Stone Mass Research Articles

SİNOP-BOYABAT KENTSEL MİMARLIK ENVANTER RAPORU 2002 YILI ÇALIŞMASI

Boyabat, a district in Sinop, has survived as a settlement and largely preserved its histo­rical urban fabric despite our country's ra­pid urbanization. The area along the Kolaz Stream that passes through the city is a very fertile region suitable for irrigated farming though slightly steep. The fortress located to Hie west of I be urban settlement dates back to the seventh century B.C. The protec­tion of Boyabat includes two studies of evi­dence and records carried out in 1979 and 1987 by the Minis try of Culture. As a result the interior of the city was designated a Si­te Region on the Boyabat Implementation Plan that went into force in 1996. Boyabat's traditional settlement fabric pos­sesses a particular characteristic, buildings have a garden and almost all buildings are situated so that they see the fortress and were planned to be like that. As examples of traditional architecture, the housing units generally consist of a ground floor and two upper floors, in total three floors. The const­ruction system has been done on the gro­und floors with stone mass and wooden support beams and on the upper floors in the masonry fill and non-filled types with wooden frames. There are also recent buil­dings made of brick and with brick decora­tion on the facades. The work on the first portion of the Boyabat urban architectural inventor)' was carried out over the course of 15 days within the re­gion designed as a Site area. During this ti­me period a total of 394 inventory entries were prepared and the survey plans of 44 buildings drawn on a scale of 1/200, in ad­dition, one house within the Site area has upper windows and is known as the oldest house in Boyabat. Because the Boyabat urban architectural in­ventory was not within the framework of the 'TUBA-TUKSEK Pilot Project, it has been largely supported by the Boyabat Mu­nicipality and also Yildiz Technical Univer­sity.

Combining Lithoclast and ultrasound power in one device for percutaneous nephrolithotomy: in vitro results of a novel and highly effective technology

Objectives A new device for percutaneous nephrolithotomy, combining Lithoclast (LC) and ultrasound (US) lithotripsy, was developed. Under standardized in vitro conditions, we evaluated the efficacy of the new technique using artificial stones. Combined application of pneumatic and US lithotripsy was compared with each of the two components alone. Methods Five different artificial stones of defined hardness were used. Disintegration was performed under defined pressure in a water bath. The time until the first fragmentation and until complete disintegration to fragments of 2 mm or smaller was measured for LC and US alone and for combined lithotripsy. Furthermore, the disintegrated partition after 1 minute and time until 50% disintegration of each stone was determined. Results With regard to first fragmentation and complete disintegration, LC and US combination showed superior efficacy. First fragmentation was achieved 25 to 200 times faster and complete disintegration in a range of 11 to 15 minutes. No complete disintegration was possible by LC and US alone within a time limit of 20 minutes. The disintegrated stone mass after 1 minute was 1.5 to 4 times larger in combined lithotripsy and the 50% disintegration time was 30% to 50% compared with LC or US alone. No technical defects occurred. Conclusions Combining LC and US in one device for percutaneous nephrolithotomy shows promising in vitro results in an artificial stone model. It seems to provide superior efficacy in the disintegration parameters important for clinical practice.

Ramper og stilladser – Løft af store sten i oldtiden

Ramper og stilladser – Løft af store sten i oldtiden

Characterisation of the realistic impact threat from runway debris

This paper describes a study to characterise the impact threat to aircraft from runway debris. This work investigated the likelihood of an event exceeding a critical impact energy; it did not address the probability of an event occurring. Runway debris was collected from six airfields and parameters such as size fraction, mass, density, bluntness and material type were characterised. The distribution of the stone mass against frequency was accurately modelled and based on this, an expression was developed for the probability of an impact exceeding a critical level during a single take-off or landing. By considering the probability of a 50J impact from runway debris as a once in a lifetime event, the implication is that the actual threat is significantly more than the currently perceived threat. This study provides the foundations for more comprehensive studies and will give the designers improved understanding of the threat to aircraft from runway debris.

ERBIUM:YAG VERSUS HOLMIUM:YAG LITHOTRIPSY

We test the hypothesis that erbium:YAG (Er:YAG) lithotripsy is more efficient than holmium:YAG (Ho:YAG) lithotripsy. Human calculi composed of greater than 97% calcium oxalate monohydrate and cystine were studied. Calculi were irradiated in water using Er:YAG or Ho:YAG lasers. Er:YAG lithotripsy was done with a 425 microm sapphire optical fiber at a pulse energy of 50 mJ at 10 Hz. Ho:YAG lithotripsy was performed with a 365 microm low hydroxy optical fiber at a pulse energy of 500 mJ at 10 Hz or a 425 microm sapphire optical fiber at a pulse energy of 50 mJ at 10 Hz. Fragmentation was defined as the initial stone mass minus the final dominant fragment mass and normalized for incident laser fluence (energy per unit area of fiber tip). Mean fragmentation plus or minus standard deviation for calcium oxalate monohydrate was 38 +/- 27 mg for Er:YAG and 22 +/- 6 for Ho:YAG (low hydroxy silica fiber) versus 5 +/- 1 for Ho:YAG (sapphire fiber, p = 0.001). When fragmentation was normalized for incident laser fluence given different optical fiber sizes, mean fragmentation efficiency was 53.6 +/- 38.7 g-microm2/J for Er:YAG lithotripsy compared with 22.6 +/- 6.4 for Ho:YAG (low hydroxy silica fiber) lithotripsy (p = 0.04). Mean cystine fragmentation was 15 +/- 3 mg for Er:YAG versus 9 +/- 1 for Ho:YAG (sapphire fiber, p = 0.0005). Er:YAG lithotripsy is more efficient than Ho:YAG lithotripsy.

Nature, Culture, Clitter

This article addresses the problem of how to distinguish between natural and humanly modified features of the cultural landscape with reference to clitter (boulder and stone) masses in the south-west of England using the example of Leskernick hill, Bodmin Moor with its well-preserved Bronze Age settlement. We first set out a series of criteria for distinguishing between natural and humanly placed stones on the basis of a series of formal geomorphological criteria. We then discuss the stones from an archaeological perspective setting out a series of archaeological criteria by means of which we can recognize the presence of humanly modified stones. From this basis we discuss four examples in detail. Finally we attempt to interpret the significance of the cultural modification of stone masses, previously regarded by both archaeologists and geomorphologists as being entirely natural in origin, by challenging the very culture/nature distinction for ascribing meaning on which the previous considerations are made. Whilst acknowledging that the distinction between a stone that has been moved by human agency, and one that has not, is important for interpretation this does not make it more or less culturally significant.

Weight lifting and health status in the black wheatear

Male black wheatears Oenanthe leucura demonstrate an exaggerated sexual display by carrying many heavy stones (on average 3.1 kg per season for this 35-g passerine) to cavities inside caves before the start of each clutch. The energetic cost of this display is mainly determined by the size of stones, which gives rise to the largest power output of a muscle ever recorded for any species (400 W/kg), rather than the total number of stones carried, which only amounts to 1% of daily energy expenditure for a black wheatear male. We tested whether stone carrying reflected male health status by removing two primaries from a group of males, but not from controls. Experimental manipulation did not significantly affect stone carrying. Similarly, male health status measured as hematocrit, leukocyte concentration, and T-cell response to an injection with phytohemagglutinin (a lectin) was not affected by experimental manipulation. Male black wheatears that carried very heavy stones, each on average more than a quarter of their own body mass, had a stronger T-cell response to injection with a lectin than males that carried light stones. Furthermore, males that carried heavy stones had a reduced hematocrit level, which may have arisen from the effects of the extremely heavy work load. Rate of stone carrying and mass of stones was not significantly related to the abundance of two species of ectoparasites. Male black wheatears with high T-cell responses were significantly more likely to survive than males with low responses, but other measures of male performance did not differ significantly between survivors and nonsurvivors. The male stone-carrying display thus reflects male health status as demonstrated by a component of immunocompetence.

AMMONIUM ACID URATE CALCULI: A REEVALUATION OF RISK FACTORS

Purpose We reevaluate the demographic and metabolic risk factors for ammonium acid urate stones. Materials and Methods Since 1986, 23 women and 21 men ranging in age from 20 to 81 years (mean 48.7) were treated for stones partly composed of ammonium acid urate. Stone composition ranged from 2 to 60% ammonium acid urate (mean 24.1) of the total stone mass. No patient had a pure ammonium acid urate stone, although 11 (25%) had stones with ammonium acid urate as the predominant crystal. Results In the 44 patients 1 or more potential risk factors for ammonium acid urate were identified. Of the patients 11 (25%) had a history of inflammatory bowel disease with 10 (22.7%) having undergone ileostomy diversion, 6 (13.6%) admitted to a history of significant laxative use or abuse, 18 (40.9%) were morbidly obese, 16 (36.4%) had a history of recurrent urinary tract infections and 9 (20.5%) had a history of recurrent uric acid stones. Conclusions Patients clearly at risk for stones with an ammonium acid urate component include those with a history of inflammatory bowel disease and ileostomy diversion or laxative abuse. Other factors that may potentially enhance ammonium acid urate stone formation include morbid obesity, recurrent uric acid calculi and recurrent urinary tract infection. A careful history followed by further metabolic evaluation is warranted in these patients.

HOLMIUM: YAG LITHOTRIPSY EFFICIENCY VARIES WITH ENERGY DENSITY

Purpose We test the hypothesis that holmium:YAG lithotripsy efficiency varies with optical fiber sizer and energy settings (energy density). Materials and Methods The 272, 365, 550 and 940 micro m. optical fibers delivered 1 kJ. total holmium:YAG energy to calcium oxalate monohydrate calculi at energy output/pulse of 0.2 to 1.5 J. Stone mass loss was measured for each fiber energy setting. Stone crater width was characterized for single energy pulses. Fiber energy outputs were compared before and after lithotripsy. Results Stone mass loss correlated inversely with optical fiber diameter (p <0.05). Stone loss correlated with energy/pulse for the 365, 550 and 940 micro m. fibers (p <0.001). The 272 and 365 micro m. fibers yielded equivalent stone loss at 0.2 and 0.5 J. per pulse. At energies of 1.0 J. per pulse or greater the 272 micro m. optical fiber was prone to damage, and yielded reduced energy output and stone loss compared to the 365 micro m. fiber (p <0.01). Stone crater width for single pulse energies correlated with energy settings for all fibers (p <0.001). Conclusions Lithotripsy efficiency with the holmium:YAG laser depends on pulse energy output and diameter of the optical delivery fiber, implying that lithotripsy efficiency correlates with energy density. The 365 micro m. fiber is indicated for most lithotripsy applications. The 272 micro m. fiber is susceptible to damage and inefficient energy transmission at energies of 1.0 J. per pulse or greater. The 272 micro m. fiber is indicated at energies of less than 1.0 J. per pulse for small caliber ureteroscopes or when maximal flexible ureteroscope deflection is required.

Le site néolithique moyen de Derrière-les-Prés à Ernes (Calvados)

The Derrière-les-Prés passage grave at Ernes (Calvados) is situated 25 km south of Caen, on the western slope of the Laizon valley. It was partially explored around 1840 par Mr Bellivet, member of the Société des Antiquaires de Normandie. The recent large scale excavation ended in 1990. Under the remains of the levelled limestone dry stone walled monument and its rubble, artefacts and features corresponding to two anterior occupation phases were fossilized in the ancient land surface. The oldest occupation can be clearly attributed to the Cerny civilisation by a concentration of pottery and lithic artefacts. The radiocarbon dating of a surface hearth (4740- 4070 B.C.) preserved under the monument enables us, with some reservations, to associate the feature to the Cerny period. The second occupation before the use of the grave is attributed to the Middle Neolithic II, by scarcer lithic and pottery artefacts. The radiocarbon dates from two hearths in shallow pits under the rubble (4072-3797 and 4080-3743 B.C.) enable us to attribute them either to a domestic occupation prior to the grave, or to an occupation associated to its erection and use. The monumental phase begins with the laying out of the funerary chamber, probably by temporary pegging, marked in the ancient ground level by a circle of post hole stones. This state has not been dated, neither has the construction of a double faced wall. The later consolidation however, consisting of an annular mass of stones, is dated by animal bones abandoned in the stone work (3950-3528 B.C.). The grave use is certified by a bone date (3950-3190 B. C.) from a single skeleton, that of a dwarf, found partially in situ. A pedestal based dish found in the sepulchral area confirms that the passage grave was in use during the Middle Neolithic II. The mid-neolithic environment is mainly defined by anthracological analysis. The results show selective use of large pines and oaks. The presence of ash shows use of valley bottom resources. Hazel and Pomaceaous trees mark the transition to the agrarian space in which we find cereal growing (wheat), and classical animal husbandry (Bovidae, Ovicapridae and pigs) in a not well defined area.

Deterioration of Pentelic marble, Portland limestone and Baumberger sandstone in laboratory exposures to NO 2: A comparison with exposures to gaseous HNO 3

The effects of nitrogen dioxide on three calcareous stones (Pentelic marble, Portland limestone and Baumberger sandstone), used extensively in historic buildings, have been investigated under different conditions of relative humidity, mass of stone and grain size of stone. It was found that all three stones are not good sinks for NO 2. Pentelic marble and Portland limestone exhibit relatively low vulnerability to NO 2 and this does not vary with relative humidity significantly. The vulnerability of Baumberger sandstone, on the other hand, decreases with an increase in relative humidity and approaches those of Portland limestone and Pentelic marble at very high relative humidities. An expression has been derived enabling the comparison of the vulnerability of each stone to NO 2 and gaseous HNO 3. Assuming that the presence of other substances in the atmosphere of a city has a negligibly small effect on the validity of this expression it has been estimated that in Athens gaseous HNO 3 is more corrosive than NO 2 for marble monuments, in spite of its presence at appreciably lower concentrations. This conclusion can be generalized for all cities with a similar nature of air pollution.

Deterioration of pentelic marble, Portland limestone and baumberger sandstone in laboratory exposures to gaseous nitric acid

The effects of gaseous nitric acid on three calcareous stones (Pentelic marble, Portland limestone and Baumberger sandstone), used extensively in historic buildings, have been investigated under different conditions of relative humidity, mass of stone, nitric acid concentration, grain size of stone and flow rate of nitric acid mixture. It was found that all three stones are good sinks for gaseous nitric acid. Pentelic marble proved to be more vulnerable at relatively high humidities in spite of its low porosity. The other two stones behave similarly in spite of the difference in their chemical constitutions. Apparently this difference is counterbalanced by their great difference in porosity.

Experience with extracorporeal shock-wave lithotripsy (ESWL) for urinary calculi.

Over a 36-month period 2800 patients were subjected to extracorporeal shock-wave lithotripsy (ESWL). A total of 5154 procedures were done. Best results were seen with renal pelvic calculi (not larger than 2.5 cm in diameter). Fragments of crushed lower calyceal calculi proved the most difficult to eliminate. As ureteral stone localization approached the bladder, the ESWL results were poorer. Post-ESWL complications were proportional to the stone mass; the higher the mass the more numerous the complications tended to be. Besides erythrocyturia and gross haematuria renal colic was the most frequent complication in almost 60% of the patients. Less prevalent were impacted ureteral stones, subcapsular haematoma and fever. At our institution, thanks to the ESWL method about 80% of the patients were spared surgery.

Color Flow Doppler Sonography for Extracorporeal Shock Wave Lithotripsy

This report documents the usefulness of color Doppler sonography for early verification of urinary stone fragmentation during extracorporeal shock wave lithotripsy with ultrasonographic focusing. In the experimental study lithotripsy was performed on human urinary stones placed in pig kidneys. Increasing color flow within the stone mass created by movement of small fragments indicated fragmentation earlier than pixel movement on the standard gray scale sonogram. The success of treatment was demonstrated macroscopically. In the clinical study 25 patients with radiopaque kidney stones were treated by color Doppler guided shock wave lithotripsy and compared to a control group of 32 patients with similar stone characteristics in whom the end point of treatment was chosen based on B-mode sonography alone. The amount of color flow within the stone reflex determined the end point of treatment. The degree of fragmentation was confirmed by fluoroscopy immediately after treatment. Disintegration was successful in all cases and fragments passed spontaneously.Color Doppler imaging during shock wave lithotripsy provides reliable information on the spatial and temporal characteristics of stone fragmentation, and is superior to B-mode sonography by providing more immediate, objective information on stone fragmentation and allowing better evaluation of the focal zone. With the help of this technique, the number of applied shock waves could be reduced by 20% compared with the control group.

Results of extracorporeal shock wave lithotripsy of gall bladder stones in 693 patients: a plea for restriction to solitary radiolucent stones.

During a period of 24 months 693 consecutive patients with symptomatic gall bladder stones (526 males, 167 females; mean age 51 years, range 18-89) were treated by extracorporeal shock wave lithotripsy with a Piezolith 2300. The procedure was carried out on an out-patient basis without analgesics or sedatives. Concomitant chemolitholytic treatment (ursodeoxycholic and chenodeoxycholic acid 7.5 mg/kg/day each) was administered until three months after total fragment clearance for a maximum therapy period of 1.5 years. In 601 patients with radiolucent stones complete clearance of all fragments was obtained after three, six, 12, and 18 months in respectively 20, 41, 64, and 78%. Actuarial analysis of the subgroups according to the stone mass (size and number) selected an ideal patient population with solitary stones less than 20 mm diameter (84% stone free after one year). The results are significantly less good when the greater the number of stones or their maximal diameter increases. Treatment was interrupted in 3.6% of the patients. In 90 sludge or fragments remain present. Twenty five patients were lost to follow up for non-biliary reasons. Stone recurrence was 5.7% at one year and was observed both in patients with solitary and multiple stones. A cost effectiveness analysis suggests that laparoscopic cholecystectomy is the most effective and economic solution, although extracorporeal shock wave lithotripsy for solitary radiolucent stones less than 2 cm is cheaper than conventional cholecystectomy. Extracorporeal shock wave lithotripsy for multiple stones is the most expensive and least effective option.

Plain Radiography, Renography, and 99mTc-DMSA Renal Scintigraphy before and after Extracorporeal Shock Wave Lithotripsy for Urolithiasis

Eighteen patients were evaluated before and 5 weeks after the first treatment with extracorporeal shock wave lithotripsy (ESWL) using abdominal plain radiography, 131I-hippuran probe renography, and 99mTc-dimercaptosuccinic acid scintigraphy. In 6 patients no urolithiasis was present on the post ESWL plain radiograph, in 7 the size had decreased, and in 5 the stone mass was unchanged. The renograms were within normal range in the 6 patients who were cured by ESWL, whereas this was the case for only 4 of the 12 who still had renal calculi. In 2 patients pelvic stones had descended into the ureter after ESWL, and the renograms indicated obstruction. Another 3 patients had ureteral stones, whereas in the remaining 7 patients only pelvic stones were found on the plain radiographs. In no patient did the scintigrams reveal scars. It is concluded that abdominal plain radiography of the urinary tract and probe renography are complementary and sufficient in the monitoring of patients with urolithiasis post ESWL.

Role of Metabolic Evaluation and Specific Prophylaxis in the Long-Term Outcome of Extracorporeal Shock Wave Lithotripsy in Children*

Children (28 boys, 24 girls) with an average age of 10.1 years (range 2–17) who underwent 63 sessions of extracorporeal shock wave lithotripsy for 64 urinary stones (57 renal, 7 ureteral) between 1984 and 1991 have been evaluated with special regard to long-term recurrences and stone regrowth. The first 10 patients were treated on a Dornier HM3, the rest on the Siemens Lithostar. Of the 52 patients, 35 were first-time stone formers, and 17 had recurrent disease. A uniform metabolic evaluation with 24-hour urinalysis was not performed in all patients. Fourteen children received urinary calcium analysis according to Pak's test. After 3 months, 93% were either stone free or had a residual stone mass of less than 3 mm. Within an average follow-up of 39.3 (9–80) months, 74% were stone free, 9.5% had recurrences, and 17% showed regrowth. Only 1 of 16 patients who received specific prophylaxis for hypercalciuria (n = 6), cystinuria (n = 6), or infection stones (n = 4) developed new stone episodes, while the other 10 patients with either recurrence or regrowth belonged to the no-prophylaxis group. We think that all children with urolithiasis should undergo a metabolic evaluation and have specific prophylaxis to enhance the long-term stone-free rate following SWL.

Management of Ureteral Stones by Extracorporeal Shock Wave Lithotripsy Using Lithostar Lithotriptor

In 282 patients 290 ureteral stones were treated with extracorporeal shock wave lithotripsy using the Lithostar lithotriptor. Stones were in the upper ureter in 198 units (68.3%), middle ureter in 36 (12.4%) and lower ureter in 56 (19.3%). The average stone mass was 11.9 mm. and the mean number of shock waves was 4,913 for all levels with a mean kv. of 16.9. The average number of sessions was 1.5 for all sites. Auxiliary measures in the form of ureteral catheterization were done in 24 patients (8.5%) and internal stenting in 12 (4.25%), all of whom had upper or middle ureteral stones. Disintegration of the stones was achieved in 99% of the upper, 93.7% of the middle and 91.7% of the lower ureteral stones. However, clearance of fragments within 3 months from the last session was achieved in 94.8% of the upper, 87.5% of the middle and 91.7% of the lower ureteral stones for an overall stone-free rate of 93.3%.

Plain Radiography, Renography, and99mTc-DMSA Renal Scintigraphy Before and After Extracorporeal Shock Wave Lithotripsy for Urolithiasis

Eighteen patients were evaluated before and 5 weeks after the first treatment with extracorporeal shock wave lithotripsy (ESWL) using abdominal plain radiography, 131I-hippuran probe renography, and 99mTc-dimercaptosuccinic acid scintigraphy. In 6 patients no urolithiasis was present on the post ESWL plain radiograph, in 7 the size had decreased, and in 5 the stone mass was unchanged. The renograms were within normal range in the 6 patients who were cured by ESWL, whereas this was the case for only 4 of the 12 who still had renal calculi. In 2 patients pelvic stones had descended into the ureter after ESWL, and the renograms indicated obstruction. Another 3 patients had ureteral stones, whereas in the remaining 7 patients only pelvic stones were found on the plain radiographs. In no patient did the scintigrams reveal scars. It is concluded that abdominal plain radiography of the urinary tract and probe renography are complementary and sufficient in the monitoring of patients with urolithiasis post ESWL.

Differences of pancreatic stone morphology and content in patients with pancreatic lithiasis

Pancreatic stones from 25 patients were compared by morphological and/or radiological examination. Twenty patients, mostly alcoholics, had calcified stones. Five (four nonalcoholic women) had radiolucent stones. Aspect and consistency of calcified stones varied from compact and resistant to coralliform and brittle but were identical in the same patient. In the coralliform type, organic fibrils with a diameter up to 10 microm and a length up to a few centimeters were observed, strongly attached to mineral crystals. The lithostathine (formerly called pancreatic stone protein, PSP) content was estimated in each stone significantly lower in the populations with larger stone mass, compared to populations with small amounts of stones. Transparent stones were built up of an amorphous material solubilized at acidic pH and corresponding to degraded forms of lithostathine-S (S for secretory). In one patient, we followed over seven years the evolution of a radiolucent calculus. We observed that the radiolucent core occurred first, and was secondarily wrapped in a calcified shell. We conclude that morphological differences observed in this study among pancreatic stones suggest that different mechanisms have been involved in their formation. Among them, lithostathine transformation into insoluble polypeptides may provide different types of protein aggregates, some of them being able to promote CaCO(3) apposition and others having no affinity for calcium.