Cobalt-Catalyzed Enantioselective Alkenylation of Aldehydes.

Catalytic enantioselective alkenylation of aldehydes with easily accessible alkenyl halides promoted by a chiral cobalt complex derived from a newly developed tridentate bisoxazolinephosphine is presented. Such processes represent an unprecedented reaction pathway for cobalt catalysis and a general approach that enable rapid construction of highly diversified enantioenriched allylic alcohols containing a 1,1-, 1,2-disubstituted and trisubstituted alkene as well as axial stereogenicity in up to 99% yield and 99:1 er without the need of preformation of alkenyl-metal reagents. DFT calculations revealed the origin of enantioselectivity.

An Analysis of Trabecular Bone Structure Based on Principal Stress Trajectory.

To understand the mechanism of Wolff's law, a finite element analysis was performed for a human proximal femur, and the principal stress trajectories of the femur were extracted using the principal stress visualization method. The mechanism of Wolff's law was evaluated theoretically based on the distribution of the principal stress trajectories. Due to the dynamics of the loads, there was no one-to-one correspondence between the stress trajectories of the fixed load and the trabeculae in the cancellous architecture of the real bone. The trabeculae in the cancellous bone were influenced by the magnitude of the principal stress trajectory. Equivalent principal stress trajectories suitable for different load changes were proposed through the change in load cycle and compared with the anatomical structure of the femur. In addition, the three-dimensional distribution of the femoral principal stress trajectory was established, and the adaptability potential of each load was discussed. The principal stress visualization method could also be applied to bionic structure design.

Orthodontic craniofacial pattern diagnosis: cephalometric geometry and machine learning.

Efficient and reliable diagnosis of craniofacial patterns is critical to orthodontic treatment. Although machine learning (ML) is time-saving and high-precision, prior knowledge should validate its reliability. This study proposed a craniofacial ML diagnostic workflow base on a cephalometric geometric model through clinical verification. A cephalometric geometric model was established to determine the landmark location by analyzing 408 X-ray lateral cephalograms. Through geometric information and feature engineering, nine supervised ML algorithms were conducted for sagittal and vertical skeleton patterns. After dimension reduction, plane decision boundary and landmark contribution contours were depicted to demonstrate the diagnostic consistency and the consistency with clinical norms. As a result, multi-layer perceptron achieved 97.56% accuracy for sagittal, while linear support vector machine reached 90.24% for the vertical. Sagittal diagnoses showed average superiority (91.60 ± 5.43)% over the vertical (82.25 ± 6.37)%, where discriminative algorithms exhibited more steady performance (93.20 ± 3.29)% than the generative (85.98 ± 9.48)%. Further, the Kruskal-Wallis H test was carried out to explore statistical differences in diagnoses. Though sagittal patterns had no statistical difference in diagnostic accuracy, the vertical showed significance. All aspects of the tests indicated that the proposed craniofacial ML workflow was highly consistent with clinical norms and could supplement practical diagnosis.

Finite element analysis on pushing the molar backwards using invisible aligner with different migration displacement.

PURPOSE: This paper examines the biomechanical mechanism behind the effect of the invisible aligner technique on tooth movement processes. METHODS: To compare the effects of different target positions on tooth movement and the periodontal ligament (PDL), two kinds of aligners were designed to provide displacements of 0.2 mm (Model A) and 0.3 mm (Model B). Different displacements of the maxillary second molar were simulated using the finite element (FE) method. RESULTS: The results of numerical simulations showed that the maximum stress was in the PDL of the distal surface and the palatal surface. The stress of the PDL in Model B was larger than Model A, with the displacement of the second molar 0.027 mm in Model A, by 44.9% lesser than that in Model B. CONCLUSIONS: The aligner that provided a displacement of 0.2 mm was more suitable for pushing the second molar backward in the initial stage. During the tooth movement processes, the displacement of the crown was larger than that of the root and the displacement decreased gradually from the crown to the root. In addition, the displacement and rotation of teeth during orthodontic treatment were measured and analysed.

Three-dimensional radiological anatomy of condyle trabecular bone based on a Volume-of-Interest analysis.

OBJECTIVES: Three-dimensional radiological anatomic characteristics of condyle trabeculae was obtained quantitatively based on a volume-of-interest (VOI) analysis. METHODS: Nine human mandibular condyle specimens were scanned by micro-computed tomography (micro-CT). A total of 34 VOIs were selected from each condyle specimen, which were divided into six layers and four parts to analyze the morphological characteristics of trabeculae based on cylindrical VOIs with a diameter and height of 2 mm. One-way analysis of variance was used to compare the regional differences of morphological parameters among each layer and part. RESULTS: Values for bone mineral density, bone volume/total volume, trabecular thickness, and trabecular bone number were greater in the anterior part compared with the posterior part; and the lateral part was larger than the medial part in the first, second, and third layers, while the medial part was larger in the fourth and fifth layers; these values in the first and sixth layers were much larger, while those in the third and fourth layers were smaller. Bone surface area/bone volume, trabecular spacing, and trabecular bone pattern factor were larger in the posterior part than in the anterior part; and the lateral part was larger than the medial part in the fourth and fifth layers, while the medial part was larger in the first and second layers. CONCLUSIONS: The morphological distribution of VOIs was anisotropic within trabecular bone of human mandibular condyles. The upper and lower ends of trabecular bone were much more compact, with higher bone density, trabecular thickness, and trabecular number than in the middle layers.

Cobalt-Catalyzed Regio-, Diastereo- and Enantioselective Intermolecular Hydrosilylation of 1,3-Dienes with Prochiral Silanes.

One of the most straightforward approaches to access chiral silanes is catalytic enantioselective hydrosilylation. Although significant advances have been achieved in enantioselective construction of either a carbon-stereogenic center or a silicon-stereogenic center through enantioselective hydrosilylation, simultaneous establishment of a carbon- and a silicon-stereogenic center in an acyclic molecule through a single intermolecular hydrosilylation remained undeveloped. Herein, an unprecedented cobalt-catalyzed regio-, diastereo- and enantioselective hydrosilylation of 1,3-dienes is presented, enabling construction of a carbon- and a silicon-stereogenic center in a single intermolecular transformation. A wide range of chiral silanes bearing a carbon- and a silicon-stereogenic center were generated in high efficiency and stereoselectivity. Functionalization of the enantioenriched silanes delivered a variety of valuable chiral building blocks that are otherwise difficult to access.

A Finite Element Analysis Model is Suitable for Biomechanical Analysis of Orbital Development.

ABSTRACT: The authors investigated orbital bone development in congenital microphthalmia (CM) using a three-dimensional finite element analysis model, after the orbital dimension deficiency was improved with a self-inflating hydrogel expander implant.Data of a 2-year-old male CM patient were examined. The orbital structure, eyeball, eye muscles, and self-inflating hydrogel expander were constructed according to computed tomography examination data. The effects of self-expanding spherical hydrogel at various locations in the muscle cone on orbital bone development were examined using 3-mL self-expanding expanders placed at shallow (model 1: 2 mm depth) and deep (model 2: 8 mm depth) muscle cone positions. This model simulated the hydrogel expansion process; the orbital bone biomechanics and radial displacement nephograms were obtained when the hydrogel volume increased 3, 5, 7, and 9 times and analyzed.The orbital bone biomechanics were concentrated at the medial orbital wall center, gradually spreading to the whole orbital wall. Biomechanics and radial displacement of the inferior temporal and lateral distal orbital wall region were the most significant, and were more significant in model 1 than in model 2.Finite element analysis is suitable for the biomechanical analysis of orbital development in CM. The shallow position inside CM patients' muscle cone is the optimal site for hydrogel implantation.

Biomechanical comparison between the custom-made mandibular condyle prosthesis and total temporomandibular joint prosthesis in finite element analysis.

PURPOSE: The purpose of this study was to compare the biomechanical behavior of the custom-made mandibular condyle prosthesis and total TMJ prosthesis. METHODS: Three models of one beagle dog, the condyle prosthesis (Model 1, replacing the right condyle only), the TMJ prosthesis (model 2, replacing the whole right TMJ) and the intact TMJ (model 3) were established, and the mechanical responses under muscle forces loading were analyzed using finite element method. RESULTS: Models 1 and 3 had the similar stress distribution on the right disc, which suggested that the condyle prosthesis did not change the disc stress so much when the muscle forces were applied. The stress of the right TMJ prosthesis in Model 2 was larger than both Models 1 and 3, and the stress of the contralateral TMJ reduced by 12% in Model 2. The anterior border of the condyle seemed to be a stress concentration region, not only for the intact condyle, but also for the condyle prosthesis and the total TMJ prosthesis. CONCLUSIONS: The total TMJ prosthesis changed the biomechanical balance of the bilateral TMJ. When the condyle prosthesis iss applied, the custom-made profile is recommended.

[Design of Real-time Disease Warning System Based on Storm Technology].

With the improvement of the quality of clinical diagnosis and treatment, the traditional scheduled "ward round" mode cannot meet the demands for real-time monitoring of acute and critically ill patients. This paper introduces the Storm, a real-time data stream processing technology and its application in the real time disease early warning system. By collecting the clinical data flow and calculating the MEWS scores in real time, the system can identify the potential deterioration of the disease, and promptly notify the medical staff. Score calculation results can be stored for further analysis and presentation as well.

Irregular Implant Design Decreases Periimplant Stress and Strain Under Oblique Loading.

OBJECTIVES: To investigate whether a different implant geometry with the same potential contact surface area (PCSA) affects the principal stress and strains in bone. MATERIAL AND METHODS: Three-dimensional finite-element models were created with a single endosseous implant embedded in bone. The irregular (IR) dental root-analog implant and regular (R) cylindrical implant with the same PCSA 350 mm were modeled, keeping the size of the thinnest implant wall 0.8 mm, and the thinnest bone wall 1 mm. The regular or irregular abutments were either 4.5 mm lower than the platform of the implants or 5 mm higher than the platform of the implants, both with the taper 1.44°. A 100 N vertical or 100 N vertical/50 N horizontal occlusal loading was applied. The biomechanical behaviors of periimplant bone were recorded. RESULTS: The IR implant design experienced lower periimplant stress and strain under oblique loading than that of R implant design. In the IR implant design, comparable stress in bone, implant, and abutment were found under 100 N vertical loading or 100 N vertical/50 N horizontal loading. In the R implant design, much higher stress in bone, implant, and abutment were found under 100 N vertical/50 N horizontal loading than that under 100 N vertical loading. CONCLUSION: Irregular dental root-analog implant is a biomechanically favorable design principle for decreasing periimplant stress and strain under oblique loading.

Long-term outcomes of epilepsy surgery in tuberous sclerosis complex.

Approximately 50% of patients with tuberous sclerosis complex (TSC) present intractable epilepsy, and surgery is an option for those patients. Hereby, we analyze long-term seizure control and neuropsychological outcomes of epilepsy surgery in patients with TSC. Clinical data were retrospectively collected from 66 patients with TSC and epilepsy followed up over 5 years, 51 of whom underwent epilepsy surgery between 2001 and 2011. Reductions in the number of seizures were analyzed at 1-year (1FU), 5-year (5FU), and 10-year (10FU) follow-ups visits after the operation. Influential factors on postoperative seizure free and intelligence quotient (IQ) and quality-of-life (QOL) outcomes were evaluated at 5FU. Resective procedures included 26 tuber resections, 15 lobectomies, and 10 tuber resections and lobectomies. Corpus callosotomies were performed as the adjunctive approach in 11 cases with low IQ. The percentages of seizure-free cases were 74.5% at 1FU, 58.8% at 5FU, and 47.8% at 10FU, and the predictive factor for long-term postoperative seizure freedom was the history of preoperative seizures and preoperative full-scale IQ. Significant improvements were found in performance IQ, full-scale IQ, and QOL in patients from the surgery group, particularly those who were seizure free after the operation. Our study showed that epilepsy surgery in TSC with epilepsy rendered improvements in seizure control, full-scale IQ, and QOL. Satisfactory long-term seizure control was often achieved with an early operation and without mental retardation, and improvements in QOL and IQ were frequently observed in postoperative patients who remained seizure free.

Prophylactic Levetiracetam for Seizure Control After Cranioplasty: A Multicenter Prospective Controlled Study.

OBJECTIVE: To study efficacy and safety of prophylactic levetiracetam (LEV) administration in adults undergoing cranioplasty. METHODS: We prospectively enrolled and randomly divided 200 adults undergoing cranioplasty into 2 groups: LEV (prophylactic LEV for 24 weeks) and control (no prophylactic antiepileptic drugs). Demographic and clinical characteristics; occurrence of postoperative seizure; changes in IQ, memory quotient, and activities of daily living scores; and postoperative side effects during hospital stay were analyzed at 2-, 24-, and 48-week follow-up visits. RESULTS: Significant differences were found between groups in both early-stage seizures in the initial 2 weeks and late-stage seizures in the 3-24 weeks after cranioplasty (P < 0.05). Postoperative seizures occurred in 17.0% in the control group and 4.1% in the LEV group 48 weeks after cranioplasty, which was found to be significant (P = 0.0020). Patients with abnormal preoperative or postoperative electroencephalography (EEG) with spikes or sharp waves presented with an increased number of postoperative seizures compared with patients with normal EEG readings at 48 weeks. Significant differences were found between patients with postoperative seizures and patients without postoperative seizures in regard to changes in IQ, memory quotient, activities of daily living, and patient satisfaction scores (P < 0.01). No significant difference was found in side effects between the 2 groups. CONCLUSIONS: Postoperative seizure is a common complication of cranioplasty, especially in patients with preoperative or postoperative abnormal EEG with spikes or sharp waves. Prophylactic LEV administration significantly reduced postcranioplasty seizures during LEV usage and had few side effects.

Influence of Different Abutment Designs on the Biomechanical Behavior of Dental Root-Analog Implant: A Three-Dimensional Finite Element Analysis.

OBJECTIVE: The aim of this study was to evaluate cross-sectional area of the abutments, strain distribution in the periimplant bone, stress in the abutments and dental root-analog implant by different abutment design under different loading conditions, through three-dimensional finite element analysis. METHODS: Two three-dimensional finite element models were established. Two types of abutments, oval cross section abutment (OCSA) and circular cross section abutment (CCSA) were designed, keeping the size of the thinnest implant wall 0.75 mm. Two types of load were applied to the abutment in each model: 100 N vertical load (V), 100 N vertical/50 N horizontal load (VH). The biomechanical behaviors of abutments, implants, and periimplant bone were recorded. RESULTS: The cross-section area of OCSA is 36.5% larger than that of CCSA. In implants, the maximum von Mises stress value in OCSA design was 24.6% lower than that in CCSA design under V and under VH. In abutments, the maximum von Mises stress value in OCSA design was 40.0% lower than that in CCSA design under V, the maximum von Mises stress value in OCSA design was 12.2% lower than that in CCSA design under VH. CONCLUSIONS AND CLINICAL SIGNIFICANCE: The irregular design offers advantages over regular design.

[Teeth segmentation from CBCT images using deformable triangle mesh model].

Considering the dental CBCT images' characteristics, the method of deformable surface of 3D triangle mesh model is proposed. The method uses a deformable model which is initialized from an icosahedron and evolves to fit the teeth's surface by the application of the locally adaptive external forces computed from the image data and internal forces coming from the model itself. The experimental results indicate that the proposed method is robust and accurate.

Anterior corpus callosotomy in patients with intractable generalized epilepsy and mental retardation.

AIMS: To prospectively study outcomes of anterior corpus callosotomy (aCCT) in patients with refractory generalized epilepsy (RGE) and mental retardation (MR), and estimate the effect of preoperative Wechsler Full Scale Intelligence Quotient (FIQ) on surgical outcomes. METHODS: Selected patients with RGE were divided into a moderate MR group (MoMR), mild MR group (MiMR) and no MR group (NMR), and all of them were treated with aCCT. Seizure outcomes were evaluated at the 1-year follow-up (1FU) and 2-year follow-up (2FU), and changes of quality of life (QOL) and IQ were tested at 2FU. RESULTS: Seizure control did not differ by group or follow-up period. Most seizure reduction was achieved in atonic or tonic seizures with 76-80% reduction at 1FU and 81-87% at 2FU; myoclonic epilepsy was the least likely to respond. QOL changes differed among groups, and 53.2% of total patients showed postoperative QOL improvement: 75% in the MoMR group, 65% in the MiMR group and 21.1% in the NMR group. No significant group difference was seen in FIQ change, although average postoperative performance IQ (PIQ) improvement in patients with MR exceeded 4 points. CONCLUSION: aCCT can reduce seizures and is a safe surgical procedure. Low IQ does not affect seizure outcome and can be associated with a good surgical outcome in PIQ and QOL improvement.

[An introduction of IHE].

This paper briefly introduces the history, definitions of some important words, working process, key concepts, connectathon testing, implementation of IHE, which can be regarded as an entry guide of IHE.

[An introduction [corrected] of RID & XDS integration profiles].

In this article, 2 IHE integration profiles-RID integration profile and XDS integration profile, which are adopted widely in the applications of healthcare information exchange, are introduced and compared with each other in applicable occasions. In addition, their current developing status and prospects are give from the technical view.

Computerized Classification Method for Differentiating Between Benign and Malignant Lesions on Breast MR Images.

Contrast-enhanced breast MRI has been shown to have very high sensitivity in the detection of breast cancers. A new computerized classification method for differentiating between benign and malignant lesions on breast MRIs was developed. This method was based on temporal feature analysis. We experimented with a set of thresholds of the contrast uptake and washout speed to automatically determine suspicious malignant areas. An angiogenesis map was generated to indicate suspicious malignant areas by color. The results obtained from the retrospective analysis on 64 malignant and 29 benign breast lesions showed that our method achieved 90.5% (57/63) sensitivity in detecting malignant lesions, and it correctly classified 55% (16/29) benign lesions as benign. The study results demonstrated the effectiveness of this temporal feature analysis method for the detection of malignant lesions and its performance in delineating malignant lesions from benign lesions.

Automated segmentation of breast lesions in ultrasound images.

Breast cancer is one of the leading causes of death in women. As a convenient and safe diagnosis method, ultrasound is most commonly used second to mammography for early detection and diagnosis of breast cancer. Here we proposed an automatic method to segment lesions in ultrasound images. The images are first filtered with anisotropic diffusion algorithm to remove speckle noise. The edge is enhanced to emphasize the lesion regions. Normalized cut is a graph theoretic that admits combination of different features for image segmentation, and has been successfully used in object parsing and grouping. In this paper we combine normalized cut with region merging method for the segmentation. The merging criteria are derived from the empirical rules used by radiologists when they interpret breast images. In the performance evaluation, we compared the computer-detected lesion boundaries with manually delineated borders. The experimental results show that the algorithm has efficient and robust performance for different kinds of lesions.