An instrument for measuring scintillators efficiently based on silicon photomultipliers

An instrument used for measuring multiple scintillators' light output and energy resolution was developed. The instrument consisted of a light sensor array which was composed of 64 discrete SiPMs (Silicon Photomultipliers), a corresponding individual channel readout electronics system, and a data processing algorithm. A Teflon grid and a large interval between adjacent SiPMs were employed to eliminate the optical cross talk among scintillators. The scintillators' light output was obtained by comparing with a reference sample with known light output. Given the SiPM temperature dependency and the difference among each SiPM, a temperature offset correction algorithm and a non-uniformity correction algorithm were added to the instrument. A positioning algorithm, based on nine points, was designed to evaluate the performance of a scintillator array. Tests were performed to evaluate the instrument's performance. The uniformity of 64 channels for light output measurement was better than 98%, the stability was better than 98% when temperature varied from 15 °C to 40 °C, and the nonlinearity under 511 keV was better than 2%. This instrument was capable of selecting scintillators and evaluating the packaging technology of scintillator arrays with high efficiency and accuracy.

Intercomparison of methods for coincidence summing corrections in gamma-ray spectrometry--part II (volume sources)

The second part of an intercomparison of the coincidence summing correction methods is presented. This exercise concerned three volume sources, filled with liquid radioactive solution. The same experimental spectra, decay scheme and photon emission intensities were used by all the participants. The results were expressed as coincidence summing corrective factors for several energies of (152)Eu and (134)Cs, and different source-to-detector distances. They are presented and discussed.

Hemisphere Differences in Accessing Lexical Knowledge of Chinese Characters

The lateralisation of lexical knowledge of Chinese characters is investigated in this study. Three experiments were conducted in which stimuli were presented unilaterally to a visual field for recognition tests. The orthographic similarity of two alternative items for choice in Experiment 1 was manipulated, and the results showed an LVF advantage effect for legal characters in the visually similar condition and a more prominent LVF than RVF character-superiority effect. The phonological similarity of two alternative items for choice was manipulated in Experiment 2. The results showed a prominent RVF advantage effect and a significant phonological similarity effect in the RVF. In Experiment 3, the semantic similarity was manipulated, and the semantic similarity effect was observed in the RVF. These results suggest hemisphere asymmetries in accessing lexical knowledge of Chinese characters.

Note: A sampling method for quantum random bit generation

In this note, we present a new sampling method for quantum random bit generation. The new method requires only one single-photon detector and does not measure the time slots of emitted photons. A binary random bit sequence obtained is independent on the time slot of the pulses and the precision of the measurement instrument. The effect of the exclusive-or operation for eliminating the bias in the raw sequences is also discussed.

Rapid diagnosis of tuberculosis directly from clinical specimens using a gene chip

The aim of this study was to explore a gene chip capable of detecting the presence of Mycobacterium tuberculosis isolates directly in clinical sputum specimens and to compare it with current molecular detection techniques. At first, we selected 13 M. tuberculosis-specific target genes to construct a gene chip for rapid diagnosis. Using the membrane array method, we diagnosed M. tuberculosis by gene chip directly from 246 sputum specimens from patients suspected of having tuberculosis. Among 80 M. tuberculosis complex (MTBC) culture-positive sputum specimens, the MTBC detection rate was 62.5% (50/80) by PCR-restriction fragment length polymorphism (RFLP), 70% (56/80) by acid-fast staining, and 85% (68/80) by the membrane array method. Furthermore, subspecies showed different gene expression patterns in the membrane array. In conclusion, MTBC could be detected directly in sputum by the membrane array method. The rapidity of detection and the capability of differentiating subspecies could make this method useful in the control and prevention of tuberculosis.

Betel quid chewing and risk of adverse birth outcomes among aborigines in eastern Taiwan

It is known that substance abuse during pregnancy is associated with increased risk of adverse birth outcomes. The aim of this study was to determine the use of alcohol, cigarettes, betel quid, and drugs among pregnant aboriginal women and to assess the risk of adverse effects of betel quid use on birth outcomes in eastern Taiwan. Of a total of 229 women recruited into this study, 32 women with adverse birth outcomes constituted the case group. Analyses revealed that adverse birth outcomes were associated with maternal betel quid chewing and maternal age. After adjusting for maternal age, the risk of adverse birth outcome was five times higher among betel quid chewing women as compared to substance nonusers. Based on this finding, it is suggested health education, especially when concerned with the harmful effects of substance abuse, which includes betel quid use during pregnancy, should be stressed in concert with routine prenatal care.

Work experience and drinking behavior: alienation, occupational status, workplace drinking subculture and problem drinking

This study explored the association between alienating job conditions and problem drinking within the context of occupational status and workplace drinking subculture. From December 1994 to March 1995, a questionnaire survey was implemented in the manufactory sector in southern Taiwan. Within the questionnaire, any perceived self-estrangement, powerlessness and social isolation that the individual experienced in his work were measured as the alienating job conditions, and any negative physical, psychological and social consequences the individual experienced during the previous month were considered as affecting problem drinking. Of the 1117 subjects, 668 (61.8%) reported imbibing one or more drinks during the preceding month; the average daily alcohol consumption being 0.2+/-0.9 drinks. In addition, 188 (16.8%) subjects reported having experienced drinking-related problems in the preceding month. Workers with low occupational status were more likely to become problem drinkers when they felt comparatively self-estranged in their work. Further, those with a family history including any habitual drinker or those under more encouraging workplace drinking subculture were more likely to have drinking-related problems. For the prevention of problem-related drinking behavior, the workplace should be considered as the focus of our future intervention and management program.

Prevalence and correlates of substance use among clinical nurses in Kaohsiung city

Though substance abuse and its deleterious health sequelae are a serious problem in Taiwan, licit and illicit substance use patterns among nurses are understudied. The purpose of this study was to investigate the prevalence of substance use and to identify its related factors among clinical nurses. A total of 907 registered nurses were recruited for this study via stratified-random sampling from hospitals in Kaohsiung city. Each participant was requested to reply to a structured questionnaire anonymously and a 98.1% response rate was achieved. Prevalence of substance use during the past year was estimated as follows: alcohol drinking (regular use-3.8%); coffee drinking (regular use-44.7%); cigarette smoking (regular use-0.2%); regular use of analgesics 21.1%; regular use of benzodiazepines 1.8%; use of narcotics (ever use-0.7%). Significant factors related to substance use were analyzed by logistic regression. This revealed that for regular alcohol use, the significant factor was a positive attitude toward substance use; for BZD drug use, they were poor mental health, positive attitude toward substance use, being unmarried, and used analgesics; for regular analgesics use, they were work in non-critical care unit, self-perceived poor health status, and BZD drug use. Results generated from this study may act as reference for nursing administration to develop an effective health promotion program of physical and mental health for the clinical nurses.

Mid-infrared w quantum-well lasers for noncryogenic continuous-wave operation

We review the recent progress of electrically injected and optically pumped mid-IR lasers based on antimonide quantum wells with the type II W configuration. W quantum-well diodes have achieved cw operation up to 195 K at lambda = 3.25 mum. Optically pumped devices that employ the diamond pressure bond heat sink have reached 290 K at 3 mum and 210 K at 6 mum. Pulsed power conversion efficiencies of up to 7% at 220 K have been attained by use of an optical pumping injection cavity approach, in which an etalon cavity for the pump beam significantly enhances its absorptance. The angled-grating distributed-feedback configuration has been used to obtain near-diffraction-limited output for an optical pumping stripe width of 50 mum.

Predictors of readmission to a medical-psychiatric unit among patients with minor mental disorders

BACKGROUND

Most studies on readmission have focused on patients with severe mental disorders such as schizophrenia and subjects were mostly collected in traditional psychiatric settings. This study investigated the predictors of readmission to a medical-psychiatric unit among patients with minor mental disorders in a general hospital.

METHODS

All 164 patients admitted to a stress ward within a one-year period were recruited into this study. Data were retrospectively obtained by reviewing medical charts. Variables used to analyze and compare between patients who were and were not readmitted included patient characteristics, clinical features and multiple axes diagnoses of DSM-IV.

RESULTS

Of 164 patients recruited, 135 were hospitalized only one time. The remaining 29 patients accounted for 61 admissions. The readmission rate was 17.7% (29/164). The significant predictors for readmission included Global Assessment of Functioning scores lower than 50 at admission, age under 40 years, previous psychiatric admission, alcohol dependence/abuse, dysthymia and comorbidity of borderline personality disorder. Using logistic regression to predict readmission within one year, we found the first four variables accurately differentiated 84.15% of patients who were readmitted from those who were not.

CONCLUSIONS

Our results indicated the incidence of relapse in certain minor mental disorders is similar to that of severe mental disorders. By identifying predictors of readmission and intervening appropriately, unnecessary readmission may be prevented.

Mental health in Asia: social improvements and challenges

Remarkable improvements in economic conditions and a considerable upgrade in the quality of life have been observed in many parts of Asia during the past several decades. At the same time, many mental health challenges face the people of Asia. Various social mental health indexes are reviewed here, with available data from China, Japan, Korea, Singapore, Malaysia, and other Asian societies. The data are compared with data from the United States, Australia in the Pacific Rim, and some other Western countries to examine patterns of similarity or difference between East and West in the process of modernization. Common trends in mental health issues associated with rapid sociocultural change observed in different Asian societies are discussed, as well as the relative shortage of mental health personnel available in many Asian societies. It is emphasized that, in addition to expanding psychiatric services, there is an even more urgent need to promote mental health knowledge and concern through education in the general population. Mental health needs to be cultivated and maintained by social forces and cultural strengths. It is stressed that there is a challenge for Asian people to advance mental health beyond economic development in the 21st century.

Neighborhood experience and mental health

BACKGROUND

The purpose of this study was to evaluate individual mental health in the context of their social environment. Specifically, variables across different levels, including a person's attributes, neighborhood experience, and community characteristics, were examined to explore their relationship with that person's mental health.

METHODS

Communities in southern Taiwan, including 1 district from Kaohsiung City and 4 townships (hsiang) from Kaohsiung County, were purposively selected to represent 3 different types (urban, suburban, and rural) of communities, after which, by random sampling, 416 subjects were recruited for the interview survey in 1998. A questionnaire containing a measure for mental health (CHQ) and perceptions of neighborhood experience was administered for data collection. At the same time, data derived from governmental archives were collected to indicate the characteristics of a community, and these included population density, community socioeconomic condition, and community stability.

RESULTS

Multivariate analysis showed that personal income, community socioeconomic condition, and perceived social support from the neighborhood were statistically significant when associated with a person's mental health status. It seems that influence of an individual's mental health status was affected not only by that person's attributes, but also by the neighborhood within which he/she experiences daily life.

CONCLUSION

With respect to the strategy for implementing future mental health promotion programs, a further clarification of the relationship between social conditions and mental health is needed.

Review of pre-eclampsia in Taiwan: a multi-institutional study

BACKGROUND

Because the reported frequency of pre-eclampsia in Taiwan varies significantly, the aims of this study were to measure the current incidence of pre-eclampsia and its correlated morbidity and mortality for both mothers and fetuses in Taiwan.

METHODS

We retrospectively studied all reported cases of pre-eclampsia and eclampsia from January 1, 1993 to December 31, 1997 in the 14 tertiary medical centers and regional hospitals in Taiwan. Recruiting criteria were pregnancy-induced hypertension (systolic blood pressure > or = 140 mmHg or diastolic blood pressure > or = 90 mmHg) with proteinuria (> or = 300 mg of urinary protein per 24 hours) and independent part edema.

RESULTS

There were 4,193 patients with pre-eclampsia and eclampsia for a frequency of 2.03% of 206,551 deliveries during the study period. Of these, 58.9% of patients were classified as having mild pre-eclampsia while 38.4% had severe pre-eclampsia. Advanced maternal age (> 35 years) (odds ratio [OR] = 4.56; 95% confidence interval [CI] = 4.23-4.90; p < 0.001), primiparity (OR = 1.71; 95% CI = 1.61-1.82; p = 0.02) and twin pregnancy (OR = 1.92; 95% CI = 1.64-2.25; p = 0.01) were significant risk factors for developing pre-eclampsia. However, multivariate analysis showed that only advanced maternal age was a significant risk factor for pre-eclampsia (OR = 3.21; 95% CI = 2.95-3.50; p < 0.001). In contrast to mild pre-eclampsia, severe pre-eclampsia resulted in significantly worse outcomes for both mothers and fetuses. Complications in patients with severe pre-eclampsia included placental abruption, acute renal failure, pulmonary edema, postpartum hemorrhage, pleural effusion, preterm labor, intrauterine growth retardation, stillbirth, neonatal mortality and low birth weight infants, all of which occurred significantly more frequently than in patients with mild pre-eclampsia (p < 0.001).

CONCLUSIONS

Pre-eclampsia remains a big challenge in modern obstetrics in Taiwan. Early diagnosis and management of patients with pre-eclampsia to prevent progression would significantly improve outcomes for mothers and fetuses.

Development of the Taiwanese Depression Questionnaire

BACKGROUND

Previous studies have shown that different cultures have various modes for emotional expression which suggest that Western scales have certain limitations. The purpose of this study was to develop a culturally relevant depression screening questionnaire: the "Taiwanese Depression Questionnaire" (TDQ) which can be used to conduct epidemiological surveys in Taiwanse society.

METHODS

Based on the results of previous studies and related references, a draft of the TDQ was constructed. After several research group discussions, the first version of a 20-item draft was developed. By purposive sampling, 48 patients, from depressive disorder and anxiety disorder groups of Chang Gung Memorial Hospital's psychiatric clinics, self-rated the draft to test the wording, sequences, and its concurrent validity. After item analysis, a meeting of experts, and draft modification, an 18-item second version of the draft was established. Afterwards, 107 community subjects, recruited from Jenwu Township of Kaohsiung County, were sampled for the receiver operating characteristic (ROC) curve analysis, conventional validity index, and internal consistency of reliability.

RESULTS

The results demonstrate that Cronbach's alpha coefficient (0.90), concurrent validity, and the area under the ROC curves (0.92) are all quite satisfactory. The 18-item TDQ had a sensitivity of 0.89 and a specificity of 0.92 at a cutoff score of 19.

CONCLUSIONS

The TDQ is a culturally relevant questionnaire, which is adaptable for screening depressive people in the local communities.

[Modulation of nerve growth factor on wound healing of burn]

OBJECTIVE

To investigate the effect of nerve growth factor(NGF) on the burn wound healing and to study the mechanism of burn wound healing.

METHODS

Six domestic pigs weighting around 20 kg were used as experimental animals. Twenty-four burn wound, each 2.5 cm in diameter, were induced on every pigs by scalding. Three different concentrations of NGF, 1 microgram/ml, 2.5 micrograms/ml, 5 micrograms/ml were topically applied after thermal injury, and saline solution used as control group. Biopsy specimens were taken at 3, 5 and 9 days following treatment and immunohistochemistry method was used to detect the epidermal growth factor(EGF), EGF receptor (EGF-R), NGF, NGF receptor (NGF-R), NGF, NGF-R, CD68 and CD3.

RESULTS

The expression of EGF, EGF-R, NGF, NGF-R CD68 and CD3 were observed in the experimental group, especially at 5 and 9 days, no expression of those six items in the control group.

CONCLUSION

NGF can not only act directly on burn wound, but also modulate other growth factors on the burn wound to accelerate the healing of burn wound.

Correlated risk factors for suicidal ideation in aboriginal Southern Taiwanese women of childbearing age

Suicide and non-accidental poisoning are two important causes of death of female aborigines in Taiwan. The purpose of this study was to estimate the prevalence of suicidal ideation and then to identify factors relating to this for female aborigines of childbearing age. Using stratified random sampling 212 female aborigines, aged between 20 and 49, were recruited into this study. Participants were interviewed at their homes by trained interviewers who used a structured questionnaire. The Suicidal Ideation Screening Questionnaire (SIS-Q) was used to help predict which participants would be more likely to have suicidal ideation. The prevalence rate of suicidal ideation within the previous 12 months was 20.3% (95% CI 14.9-25.7%). Significant related factors of suicidal ideation, which were analyzed by multiple logistic regression, revealed that women suffering depressive mood, living within a extended family, and perceiving poor health status were more likely to have suicidal ideation. Results generated from this study may be used, in primary care, for guidance as to how to prevent suicide. Outreach community programs incorporating a valid and sensitive screening instrument, such as the SIS-Q, should be implemented to help prevent suicides in aboriginal communities.

Posterior uterine wall rupture during labour

Vaginal births after Caesarean section (VBAC) are well-accepted procedures when pregnant women do not have any contra-indications. The possibilities of the uterine dehisence and rupture during VBAC should always be considered. This occurrence is usually related to the previous scar tissue and subsequent risk is acceptable. Nevertheless, rupture that occurs in presumably normal tissue areas of the uterus instead of in scar tissue areas with resultant perinatal death is extremely rare. We present a 31 year old woman who had posterior uterine rupture when she tried VBAC at 38 weeks gestation. During the course of VBAC, she had a smooth labour course without use of any augmentation medication, but her condition was complicated with uterine rupture without any premonitory signal. It resulted in maternal shock and sequentially the death of the newborn 7 days after delivery. By reviewing this case report, we should keep in mind that prompt response to every woman during labour is of paramount importance to avoid repeating the occurrence of uterine rupture, partly because uterine rupture could occur without prominent signals and partly because subsequent dangers seem to be those created by acts of omission. Finally, the benefits and safety of VBAC have not been undermined because this patient is an isolated and extremely rare case.

Treatment refusal: analysis of 15 cases

BACKGROUND

In this paper, we investigate the reasons for treatment refusal at Linkou and Kaohsiung Chang Gung Memorial Hospitals, and offer ways to improve the doctor-patient relationship.

METHODS

Cases were collected during a 2-year period according to the criterion of notification of "refused treatment" on consultation sheets, with a total of 1631 consultation sheets. All cases were discussed once a week in detail by psychiatrists and the consulting medical staff, and were followed up from 1 to 4 weeks. All cases were treated by the processes of informed consent and crisis intervention. The final results for the reasons of treatment refusal and psychiatric diagnoses were made by psychiatrists and the consulting medical staff.

RESULTS

The number of cases compatible with the criterion was 15 (10 men and 5 women). The reasons for treatment refusal included poor communication, inadequate information, lack of competency, denial and shock reaction, reappearance of the suffered experience, and autonomy of patients. The distribution of psychiatric diagnoses included 8 with major depressive disorders, 2 with delirium, 1 with schizophrenic disorder, 1 with adjustment disorder, 1 with acute stress disorder (post-traffic accident), 1 with alcohol dependence, and 1 was deferred. After adequate processes of informed consent and crisis intervention, 12 persons accepted medical treatment.

CONCLUSION

We should give patients adequate informed consent and crisis intervention to establish a good doctor-patient relationship and to respect the patients' autonomy for their choice of treatment.

Biphasic changes in autonomic nervous activity during pregnancy

To understand the sequential response of the autonomic nervous system to pregnancy, we studied heart rate variability in 23 first trimester, 23 second trimester and 21 third trimester pregnant women. Twenty non-pregnant women were recruited as controls. Time and frequency domain measures of heart rate variability in three recumbent positions were compared. We found that normalized high-frequency power in the supine position increased significantly in the first trimester (42.2 (95% confidence interval (CI) 5.4) nu (normalized unit); P < 0.05) compared with non-pregnant controls (33.0 (6.0) nu), and then decreased progressively in the second (27.3 (6.7) nu) and third (21.8 (6.0) nu; P < 0.05) trimesters. The low-/high-frequency power ratio in the supine position decreased significantly in the first trimester (0.8 (0.3); P < 0.05) compared with that of non-pregnant controls (1.1 (0.3)) and increased progressively in the second (1.5 (0.4)) and third (2.1 (0.8); P < 0.05) trimesters. When the position was changed from the supine to the right lateral decubitus, the percentage change in normalized high-frequency power correlated significantly and negatively with normalized high-frequency power in the supine position in non-pregnant controls (r = -0.56, P = 0.01) and in pregnant women in the first (r = -0.44, P = 0.034), second (r = -0.68, P < 0.001) and third (r = -0.68, P < 0.001) trimesters. These results indicate that autonomic nervous activity shifted towards a lower sympathetic and higher vagal modulation in the first trimester, and changed towards a higher sympathetic and lower vagal modulation in the third trimester as gestational age increased. The balance between the haemodynamic changes of pregnancy and aortocaval compression caused by the enlarging gravid uterus may be responsible for the biphasic changes in autonomic nervous activity during pregnancy.

Return of autonomic nervous activity after delivery: role of aortocaval compression

We have compared measures of heart rate variability (HRV) in 15 women in late pregnancy before and 3 months after delivery and in 20 non-pregnant controls, to study the effect of aortocaval compression on autonomic nervous activity. Normalized high-frequency power was used as an index of vagal activity and the low-/high-frequency power ratio as index of sympathovagal balance. We found that the decrease in vagal activity and increase in sympathovagal balance before delivery returned to normal 3 months after delivery. Percentage changes in vagal activity and sympathovagal balance 3 months after delivery in the left lateral decubitus position were least among three recumbent positions. The relief of aortocaval compression as a result of delivery of the fetus may be the main cause of return of autonomic nervous activity 3 months after delivery. Postpartum hormonal changes may also contribute to return of autonomic nervous activity after delivery.

Comparison of supine and upright positions on autonomic nervous activity in late pregnancy: the role of aortocaval compression

In order to understand the effect of aortocaval compression on autonomic nervous activity, we compared the effects of supine and upright postures on measures of heart rate variability in late pregnancy. Thirty-two women in late pregnancy and 23 nonpregnant age-matched women were studied. Both time and frequency domain heart rate variability measures were compared between the supine and upright positions, and between pregnant women and controls. The pregnant women had smaller mean RR interval, standard deviation of RR intervals and normalised high-frequency power, and a larger low- to high-frequency power ratio than nonpregnant women in the supine position. When the position was changed from upright to supine in nonpregnant women, the percentage change in the mean RR interval and normalised high-frequency power were increased, whereas the percentage change in the coefficient of variation of RR interval and low- to high-frequency power ratio were decreased. In contrast, the percentage change in normalised high-frequency power was decreased and the percentage change in low- to high-frequency power ratio was increased in pregnant women when the position was changed from upright to supine. These results indicate that the vagal enhancing effect seen in normal subjects when changing position from upright to supine was reversed in women in late pregnancy. Aortocaval compression in the supine position in pregnant women might be responsible for this reversal in the autonomic response to lying down.

Color Doppler waveforms of maternal cervical internal carotid arteries in normotensive and preeclamptic gravidas

The objective of this study was to investigate and determine fitted percentiles of blood flow resistance of cervical internal carotid arteries in normal pregnancies from gestational weeks 20 to 42 and to compare the resistance indices and mean velocities of the these arteries in normotensive and preeclamptic gravidas. A duplex color apparatus with pulsed Doppler ultrasound scanner (7.5 MHz) was used to determine the resistance index and mean velocity values of maternal cervical internal carotid arteries in 310 healthy singleton gravidas (group 1) and 74 singleton preeclamptic gravidas (group 2). The resistance index and mean velocity values of the maternal cervical internal carotid arteries decrease as the gestational age increases in normal gravidas, whereas in preeclamptic pregnancies these values are no different from those in normal gravidas during the second half of the gestational period.

Color Doppler ultrasound velocimetry of internal carotid arteries in normal pregnancies

BACKGROUND

There are few reports on maternal cerebral circulation during pregnancy. Using the hypothesis that cerebral blood flow resistance decreases progressively with advancing gestational age (GA) as a consequence of estrogenic effects on the vascular system during pregnancy, we calculated the pulsatility index (PI) and the mean velocity (MV) of the maternal right internal carotid artery (ICA) in order to build fitted reference centiles.

METHODS

A total of 315 pregnant women with a single fetus were studied at 20-42 weeks' gestation. The patients had uncomplicated singleton pregnancies and were without any known fetal or maternal risk factors. Duplex color ultrasound with a pulsed Doppler scanner (7.5 MHz) was used to determine the PI and MV of the maternal ICA.

RESULTS

Among the 315 healthy pregnant women, the PI of maternal ICA decreased progressively with advancing GA, PI50th = Exp (0.3124-0.0084 x GA), (p = 0.0003), during the second half of pregnancy. The predicted 50th percentile PI values of the ICA decreased from 1.117 (5th% = 0.755, 95th% = 1.654) at 24 weeks' gestation to 0.917 (5th% = 0.659, 95th% = 1.448) at 40 weeks' gestation. The MV of the maternal ICA also decreased progressively with advancing GA, MV50th = Exp (3.855-0.0093 x GA), (p = 0.0005), during the second half of pregnancy. The predicted 50th percentile MV values in the ICA decreased from 37.811 cm/sec (5th% = 24.177 cm/sec, 95th% = 59.138 cm/sec) at 24 weeks' gestation to 32.591 cm/sec (5th% = 20.818 cm/sec, 95th% = 51.021 cm/sec) at 40 weeks' gestation.

CONCLUSIONS

Both the PI and MV of the maternal ICA decreased with GA during the second half of normal pregnancy as a result of intracerebral vessel dilatation.