75.6% and 94.9% in groups A and B, respectively. There was no significant difference in the time interval from initiation of renal colic to arrival at the ED between groups A and B (p=0.422). Stone diameter was a significant predictor of MET failure (odds ratio [OR], 1.795; p=0.005) but the initial stone location was not (OR, 0.299; p=0.082). Conclusions The upper ureter and UVJ are 2 peak sites at which stones lodge. For stone size 10 mm or less, initial stone lodge site is not a significant predictor of MET failure in patients who have no previous history of active stone treatment in the ureter. PMID:26495073

  18. 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.

  19. 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,…

  20. 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,

  1. Optimizing Stone-free Rates With Ureteroscopy

    PubMed Central

    Reddy, Thanmaya G; Assimos, Dean G

    2015-01-01

    Ureteroscopy is being increasingly utilized in the treatment and management of patients with renal and ureteral stones. Improving stone-free rates with ureteroscopy decreases the need for ancillary procedures and improves patient outcomes and satisfaction. This article reviews contemporary literature regarding the efficacy of a wide range of currently available techniques for improving stone-free rates with this procedure. PMID:26543430

  2. 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...

  3. Regulation by macromolecules of calcium oxalate crystal aggregation in stone formers.

    PubMed

    Wesson, J A; Ganne, V; Beshensky, A M; Kleinman, J G

    2005-06-01

    Based on the structure of kidney stones, it is likely that they form as aggregations of preformed crystals, mostly calcium oxalate monohydrate (COM). In this study, we examined the ability of a macromolecular mixture isolated from the urine of normal individuals and stone formers to inhibit aggregation of preformed COM seed crystals in a simple ionic solution using measurements of changes in the particle size distribution (PSD) of preformed COM crystal aggregates. We also examined the effect in this assay of a number of synthetic homopolymers, naturally occurring urine macromolecules, and binary mixtures thereof. The macromolecular mixtures from urine of normals and most stone formers reduced the degree of aggregation of the seed crystals, whereas 22% of stone former urine macromolecules either did not disaggregate or actually promoted further aggregation. Stone formers within one family shared this property, but a non-stone forming sibling did not. Polyanions, either synthetic or naturally occurring, induced disaggregation to an extent similar to that exhibited by normal urine macromolecules, while polycations had no effect on the PSD. However, mixing a polyanion, either poly-aspartate or osteopontin, with the polycation poly-arginine, changed their behavior from disaggregation to aggregation promotion. The disaggregating behavior of normal urinary macromolecules provides a defense against aggregation, but a minority of stone forming individuals lacks this defense, which may contribute to stone formation. PMID:15864572

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

    DOEpatents

    Li, Ruijian (Katy, TX); Karanikas, John Michael (Houston, TX)

    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.

  5. 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

  6. Endoscopic management of upper urinary tract stones.

    PubMed Central

    Tolley, D. A.; Buist, T. A.

    1986-01-01

    In a two year period from March 1983, 157 patients with upper urinary tract stones were managed primarily by endoscopy. Of 90 patients with renal stones, extraction was achieved in 91% of patients with complete extraction in 76%. Of the remaining patients with ureteric stones, successful extraction was achieved in 75%. Ten patients required open surgery which was for failed extraction in 9. Morbidity is low with a mean hospital stay of 4.7 days for patients with kidney stones, and of 3.7 days for patients undergoing extraction of ureteric stones. Images Fig. 2 PMID:3954313

  7. 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

  8. [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

  9. 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.

  10. Method and apparatus for production of subsea hydrocarbon formations

    DOEpatents

    Blandford, Joseph W. (15 Mott La., Houston, TX 77024)

    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.

  11. 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.

  12. Outcomes and Safety of Retrograde Intra-Renal Surgery for Renal Stones Less Than 2 cm in Size

    PubMed Central

    HO, Christopher C. K.; Hee, Tan Guan; Hong, Goh Eng; Singam, Praveen; Bahadzor, Badrulhisham; Md Zainuddin, Zulkifli

    2012-01-01

    Background Retrograde intra-renal surgery (RIRS) has been used to remove stones of less than 2 cm in the kidney. However, its role is not well defined. Objectives The objective of this study was to evaluate the outcomes and safety of RIRS, used either as a primary or secondary procedure, and to analyze factors predicting the stonefree rate (SFR). Patients and Methods A retrospective analysis was performed on data from patients who underwent RIRS over a 10-year period (20022012). Stone size was measured as the surface area and was calculated according to the EAU guidelines. In cases of multiple stones, the total stone burden was calculated as the sum of each stone size. Stone burden was then classified as ? 80 mm2 or > 80 mm2. RIRS was classified as primary procedure or secondary procedure (after failed extracorporeal shockwave lithotripsy or percutaneous nephrolithotripsy).Stone clearance was defined as a complete absence of stones or stones < 4 mm, which were deemed insignificant on ultrasonography and plain radiography. Results The overall SFR for renal stones treated with RIRS in our center was 55.4%, and the complication rate was 1.5%, which consisted of one case of sepsis. The only factor affecting SFR in this study was the indication for RIRS. When performed as a primary operation, RIRS showed a significantly better SFR (64.3%). The SFR for lower pole stones was only 44.4%. There were no statistically significant effects of stone burden, radio-opacity, or combination with ureteral stones on SFR. Conclusions RIRS should be used as the primary treatment for renal stones whenever possible. PMID:23573465

  13. 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

  14. 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.

  15. 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

  16. Distinguishing Characteristics of Idiopathic Calcium Oxalate Kidney Stone Formers with Low Amounts of Randall's Plaque

    PubMed Central

    Wang, Xiangling; Krambeck, Amy E.; Williams, James C.; Tang, Xiaojing; Rule, Andrew D.; Zhao, Fang; Bergstralh, Eric; Haskic, Zejfa; Edeh, Samuel; Holmes, David R.; Hernandez, Loren P. Herrera

    2014-01-01

    Background Overgrowth of calcium oxalate on Randall's plaque is a mechanism of stone formation among idiopathic calcium oxalate stone-formers (ICSFs). It is less clear how stones form when there is little or no plaque. Design, setting, participants, & measurements Participants were a consecutive cohort of ICSFs who underwent percutaneous nephroscopic papillary mapping in the kidney or kidneys containing symptomatic stones and a papillary tip biopsy from a representative calyx during a stone removal procedure between 2009 and 2013. The distribution of Randall's plaque coverage was analyzed and used to divide ICSFs into those with a high (?5%; mean, 10.5%; n=10) versus low (<5%; mean, 1.5%; n=32) amount of plaque coverage per papilla. Demographic and laboratory features were compared between these two groups. Results Low-plaque stone formers tended to be obese (50% versus 10%; P=0.03) and have a history of urinary tract infection (34% versus 0%; P=0.04). They were less likely to have multiple prior stone events (22% versus 80%; P=0.002) and had a lower mean 24-hour urine calcium excretion (18786 mg versus 29199 mg; P<0.01). Morphologically, stones from patients with low amounts of plaque lacked a calcium phosphate core by microcomputed tomography. Papillary biopsies from low plaque stone-formers revealed less interstitial and basement membrane punctate crystallization. Conclusions These findings suggest that other pathways independent of Randall's plaque may contribute to stone pathogenesis among a subgroup of ICSFs who harbor low amounts of plaque. PMID:25092598

  17. 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

  18. Intrahepatic biliary stones in children.

    PubMed

    Enriquez, G; Lucaya, J; Allende, E; Garcia-Pea, P

    1992-01-01

    Intrahepatic biliary stones in seven non-Oriental patients were studied in all by sonography, in four patients by computed tomography and in four patients by percutaneous transhepatic cholangiography. For patients had extrahepatic biliary atresia treated with portoenterostomies, one patient had undergone partial liver transplantation and of the remaining two, one had cystic fibrosis and the other immunodeficiency syndrome. All sonograms were abnormal and showed echogenic foci within the liver, with or without associated signs of biliary tract dilatation. CT confirmed the biliary tract dilatation yet calculi were identified in one patient only. PTC was particularly helpful in the patient with immunodeficiency in whom features typical of sclerosing cholangitis were found. This report emphasizes the variable radiological appearance of bile stones which to our knowledge have rarely been described in children with entities other than Oriental cholangitis. PMID:1523054

  19. 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

  20. 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)

  1. 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.

  2. 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

  3. 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

  4. 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.

  5. Method and apparatus for production of subsea hydrocarbon formations

    DOEpatents

    Blandford, Joseph W. (15 Mott La., Houston, TX 77024)

    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.

  6. Method and apparatus for production of subsea hydrocarbon formations

    DOEpatents

    Blandford, Joseph W. (15 Mott La., Houston, TX 77024)

    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.

  7. 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.

  8. 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.

  9. 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

  10. 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

  11. 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

  12. Prolonged Sleep under Stone Age Conditions

    PubMed Central

    Piosczyk, Hannah; Landmann, Nina; Holz, Johannes; Feige, Bernd; Riemann, Dieter; Nissen, Christoph; Voderholzer, Ulrich

    2014-01-01

    Study Objectives: We report on a unique experiment designed to investigate the impact of prehistoric living conditions on sleep-wake behavior. Methods: A group of five healthy adults were assessed during life in a Stone Age-like settlement over two months. Results: The most notable finding was that nocturnal time in bed and estimated sleep time, as measured by actigraphy, markedly increased during the experimental period compared to the periods prior to and following the experiment. These increases were primarily driven by a phase-advance shift of sleep onset. Subjective assessments of health and functioning did not reveal any relevant changes across the study. Conclusions: Our observations provide further evidence for the long-held belief that the absence of modern living conditions is associated with an earlier sleep phase and prolonged sleep duration. Commentary: A commentary on this article appears in this issue on page 723. Citation: Piosczyk H, Landmann N, Holz J, Feige B, Riemann D, Nissen C, Voderholzer U. Prolonged sleep under Stone Age conditions. J Clin Sleep Med 2014;10(7):719-722. PMID:25024647

  13. Percutaneous Nephrolithotomy Performed on the Kidney Stone in a Patient With Ankylosing Spondylitis: A Case Study

    PubMed Central

    Sari, Sercan; Baylan, Burhan; Sezer, Evginar; Cataroglu, Cem Koray; Ozok, Hakki Ugur; Ersoy, Hamit

    2015-01-01

    A 68-year-old man with serious cervical kyphosis and dorsolumbar scoliosis due to ankylosing spondylitis was admitted with a stone 17mm in size in left kidney lower calyx. A percutaneous nephrolithotomy operation was decided considering the size and location of stone and the anatomical deformities of patient. The kidney was accessed through monoplaner triangulation method by giving a special position of the patient's spinal deformity and stone was successfully removed. Percutaneous nephrolithotomy is a feasible method in ankylosing spondylitis patients in case that the right position is achieved. Each patient should be assessed individually deciding on treatment methods.

  14. 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.

  15. Coding region analysis of vitamin D receptor gene and its association with active calcium stone disease.

    PubMed

    Basiri, Abbas; Shakhssalim, Nasser; Houshmand, Massoud; Kashi, Amir H; Azadvari, Mohaddeseh; Golestan, Banafsheh; Mohammadi Pargoo, Esmaeel; Pakmanesh, Hamid

    2012-02-01

    The purpose of this study was to evaluate the impact of vitamin D receptor (VDR) gene polymorphisms on the status of active renal calcium stone formation. Male active renal calcium stone formers (ASF, final N = 106) with two episodes of stone relapse in the past 5 years were enrolled from December 2008 to April 2009. Controls (N = 109) were selected from age range- and gender-matched individuals who had no evidence or history of stone disease. Sequencing and single-strand conformational polymorphism were used to determine VDR polymorphisms in the patients and controls. Three polymorphisms were identified in the VDR gene: (1) start codon polymorphism (rs2228570T>C; p.M1T); (2) C/T polymorphism in the second intron (NT-029419.12: g.10416049C>T); (3) a silent polymorphism in exon 9 (rs731236T>C; p.I352I). Start codon polymorphism was the only one that was associated with the status of calcium stone formation (p < 0.05). We performed a complete coding genome analysis of VDR gene and observed that only start codon polymorphism was related to the status of active calcium stone formation. PMID:21814771

  16. 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

  17. 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.

  18. 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.

  19. Extracorporeal Shock Wave Lithotripsy for Management of Residual Stones after Ureterolithotripsy versus Mini-Percutaneous Nephrolithotomy: A Retrospective Study

    PubMed Central

    Huang, Zhichao; Zhao, Xiaokun; Zhang, Lei; Zhong, Zhaohui; Xu, Ran; Zhang, Lianping

    2013-01-01

    Purpose To compare the efficacy of extracorporeal shock wave lithotripsy in managing residual stones after ureterolithotripsy and mini-percutaneous nephrolithotomy. Materials and Methods A retrospective study was carried out of 71 patients with proximal urinary tract stones (greater than 10 mm) who underwent ureterolithotripsy or mini-percutaneous nephrolithotomy at a single institution from 2009 to 2011. The 71 patients were divided into two groups: group I (n = 37) comprised patients who underwent ureterolithotripsy, and group II (n = 34) comprised patients who underwent mini-percutaneous nephrolithotomy. Clinical characteristics, stone-free rates, stone demographics, and complications were evaluated. Results The overall stone-free rate was 90.1%. The stone-free rates in groups I and II were 97.3% and 82.4%, respectively. There was a statistically significant difference in the stone-free rates between groups I and II (P = 0.035). Neither serious intraoperative nor postoperative complications were observed. No significant difference in complications was observed between the two groups (P = 0.472). Conclusions The results of our study suggest that extracorporeal shock wave lithotripsy is an effective and safe auxiliary procedure for managing residual stones after primary endoscopic surgery. This procedure is associated with a satisfactory stone-free rate and a low complication rate, particularly for residual stones after ureteroscopic procedures. PMID:23785516

  20. 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

  1. 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.

  2. 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.

  3. 6. GRIST MILL STONES IN CENTER (VERTICAL STAND WITH HANDLE ...

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

    6. GRIST MILL STONES IN CENTER (VERTICAL STAND WITH HANDLE TO LEFT OF STONES ADJUSTS SPACE BETWEEN STONES, THUS CONTROLING FINENESS OF FLOUR. STONE CRANE AT RIGHT USED TO LIFT STONES FOR DRESSING). OTHER EQUIPMENT NOT IDENTIFIED. NOTE STAIRS IN LEFT REAR. - Hildebrand's Mill, Flint, Delaware County, OK

  4. 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 Review Board of our institution. A retrospective review was performed for 100 patients who underwent a single-session RIRS. Patients were included if the main stone had a maximal diameter between 10 and 30 mm. The presence of a residual stone was checked on postoperative day 1 and at one-month follow-up visit. Fragmentation efficacy was calculated removed stone volume (mm3) divided by operative time (min). CUSUM analysis was used for monitoring change in fragmentation efficacy, and we tested whether or not acceptable surgical outcomes were achieved. Results The mean age was 54.714.8 years. Serum creatinine level did not change significantly. Estimated GFR and hemoglobin were within normal limits postoperatively. The CUSUM curve tended to be flat until the 25th case and showed a rising pattern but declined again until the 56th case. After that point, the fragmentation efficacy reached a plateau. The acceptable level of fragmentation efficacy was 25 ml/min. Multivariate logistic regression analyses showed that stone-free rate was significantly lower for cases with multiple stones than those with a single stone (OR?=?0.147, CI 0.032 0.674, P value ?=?0.005) and for cases with higher number of sites (OR?=?0.676, CI 0.517 0.882, P value ?=?0.004). Conclusions The statistical analysis of RIRS learning experience revealed that 56 cases were required for reaching a plateau in the learning curve. The number of stones and the number of sites were significant predictors for stone-free status. PMID:24454757

  5. 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.

  6. 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.

  7. Method for determining formation quality factor from seismic data

    SciTech Connect

    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.

  8. The future of stone research: rummagings in the attic, Randall's plaque, nanobacteria, and lessons from phylogeny.

    PubMed

    Ryall, Rosemary Lyons

    2008-05-01

    The prevention or cure of stone disease will be achieved only by identifying biochemical, physiological and molecular mechanisms operating before the formation of a calculus. Yet, the gradual increase in the total number of papers devoted to the study of kidney stones that has occurred since the beginning of the 21st century can be attributed almost entirely to papers concerned with the investigation of factors associated with urolithiasis after stones have already formed. The need to prevent stones by discovering how the human body routinely stops their formation in those of us who do not suffer from them is therefore as exigent as ever and a new approach to investigating the causes of stones is urgently needed. In this paper, I develop the view that stone research will best progress by examining and understanding how healthy plants and animals control the formation of biominerals. In addition to structures like bones, teeth, shells and spines, many organisms spanning the entire phylogenetic tree form intra- and extracellular granules which are use as storage depots for calcium and other important ions, which they can reclaim to maintain homeostasis or to satisfy specific needs during periods of high demand, such as shell formation, moulting or skeletal development. These electron-dense granules, which also bear an uncanny resemblance to calcified nanobacteria, are remarkably similar in general structure, size and composition to particles observed in healthy human kidneys and in Randall's plaque. Therefore, it is likely that the granules in human kidneys fulfil analogous functions to those in other organisms-particularly in calcium homeostasis. Their study in a large range of creatures has already provided a deep well of information about their structure, movement, composition, macromolecular content, synthesis and resorption, from which we can draw to quench our thirst for knowledge of basic mechanisms and events involved in the formation of human kidney stones. PMID:18286270

  9. Seeding method with silicon powder for the formation of silicon spheres in the drop method

    NASA Astrophysics Data System (ADS)

    Liu, Zhengxin; Nagai, Takehiko; Masuda, Atsushi; Kondo, Michio; Sakai, Kazutoshi; Asai, Koichi

    2007-05-01

    Silicon spheres with a size distribution around 1.0 mm diameter, which are applicable to spherical solar cells, were formed by dropping molten silicon through a nozzle in a free-fall tube, namely, the drop method. Here we show a seeding technique for the formation of silicon spheres. In this technique, pure silicon powders with a size distribution of 1-75 ?m were ejected to the molten silicon droplets at a selected part of the free-fall tube using argon carrier gas. It was considered that the attached silicon powders on the droplets worked as nuclei and stimulated the solidification to occur at low undercooling from one place. Characterizations with scanning electron microscope, carrier lifetime, and photoluminescence measurements demonstrated that the crystallinity of silicon spheres were significant improved by the seeding method. The undercooling of molten silicon droplets at solidification was speculated to decrease from 250 C to below 50 C by seeding power ejection. This resulted in an increase of average minority carrier lifetime from <0.1 ?s to >1.0 ?s.

  10. 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.

  11. 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.

  12. 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.

  13. 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

  14. 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 17.42.12 in the PCNL group compared with 17.672.04 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

  15. A Novel Device to Prevent Stone Fragment Migration During Percutaneous Lithotripsy.

    PubMed

    Friedlander, Justin; Antonelli, Jodi A; Beardsley, Heather; Faddegon, Stephen; Morgan, Monica Sc; Gahan, Jeffrey C; Pearle, Margaret S; Cadeddu, Jeffrey A

    2014-09-12

    Purpose: We developed a novel device to capture stones in vivo in an enclosed bag ("PercSac") in order to prevent dispersion of stone fragments during percutaneous nephrolithotomy (PCNL) or cystolitholapaxy. We report on our initial feasibility trials of the PercSac device. Materials and methods: PercSac consists of a specially designed polyethylene bag that is fitted over the shaft of a rigid nephroscope. The bag is used to first entrap the target stone, then tighten around it to allow fragmentation within the bag. Matched pairs of 10 canine bladder stones (2.5 cm maximum diameter) were fragmented in a human bladder model using the CyberWand (Olympus America, Inc.) and the procedure was assessed for markers of efficiency and effectiveness. Results: Median time to entrap the stone within the PercSac was 67 sec (range 51 to 185 seconds). Median time for stone fragmentation was significantly shorter with the PercSac than without (182.0 sec [range 108-221] vs. 296.5 sec [range 226-398], p=0.004). Overall, however, there was no significant difference in the total time to entrap and fragment the stones between the 2 groups. A stone free state was not achieved for any trial without the PercSac, while 9 of 10 trials with the PercSac resulted in a stone free state. Conclusions: Use of the PercSac in conjunction with stone fragmentation has the potential to reduce the occurrence of residual fragments after PCNL or cystolitholapaxy. Further in vitro testing in a kidney model is planned. PMID:25215895

  16. 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

  17. 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.

  18. 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.

  19. 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

  20. Proper dimensioning of stone paving slabs

    NASA Astrophysics Data System (ADS)

    Schouenborg, Bjrn; Loorents, Karl-Johan; Larsson, Jrgen; Holstad, Terje

    2015-04-01

    In Europe, dimensioning of stone paving slabs is usually made according to the European product standard EN 1341: Slabs of natural stone for external paving - Requirements and test methods. An informative annex provides guidelines for determining the slab thickness depending on the flexural strength, traffic loads and surface dimensions of the slab. The present edition of the standard has been updated with a possibility to use different safety factors depending on the type of foundation, e.g. paving over a bound construction, unbound or over a gap supported on two or four sides or four corners. In addition, the safety factors differ depending on the length of the slabs. Slabs larger than 600 mm are "punished" by larger safety factors. However, these safety factors are not uncontroversial. A project was therefore undertaken to compare the calculated thickness of paving slabs strictly according to the standard requirements and the measured breaking load of tested slabs on different foundations/supports. The standard way of determining the thickness is based on measurement of the flexural strength of test prisms according to EN 12372: Natural stone test methods - Determination of flexural strength under concentrated load, e.g. with 50x50x300 mm sized prisms. The conversion into breaking load of the final slab and its thickness is based on a standard beam theory, also given in the annex of the standard. The questions to be answered by the project were whether the beam theory is appropriate for slabs, if the safety factors for different foundations are realistic and if the difference in safety factors above and below 600 mm length is relevant. The Evja granite from the SW Sweden was used for the tests on unbound and bound paving. The Offerdal schist from NW Sweden was used for testing paving over a gap with support on four corners. A large number of granite slabs ranging from 350 x 350 x 40 mm up to 1050 x 1050 x 40 mm were tested. As regards the schist specimens, the four following, commonly used dimensions were tested: 500 x 400 x 25 mm, 500 x 400 x 30 mm, 800 x 400 x 25 mm and 800 x 400 x 30 mm. In short, the results clearly indicated that the product standard recommendations generate very conservative thicknesses, i.e. too thick slabs. The use of the recommendations in the standard's annex thus results in unnecessarily high consumption of natural resources, increased environmental loads due to heavy freights, handling and more expensive paving construction. All test results will be presented together with a reasoning about an improved dimensioning system.

  1. 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.

  2. What I Need to Know about Kidney Stones

    MedlinePLUS

    ... on the type of kidney stone you had: Calcium Oxalate Stones reduce sodium reduce animal protein, such as ... Kidney stones are caused by high levels of calcium, oxalate, and phosphorus in the urine. You may have ...

  3. Changes in stone composition over two decades: evaluation of over 10,000 stone analyses.

    PubMed

    Moses, Rachel; Pais, Vernon M; Ursiny, Michal; Prien, Edwin L; Miller, Nicole; Eisner, Brian H

    2015-04-01

    To examine the changes in stone composition from 1990 to 2010. A retrospective review was performed of all renal and ureteral stones submitted from the state of Massachusetts to a single laboratory (Laboratory for Stone Research, Newton, MA) for the years 1990 and 2010. Stone composition was determined by infrared spectroscopy and/or polarizing microscopy. A total of 11,099 stones were evaluated (56.7% from 1990, 43.3% from 2010). From 1990 to 2010, the percentage of stones from females (i.e., female/male ratio) increased significantly (29.8% in 1990 to 39.1% in 2010, p < 0.001). Among women, from 1990 to 2010, there was a significant increase in stones which were >50% uric acid (7.6-10.2%, p < 0.005) and a significant decrease in struvite stones (7.8-3.0%, p < 0.001). Among women with calcium stones, the % apatite per stone decreased significantly (20.0 vs. 11.7%, p < 0.001). Among men, there were no changes in stones which were majority uric acid (11.7-10.8%, p = 0.2). Among men with calcium stones, the % apatite per stone increased significantly (9.8 vs. 12.5%, p < 0.001). Males also demonstrated a significant increase in both cystine (0.1-0.6%, p < 0.001) and struvite stones (2.8-3.7%, p = 0.02). The epidemiology of stone disease continues to evolve and appears to vary according to gender. While some of these findings may be related to population changes in body mass index and obesity, the etiology of others remains unclear. PMID:25689875

  4. 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.

  5. Method of junction formation for CIGS photovoltaic devices

    DOEpatents

    Delahoy, Alan E. (Rocky Hill, NJ)

    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.

  6. 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.

  7. 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

  8. 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.

  9. 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

  10. Orientation patterns of stone pavements as a result of modern geomorphologic processes

    NASA Astrophysics Data System (ADS)

    Dietze, Michael; Kleber, Arno

    2010-05-01

    Stone pavements are typical surface features of climate-sensitive, arid environments. They form a tightly interlocking mosaic of clasts, covering virtually stone-free aeolian material. However, this mosaic does not generally exhibit random orientation of its constituents. Rather, there are systematic unimodal to bimodal distributions of stone length axes present. These orientation patterns may be the result of active geomorphologic processes, implying the unstable and fragile nature of this landform as well as a dominant lateral geomorphologic component, not considered in existing models of stone pavement formation. Responsible processes should be controlled by relief properties and may thus be described by topographic attributes. From three study areas (Laguna Salada, Mexico, eastern Mojave Desert and southern Sevier Basin, USA) we present measurements of pavement stone orientations and their relationship to landscape parameters. From 1 by 1 m sized plots azimuthal digital images were taken, corrected, georeferenced and length as well as orientation angle of the a- and b-axes of at least 100 stones were digitised. Subsequently, statistical parameters of circular data were calculated. From a digital elevation model relief attributes were derived to test their influence on pavement patterns. Three general types of orientation patterns were identified from all study areas: unimodal, bimodal and unoriented. These types are clustered together and may change within small lateral distance. The type of pattern is not influenced by stone dimensions or the formation character of the site (i.e. basalt flow vs. alluvial fan). Relief properties (e.g. slope length, specific catchment, inclination), controlling lateral geomorphologic processes appear to play a major role in generating orientation patterns in stone pavement surfaces. Hence, from pattern analysis the dynamic nature of these features can be drawn.

  11. 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

  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. 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

  14. 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

  15. 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

  16. 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.

  17. 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).

  18. 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.

  19. 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.

  20. 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.

  1. [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

  2. 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

  3. Are Hounsfield densities of ureteral stones a predictive factor for effectiveness of extracorporeal shock wave lithotripsy?

    PubMed Central

    Cakiroglu, Basri; Eyyupoglu, S Erkan; Tas, Tuncay; Balci, MB Can; Hazar, Ismet; Aksoy, S Hilmi; Sinanoglu, Orhun

    2014-01-01

    Extracorporeal Shock Wave Lithotripsy (SWL) has long been used successfully to dissolve ureteral stones. We researched whether Hounsfield values of ureteral stones is a factor that affects the success of SWL. Methods: Data from 144 patients who had diagnoses of ureteral stones and underwent SWL, were retrospectively reviewed between January 2011 and December 2012. Urinary tomography of patients was processed and classified into 3 groups by Hounsfield units (Group 1, < 500 HU; Group 2, 500-1000 HU; and Group 3, > 1000 HU) and 2 groups by stone size (Group A; < 1 cm, Group B; > 1 cm). SWL success was analyzed for both of these group types. Failure was defined as any fragments of the stone that remained within the ureter. Results were analyzed by evaluating the predictive factors in both groups. Results: The study included 144 patients (100 men, 44 women) who fit the inclusion criteria. In Hounsfield unit Group 1 (12 women and 44 men), the mean age was 37.2 13.2, stone size was 8.5 2.5 mm, number of shocks was 3240 1414 (1200-7500) and number of treatments was 1.4 0.6. In Group 2 (26 women and 32 men), the mean age was 33.6 7.6, stone size was 9.6 3.1 mm, process number was 3375 2103 (1200-8750) and shock amount was 1.6 0.8. In Group 3 (6 women and 24 men), the mean age was 42.2 13.6, stone size was 11.7 3.0 mm, number of shocks was 4513 2458 (1300-8700) and number of treatments was 2.1 1.2. In size Group 1 (28 women and 74 men), the mean age was 35.8 10.6, stone size was 8.1 1.4 mm, process number was 3105 1604, shock amount was 1.4 0.5 and HU value was 580 297. In Group 2 (16 women and 26 men), the mean age was 39.9 14.2, stone size was 13.9 2.4 mm, number of shocks was 4722 2467, number of treatments was 2.3 1.1 and HU value was 912 270. Conclusion: Although stone density predicted the failure of SWL, size of the stone is more important criterion for successful lithotripsy of ureteral stones. PMID:24995083

  4. 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 43.71.4 and 81.36.1 mT. Most fall within the expected range of secular variation for New Zealand. However the palaeointensity of 81.346.08mT, from an archaeological site at Opihi in the south of the South Island, dated at 38220 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.

  5. Optimum nutrition for kidney stone disease.

    PubMed

    Heilberg, Ita P; Goldfarb, David S

    2013-03-01

    We summarize the data regarding the associations of individual dietary components with kidney stones and the effects on 24-hour urinary profiles. The therapeutic recommendations for stone prevention that result from these studies are applied where possible to stones of specific composition. Idiopathic calcium oxalate stone-formers are advised to reduce ingestion of animal protein, oxalate, and sodium while maintaining intake of 800 to 1200 mg of calcium and increasing consumption of citrate and potassium. There are few data regarding dietary therapy of calcium phosphate stones. Whether the inhibitory effect of citrate sufficiently counteracts increasing urine pH to justify more intake of potassium and citrate is not clear. Reduction of sodium intake to decrease urinary calcium excretion would also be expected to decrease calcium phosphate stone recurrence. Conversely, the most important urine variable in the causation of uric acid stones is low urine pH, linked to insulin resistance as a component of obesity and the metabolic syndrome. The mainstay of therapy is weight loss and urinary alkalinization provided by a more vegetarian diet. Reduction in animal protein intake will reduce purine ingestion and uric acid excretion. For cystine stones, restriction of animal protein is associated with reduction in intake of the cystine precursor methionine as well as cystine. Reduction of urine sodium results in less urine cystine. Ingestion of vegetables high in organic anion content, such as citrate and malate, should be associated with higher urine pH and fewer stones because the amino acid cystine is soluble in more alkaline urine. Because of their infectious origin, diet has no definitive role for struvite stones except for avoiding urinary alkalinization, which may worsen their development. PMID:23439376

  6. 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.

  7. 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

  8. The short-term effects of mortar joints on salt movement in stone

    NASA Astrophysics Data System (ADS)

    Perry, S. H.; Duffy, A. P.

    Salt-induced decay processes are one of the most important reasons for the decay of many stone buildings and monuments. This paper investigates the role played by masonry mortars in the movement of salts within Baumberger sandstone and Portland limestone. The methodology used involved the monitoring of stone units containing mortar joints which were exposed to a city-centre environment. Rain-water run-off was collected from the stone/mortar units during the exposure period; the units were subsequently destructively analysed. The methods of run-off and destructive sample analysis used included ion chromatography and atomic absorption spectrophotometry; stone and mortar samples were also analysed petrographically. Mortars were found to act as sinks of environmentally derived ions and as sources of mortar-derived ions in well washed surface environments. Mortar enrichment by sulphate (SO 4-), sodium (Na 2+) and chloride (Cl -) ions, which may lead to salt damage of stone around joints, was observed. High levels of calcium (Ca 2+) ions, in the form of reprecipitated calcite, were recorded in the stone, leadingto a reduction in the surface permeability of the stone, a common cause of delamination.

  9. 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

  10. Extracorporeal shock wave lithotripsy: the use of chemical treatments for improved stone comminution.

    PubMed

    Akers, S R; Cocks, F H; Weinerth, J L

    1987-11-01

    Extracorporeal shock wave lithotripsy (ESWL) can require more than two thousand acoustic shocks to achieve an adequate degree of renal calculus comminution. A decrease in the number of shocks necessary for effective treatment offers both technical and clinical benefits. The results presented here demonstrate that it is possible in particular cases to increase substantially the degree of comminution produced using a fixed number of acoustic impulses by exposing the stones to solutions of controlled pH and chemical composition during acoustic shock treatment. The largest increase in comminution was observed for magnesium ammonium phosphate hexahydrate/apatite stones exposed to citrate solutions. The smaller particle sizes are shown to result not only from stone dissolution but also from an increase in the ease of stone fracture during acoustic shocking. The degree of comminution of the largest fragment sizes was also found to be slightly increased for calcium oxalate stones by exposure to synthetic urine of elevated pH. These chemical methods of increased stone comminution appear to be directly applicable to particular cases and may have general clinical utility if suitable conditions affecting all stones can be found. PMID:3669190

  11. 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

  12. 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.

  13. 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.

  14. Various Techniques for the Surgical Treatment of Common Bile Duct Stones: A Meta Review

    PubMed Central

    Shojaiefard, Abolfazl; Esmaeilzadeh, Majid; Ghafouri, Ali; Mehrabi, Arianeb

    2009-01-01

    Common bile duct stones (CBDSs) may occur in up to 3%14.7% of all patients for whom cholecystectomy is preformed. Patients presenting with CBDS have symptoms including: biliary colic, jaundice, cholangitis, pancreatitis or may be asymptomatic. It is important to distinguish between primary and secondary stones, because the treatment approach varies. Stones found before, during, and after cholecystectomy had also differing treatments. Different methods have been used for the treatment of CBDS but the suitable therapy depends on conditions such as patient' satisfaction, number and size of stones, and the surgeons experience in laparoscopy. Endoscopic retrograde cholangiopancreatography with or without endoscopic biliary sphincterotomy, laparoscopic CBD exploration (transcystic or transcholedochal), or laparotomy with CBD exploration (by T-tube, C-tube insertion, or primary closure) are the most commonly used methods managing CBDS. We will review the pathophysiology of CBDS, diagnosis, and different techniques of treatment with especial focus on the various surgical modalities. PMID:19672460

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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

  1. Percutaneous nephrolithotomy for treating staghorn stones: 10years of experience of a tertiary-care centre

    PubMed Central

    El-Nahas, Ahmed R.; Eraky, Ibrahim; Shokeir, Ahmed A.; Shoma, Ahmed M.; El-Assmy, Ahmed M.; El-Tabey, Nasr A.; El-Kappany, Hamdy A.; El-Kenawy, Mahmoud R.

    2012-01-01

    Objective To present the results of percutaneous nephrolithotomy (PCNL) for treating staghorn stones. Patients and methods A database was compiled from the computerised files of patients who underwent PCNL for staghorn stones between 1999 and 2009. The study included 238 patients (128 males and 110 females) with a mean (SD) age of 48.9 (14) years, who underwent 242 PCNLs, and included staghorn stones that were present in the renal pelvis and branched into two or more major calyces. PCNL was performed or supervised by an experienced endourologist. All perioperative complications were recorded. The stone-free status was evaluated after PCNL and again after 3months. Results Multiple tracts were needed in 35.5% of the procedures, and several sessions of PCNL were needed in 30% of patients. There were perioperative complications in 54 procedures (22%); blood transfusion was needed in 34 patients (14%). The stone-free rate for PCNL monotherapy was 56.6% (137 patients). Secondary procedures were required for 51 patients (21%), and included shock-wave lithotripsy for 49 and ureteroscopy for two. The 3-month stone-free rate was 72.7% (176 patients). Multiple tracts resulted in an insignificantly higher overall complication rate than with a single tract (P=0.219), but the reduction in the haemoglobin level was statistically significant with multiple tracts (P=0.001). Conclusions PCNL for staghorn stones must be done by an experienced endourologist in a specialised centre with all the facilities for stone management and treatment of possible complications. The patients must be informed about the range of stone-free and complication rates, and the possibility of multiple sessions or secondary procedures. PMID:26558044

  2. 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

  3. 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.

  4. 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

  5. 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 placesPetra, Giza, Angkor, Stonehenge, Tikal, Macchu Picchu, Rapa Nui, to name a feware 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.

  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. Impact of Colic Pain as a Significant Factor for Predicting the Stone Free Rate of One-Session Shock Wave Lithotripsy for Treating Ureter Stones: A Bayesian Logistic Regression Model Analysis

    PubMed Central

    Chung, Doo Yong; Cho, Kang Su; Lee, Dae Hun; Han, Jang Hee; Kang, Dong Hyuk; Jung, Hae Do; Kown, Jong Kyou; Ham, Won Sik; Choi, Young Deuk; Lee, Joo Yong

    2015-01-01

    Purpose This study was conducted to evaluate colic pain as a prognostic pretreatment factor that can influence ureter stone clearance and to estimate the probability of stone-free status in shock wave lithotripsy (SWL) patients with a ureter stone. Materials and Methods We retrospectively reviewed the medical records of 1,418 patients who underwent their first SWL between 2005 and 2013. Among these patients, 551 had a ureter stone measuring 420 mm and were thus eligible for our analyses. The colic pain as the chief complaint was defined as either subjective flank pain during history taking and physical examination. Propensity-scores for established for colic pain was calculated for each patient using multivariate logistic regression based upon the following covariates: age, maximal stone length (MSL), and mean stone density (MSD). Each factor was evaluated as predictor for stone-free status by Bayesian and non-Bayesian logistic regression model. Results After propensity-score matching, 217 patients were extracted in each group from the total patient cohort. There were no statistical differences in variables used in propensity- score matching. One-session success and stone-free rate were also higher in the painful group (73.7% and 71.0%, respectively) than in the painless group (63.6% and 60.4%, respectively). In multivariate non-Bayesian and Bayesian logistic regression models, a painful stone, shorter MSL, and lower MSD were significant factors for one-session stone-free status in patients who underwent SWL. Conclusions Colic pain in patients with ureter calculi was one of the significant predicting factors including MSL and MSD for one-session stone-free status of SWL. PMID:25902059

  8. 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

  9. Effect of urinary stone disease and its treatment on renal function.

    PubMed

    Mehmet, Necmettin Mercimek; Ender, Ozden

    2015-05-01

    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

  10. 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

  11. 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

  12. 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

  13. 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.

  14. Melamine-related kidney stones and renal toxicity.

    PubMed

    Dalal, Rishikesh P; Goldfarb, David S

    2011-05-01

    Several well-documented outbreaks of melamine poisoning have occurred in both animals and humans during the past 7 years, which led to the identification of melamine and cyanuric acid as nephrotoxins. This Review provides an overview of the known experimental and observational data (including toxicology, epidemiology, and pathology) concerning melamine contamination of foodstuffs, both alone and in combination with cyanuric acid. The various renal effects of ingestion of these compounds in both animals and humans are described, and a hypothesis on the mechanism of formation of melamine-based kidney stones is presented. Finally, the public health measures taken in the wake of the melamine contamination events are discussed. PMID:21423252

  15. Kidney Stones in Children (Beyond the Basics)

    MedlinePLUS

    ... stones in children (Beyond the Basics) Authors Jodi Smith, MD, MPH F Bruder Stapleton, MD Section Editor ... Deputy Editor Melanie S Kim, MD Contributor disclosures Jodi Smith, MD, MPH Nothing to disclose. F Bruder Stapleton, ...

  16. 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

  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. 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.

  19. Kinetic factors influencing the dissolution behavior of calcium oxalate renal stones: a constant composition study.

    PubMed

    White, D J; Coyle-Rees, M; Nancollas, G H

    1988-11-01

    A constant composition method has been used to examine the dissolution kinetics of calcium oxalate renal stones over a wide range of undersaturation in vitro. Demineralization experiments have been carried out with the concentrations of calcium and oxalate ions and ionic strength (hence the solution undersaturation) held constant by the potentiometrically controlled addition of medium electrolyte solution as diluent, triggered by a calcium ion electrode. Kinetic data for renal stones have been compared with results obtained for synthetic calcium oxalate. In addition, constant composition results have been directly compared with results obtained using conventional dissolution methods for both calculi and synthetic calcium oxalate. Overall, calcium oxalate renal stones exhibited markedly different kinetic dissolution behavior as compared with synthetic controls. The renal stone samples dissolved more slowly at all undersaturations, exhibited increased kinetic orders of reaction, and showed reduced sensitivity to solution hydrodynamics. Stones composed of mixed hydrates of calcium oxalate (mono- and di-) came to dihydrate equilibrium in conventional experiments and underwent net dissolution in solutions supersaturated to monohydrate under constant composition conditions. No conversion of di- to monohydrate was observed under these experimental conditions. These results indicate that stone dissolution is strongly influenced by adsorbed inhibitors, presumably including matrix components, which may complicate efforts to develop systemic and/or irrigation measures effective for in situ solubilization. PMID:3145798

  20. 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

  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. 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.

  3. 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.

  4. Endoscopic management of bile duct stones.

    PubMed

    Sivak, M V

    1989-09-01

    Endoscopic sphincterotomy is the procedure of choice for choledocholithiasis in patients who have had a cholecystectomy. The bile duct is cleared of stones in about 80 to 90 percent of patients. Available data, largely retrospective, suggest that surgery and endoscopic sphincterotomy are about equal with respect to removal of stones, morbidity, and mortality. Certain technical problems are discussed, including inability to insert the papillotome, the large stone, and problems relating to anatomy such as peripapillary diverticulum and prior gastrectomy. The treatment of patients with bile duct stones who have not had a cholecystectomy, with and without cholelithiasis, is controversial. Endoscopic sphincterotomy without subsequent cholecystectomy is adequate treatment for the majority of patients who are unfit for surgery, even if there are stones in the gallbladder, provided they are asymptomatic after endoscopic removal of stones from the bile ducts. Endoscopic sphincterotomy has been performed in the treatment of gallstone-induced pancreatitis, acute obstructive cholangitis, and sump syndrome. The complication rate for endoscopic sphincterotomy ranges from 6.5 to 8.7 percent, with a mortality rate of 0 to 1.3 percent. The most common serious complications are perforation, hemorrhage, acute pancreatitis, and sepsis. PMID:2672845

  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. 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

  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. Using case method to explicitly teach formative assessment in preservice teacher science education

    NASA Astrophysics Data System (ADS)

    Bentz, Amy Elizabeth

    The process of formative assessment improves student understanding; however, the topic of formative assessment in preservice education has been severely neglected. Since a major goal of teacher education is to create reflective teaching professionals, preservice teachers should be provided an opportunity to critically reflect on the use of formative assessment in the classroom. Case method is an instructional methodology that allows learners to engage in and reflect on real-world situations. Case based pedagogy can play an important role in enhancing preservice teachers' ability to reflect on teaching and learning by encouraging alternative ways of thinking about assessment. Although the literature on formative assessment and case methodology are extensive, using case method to explore the formative assessment process is, at best, sparse. The purpose of this study is to answer the following research questions: To what extent does the implementation of formative assessment cases in methods instruction influence preservice elementary science teachers' knowledge of formative assessment? What descriptive characteristics change between the preservice teachers' pre-case and post-case written reflection that would demonstrate learning had occurred? To inve