Journal of maternal-fetal investigation : the official journal of French Society of Ultrasound in Medicine and Biology ... [et al.]最新文献

{"title":"The Effect of Oral Ketanserin on Fetal Heart Rate Parameters.","authors":"Steyn,&nbsp;Odendaal","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>> Objective: To determine the effects of ketanserin given from early in the midtrimester of pregnancy on fetal heart rate parameters later in pregnancy. Methods: Patients with diastolic blood pressure persistently higher than 80 mm Hg between 12 and 20 weeks' gestational age were randomized to receive either ketanserin or placebo. Both groups also got 75 mg of aspirin per day. The fetal heart rate was monitored once every fortnight from 28 weeks' gestation and weekly from 36 weeks onward. Recordings were made with the Sonicaid System 8000 and continued until the Dawes and Redman criteria were met. Results: The Dawes and Redman criteria were met within 10 min in 54% of recordings in both study groups, whereas they were not met in 4.5 and 3.3% of recordings in the ketanserin group and placebo group, respectively (P = 0.58). The mean time to meet these criteria duration per recording was 16.9 min in the ketanserin group and 16.2 min in the placebo group (P = 0.83). There were no significant differences between the two study groups in fetal heart rate variability, accelerations, or decelerations before 38 weeks' gestation. Thereafter the mean minute range and short-term and baseline variability were significantly higher in the ketanserin group, and significantly more accelerations of the fetal heart were recorded in the ketanserin group. Conclusions. Ketanserin does not influence the fetal heart rate adversely and may even be associated with improved recordings late in pregnancy.</p>","PeriodicalId":79506,"journal":{"name":"Journal of maternal-fetal investigation : the official journal of French Society of Ultrasound in Medicine and Biology ... [et al.]","volume":"8 3","pages":"126-129"},"PeriodicalIF":0.0,"publicationDate":"1998-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20658771","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Differences between Twin Umbilical Coiling Indices Correlate to Differences in Twin Weight and Doppler Indices.","authors":"Degani,&nbsp;Lewinsky,&nbsp;Aharoni,&nbsp;Gonen,&nbsp;Ohel","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>> Objective: The aim of our study was to evaluate sonographic and Doppler detectable differences in umbilical coiling index and fetoplacental circulation of discordant twins. Study Design: Doppler blood flow studies in 13 pairs of concordant and 20 pairs of discordant twins were performed from umbilical artery, middle cerebral artery, inferior vena cava, and ductus venosus. Flow studies were compared and correlated with the antenatal sonographic coiling index and the actual umbilical cord length, number of vascular helices, and birth weight. All studies were performed within 72 h before delivery. Pulsatility index (PI) values were calculated for the arteries and preload index (PLI) values for the veins. The umbilical coiling index (CI) was calculated using sonographic longitudinal views of cord vessels from several segments antenatally and by dividing the total number of helices by cord length (cm) postnatally. Discordancy was defined as a more than 20% intrapair actual birth weight difference. For all these index values the intertwin differences (Delta values) were calculated by subtracting the values obtained in the larger twin with those of the smaller twin. Results: The mean +/- SD intertwin difference in umbilical coiling index was 27.4 +/- 10.5% in the antepartum period and 28.9 +/- 10.0% after birth. Regression analysis showed a significant linear trend (r = 0.77, P < 0.001) between intertwin birth weight difference (DeltaBW) and intertwin coiling index difference (DeltaCI). A good correlation was found between DeltaCI and DeltaPLI in the ductus venosus (r = 0.63, P < 0.05), DeltaPLI in the inferior vena cava (r = 0.51, P < 0.005), and DeltaPI in the middle cerebral artery (r = 0.44, P < 0.05). Conclusions: Intertwin difference in antepartum umbilical coiling index can be determined by ultrasound and correlates well with: 1) the actual difference in coiling indices at birth, 2) the intertwin birth weight difference and 3) the intertwin Doppler flow characteristics in the fetal cerebral and venous circulation.</p>","PeriodicalId":79506,"journal":{"name":"Journal of maternal-fetal investigation : the official journal of French Society of Ultrasound in Medicine and Biology ... [et al.]","volume":"8 3","pages":"130-133"},"PeriodicalIF":0.0,"publicationDate":"1998-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20658772","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Elevated Amniotic Fluid Interleukin-6 as a Predictor of Neonatal Periventricular Leukomalacia and Intraventricular Hemorrhage.","authors":"Martinez,&nbsp;Figueroa,&nbsp;Garry,&nbsp;Visintainer,&nbsp;Patel,&nbsp;Verma,&nbsp;Sehgal,&nbsp;Tejani","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>> Objective: To investigate the relationship between amniotic fluid interleukin-6 levels and the development of periventricular leukomalacia and intraventricular hemorrhage in the preterm neonate and to compare the value of amniotic fluid interleukin-6 with amniotic fluid culture and histologic chorioamnionitis in the prediction of periventricular leukomalacia and intraventricular hemorrhage. Methods: 119 women, between 20 and 34 weeks gestation, in preterm labor with intact membranes, underwent transabdominal amniocentesis. Amniotic fluid was cultured for aerobic and anaerobic bacteria, Ureaplasma urealyticum and Mycoplasma hominis. Amniotic fluid interleukin-6 levels were determined by enzyme-linked immunosorbent assay. The placentas were examined for histopathologic evidence of inflammation. Where the birth weight was <2,000 g, transfontanelle cranial sonography was performed on the 3rd and 7th days of life for diagnosis of periventricular leukomalacia and intraventricular hemorrhage. Student's t test, the Mann-Whitney U test, likelihood ratio chi2, logistic regression, and receiver-operator characteristic curve were used for analysis. Results: 33 women were excluded from the analysis because they delivered at other institutions. The neonates of 33 women did not have sonography because they weighed >2,000 g at birth. Two neonates died before sonography was performed; four neonates who weighed <2,000 g at birth did not have sonography. In the definitive study group of 47 women, those with neonates who developed periventricular leukomalacia and intraventricular hemorrhage (n = 14) had higher median amniotic fluid interleukin-6 levels (42,795 pg/ml versus 8,020 pg/ml; P = 0.009), more positive amniotic fluid cultures (64% vesus 21%; P < 0.003), and a shorter median amniocentesis-to-delivery interval (16 h versus 24 h; P = 0.045) than women (n = 33) who delivered neonates without periventricular leukomalacia or intraventricular hemorrhage. The groups did not differ in gestational age at admission (P = 0.15), birth weight (P = 0.09), or histologic chorioamnionitis (P = 0.37). An amniotic fluid interleukin-6 level >/=20,000 pg/ml had a sensitivity of 71% and a specificity of 70% compared with a sensitivity of 69% and specificity of 79% for amniotic fluid culture, and a sensitivity of 71% and specificity of 42% for histologic chorioamnionitis in the prediction of periventricular leukomalacia and intraventricular hemorrhage. Women with amniotic fluid interleukin-6 levels >/=20,000 pg/ml (n = 20) had more neonates with periventricular leukomalacia or intraventricular hemorrhage than women with amniotic fluid interleukin-6 levels <20,000 pg/ml (n = 27) (50% versus 15%; P = 0.009). They also were of lower birth weight (P = 0.02), had more neonatal morbidity (P = 0.01), had more positive amniotic fluid cultures (P = 0.01), and more histologic chorioamnionitis (P = 0.02). Logistic regression analysis demonstrated that amniotic fluid interleukin-6 was","PeriodicalId":79506,"journal":{"name":"Journal of maternal-fetal investigation : the official journal of French Society of Ultrasound in Medicine and Biology ... [et al.]","volume":"8 3","pages":"101-107"},"PeriodicalIF":0.0,"publicationDate":"1998-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20658767","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparison between Intravenous Prostaglandin E2 and Extraamniotic Prostaglandin F2alpha Instillation for Termination in Second-Trimester Pregnancy.","authors":"Lee,&nbsp;Cheng,&nbsp;Lai,&nbsp;Shyu,&nbsp;Chen,&nbsp;Wu,&nbsp;Shih,&nbsp;Hsieh","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>> Objective: To evaluate the efficacy and safety of two different methods, intravenous prostaglandin E2 and extraamniotic prostaglandin F2alpha instillation, in second-trimester pregnancy termination. Methods: We designed a prospective randomized longitudinal study. 130 consecutive patients with various indications for second-trimester pregnancy termination were recruited. Patients were managed randomly with either intravenous continuous prostaglandin E2 infusion or extraamniotic prostaglandin F2alpha instillation. Laminaria were inserted in patients with unfavorable cervixes. The instillation-abortion time, success rate within 24 hours, dosage of both medications, and side effects were recorded and analyzed. Results: There was a significantly shorter instillation-abortion time (11.85 +/- 9.65 versus 22.18 +/- 16.83 hours, P < 0.001), higher complete abortion rate (71.91% versus 41.5%, P = 0.013), and a higher rate of successful abortion within 24 hours (87.6% versus 56.1%, P < 0.001) in patients treated with intravenous prostaglandin E2 than in those with extraamniotic prostaglandin F2alpha. Conclusions: Prostaglandin E2 had a higher rate of successful abortion and fewer side effects than prostaglandin F2alpha. This implies that intravenous prostaglandin E2 might be a better choice for second-trimester pregnancy termination compared with extraamniotic prostaglandin F2alpha.</p>","PeriodicalId":79506,"journal":{"name":"Journal of maternal-fetal investigation : the official journal of French Society of Ultrasound in Medicine and Biology ... [et al.]","volume":"8 3","pages":"134-138"},"PeriodicalIF":0.0,"publicationDate":"1998-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20658773","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Outcome of Two Pregnancies in a Patient with Gitelman's Syndrome-A Case Report.","authors":"Jones,&nbsp;Dorrell","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>> Gitelman's syndrome is primary renal tubular hypokalemic metabolic alkalosis with hypocalciuria and magnesium deficiency. We present the prenatal course and outcome of two pregnancies in a patient with Gitelman's syndrome. The complication encountered was oligohydramnios. Close monitoring of serum magnesium and potassium, amniotic fluid volume, and fetal growth is required.</p>","PeriodicalId":79506,"journal":{"name":"Journal of maternal-fetal investigation : the official journal of French Society of Ultrasound in Medicine and Biology ... [et al.]","volume":"8 3","pages":"147-148"},"PeriodicalIF":0.0,"publicationDate":"1998-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20659249","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Clinical Usefulness of Flow Cytometry in Detection and Quantification of Fetomaternal Hemorrhage.","authors":"Fung,&nbsp;Giulivi,&nbsp;Chisholm,&nbsp;Laberge,&nbsp;Palmer","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>> Objective: To compare the technique of immunofluorescence flow cytometry against traditional Kleihauer testing with respect to the sensitivity and specificity of clinical detection of fetomaternal hemorrhage. Methods: Blood samples from D-negative unsensitized postpartum women were analyzed by flow cytometry (customized, directly conjugated monoclonal anti-D) and Kleihauer testing using commercial kits as well as a manual technique. Results: Both flow cytometry and manual Kleihauer tests performed well in vitro against known standards, giving similar results with detectable fetal cells in the range of 2-10%. Correlation of in vivo results obtained by flow cytometry and either Kleihauer method was poor. The percentage of fetal red cells detected by flow cytometry was approximately twice that of the manual Kleihauer. Commercial Kleihauer testing proved unreliable in the in vivo setting. Conclusions: Flow cytometry offers a reliable alternative to traditional Kleihauer testing for detecting fetomaternal hemorrhage and may, with standardized methodology, help optimize immunoprophylaxis against erythroblastosis fetalis.</p>","PeriodicalId":79506,"journal":{"name":"Journal of maternal-fetal investigation : the official journal of French Society of Ultrasound in Medicine and Biology ... [et al.]","volume":"8 3","pages":"121-125"},"PeriodicalIF":0.0,"publicationDate":"1998-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20658770","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparisons of Nitric Oxide Synthases in Normal Human Placenta from 37 to 41 Weeks Gestation: Qualitative and Quantitative Analyses.","authors":"Otsubo,&nbsp;Hori,&nbsp;Nishino,&nbsp;Araki","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>> Objective: The purpose of this study was to determine the type of nitric oxide synthase isoform and to measure the quantities of nitric oxide synthase mRNA in the human placenta. Methods: The isoforms of nitric oxide synthase were determined in ten placentas of normal pregnant women using information regarding calcium dependence and inhibition by arginine analogs and findings from Western blot analyses and reverse transcriptase-polymerase chain reaction. Results: The activity of nitric oxide synthase was largely calcium dependent, although a small element of calcium-independent activity was observed. A stronger inhibition was shown with Nomega-nitro-l-arginine than with Nomega-monomethyl-l-arginine. On Western blots endothelial nitric oxide synthase was detected as a band of 140 kilodaltons, without evidence of inducible nitric oxide synthase. Messenger RNA of endothelial nitric oxide synthase was readily detected by reverse transcriptase-polymerase chain reaction, but that of inducible nitric oxide synthase was barely detected. The quantity of mRNA of inducible nitric oxide synthase was about 100-fold less than that of endothelial nitric oxide synthase. Conclusions: These results point to the constitutive endothelial type as the predominant isoform of nitric oxide synthase in human placenta from 37 to 41 weeks gestation, although protein and mRNA of inducible nitric oxide synthase may exist.</p>","PeriodicalId":79506,"journal":{"name":"Journal of maternal-fetal investigation : the official journal of French Society of Ultrasound in Medicine and Biology ... [et al.]","volume":"8 3","pages":"139-144"},"PeriodicalIF":0.0,"publicationDate":"1998-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20659247","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optical Brain Monitoring of the Cerebrovascular Effects Induced by Acute Cocaine Exposure in Neonatal Pigs.","authors":"Stankovic,&nbsp;Fujii,&nbsp;Maulik,&nbsp;Kirby,&nbsp;Stubblefield","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>> Objective: The purpose of this study was to assess the direct effects of cocaine on cerebral blood flow and oxygenation in newborn piglets using optical spectroscopy. Optical spectroscopy is capable of monitoring changes in cerebral oxyhemoglobin, deoxyhemoglobin, and total hemoglobin continuously, noninvasively, and in real time. Methods: Five anesthetized and ventilated newborn piglets were injected intravenously with 1 mg/kg cocaine through a central venous catheter over 60 seconds. Cerebral blood flow and oxygenation were assessed by optical spectroscopy and standard physiologic monitoring: mean arterial pressure, carotid blood flow, cerebrovascular resistance, and arterial hemoglobin oxygen saturation (by pulse oximetry). Results: Cocaine induced a profound increase in cerebrovascular resistance, a decrease in carotid blood flow, and a decrease in mean arterial pressure and heart rate. Cerebrovascular changes were detected readily by optical spectroscopy (i.e. a decrease in cerebral oxyhemoglobin was associated with an increase in deoxyhemoglobin). The hypotensive response augmented the cerebral vasoconstriction effect on carotid blood flow. A good correlation existed between the changes in carotid Doppler blood flow and total hemoglobin in each animal and for all animals combined. Peripheral arterial hemoglobin oxygen saturation measured by pulse oximetry remained normal throughout the experiment. Conclusions: The cause for the apparent idiosyncratic hypotensive response to intravenous injections of cocaine is uncertain and requires further investigation. Our study clearly demonstrates that optical spectroscopy might become an extremely useful tool for monitoring cerebral hemodynamics and oxygenation in cocaine-exposed fetuses and infants.</p>","PeriodicalId":79506,"journal":{"name":"Journal of maternal-fetal investigation : the official journal of French Society of Ultrasound in Medicine and Biology ... [et al.]","volume":"8 3","pages":"108-112"},"PeriodicalIF":0.0,"publicationDate":"1998-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20658768","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Acute Effects of Maternal Smoking on the Uterine and Umbilical Artery Blood Velocity Waveforms","authors":"Kimya,&nbsp;Cengiz,&nbsp;Ozan,&nbsp;Kolsal","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>> Objective: The acute effects of smoking during pregnancy on the uterine and umbilical blood flow velocity waveform were assessed. Methods: Twenty-two chronic women smokers at a mean gestational age of 194.17 +/- 58.02 days and 21 women non-smokers at a mean gestational age of 193.24 +/- 34.71 days were studied. Systolic-diastolic (S/D) ratio, resistance index, and pulsatility index of uterine and umbilical arteries were measured in the control group and before and after smoking a single standard 100-mm filtered cigarette in the study group. Results: There was no significant change in the uterine artery and umbilical artery blood velocity waveform indices that could be attributed to the acute effect of smoking in the study group, but all of the uterine artery indices and S/D ratio in the umbilical artery were statistically higher in the study group in comparison with the control group both before and after smoking. Conclusion: Our results suggest that smoking causes an increase in vascular resistance of the placenta and umbilical cord when used chronically.</p>","PeriodicalId":79506,"journal":{"name":"Journal of maternal-fetal investigation : the official journal of French Society of Ultrasound in Medicine and Biology ... [et al.]","volume":"8 2","pages":"79-81"},"PeriodicalIF":0.0,"publicationDate":"1998-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20601339","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"European Study on Maternal and Fetal Management of Fetal Supraventricular Tachyarrhythmia:Proposed Protocol for an International Project","authors":"Azancot-Benisty,&nbsp;Areias,&nbsp;Oberhänsli,&nbsp;Schmidt,&nbsp;Tulzer,&nbsp;Viart","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>> Objectives: This European protocol is designed to estimate the efficacy of transplacental digoxin administered intravenously to the mother in sustained fetal supraventricular tachyarrhythmias (FSVT) with or without cardiac failure and in intermittent runs of FSVT with cardiac failure. The natural history of FSVT is evaluated in self-limited runs of FSVT without cardiac failure. Study structure: The fetal criteria for inclusion in the study are: gestational age <35 weeks, a normal cardiac anatomy, no severe extracardiac anomalies and a heart rate of the FSVT >200 beats/min. The maternal criteria include no prior treatment with digoxin or drugs effecting fetal heart rate and hemodynamics, and no contraindication to digoxin. Doppler fetal echocardiography is utilized for the diagnosis of the type of FSVT, sequential evaluation, and assessment of fetal hemodynamics. Fetuses are assigned two groups: Group I includes all fetuses with sustained FSVT and those with intermittent runs and cardiac failure; Group II comprises fetuses with intermittent runs and no cardiac failure. Fetuses in Group I will be treated. Group II will receive no treatment initially and will be observed. Treatment is based on a acute loading phase with digoxin administered intravenously to the mother for a period of 7 days. Doses are adjusted to through levels of maternal digoxin, maternal clinical condition, and electrocardiogram. If sinus rhythm is obtained, a maintenance phase follows with oral digoxin. Another drug, according to local experience and preference, is added to oral digoxin if digoxin intravenously fails to restore sinus rhythm and gestational age is <36 weeks. Post natal outcome will be followed by sequential clinical and Holter examinations. The data collected will be reviewed in a blinded fashion. The collection of the data for the protocol requires extensive information on the maternal, fetal, and long-term follow-up studies. They are detailed in the Appendix section. Expected results: We propose to obstetricians and pediatric cardiologists involved in fetal cardiology a rationale for the management and treatment of FSVT. Our expectation is to obtain a controlled study on a large number of cases at an international scale and thus provide a homogeneous maternal and fetal therapeutic strategy for FSVT.</p>","PeriodicalId":79506,"journal":{"name":"Journal of maternal-fetal investigation : the official journal of French Society of Ultrasound in Medicine and Biology ... [et al.]","volume":"8 2","pages":"92-7"},"PeriodicalIF":0.0,"publicationDate":"1998-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20601343","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}