Brain and skull

Topographical and morphological evaluation of the ligaments of the ankle joint: Anatomical reference for surgical reconstruction.

Precise structural analysis of α-helical polypeptide by quantum-chemical calculation related to reciprocal side-chain combination of two L-phenylalanine residues

Study of anatomical variations of the zygomaticofacial foramen and calculation of reliable reference points for operation

با رشد روز افزون استفاده از سازههای فضاکار، نیاز به تحلیل و طراحی دقیق این سازهها بیش از پیش احساس می‌شود. شبکههای تک لایه مستوی از جمله سازههای فضاکار می‌باشند که در عرشه پلها و کشتیها و پوشش سقفها با دهانههای کوتاه به کار می‌روند. با وجود روش‌های گوناگون پیشنهادی برای تحلیل سازه‌ها و رابطه‌های ساده و مشخصی که برای تحلیل و طراحی شبکه‌های تک لایه با روش مومسان به دست می‌آیند، باید برای تحلیل صحیح و دقیق‌تر سازه‌ها به اثر و نقش هریک از فرضیات در نتیجه‌های تحلیل آگاه بود. در این نوشته نخست به تحلیل و طراحی مومسان شبکههای مستوی با روش حل کران بالا و روش حل کران پایین پرداخته شد. این کار به یافتن رابطه‌های بسته‌ای منجر شد که با کمک آن‌ها تحلیل‌های غیر خطی با در نظر گرفتن الگوی رفتاری غیرخطی مصالح و غیرخطی هندسی انجام پذیرفت. در ادامه، شبکه‌های تک لایه بدون درنر گرفتن رفتار غیرخطی با برنامه‌های SAP و ABAQUS تحلیل شدند و نتیجه‌ها با یکدیگر و با نتیجه‌های تحلیل مومسان مورد مقایسه قرار گرفتند. سپس اثر فرض‌های ساده کننده در تحلیل شبکه‌ها بررسی و موردهای کاربرد مجاز هریک از تحلیل‌ها ارائه شد.

Objectives: The primary objective of the study is to classify the blood pressure (BP) levels using advanced machine learning (ML) techniques for predictive purposes. The study assesses the efficacy of the Naïve Bayes, AdaBoost, feedforward neural networks (FNNs), and long short-term memory (LSTM) algorithms over the conventional multinomial logistic model using standard performance evaluation metrics. Methods: The dataset comprised 15,000 entries obtained from the National Health Service, England, each containing eight variables. The variables include BP, age, weight, height, gender, smoking habit, alcohol consumption, and fitness level. The Naïve Bayes, AdaBoost, FNN, LSTM, and multinomial logistic models were employed in the study. Each model underwent training, testing, validation, and evaluation using suitable metrics such as accuracy, F1-Score, kappa statistics, sensitivity, specificity, and area under the curve score. Results: The FNN model gives the highest test accuracy of 89.47% and balanced performance, making it the most appropriate model for predicting BP levels. The LSTM model demonstrated strong proficiency in capturing temporal patterns. AdaBoost was highly effective for dealing with class imbalance, but Naïve Bayes was a dependable benchmark. The multinomial logistic model established a reliable and stable reference point. The results represented a notable improvement over previous research, which typically reported median accuracy rates in the 80–85% range. Conclusion: The study reveals that knowing an individual’s age, weight, height, gender, smoking habit, alcohol consumption, and fitness level is useful in predicting his/her BP level. Thus, the advanced ML algorithms demonstrate potential in accurately classifying BP levels and can aid in the prevention, detection, and management of hypertension.

Three-dimensional analysis of models articulated in the seated condylar position from a deprogrammed asymptomatic population: A prospective study. Part 1

The phlebostatic axis--the junction of the fourth intercostal space and the midpoint of the anterior-posterior diameter--has been accepted as a reliable external reference point for the mid-right and mid-left atrium. Acceptance of this reference point is based upon research conducted in 1945 that measured venous pressures in the hands of subjects positioned with the head of the bed raised to different levels. The validity of this reference point for intracardiac pressure measurements in supine or laterally positioned patients has not been established. To determine the validity of the phlebostatic axis in the supine and lateral positions. To determine validity in the supine position, we compared the distance from the phlebostatic axis to a fixed external point (the bed surface) and the distance from the right and left atria in the supine position to this same fixed external point. The distances from the right and left atria to the bed surface were determined with echocardiography and were used as the standard for the proper position of external reference points. To determine the validity of the phlebostatic axis in lateral positions, we compared the distances from the right atrium and left atrium to the bed surface in the supine position with those distances in different lateral positions. We analyzed the data of 25 normal, healthy subjects. The study findings show that the phlebostatic axis is a valid reference point for the right atrium, and the phlebostatic axis and midanterior-posterior diameter are valid reference points for the left atrium in the supine position. However, neither is a valid external reference point in the lateral positions. Pressure measurements obtained when patients are in the lateral positions are not accurate. There remains a need to develop valid methods of accurate pressure measurements in various body positions.

In this little book, the authors have chosen the formidable task of integrating psychoanalytic concepts into group and organizational dynamics. Their central theme is how individuals can use introspective understanding of their own lives to further their understanding of their group's dynamics. They begin by establishing the notion that, because we live in a rapidly changing social environment, the stability we used to experience in our social institutions no longer seems a reliable reference point from which to establish our sense of who we are. As a result, as the title suggests, many of us are lost in familiar places. First, the family is examined to explore how the individual interfaces with his first group experience. The authors introduce the concept of personal boundaries and how excessive certainty and a lack of interpersonal curiosity may stifle a child's ability to negotiate her interpretation of her innner and outer environment. A

<p>Bulgarian archaeomagnetic database is the longest local geomagnetic field record covering almost completely the last 8000 years. However, very poorly constrained periods in need of elucidation still exist. Among the most problematic are the last 1200 years BC corresponding to the Iron Age in Bulgarian lands. In contrast to the relatively well studied Neolithic, Eneolithic and Bronze Age settlements, the Iron Age sites (especially in the Early Iron Age phase) are not sufficiently investigated from the archaeological point of view. The lack of precise stratigraphic frames significantly hampers the specification of sites chronology, and as a result, baked clay features that could serve as reliable reference points are rather scarce.</p><p>The most recent compilation of the Bulgarian archaeomagnetic database contains 18 intensity and 16 directional reference points belonging to the Iron Age, which have very uneven temporal distribution. To extend the coverage, 26 baked clay structures from nine different archaeological sites were sampled and archaeomagnetically studied producing ten new directional, but only five intensity data. It seems quite often materials from Iron Age combustion structures to possess magnetic properties unfavorable for archaeomagnetism, generally reflected in non-linear and concave Arai plots. Hereby, the lowest success rate of archaeointensity determination experiments is registered for this period within the whole database. Usually it is much easier to determine the past geomagnetic field direction compared to the intensity and the failure of the Thellier experiment is not surprising. Nevertheless, more than 90% of the investigated features belonging to all the other epochs except Iron Age normally display success rates over 50%, as only for 1-2% the archaeointensity determination experiments fail completely. In contrast, in the Iron Age the successful features comprise only 56% of the total number studied with 28% failure. A possible explanation for this observation was sought in some specific inappropriate conditions during firing/burial time that affect magnetic properties of baked clay materials during and/or after their thermoremanence acquisition.</p><p>This study is supported by the grant KP-06-Russia-10 from the Bulgarian National Science Fund and Russian Foundation of the Basic Research grant 19-55-18006.</p>

We construct an automatic secure fingerprint verification system based on the fuzzy vault scheme to address a major security hole currently existing in most biometric authentication systems. The construction of the fuzzy vault during the enrollment phase is automated by aligning the most reliable reference points between different templates, based on which the converted features are used to form the lock set. The size of the fuzzy vault, the degree of the underlying polynomial, as well as the number of templates needed for reaching the reliable reference point are investigated. This results in a high unlocking complexity for attackers with an acceptable unlocking accuracy for legal users.

Publisher Summary This chapter reviews the current results about high-resolution electron microscopy studies on quasicrystals. From the results it can be concluded that structures of icosahedral and decagonal quasicrystals can be described as aperiodic arrangements of some atom clusters, which have the same symmetry as those of the quasicrystals, with definite linkages. There is variety in aperiodic arrangement of the atom clusters and atomic arrangements in the atom clusters, depending on quasicrystalline alloys. High-resolution electron microscopy is the most powerful tool for studying the varied structures. However, it has many limitations for carrying out precise structure analysis about atomic arrangements, because of its limited resolution compared with diffraction and the use of images projected along the incident beam. To proceed to the more precise structure analysis of the quasicrystals, combining high-resolution electron microscopy with the diffraction method becomes more important. The atomic arrangements of Al–Ni–Co, Al–Pd–Mn, and Al–Pd decagonal quasicrystals, were proposed using the results of x-ray diffraction.

There is much interest and focus on solid forms of famciclovir. However, in spite of the abundance of reported differences in oral bioavailability, compressibility, and other physical–chemical properties of the various crystal forms of this drug, very little precise structural analysis is available in the literature to date. The form used in the commercial formulation is the anhydrous form I. Patents and patent applications report three different anhydrous crystalline forms on the basis of unindexed powder diffraction patterns. Single-crystal and variable-temperature X-ray diffraction experiments using the commercially available anhydrous form of famciclovir were carried out and led not only to the crystal structure determination of the anhydrous form I, but also to discovery of a new crystal form of anhydrous famciclovir from powder data.

Crystal structure of layered magnetic semiconductors (La1−xCaxO)Cu1−xNixS which show ferromagnetism even at room temperature has been investigated precisely using synchrotron x‐rays to understand their physical properties from a view point of the crystal structure and check magnetic impurities. No magnetic impurities were found and this means that these ferromagnetic characters are intrinsic properties. Precise structural analysis indicate that the interlayer distance between S‐Cu2‐S and La‐O2‐La layers decreases with increasing concentration x. The increase of x leads to reduce the electrical resistivity. From these results, the interaction between LaO and CuS layers is therefore important in controlling the physical properties of these compounds.

Our objective is to investigate the reliability and usefulness of anatomic point-based lung zone segmentation on chest radiographs (CXRs) as a reference standard framework and to evaluate the accuracy of automated point placement. Two hundred frontal CXRs were presented to two radiologists who identified five anatomic points: two at the lung apices, one at the top of the aortic arch, and two at the costophrenic angles. Of these 1000 anatomic points, 161 (16.1%) were obscured (mostly by pleural effusions). Observer variations were investigated. Eight anatomic zones then were automatically generated from the manually placed anatomic points, and a prototype algorithm was developed using the point-based lung zone segmentation to detect cardiomegaly and levels of diaphragm and pleural effusions. A trained U-Net neural network was used to automatically place these five points within 379 CXRs of an independent database. Intra- and inter-observer variation in mean distance between corresponding anatomic points was larger for obscured points (8.7mm and 20mm, respectively) than for visible points (4.3mm and 7.6mm, respectively). The computer algorithm using the point-based lung zone segmentation could diagnostically measure the cardiothoracic ratio and diaphragm position or pleural effusion. The mean distance between corresponding points placed by the radiologist and by the neural network was 6.2mm. The network identified 95% of the radiologist-indicated points with only 3% of network-identified points being false-positives. In conclusion, a reliable anatomic point-based lung segmentation method for CXRs has been developed with expected utility for establishing reference standards for machine learning applications.

Unfavorable fractures and blood vessel injuries encountered during 196 operations on 185 patients who underwent surgical correction of jaw deformities were studied to analyze the causes. There were 12 unfavorable fractures (6.1%) and 9 blood vessel injuries (4.6%). All complications occurred in two-jaw surgery and sagittal splitting ramus osteotomy (SSRO). Blood loss and operation time were significantly higher in cases with complications than in those without complication in SSRO.SSRO. With the exception of one case, all fractures were encountered during SSRO. Most of them were minor fractures occurring along the osteotomy line, but relatively large segments of the proximal segment were fractured in 3 cases, 2 of which were not repositioned. Blood vessel injury of the descending palatine artery was encountered in 2 cases of Le Fort I osteotomy. In SSRO, injuries of the inferior alveolar artery, facial artery, and unidentified artery occurred in 3, 1, and 3 cases, respectively. Ligation of the arteries was required to stop bleeding in 2 cases, whereas in the other cases, bleeding was controlled by packing of gauze or oxidized regenerated cellulose.Insufficient bony cut, forcible splitting, and careless handling of surgical instruments were the main causes of the complications. It is thought that the complications can be avoided by precise analysis of structures at the operation site by computed tomography, sufficient bony cut, and careful handling of surgical instruments.