Value Of Pi Research Articles

Analisis dan Simulasi Efisiensi Kinerja Sepic Konverter Berbasis Kontroler Konvensional

The technology of components and electronic hardware has evolved to be able to produce a DC/DC current system for power, which is achieved by converting the DC power to higher or lower voltage. This DC voltage variable is commonly called the DC-DC Converter. This final task aims to find out the performance of the DC-DC Sepic Converter series design. The simulated testing of the system using SIMULINK/MATLAB software is subsequently obtained from the data analysis of the theoretical output voltage data and the monitoring of measurements that can be analyzed to determine the error level as well as the level of efficiency of the design of the sepic converter. The test was conducted by setting a constant input voltage of 12 V, a frequency of 50 kHz, with a duty cycle variation of 5% to 65% and a given load of 20 Ω. The result of the design of the Sepic Converter at the time of open loop mode with the value of duty Cycle of 5% produces a minimum voltage that is 0,38 V. Subsequently, when given the duty cicle value of 65%, the maximum voltage is 21,22 V error with the highest error rate of 1 V obtained at the 13th data trial. The average error value is 0,642 V and the standard deviation value is 0,453 V, the greatest efficiency point is 78,50% at the moment of the cycle duty value of 65. While the results of the testing of the Set of Sepic Konverters at the close loop mode, the input tension is given constantly 12 V. The configuration for the parameter value of PI is also constant, namely at the set point of 22,22 V, it is 21,97 V with an error difference 0,25 V.

PERANCANGAN PEMBANGKIT LISTRIK TENAGA SURYA ATAP DI HOTEL MEGA DANA

The utilization of renewable energy is one of the solutions to overcome the increasing electricity demand. One of these solutions is to install Solar Power systems on the roofs of offices, industries, or households. This study targets to meet electricity demand by utilizing the roof of the Mega Dana Hotel as a place for the installation of solar panels, the solar panel will later produce electrical energy to meet the electricity needs of the hotel bars. The simulation results of the production of electric energy at Hotel Mega Dana's solar panel system using an application called Helioscope. This study analyzes the economics of designing a rooftop solar power system at Hotel Mega Dana. The feasibility of this research investment is assessed from the value of NPV, PI, and DPP. According to the data obtained, the Hotel Mega Dana building has a roof area of 655.92 m 2. The study used 39 solar panel modules, 1 20kW inverter, and 5 48V 100 Ah TLO batteries, the system can produce 17,6 kWp of power, with a total annual energy production of 21.83 MWh to supply electricity for the bar at Hotel Mega Dana. This research was planned with an initial capital of IDR 254,578,500, a PI value of 1.09, and a DPP value of 21.9 years. The results of this research analysis can be considered feasible because the design has a positive NPV value and is expected to return investment at 21.9 years out of 25-years project life.

Isolation, Purification and some Properties of Staphylolytic Enzyme from <i>Staphylococcus hyicus</i>

The paper presents data on the identification of a new staphylolytic enzyme from the cultural liquid of Staphylococcus hyicus B-8870. The primary sequence of the enzyme has the maximum similarity to the CHAP domain of N-acetylmuramoyl-L-alanine amidase from Staphylococcus sciuri DD 4747. The enzyme is active against a wide range of microorganisms of the Staphylococcus genus, including MRSA strains. The molecular weight of the enzyme is 13993 Da, the absorption coefficient at 280 nm is \(\varepsilon \frac{{{\text{mg}}}}{{{\text{ml}}}}\) 3.94, the value of the isoelectric point pI 10.35. The specific activity of the enzyme in relation to the cell suspension of S.aureus FDA 209P is 1518 U/mg with an optimum pH of 7.7 and a temperature of 40°C.

The Exact Measurement of Pi

Abstract: This research study gives the actual value of PI (π), a mathematical constant that describes the relationship between a circular structure's circumference and diameter. It also highlights the lacuna in the most commonly used approximations of PI (π), such as 3.14159…, which were supplied by Archimedes. It also rejecting all the values of PI calculated by various mathematicians in almost 4000 years of mathematical history, and presents the absolute 100% true value of PI through various mathematical process and conclusions

Pi Calculation Reinvented a Trigonometry

In this study, we present a novel method for determining the mathematical value of pi by utilizing the relationship between pi and the tangent function in trigonometry. By examining the relationship between the circumference of a circle and a right-angled triangle, we can derive a new equation for pi, that can be used to simplify the mathematical and physical equations that involve pi.

A Prospective Study of Renal Blood Flow during Retrograde Intrarenal Surgery.

(I) Introduction: The use of Doppler ultrasound allows us to indirectly assess the effect of increased intrarenal pressure on renal blood flow during retrograde intrarenal surgery (RIRS). On the basis of vascular flow spectra from selected blood vessels in the kidney, it is possible to determine Doppler parameters that reflect the renal perfusion status, which indirectly shows the degree of vasoconstriction and reflects the resistance of kidney tissue. (II) Materials and methods: A total of 56 patients were included in the study. The study assessed the changes of three Doppler parameters of intrarenal blood flow: resistive index-RI, pulsatility index-PI, and acceleration time-AT in the ipsilateral and contralateral kidneys during RIRS. The effects of mean stone volume, energy used, and pre-stenting were examined as predictors and calculated at two time intervals. (III) Results: The mean value of RI and PI was significantly higher in the ipsilateral kidney than in the contralateral kidney just after RIRS. The mean value of the acceleration time was not significantly different before and after RIRS. The values of all three parameters 24 h after the procedure were comparable to their values immediately after the RIRS. The size of the stone exposed to laser lithotripsy, the value of the energy used, and pre-stenting are not factors that significantly influence Doppler parameters during RIRS. (IV) Conclusions: The significant increase in RI and PI after RIRS in the ipsilateral kidney suggests a vasoconstriction of the interlobar arteries generated by increased intrarenal pressure during the procedure.

Learning programs with magic values

A magic value in a program is a constant symbol that is essential for the execution of the program but has no clear explanation for its choice. Learning programs with magic values is difficult for existing program synthesis approaches. To overcome this limitation, we introduce an inductive logic programming approach to efficiently learn programs with magic values. Our experiments on diverse domains, including program synthesis, drug design, and game playing, show that our approach can (1) outperform existing approaches in terms of predictive accuracies and learning times, (2) learn magic values from infinite domains, such as the value of pi, and (3) scale to domains with millions of constant symbols.

Spatial distribution of soil erosion and its impacts on soil productivity in Songnen typical black soil region

Soil erosion is an important reason for land degradation. The black soil region of Northeast China is the main grain production base in China, however, the black soil productivity in this region is at risk and unsustainable now because there was few soil conservation measures in nearly 100 years of cultivation. To assess the impact of erosion on land productivity, both 210 sampling points for 137Cs measurement and 112 sampling points for soil profile features were laid out on cultivated land of Songnen typical black soil region in combination with the 2010 China land use map. The current soil erosion/deposition rate and land productivity index PI were calculated over the study area, and then the PI values were predicted erosion by 20, 50, 100, and 200 years without soil and water conservation measures based on the current erosion rate and soil profile characteristics. The results showed that the average soil erosion rate of cultivated land in the study area was 705.8 t/(km2⋅a), and 77.0% of the cultivated land had soil erosion rate larger than the soil loss tolerance of 200 t/(km2⋅a). Spatially, the soil erosion rate in the northern region was greater than that in the southern region significantly, which was mainly affected by slope steepness. The relationship between soil erosion rate (SL) and slope steepness (θ) in degree was established according to the results of 137Cs measured at 210 sample points: SL = 556.4∗θ or SL = 0.464∗θ in mm/a (given soil bulk density is 1200 kg/m3). The current mean value of PI for cultivated land was 0.59, decreasing significantly from north to south, which was mainly influenced by organic matter content. The predicted PI values decreased significantly with the increase of erosion years in the northern area. This is related to the topography of rolling and hills in the northern area with a greater soil loss rate, leading to a rapid decrease of organic matter content and the increase of sand content in the topsoil in the future. The spatial distributions of the current soil erosion rates and predicted PI values after years of erosion for cultivated land would be helpful for soil conservation policy-making.

The Perfusion Index of the Ear as a Predictor of Hypotension Following the Induction of Anesthesia in Patients with Hypertension: A Prospective Observational Study.

Patients with hypertension develop hemodynamic instability more frequently during anesthesia-particularly post-induction. Therefore, different monitoring methods may be required in patients with hypertension. Perfusion index-the ratio of the pulsatile blood flow to the non-pulsatile static blood flow in a patient's peripheral tissues, such as the fingers or ears-can show the hemodynamic status of the patient in a non-invasive way. Among the sites used for measuring the perfusion index, it is assumed that the ear is more reliable than the finger for hemodynamic monitoring, because proximity to the brain ensures appropriate perfusion. We hypothesized that the low value of preoperative ear PI could be a predictor of post-induction hypotension in patients with hypertension. Thirty patients with hypertension were enrolled. The perfusion index and pleth variability index were measured using the ear, finger, and blood pressure, and heart rate was recorded to monitor hypotension. After insertion of the supraglottic airway, 20 patients developed post-induction hypotension. Those who developed hypotension showed a significantly lower preoperative perfusion index of the ear. The preoperative perfusion index of the ear could predict post-induction hypotension in patients with hypertension.

Comparative characteristics of sagittal balance in normal children and with spondylolisthesis

BACKGROUND: The measurement of sagittal parameters is an important part of preoperative planning and is also used to evaluate the results of surgical treatment. It is known that in spondylolisthesis (especially at high degrees) the sagittal parameters of the spine differ from those in healthy people. The difference in spinal-pelvic parameters in children and adults without orthopedic pathology has also been proven. One of the tasks of surgical treatment of spondylolisthesis is the restoration of sagittal balance or its maximum approximation to normal values. However, today there is no single accepted norm of sagittal parameters for children, therefore, the question of the optimal tactics of surgical treatment of spondylolisthesis in children remains open.
 AIM: To determine the parameters of the sagittal balance in normal children and in children with spondylolisthesis.
 MATERIAL AND METHODS: A retrospective analysis of postural radiographs of 68 children was performed. Patients were divided into 2 groups: group I 43 patients from 8 to 17 years old without spinal pathology. Group II 25 patients with spondylolisthesis from 8 to 17 years old. For each patient, the main spinal and pelvic parameters (PT; PI; SS; LL; PI-LL; TK) were measured and statistical analysis of the data was performed.
 RESULTS: The study proved that the main parameters of the sagittal balance (PI, PT, SS, LL, TK, PI-LL) in children and adults without pathological deformities of the spinal column are statistically significantly different. Also, there are statistically significant differences between the parameters of the sagittal balance in children and adolescents without spinal pathology and with spondylolisthesis (PI, PT, SS, LL, TK, SFD, PI-LL). In patients with high grade spondylolisthesis, the parameters of thoracic kyphosis and lumbar lordosis are significantly reduced, which should be assessed as a compensatory mechanism for maintaining the vertical position of the body. Children with spondylolisthesis are characterized by a significantly higher PI value.
 CONCLUSION: The sagittal parameters of the spine in children and adults are different, therefore, for correct preoperative planning, it is necessary to establish the norm of sagittal parameters for children. It is also necessary to take into account the high value of PI in children and adolescents with spondylolisthesis, which may be the etiological factor of this disease. The existing formulas for measuring sagittal balance for children with spondylolisthesis should be used with caution, because a high PI can lead to unreliable theoretical values of PT, SS, LL and TK. The cause of sagittal imbalance can be not only high degrees of spondylolisthesis, but also the tight hamstrings.

Errors in Initial Pressure Measurement Affect Rate-Transient Analysis

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper URTeC 208321, “Effect of Errors in Initial Pressure Measurement on Rate-Transient Analysis in Unconventional Reservoirs,” by Himanshu S. Jha, SPE, Texas A&M University; Aaditya Khanal, The University of Texas at Tyler; and W. John Lee, SPE, Texas A&M University. The paper has not been peer reviewed. This paper presents a mathematical analysis of how incorrect estimates of initial reservoir pressure (pi) may affect rate-transient analysis (RTA) in ultralow-permeability reservoirs. Measured values of pi are rarely available, and the value estimated using alternative approaches, such as a diagnostic fracture injection test (DFIT), can be time-consuming and expensive and also may be inaccurate. In the complete paper, the authors examine what can and cannot be achieved with accuracy when reliable estimates of pi are not available. Introduction RTA and production forecasting using historical production data require flow-regime identification for model parameter calculation. The task of flow-regime identification is best achieved under constant-rate flowing conditions. However, field conditions and operational changes almost always cause flowing bottomhole pressure (BHP) to change during production. Use of rate-normalized pressure (RNP) can help mitigate the effect of changing BHP under smoothly changing conditions. Calculation of RNP requires an accurate estimate of pi, which often is unavailable. The authors’ work shows that the slope of a log-log plot of RNP vs. time or material balance time (MBT) is relatively insensitive to the value of pi. However, a Cartesian plot of RNP vs. timen (where n may be 0.5 for transient linear flow or a different value for more general “power-law behavior”) rotates the expected straight line for different values of pi or used in calculation of RNP. Therefore, the task of flow-regime identification can be achieved with reasonable certainty with only an estimate of initial pressure, but analysis with RNP vs. timen Cartesian plots may be unreliable.

Design of a cryptographically secure pseudo random number generator with grammatical evolution

This work investigates the potential for using Grammatical Evolution (GE) to generate an initial seed for the construction of a pseudo-random number generator (PRNG) and cryptographically secure (CS) PRNG. We demonstrate the suitability of GE as an entropy source and show that the initial seeds exhibit an average entropy value of 7.940560934 for 8-bit entropy, which is close to the ideal value of 8. We then construct two random number generators, GE-PRNG and GE-CSPRNG, both of which employ these initial seeds. We use Monte Carlo simulations to establish the efficacy of the GE-PRNG using an experimental setup designed to estimate the value for pi, in which 100,000,000 random numbers were generated by our system. This returned the value of pi of 3.146564000, which is precise up to six decimal digits for the actual value of pi. We propose a new approach called control_flow_incrementor to generate cryptographically secure random numbers. The random numbers generated with CSPRNG meet the prescribed National Institute of Standards and Technology SP800-22 and the Diehard statistical test requirements. We also present a computational performance analysis of GE-CSPRNG demonstrating its potential to be used in industrial applications.

Indicators of rheoencephalography in recurrent acutraumatic lesions in real combat conditions

Topicality: Recurrent acute trauma is common in patients who have received acutrauma in the combat zone. In such patients it is advisable to diagnose cerebral hemodynamic disorders for timely targeted medical care. Objectives of the study: The purpose of the work is to assess the quantitative and qualitative indicators of rheoencephalography in servicemen who received repeated acute trauma in real combat conditions. Materials and methods: We analysed the rheoencephalography of 52 patients with recurrent acute trauma and 15 healthy normal hearing subjects. Results: In the qualitative assessment of the rheograms of the examined patients, we found signs of cerebral circulatory disorders in both carotid (FM) and vertebrobasilar (OM) systems. In 28,3 % of the surveyed OOS fighters, we observed an increase in the tone of cerebral vessels with symptoms of angiospasm. Difficulty with venous outflow occurred in 72,1 % of cases in the carotid system and in 87,6 % - in the vertebrobasilar. Among the studied patients, we also often recorded a decrease in cerebral vascular tone (25,7 %) and cases of atonic curve (24,1 %). There was a significant proportion of patients with unstable vascular tone with a tendency to increase it 47,4 % or decrease 27,7 % in both cerebral circulatory systems. With regard to pulse blood supply, in patients with acutrauma were recorded (58,2 %) cases of its reduction in the carotid system and (89,7 %) in the vertebrobasilar basin. In the vertebrobasilar system, the asymmetry of REG curves (12,1 %) was also observed in real combat conditions. Analysis of quantitative indicators of REG in the carotid and vertebrobasilar systems in the subjects compared with the control group (K) revealed the following. In the examined patients there were changes in cerebral vascular tone and difficulty in venous outflow, as well as a decrease in pulse blood supply, as evidenced by significant changes in α, dichroic (DKI), diastolic (DSI) and rheographic (RI) indices of the REG curve. Thus, in the vertebrobasilar system, the value of Pi, which characterizes the pulse blood supply, was 0,57±0,04 (P<0,01) (at a rate of 1,19±0,03), and DKI was 59,63±1,18% (P<0,01) (at a rate of 51,2±1,4%). Thus, in patients with recurrent acute trauma there are severe disorders of cerebral circulation, especially in the vertebrobasilar basin. Conclusions: 1. According to rheoencephalography, fighters who received repeated acute trauma in the area of environmental protection have severe cerebrovascular disorders, with venous outflow difficulties, decreased pulse blood flow, tendency to decrease and unstable tone of cerebral vessels predominate. 2. Significant (P<0,05) deviations from the norm in the indicators of DKI, DSI and Ri, especially in the vertebrobasilar basin, take place in the examined fighters with repeated acute trauma. This indicates a pronounced violation of cerebral circulation, venous outflow and decreased pulse blood supply during repeated combat acutrauma. 3. In case of repeated combat acutrauma, there are pronounced extraural disorders of the cerebral circulation, which need to be taken into account when providing medical care to such patients.

Pancreatic CT density is an optimal imaging biomarker for earlier detection of malignancy in the pancreas with intraductal papillary mucinous neoplasm

BackgroundIntraductal papillary mucinous neoplasms (IPMNs) are typically detected as incidental findings by computed tomography (CT); however, the conventional surveillance is not valid for the early detection of concomitant pancreatic cancer. The pancreas of IPMN is often accompanied by fatty infiltration in the parenchyma, and pancreatic fatty infiltration could be evaluated by pancreatic CT density (pancreatic index, PI). We aimed to investigate whether PI could be an imaging biomarker for the early prediction of malignancies in the pancreas with IPMN. MethodsTwo different cohorts were investigated. (Investigation cohort): A total of 1137 patients with initially low-risk IPMN were compensated by initial IPMN findings, and 2 groups (malignancy/possible benign, 50 cases each) were investigated for yearly changes in PI and for the cutoff value of PI indicating the development of malignancies. (Validation cohort): To validate the cutoff value, 256 patients radiologically suspected of having IPMNs were investigated. Results(Investigation-cohort): The malignancy group showed a gradual decrease in PI every year, and PI significantly differed among the 2 groups 1 year prior to the last investigation. The cutoff value of PI was set at 0.65. (Validation-cohort): A total of 55% of the patients with a PI below the cutoff value had malignancy in the pancreas, including concomitant pancreatic cancer, and the cutoff value was the most significant risk factors for the development of malignancies in the pancreas compared to the conventional risk factors for IPMN. ConclusionsDecreasing PI would be an optimal imaging biomarker for earlier detection of malignancies in the pancreas with IPMN.

A new approach to the design of acyclic chemical compounds using skeleton trees and integer linear programming

Intelligent systems are applied in a wide range of areas, and computer-aided drug design is a highly important one. One major approach to drug design is the inverse QSAR/QSPR (quantitative structure-activity and structure-property relationship), for which a method that uses both artificial neural networks (ANN) and mixed integer linear programming (MILP) has been proposed recently. This method consists of two phases: a forward prediction phase, and an inverse, inference phase. In the prediction phase, a feature function f over chemical compounds is defined, whereby a chemical compound G is represented as a vector f(G) of descriptors. Following, for a given chemical property pi, using a dataset of chemical compounds with known values for property pi, a regressive prediction function psi is computed by an ANN. It is desired that psi (f(G)) takes a value that is close to the true value of property pi for the compound G for many of the compounds in the dataset. In the inference phase, one starts with a target value y^* of the chemical property pi, and then a chemical structure G^* such that psi (f(G^*)) is within a certain tolerance level of y^* is constructed from the solution to a specially formulated MILP. This method has been used for the case of inferring acyclic chemical compounds. With this paper, we propose a new concept on acyclic chemical graphs, called a skeleton tree, and based on it develop a new MILP formulation for inferring acyclic chemical compounds. Our computational experiments indicate that our newly proposed method significantly outperforms the existing method when the diameter of graphs is up to 8. In a particular example where we inferred acyclic chemical compounds with 38 non-hydrogen atoms from the set {C, O, S} times faster.

Large Number System from Vedas and Vedic Literature

Hinduism is undoubtedly the oldest religion of the world and though there are disagreement over the period amongst some historian but it was during 1900 to 1500 BC when Hindu religion came into existence. The foremost religious text of Hindu is Vedas and the origin of the Vedas can be traced back as far as 1500 BCE, when a large group of Aryans crossed the Hindu Kush Mountains and came to Indian subcontinent. The Vedas are full of knowledge.The Vedas have guided the Indian civilization for thousands of years and the Four Vedas are the pillar of Hinduism. The very word Veda has a derivational meaning – the fountainhead and illimitable storehouse of all knowledge. This article will only focus on the mathematical content available in Vedas, Puranas, Ramayana and Mahabharata. In Rig Veda and Atharva Veda, there are several instance where numbers in the power of tens, even numbers, odd numbers, multiples of four, value of pi, mathematical operation such as addition, subtraction, multiplication and division have been discussed not in the way we use in our courses but the presence of larger number even up to 1060 is evident. The speed of light, about seven colourful rays of sunlight all these are enough to make a belief that Vedas have put a strong foundation of number system and decimal system. Not even that, even geometrical knowledge found in Sulbha sutra as par excellence and many of them have origin prior to Greek mathematician to whom we owe everything.

Penerapan Metode AHP dan OCRA dalam Pengambilan Keputusan Menentukan Santri Berprestasi

The selection of outstanding students is an appreciation given by the boarding school to the students who have the highest scores. However, the election is usually still done subjectively and manually, and there is no support system in creating decisions, which make the selection process long and inaccurate. This study aims to implement a decision support system in determining outstanding students at Mamba'ussholihin Islamic Boarding School predetermined with criteria. The process of selecting uses the method Analytical Hierarchy Process (AHP) for weighting criteria and Operational Competitiveness Rating Analysis (OCRA) for ranking. The OCRA value obtained is in the form of Pi, which is ranked to get the best students. The findings show that the error consistency level is less than 10% and the consistency index value is accepted, so that it can be used as an initial weight with a relative number = 1. After calculating the OCRA method from the initial 75 alternative data, the top 10 alternative data obtained are in the form of the value of Pi will be entitled to an award as an outstanding student, so by applying these two methods it can speed up the results of the decision, it does not take a long time and the results obtained are also precise.

Analysis Of Response Speed Settings Flame Sensor Fire Fighting Robots Using Pid

The fire fighting robot is designed to automatically maneuver through a room where there are hotspots and is able to extinguish the fire. In order to complete the task of extinguishing fire the robot is also designed to use a fire sensor. The robot uses a flame sensor to detect the light generated by the fire source. The Ercomp fire fighting robot, University of Muhammadiyah Ponorogo uses a 28-bit flame sensor with a detection range of 360o. The robot is set using the KP and KD control system with the parameter values ​​used are KP = 9 and KD = 10. In detecting hotspots, the robot must be fast when tracing hotspots. In this study, the application of PID control is expected to produce the best comparison value of PD, PI and PID values ​​to be implemented on legged fire fighting robots. This study is to determine the value of the control tested using the trial and error method and PID tuner. The best results from the test are PID control with Kp = 90, Ki = 20 and Kd = 10, it can be seen from the response parameters that the system has no overshoot, a rise time of 0.59 seconds, and a settling time of 1.15 seconds.

Screening of High-Risk Patient by Uterine Artery Doppler Analysis in The 1st Trimester to Predict Early Onset Pre-Eclampsia

Background: Preeclampsia (PE) is still a major obstetrical problem world-wide. First trimester prediction of PE is of great clinical importance, as it would allow clinicians to focus on high-risk groups and initiate prophylactic medical treatment. The first stage of pre-eclampsia begins in the first trimester by impaired placentation. High-resistant spiral arteries can be detected from the 11th week of gestation by uterine artery (UtA) Doppler examination. Objective: To assess the relationship between 1st trimester uterine artery pulsatility index (UtA PI) and the development of early onset PE.Patients and Methods: Prospective observational study was performed at Mansoura University Hospital. This study was conducted on 109 pregnant women who attended their routine antenatal care visits at the Outpatient Obstetrics and Gynecology Clinic of Mansoura University Hospital. Results: There were statistically high significant difference between both groups in the BMI (p = 0.003), and no statistically significant difference as regards the age, gravidity and gestational age (p > 0.05). Statistically significant difference was evident between two groups in the mean values of UtA PI (p = 0.028). The best cutoff value of UtA PI for the prediction of early onset preeclampsia was ≥ 2.03 with accuracy of 0.79, and that of BMI was ≥ 35 with accuracy of 0.93. Conclusion: This study revealed that first trimester uterine artery Doppler can be used as a reliable screening test for prediction of preeclampsia in high risk women. It is a reliable, noninvasive method of examining uteroplacental perfusion. Abnormal UA Doppler ultrasonography (elevated PI) in 11–14 weeks' gestation can predict pre-eclampsia.

Study of Maternal and Fetal Doppler Velocimetry, Histopathology of Placental Bed in Diabetic Pregnancy and Its Correlation to Fetal Outcome

Diabetes mellitus still represents an important medical problem during pregnancy, causing perinatal morbidity and mortality. Despite improved outcome reflected by a steep decline in perinatal mortality over the past few decades, controversy still exists regarding the care of the pregnant woman with both pre-existing and gestational Diabetes Mellitus. Doppler ultrasound is especially valuable during pregnancy because fetal maternal and placental circulations can be studied. The aim of this work was to study the vascular changes in the uteroplacental and fetoplacental circulations, and to correlate these findings with histopathology of the placenta and placental bed, which may occur in association with diabetic pregnancies. The study was carried out on 100 pregnant women of comparable age and parity. They were divided into 2 groups. The control group comprising 20 normal non-diabetic pregnant women and the normotensive diabetic group comprising 80 pregnant diabetic women. All were singleton pregnancies of 34 weeks or more and were delivered by C.S the control and the study cases were subjected to history taking and thorough physical examination. They were also subjected to ultrasonographic examination for fetal biometric parameters and for Doppler examination. Doppler examination included umbilical artery, uterine arteries fetal middle cerebral artery. At the time of C.S the placenta and placental bed biopsy was obtained. After delivery, the Apgar score of the newborn was assessed at 1 and 5 minutes, the body weight was measured, and the fetus was followed up for any complications. Result: There was a positive correlation between the umbilical artery PI and the mean blood glucose levels indicating that poor diabetic control is probably associated with increased umbilical artery PI. However, there was no significant difference between the mean value of the umbilical artery PI in the diabetic and control groups. The uterine arteries Doppler indices showed no significant findings between the diabetic and the control groups. Neither did the uterine arteries Doppler indices show a correlation with the mean blood glucose levels. There was no significant difference between the middle cerebral artery PI in the diabetic and control groups. This observation indicates that there was no redistribution in the fetal circulation in the fetuses of the diabetic group. There was also non correlation between the MCA Doppler indices and the glycemic control. Histopathologic studies of the placental bed showed marked difference between the diabetic group and the control group as regards lack of physiologic changes and arteriosclerotic changes, which emphasizes the effect of diabetes on the placental bed vasculature. Conclusion: Abnormal umbilical artery waveform analysis is one of significant predictors of fetal compromise in diabetic pregnancy, but fetal compromise can occur in association with normal Doppler waveform analysis. In maternal diabetes the classic redistribution seen in fetal hypoxemia due to uteroplacental insufficiency may not occur in diabetic patient even in severely compromised fetuses. In maternal diabetes mellitus, maternal glycemic control has no effect on impedance to flow in the uterine and middle cerebral arteries. No relationship was found between the uterine or umbilical arteries Doppler indices and the placental bed decidual vascular pathology in diabetic pregnancies. There was no correlation between placental findings and the Doppler waveform analysis of the umbilical and the uterine arteries.