Objective The national lifetime prevalence of urolithiasis is estimated at 6.6%in Iran.However,reports on the composition of kidney stones have been based on imprecise methods like the chemical analysis.No prior large...Objective The national lifetime prevalence of urolithiasis is estimated at 6.6%in Iran.However,reports on the composition of kidney stones have been based on imprecise methods like the chemical analysis.No prior large-scale study has reported the composition of kidney stones based on the gold-standard methods(X-ray diffraction or infrared spectroscopy)in Iran.This study aimed to provide the composition of kidney stones based on Fourier transform infrared spectroscopy.Methods This is a cross-sectional study assessing urinary stone composition from various cities in Iran at a referral center using infrared spectroscopy from February 2019 to March 2023.Results This study determined the stone composition of 1092 patients from 10 cities in Iran.Overall,the majority of stones were composed of calcium oxalate(n=498;45.6%)and uric acid(UA,n=488;44.7%)followed by cystine(n=49;4.5%)and struvite(n=28;2.6%).Stone composition in Shiraz and Isfahan was roughly similar with a higher percentage of UA stones(53.4%and 53.6%,respectively)while the capital city of Iran(Tehran)had less frequent UA stones(39.9%)with a higher percentage of calcium oxalate stones.The percentage of UA stones increased with age as it was 11.1%in children,42.7%in adults,and 83.3%in geriatric patients(p<0.001).About 29.6%of cystine stones were observed in children.Conclusion The most frequent stone composition among kidney stones in Iran was calcium oxalate and UA stones.This relative frequency of UA stones is considerably higher than many international reports from neighboring as well as distant countries.More cystine stones were observed in children and women.Geriatric patients’stones were mostly composed of UA.展开更多
Purpose: The aim of the study was to determine urodynamic findings in young women (<40 years old) with bothersome lower urinary tract symptoms. Materials and Methods: The records of 315 women were reviewed during 2...Purpose: The aim of the study was to determine urodynamic findings in young women (<40 years old) with bothersome lower urinary tract symptoms. Materials and Methods: The records of 315 women were reviewed during 2002 to 2010. Those with neurological disease, history of urogenital malignancies, urethral stricture or trauma, acute UTI, unsterile urine analysis, congenital urological disease, pelvic organ prolapse, diabetes mellitus or a primary complaint of stress incontinence were excluded. All completed the American Urological Association Symptom Index (AUASI) and underwent urodynamic studies. Results: Bladder dysfunction was diagnosed in 78.4% of the patients with urge incontinence. Bladder and voiding phase dysfunction were found in 134 (42.5%) and 110 (34.9%) of patients, respectively. Occult neurological disease was later diagnosed in 10 women (3.17%) with urge incontinence and bladder dysfunction. Discussion: Urge incontinence and voiding symptoms are frequently associated with urodynamical abnormalities. Urge incontinence and bladder dysfunction may be a sign of occult neurological disease in this population. The presenting symptoms are useful in determining the advantage of urodynamic study in this population.展开更多
One of the most important problems in the study of transient stability of power systems is the determination of perturbation’s maximum time of permanence without losing the synchronism of the generators that feed the...One of the most important problems in the study of transient stability of power systems is the determination of perturbation’s maximum time of permanence without losing the synchronism of the generators that feed the network. The problem is generally solved by either the application of the equal-area criterion or through numerical integration methods. In the present work, the phase-plane is proposed as an alternative tool to solve the above-mentioned problem with greater efficiency.展开更多
In countries like Argentina,whose economy depends heavily on crop production,the estimation of harvests is an elementary requirement.Besides providing objectivity,the use of remote sensing allows estimating yield in a...In countries like Argentina,whose economy depends heavily on crop production,the estimation of harvests is an elementary requirement.Besides providing objectivity,the use of remote sensing allows estimating yield in advance.Since the time of maximum leaf area in wheat corresponds with the critical period of the crop,a good relationship is expected between the Normalized Difference Vegetation Index(NDVI)and yield.The present study was carried out in the North of Buenos Aires province,Argentina.Based on the type of soil,the study area can be divided into two homogeneous subzones:a subzone with lower clay content in the southwestand a subzone with higher clay content in the northeast.Nine growing seasons(2003–2011)were studied.In the first five years,an empirical model was calibrated and validated with field-observed wheat yields and MOD13q1 product-NDVI data,whereas in the other four years,the calibrated model was applied by means of yield maps and by comparing with official yields.The MOD13q1 image corresponding to Julian day 289 showed the best fit between NDVI and yield to estimate wheat yield early.Through yield maps,better weather conditions showedhigher yields and higher soil productivity presented a greater proportion of the area occupied by higher yields.At department level,an R2 value of 0.75 was found after relating the estimation of the calibrated empirical model with official yields.The method used allows predicting wheat yield 30 days before harvest.Through yield maps,the NDVI perceived the temporal and spatial variability in the study area.展开更多
文摘Objective The national lifetime prevalence of urolithiasis is estimated at 6.6%in Iran.However,reports on the composition of kidney stones have been based on imprecise methods like the chemical analysis.No prior large-scale study has reported the composition of kidney stones based on the gold-standard methods(X-ray diffraction or infrared spectroscopy)in Iran.This study aimed to provide the composition of kidney stones based on Fourier transform infrared spectroscopy.Methods This is a cross-sectional study assessing urinary stone composition from various cities in Iran at a referral center using infrared spectroscopy from February 2019 to March 2023.Results This study determined the stone composition of 1092 patients from 10 cities in Iran.Overall,the majority of stones were composed of calcium oxalate(n=498;45.6%)and uric acid(UA,n=488;44.7%)followed by cystine(n=49;4.5%)and struvite(n=28;2.6%).Stone composition in Shiraz and Isfahan was roughly similar with a higher percentage of UA stones(53.4%and 53.6%,respectively)while the capital city of Iran(Tehran)had less frequent UA stones(39.9%)with a higher percentage of calcium oxalate stones.The percentage of UA stones increased with age as it was 11.1%in children,42.7%in adults,and 83.3%in geriatric patients(p<0.001).About 29.6%of cystine stones were observed in children.Conclusion The most frequent stone composition among kidney stones in Iran was calcium oxalate and UA stones.This relative frequency of UA stones is considerably higher than many international reports from neighboring as well as distant countries.More cystine stones were observed in children and women.Geriatric patients’stones were mostly composed of UA.
文摘Purpose: The aim of the study was to determine urodynamic findings in young women (<40 years old) with bothersome lower urinary tract symptoms. Materials and Methods: The records of 315 women were reviewed during 2002 to 2010. Those with neurological disease, history of urogenital malignancies, urethral stricture or trauma, acute UTI, unsterile urine analysis, congenital urological disease, pelvic organ prolapse, diabetes mellitus or a primary complaint of stress incontinence were excluded. All completed the American Urological Association Symptom Index (AUASI) and underwent urodynamic studies. Results: Bladder dysfunction was diagnosed in 78.4% of the patients with urge incontinence. Bladder and voiding phase dysfunction were found in 134 (42.5%) and 110 (34.9%) of patients, respectively. Occult neurological disease was later diagnosed in 10 women (3.17%) with urge incontinence and bladder dysfunction. Discussion: Urge incontinence and voiding symptoms are frequently associated with urodynamical abnormalities. Urge incontinence and bladder dysfunction may be a sign of occult neurological disease in this population. The presenting symptoms are useful in determining the advantage of urodynamic study in this population.
文摘One of the most important problems in the study of transient stability of power systems is the determination of perturbation’s maximum time of permanence without losing the synchronism of the generators that feed the network. The problem is generally solved by either the application of the equal-area criterion or through numerical integration methods. In the present work, the phase-plane is proposed as an alternative tool to solve the above-mentioned problem with greater efficiency.
基金This study was supported by INTA,the Argentinean National Institute of Agricultural Technology.
文摘In countries like Argentina,whose economy depends heavily on crop production,the estimation of harvests is an elementary requirement.Besides providing objectivity,the use of remote sensing allows estimating yield in advance.Since the time of maximum leaf area in wheat corresponds with the critical period of the crop,a good relationship is expected between the Normalized Difference Vegetation Index(NDVI)and yield.The present study was carried out in the North of Buenos Aires province,Argentina.Based on the type of soil,the study area can be divided into two homogeneous subzones:a subzone with lower clay content in the southwestand a subzone with higher clay content in the northeast.Nine growing seasons(2003–2011)were studied.In the first five years,an empirical model was calibrated and validated with field-observed wheat yields and MOD13q1 product-NDVI data,whereas in the other four years,the calibrated model was applied by means of yield maps and by comparing with official yields.The MOD13q1 image corresponding to Julian day 289 showed the best fit between NDVI and yield to estimate wheat yield early.Through yield maps,better weather conditions showedhigher yields and higher soil productivity presented a greater proportion of the area occupied by higher yields.At department level,an R2 value of 0.75 was found after relating the estimation of the calibrated empirical model with official yields.The method used allows predicting wheat yield 30 days before harvest.Through yield maps,the NDVI perceived the temporal and spatial variability in the study area.
