Matching Criteria Research Articles

Lipoprotein(a) and Hyperinsulinemia in Healthy Normal-weight, Prepubertal Mexican Children

ABSTRACT Background. Given the numerous gaps in our knowledge about the biological interactions of lipoprotein(a) [Lp(a)], we determined whether Lp(a) was associated with hyperinsulinemia in healthy normal-weight, prepubertal children. Methods. A total of 131 healthy normal-weight Mexican children aged 6 to 9 years at Tanner stage 1 who were born appropriate for gestational age were enrolled in a case–control study. Children with hyperinsulinemia were allocated into the case group (n = 32), and children with normal insulin levels were allocated into the control group (n = 99). Birth weight, age, and body mass index were matching criteria. Multivariate logistic regression analysis was used to compute the odds ratio (OR) between Lp(a) and both hyperinsulinemia and insulin resistance. Furthermore, a multivariate linear regression analysis was performed to evaluate the association between Lp(a) and both insulin levels and HOMA-IR. Both models were adjusted by sex, age, birth weight, and body mass index. Results. The median (25–75 percentile) serum levels of Lp(a) [20.0 (13.7–29.6) versus 14.6 (10.6–26.7) mg/dL, p = .003] and insulin [24.5 (6.0–30) versus 7.9 (4.3–9.0) µU/L, p < .0005] were higher in the case group than in the control group. The logistic regression analysis showed that Lp(a) was associated with hyperinsulinemia (OR 5.86; 95%CI 2.5–13.6, p < .0005) and insulin resistance (OR 2.01; 95%CI 1.1–9.9, p = .004). In addition, the linear regression analysis showed a significant association between serum Lp(a) and insulin levels (β 11.1; 95%CI 1.8–10.9, p < .0001) and the HOMA-IR index (β 2.606; 95%CI 2.3–2.9, p < .0005). Conclusion. Lp(a) was associated with hyperinsulinemia and insulin resistance in healthy normal-weight, prepubertal children.

Faster dense deformable image registration by utilizing both CPU and GPU.

.Purpose: Image registration is an important aspect of medical image analysis and a key component in many analysis concepts. Applications include fusion of multimodal images, multi-atlas segmentation, and whole-body analysis. Deformable image registration is often computationally expensive, and the need for efficient registration methods is highlighted by the emergence of large-scale image databases, e.g., the UK Biobank, providing imaging from 100,000 participants.Approach: We present a heterogeneous computing approach, utilizing both the CPU and the graphics processing unit (GPU), to accelerate a previously proposed image registration method. The parallelizable task of computing the matching criterion is offloaded to the GPU, where it can be computed efficiently, while the more complex optimization task is performed on the CPU. To lessen the impact of data synchronization between the CPU and GPU, we propose a pipeline model, effectively overlapping computational tasks with data synchronization. The performance is evaluated on a brain labeling task and compared with a CPU implementation of the same method and the popular advanced normalization tools (ANTs) software.Results: The proposed method presents a speed-up by factors of 4 and 8 against the CPU implementation and the ANTs software, respectively. A significant improvement in labeling quality was also observed, with measured mean Dice overlaps of 0.712 and 0.701 for our method and ANTs, respectively.Conclusions: We showed that the proposed method compares favorably to the ANTs software yielding both a significant speed-up and an improvement in labeling quality. The registration method together with the proposed parallelization strategy is implemented as an open-source software package, deform.

586 Decreased fetal movement and anterior placentation: a case control study

Decreased fetal movement (DFM) is a common obstetrical complaint, with an incidence of up to 16% of pregnancies. DFM is often attributed to anterior placentation, however, there is limited data to support this belief. There are no case control studies or studies performed in the United States which address this relationship. This was a case control study of patients who presented to Stamford Hospital with DFM from January 2017 to December 2017. The control group included patients who presented for delivery during this time. Exclusion criteria included presentation prior to 24 weeks gestational age, multi-fetal gestation, and intrauterine fetal demise. Variables collected were placentation, age, parity, gestational age, fetal presentation, BMI, and presence of hypertensive or diabetic disorder. Cohorts were matched by BMI and parity. Discrete variables were analyzed with chi-square statistics and continuous variables were analyzed with independent t-test. Propensity score matching was conducted using the nearest neighbor matching criteria in ‘R.’ Logistic regression was used to calculate adjusted odds ratios. 123 patients presented with DFM and 127 control patients were identified. 112 patients were matched in each group. In the DFM group, 56 (58.3%) had an anterior placenta, compared with 33 (35.1%) in the control group (p=0.001). Patients that presented with DFM were 2.9 times as likely to have an anterior placenta (CI 1.5-5.5). Average maternal age in the DFM group was 30.7 years, compared with 32.7 years in the control group (p=0.005). Patients that presented with DFM were not at an increased odds of presenting with non-vertex presentation (CI 0.10-1.2). There was also no increased odds of hypertensive or diabetic disorder in the DFM group (CI 0.24-2.95; CI 0.30-2.03). Our study supports that patients who present for decreased fetal movement compared with matched controls are at an increased odds of having an anterior placenta. These patients are also younger. There is no increased odds of non-vertex presentation or of having a hypertensive or diabetic disorder.

Carbon-fiber reinforced PEEK instrumentation for spondylodiscitis: a single center experience on safety and efficacy

Radiolucent carbon-fiber-reinforced (CFR) polyethyl-ether-ether-ketone (PEEK) has been established in spinal instrumentation for oncological reasons. Laboratory data reported comparable bacterial adhesion as titanium. Thus, using of CFR-PEEK spinal instrumentation for spondylodiscitis bases on artifact-free imaging to evaluate therapeutic success. Studies comparing the rate of pedicle screw loosening and relapse of spondylodiscitis following titanium versus CFR-PEEK instrumentation do not exist so far. This study evaluates the rate of pedicle screw loosening and recurrence of spondylodiscitis after CFR-PEEK instrumentation for spondylodiscitis compared to titanium. We conducted a prospective single center study between June 2018 and March 2019 on consecutive 23 patients with thoracolumbar spondylodiscitis. Imaging data was evaluated for screw loosening at a minimum of three months after surgery. A matched-pair analysis was performed using spondylodiscitis cases between 2014 and 2016 using titanium instrumentation for equal localization, surgery, and microorganism class. Among 17 cases with follow-up imaging, six cases (35%) showed screw loosening while only 14% (two patients) with titanium instrumentation were loosened (p = 0.004). In both groups the most frequent bacterium was Staphylococcus aureus, followed by Staphylococcus epidermidis. From the S. aureus cases, one infection in both groups was caused by methicillin resistant species (MRSA). No difference was found in the rate of 360° fusion in either group due to matching criteria. As opposed to other indications CFR-PEEK screws show more loosening than titanium in this series with two potentially underlying reasons: a probably stronger bacterial adhesion on CFR-PEEK in vivo as shown by a statistical trend in vitro and instrumentation of spondylytic vertebrae. Until these factors are validated, we advise caution when implanting CFR-PEEK screws in infectious cases.

Self-adaptive match algorithm for transmitter–receiver in the middle and upper atmospheric lidar

A precise matching is required between the emitted laser beam and Field-of-View (FOV) of the received telescope to ensure useful observation of middle and upper atmospheric lidar. Nowadays, manual matching is commonly used, but it is time-consuming and has poor stability. Automatic matching is still hard to meet the actual application requirement because it is challenging to balance accuracy and efficiency. Thus, in this paper, a self-adaptive matching algorithm is proposed. In this process, the correlation coefficient between the echo signal and the standard pattern is considered as the matching criterion. It adaptively updates the adjustment step according to the current position’s matching state and uses the correlation coefficient’s increasing gradient as the adjustment direction. The above matching process is iteratively conducted until meeting the convergence condition. The matching process is within 3∼5min. These results suggest that the proposed automated matching algorithm can play an important role in unattended atmospheric lidars.

Fuzzy based Search in Motion Estimation for Real Time Video Compression

Video compression ratio, quality and efficiency are determined by the motion estimation algorithm. Motion estimation is used to perform inter frame prediction in video sequences. The individual frames are divided into blocks the motion estimation is computed by a video codec such as H.264. A video codec computes the displacement of block between the previous frame (reference frame) and the current frame, for each block in current frame the best motion vector is determined in the reference frame as a block belongs to a current frame. In this, research paper, a novel technique has been presented for motion vector calculation, using fuzzy Gaussian membership function. The motion estimation block uses fuzzy membership function to estimate the connectedness of different blocks of the current frame to that of the reference frame The fuzzy decision matching is done based on the matching criterion and the best matching block is selected. The motion vectors are thus calculated with respect to the reference frame. The fuzzification process produces optimally matched blocks, which are then utilized to calculate the motion vectors of the predicted frame. Using fuzzy based search the search area is automatically updated and adaptive search steps provides an optimized result of search. As in real time streaming no file is exchanged during the transmission user is not able to download the file the only way for smooth transmission is frame management fuzzy based search for the motion estimation provides a better compression for the predicted frames.

Breast Mass Detection With Faster R-CNN: On the Feasibility of Learning From Noisy Annotations

In this work we study the impact of noise on the training of object detection networks for the medical domain, and how it can be mitigated by improving the training procedure. Annotating large medical datasets for training data-hungry deep learning models is expensive and time consuming. Leveraging information that is already collected in clinical practice, in the form of text reports, bookmarks or lesion measurements would substantially reduce this cost. Obtaining precise lesion bounding boxes through automatic mining procedures, however, is difficult. We provide here a quantitative evaluation of the effect of bounding box coordinate noise on the performance of Faster R-CNN object detection networks for breast mass detection. Varying degrees of noise are simulated by randomly modifying the bounding boxes: in our experiments, bounding boxes could be enlarged up to six times the original size. The noise is injected in the CBIS-DDSM collection, a well curated public mammography dataset for which accurate lesion location is available. We show how, due to an imperfect matching between the ground truth and the network bounding box proposals, the noise is propagated during training and reduces the ability of the network to correctly classify lesions from background. When using the standard Intersection over Union criterion, the area under the FROC curve decreases by up to 9%. A novel matching criterion is proposed to improve tolerance to noise.

Antiviral treatment associated with reduced risk of clinical Alzheimer's disease-A nested case-control study.

IntroductionIn this nested case‐control study, we investigated if antiviral treatment given prior to onset of Alzheimer's disease (AD) could influence incident AD.MethodsFrom a large population‐based cohort study in northern Sweden, 262 individuals that later developed AD were compared to a non‐AD matched control group with respect to prescriptions of herpes antiviral treatment. All included subjects were herpes simplex virus 1 (HSV1) carriers and the matching criteria were age, sex, apolipoprotein E genotype (ε4 allele carriership), and study sample start year.ResultsAmong those who developed AD, 6 prescriptions of antivirals were found, compared to 20 among matched controls. Adjusted for length of follow‐up, a conditional logistic regression indicated a difference in the risk for AD development between groups (odds ratio for AD with an antiviral prescription 0.287, P = .018).DiscussionAntiviral treatment might possibly reduce the risk for later development of HSV1‐associated AD.

A tightly coupled dipole array used for radiation power improvement on finite radiation aperture

Radiation power of an electromagnetic wave plays a decisive role in its transmission distance. Traditionally, the radiation power can be improved by expanding the radiation aperture size of the antenna array or increasing input power of the unit cell. However, the radiation aperture size is always restricted by assembly space. The input power improvement of the unit cell is always limited by the signal source. It is difficult to improve radiation power on a finite radiation aperture. However, the radiation power on a finite radiation aperture is related closely to the number of antenna elements and the radiation efficiency of the antenna array. It is useful to arrange more elements and improve radiation efficiency of the antenna array to improve the radiation power on a finite radiation aperture. Wideband wide-angle scanning phased array is able to make full use of a finite radiation aperture. The wide-angle scanning properties make it possible for the radiated power to cover a wide area. In this paper, a compact wideband wide-angle scanning tightly coupled dipole array (TCDA) is proposed. A high permittivity substrate and compact wideband balun are used for miniaturizing the antenna array. The period of the unit cell is only 0.144&lt;i&gt;λ&lt;/i&gt;&lt;sub&gt;high&lt;/sub&gt; × 0.144&lt;i&gt;λ&lt;/i&gt;&lt;sub&gt;high&lt;/sub&gt; (&lt;i&gt;λ&lt;/i&gt;&lt;sub&gt;high&lt;/sub&gt; is the wavelength at the highest operation frequency in free space). Parameters of the balun are optimized to improve impedance matching between the balun and the antenna array. Two bilateral frequency selective surfaces (FSSs) are used to replace traditional dielectric superstrate to improve the impedance matching between the antenna array and free space. A low-loss dielectric substrate is used to reduce dielectric loss of the antenna array. In these ways, the radiation efficiency is greatly improved. The simulation results show that the proposed antenna array operates at 1.7–5.4 GHz (3.2:1) while scanning up to 65° in the E plane, 45° in the H plane and 60° in the D plane with following a rigorous impedance matching criterion (active VSWR &lt; 2). A 16 × 16 prototype array is fabricated and measured. Good agreement is achieved between the simulation results and the measurement results. Compared with the designs in the literature, the proposed antenna array has an excellent performance in radiation power on a finite radiation aperture.

An Interlaboratory Study to Evaluate the Forensic Analysis and Interpretation of Glass Evidence

The results of an interlaboratory study using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and the standard test method (ASTM E2927-16e1) for the forensic analysis and comparison of glass evidence is reported. The aims were to evaluate the performance of the CFGS2 calibration standard for the quantitative analysis of simulated casework samples, evaluate the comparison criterion as recommended by the ASTM E2927 (association or non-association) and the use of a likelihood ratio (LR) as a quantitative determination of the strength of any association found. Each laboratory determined a LR to report the significance of glass source comparisons for a set of glass samples of known origin. Two different background databases were used for the calculation of the LR to evaluate the effect of the size and composition of the databases on the calculation of the LR. As expected, glass that originated from the same windowpane was found to be indistinguishable using the ASTM E2927 match criteria and result in a high LR value (strong support for an association) and glass that originated from different vehicles are distinguished (strong support for an exclusion). Glass samples that originated from different vehicles but that were the same make, model and year (or comparisons between the inner and outer pane of the same windshield) were found to exhibit chemical similarity that is sometimes reflected in a low LR. Good agreement among the laboratories was also reported with relative standard deviations < 5 % among participating in the study with few exceptions.

Pool Testing with Dilution and Heterogeneous Priors

In light of the ongoing pandemic, many countries have struggled to implement massive testings due to their lack of resources. To minimize the number of tests required to diagnose a population, some countries have resorted to the Dorfman's pool testing procedure, a process that consists of pooling samples of different patients together, and then testing the merged sample as though it originated from the same subject; if the merged sample tests positive for infection, then each of its subjects is tested individually. Through this procedure, laboratories avoid conducting individual tests whenever the test for the pooled sample does not accuse infection. In this paper we study a very simple criterion used to match patients to form the pools. The procedure, which we call ordered pooling, consists of ordering patients from lowest to highest probability of infection, and then matching together those with similar probability of infection into groups of equal size in order to implement the Dorfman's procedure. We show that, keeping the pool size constant, this matching criterion minimizes the expected number of tests required to diagnose the population, and minimizes the expected number of healthy patients who are incorrectly diagnosed as infected, as long as the dilution effect is sufficiently small. The tradeoff is that in this case ordered pooling may not necessarily minimize the expected number of false negatives, namely, the expected number of cases in which sick patients are incorrectly diagnosed as healthy.

Distributed Video Compressed Sensing Secondary Reconstruction Based on Inter-Frames Similarity Structure

The emergence of distributed video compressed sensing technology has effectively reduced the computational cost and power consumption of the video system. As the core content of the DCVS research, reconstruction algorithms are mostly focused on improving the reconstruction quality of CS frames, while neglecting the reconstruction quality of the key frame. The key frame is not fully utilized as well. Focus on these problems, the paper proposes a distributed video compressed sensing secondary reconstruction algorithm based on similar structure between frames. In order to eliminate the influence of non-overlapping block CS that may introduce noise and block effects on key frames, firstly, the fractional total variation algorithm is used to initially reconstruct the key frames, which improves the reconstruction quality while reducing the computational complexity. Then, a CS frame secondary reconstruction algorithm based on structural similarity is proposed, which uses SSIM as the matching criterion to search for matching block groups similar to the current frame from multiple reference frames, as a regular term to achieve the secondary reconstruction of CS frames. The experimental results show that the overall performance of the proposed algorithm is better than the current advanced DCVS method. The research results of the thesis can be used for reliable compressed sensing reconstruction of video and image.

Research on emotion recognition method of weightlifters based on a non-negative matrix decomposition algorithm

In order to overcome the problems of high recognition error rate and low recognition efficiency existing in the traditional method of emotional recognition of weightlifters, a method of emotional recognition of weightlifters based on a non-negative matrix decomposition algorithm is proposed. The database of emotion recognition matching criteria is established, and the mapping relationship among emotion, facial expression of far mobilisation and weight lifting posture is formed. The real-time motion images of weightlifters are collected, and the image classifier is designed by using the non-negative matrix decomposition algorithm. The real-time images are divided into facial expression images and whole body motion images, and the features of the two images are extracted respectively. The extracted results are matched with the results of the standard database, and the real-time emotion recognition results of weightlifters are obtained. The experimental results show that compared with the traditional emotion recognition method, the proposed method improves the accuracy of emotion recognition by 50%.

MIMO Radar Waveform Joint Optimization in Spatial-Spectral Domain for Anti-Interference

Aiming at the target detection problem of MIMO radar under the condition of both spatial and spectral domain interferences, a waveform design method for MIMO radar based on joint optimization of spatial and spectral domain interferences suppression in multi-target scenarios is proposed. Compared with the traditional synthetic waveform method based on the transmitting signal covariance matrix, this method directly performs waveform design in the space-spectral domain in turn, considering target characteristics and spatial-spectral environment comprehensively. Firstly, according to the target characteristics and energy allocation strategy, the fast time transmission pulse set is divided into a group of sub-pulse sets whose number equals to the number of targets. Meanwhile a set of transmit filter weighting factor vectors are introduced and the number of vectors equals to the number of spatial interferences. Furthermore, the spatial waveform optimization model is constructed according to the pattern matching criterion, subjecting to the peak-to-average power ratio of the transmitted signal. The sub-pulse sets are obtained through convex optimization, and the full matrix of the emission waveform is formed by the sub-pulse sets. Then, according to the invariability of radar transmit pattern with changing the initial phase of the sub-pulse, the transmitted waveform with desired beam pattern and spectrum distribution is obtained by optimizing the initial phase matrix through convex optimization. Finally, the optimized transmit waveform of MIMO radar with the ability of simultaneously suppressing space frequency interferences is generated. The simulation results prove the effectiveness of the proposed method.

Slightly and Moderately Lame Cows in Tie Stalls Behave Differently From Non-lame Controls. A Matched Case-Control Study.

Lameness affects dairy cows worldwide and is usually associated with pain. Behavioral differences in lame compared to non-lame tie-stall-housed dairy cows might be less pronounced than in free-stall-housed, since the principle demands to a cow's locomotor system and thus the impact of lameness on behavior seem to be lower in tie stalls. Behavioral differences between lame and non-lame cows might be used to estimate the impact of lameness on the well-being of tied dairy cows. In the current study, lame cows were categorized as locomotion scoring between 2.25 and 3.25 on a 1–5 scale. The aim was to compare the eating, rumination and lying behavior of lame cows against non-lame tied dairy cows, in order to draw conclusions on the association of lameness, behavior and well-being in tied dairy cows. The eating and rumination behavior of 26, the lying behavior of 30, and the relative upright and lying activities of 25 matched case-control pairs were analyzed, considering the matching criteria farm, breed-type, and parity-group. Lame cows had fewer [mean of the pairwise differences (case–control) (meandiff) = −2.6 bouts, CI95% (−3.8–−1.4) bouts, p = 0.001], but longer lying bouts [meandiff = 26.7 min per bout, CI95% (10.1–43.4) min per bout, p = 0.006]. The lying time was shorter [meandiff = −64.7 min, CI95% (−104.4–−24.9) min, p = 0.006] in lame cows compared to their non-lame controls. Lame cows had a shorter eating time [meandiff = −27.7 min, CI95% (−51.5–−4.0) min, p = 0.042] and spent a larger proportion of their upright time ruminating [meandiff = 7.2%, CI95% (3.2–11.1)%, p = 0.001] instead of eating. The results of the current study indicate that the eating, rumination, and lying behavior of lame tied dairy cows is altered. These findings indicate that slight and moderate lameness (locomotion score between 2.25 and 3.25 on a 1–5 scale) are likely to be associated with an impaired well-being in affected tied dairy cows. This underlines the need to continuously reduce the lameness prevalence and severity in tied dairy herds.

Comparing Winds near Tropical Oceanic Precipitation Systems with and without Lightning

In order to examine how robust updraft strength and ice-based microphysical processes aloft in storms may affect convective outflows near the surface, ocean winds were compared between tropical maritime precipitation systems with and without lightning. The analysis focused on Cyclone Global Navigation Satellite System (CYGNSS) specular point tracks, using straightforward spatiotemporal matching criteria to pair CYGNSS-measured wind speeds with satellite-based precipitation observations, Advanced Scatterometer (ASCAT) wind speeds, and lightning flash data from ground-based and space-based sensors. Based on the results, thunderstorms over the tropical oceans are associated with significantly heavier rain rates (~200% greater) than non-thunderstorms. However, wind speeds near either type of precipitation system do not differ much (~0.5 m s−1 or less). Moreover, the sign of the difference depends on the wind instrument used, with CYGNSS suggesting non-thunderstorm winds are slightly stronger, while ASCAT suggests the opposite. These observed wind differences are likely related to lingering uncertainties between CYGNSS and ASCAT measurements in precipitation. However, both CYGNSS and ASCAT observe winds near precipitation (whether lightning-producing or not) to be stronger than background winds by at least 1 m s−1.

Antenatal screening practices in the WHO European Region: a mixed methods study.

BackgroundLiterature suggests an increasing trend towards more screening tests, while awareness of potential harms of screenings has been reported to be sub-optimal. This paper aimed to characterize ANC screening practices within the 53 countries of the WHO Europe Region and compare these to evidenced-based recommendations from WHO and from other key reference sources.MethodsFrom January 2019 to July 2019 we conducted a survey among key informants (KIs) in the 53 countries of the WHO European Region and a systematic review of literature. KIs were invited to answer an online structured questionnaire, available both in English and Russian. Published and unpublished guidelines, policies or cross-sectional studies on ANC screening practices were searched for in four electronic databases (MEDLINE, Global Health Library, Web of Science, Google) and also sent by KIs. Data obtained from both methods were analysed and triangulated by two independent authors.ResultsOverall 42 countries participated in the survey. Among these, 36 (86%) reported national guidelines on ANC screening, but only 26 (61.9%) reported up-to-date and comprehensive guidelines. All countries reported supplemental use other guidelines, with 19 (45.2%) using more than three. When looking at current evidence-based recommendations, only one (ultrasound before 24 weeks) was reported to be implemented in all countries. Overall, 35 (83.3%) countries reported using at least five not-recommended ANC screening practices, with 21 (50%) implementing ≥10 not-recommended ANC screening practices. The systematic review resulted in 11871 records, with 111 (90 guidelines, 4 policies, 17 cross-sectional studies) matching inclusion criteria. Findings from the systematic review were largely consistent with those of the online survey: among the most comprehensive national guidelines identified, only six (24%) had a concordance ≥75% with the reference recommendations, independently from their publication date, while the few existing cross-sectional studies highlighted large heterogeneity in the implementation of ANC practices among countries.ConclusionsGuidance on and implementation of evidenced-based recommendations on ANC screening is suboptimal in the WHO European Region. It is necessary to increase the availability of evidence-based high-quality national guidelines and their concrete use in routine practice.

Theoretical Investigation on Regioselectivities of Diels‐Alder Reactions by Conjugated Effect

Summary of main observation and conclusionThe regioselectivities of 76 Diels‐Alder reactions between unsymmetrical dienes and dienophiles were investigated by local softness and generalized local softness at atomic and chemical bond view, respectively, where the reactivity descriptors were calculated by finite difference approximation and ABEEMσπ model. Based on local HSAB principle and matching criterion of local softness, reasonable explanation and prediction on regioselectivities of all reactions through ABEEMσπ model have been obtained, which are in agreement with the experimental results. Especially, at π‐bond level, while the 1‐substituents of dienes were NH2, NMe2, and NEt2, because of the p‐π conjugated effect between the lone pairs of N atom and the conjugated π‐bond of the four double‐bonded carbon atoms in diene, it made the dienophile not easy to approach diene by Manner A, hence, Manner B can forecast the ortho regioisomer as main product well, and Manner A cannot. As to the other reactions, both Manner A and Manner B can predict their regioselectivities. It can be seen that the ABEEMσπ model can take the effect of the chemical environment on the reaction reactivity into account richly, especially the system includes π‐bond and lone pairs. However, the results through the finite difference approximation are not reasonable.

Combining Sparse and Dense Features to Improve Multi-Modal Registration for Brain DTI Images.

A new solution to overcome the constraints of multimodality medical intra-subject image registration is proposed, using the mutual information (MI) of image histogram-oriented gradients as a new matching criterion. We present a rigid, multi-modal image registration algorithm based on linear transformation and oriented gradients for the alignment of T2-weighted (T2w) images (as a fixed reference) and diffusion tensor imaging (DTI) (b-values of 500 and 1250 s/mm2) as floating images of three patients to compensate for the motion during the acquisition process. Diffusion MRI is very sensitive to motion, especially when the intensity and duration of the gradient pulses (characterized by the b-value) increases. The proposed method relies on the whole brain surface and addresses the variability of anatomical features into an image stack. The sparse features refer to corners detected using the Harris corner detector operator, while dense features use all image pixels through the image histogram of oriented gradients (HOG) as a measure of the degree of statistical dependence between a pair of registered images. HOG as a dense feature is focused on the structure and extracts the oriented gradient image in the x and y directions. MI is used as an objective function for the optimization process. The entropy functions and joint entropy function are determined using the HOGs data. To determine the best image transformation, the fiducial registration error (FRE) measure is used. We compare the results against the MI-based intensities results computed using a statistical intensity relationship between corresponding pixels in source and target images. Our approach, which is devoted to the whole brain, shows improved registration accuracy, robustness, and computational cost compared with the registration algorithms, which use anatomical features or regions of interest areas with specific neuroanatomy. Despite the supplementary HOG computation task, the computation time is comparable for MI-based intensities and MI-based HOG methods.

One-year clinical evaluation of two high-viscosity glass-ionomer cements in class II restorations of primary molars.

Little information exists on the clinical performance of restorative materials on primary teeth of preschool children. This study aimed to evaluate clinical performance of compomer, glass-hybrid-added high-viscosity glass-ionomer cement and zinc-added high-viscosity glass-ionomer cement materials in class ΙΙ restorations of primary molars. The study included 251 teeth of 57 patients aged 4-7years with proximal caries in primary molars. The teeth were divided into three groups, and each restorative material was randomly distributed. Dyract XP, Equia Forte and ChemFil Rock materials were placed after cavity preparation and clinically evaluated at 3, 6, 9 and 12months using modified United States Public Health Service criteria. Statistical analyses were performed using chi-square and z tests. At the end of 12months, a total of three restorations in Dyract XP group, 22 in Equia Forte group and 11 in ChemFil Rock group failed in retention criteria. No statistically significant difference existed between retention, colour match and surface texture criteria of all groups at 3 and 6months, but a statistically significant difference was found at 12months (P<0.05). For class ΙΙ restorations of primary molars, the success of compomer material was superior to high-viscosity glass-ionomer materials.