Glioma segmentation based on dense contrastive learning and multimodal features recalibration.

Accurate segmentation of different regions of gliomas from multimodal magnetic resonance (MR) images is crucial for glioma grading and precise diagnosis, but many existing segmentation methods are difficult to effectively utilize multimodal MR image information to recognize accurately the lesion regions with small size, low contrast and irregular shape. To address this issue, this work proposes a novel 3D glioma segmentation model DCL-MANet. DCL-MANet has an architecture of multiple encoders and one single decoder. Each encoder is used to extract MR image features of a given modality. To overcome the entangle problems of multimodal semantic features, a dense contrastive learning (DCL) strategy is presented to extract the modality-specific and common features. Following that, feature recalibration block (RFB) based on modality-wise attention is used to recalibrate the semantic features of each modality, enabling the model to focus on the features that are beneficial for glioma segmentation. These recalibrated features are input into the decoder to obtain the segmentation results. To verify the superiority of the proposed method, we compare it with several state-of-the-art (SOTA) methods in terms of Dice, average symmetric surface distance (ASSD), HD95 and volumetric similarity (Vs). The comparison results show that the average Dice, ASSD, HD95 and Vs of DCL-MANet on all tumor regions are improved at least by 0.66%, 3.47%, 8.94% and 1.07% respectively. For small enhance tumor (ET) region, the corresponding improvement can be up to 0.37%, 7.83%, 11.32%, and 1.35%, respectively. In addition, the ablation results demonstrate the effectiveness of the proposed DCL and RFB, and combining them can significantly increase Dice (1.59%) and Vs (1.54%) while decreasing ASSD (40.51%) and HD95 (45.16%) on ET region. The proposed DCL-MANet could disentangle multimodal features and enhance the semantics of modality-dependent features, providing a potential means to accurately segment small lesion regions in gliomas.

Reinforcement Learning-Based Adaptive Optimal Control for Nonlinear Systems With Asymmetric Hysteresis.

This article investigates the adaptive optimal tracking problem for a class of nonlinear affine systems with asymmetric Prandtl-Ishlinskii (PI) hysteresis nonlinearities based on actor-critic (A-C) learning mechanisms. Considering the huge obstacles arising from the uncertainty of hysteresis nonlinearity in actuators, we develop a scheme for the conflict between the construction of Hamilton functions and hysteresis nonlinearity. The actuator hysteresis forces the input into a hysteresis delay, thus preventing the Hamilton function from getting the current moment's input instantly and thus making optimization impossible. In the first step, an inverse model is constructed to compensate for the hysteresis model with a shift factor. In the second step, we compensate for the control input by designing a feedback controller and incorporating the estimation and approximation errors into the Hamilton error. Optimal control, the other part of the actual control input, is obtained by taking partial derivatives of the Hamiltonian function after the nonlinearities have been circumvented. At the end, a simulation is given to validate the developed solution.

Enabling robust and hour-level organic long persistent luminescence from carbon dots by covalent fixation.

The first carbon dot (CD)-based organic long persistent luminescence (OLPL) system exhibiting more than 1 h of duration was developed. In contrast to the established OLPL systems, herein, the reported CDs-based system (named m-CDs@CA) can be facilely and effectively fabricated using a household microwave oven, and more impressively, its LPL can be observed under ambient conditions and even in aqueous media. XRD and TEM characterizations, afterglow decay, time-resolved spectroscopy, and ESR analysis were performed, showing the successful composition of CDs and CA, the formation of exciplexes and long-lived charged-separated states. Further studies suggest that the production of covalent bonds between CA and CDs plays pivotal roles in activating LPL and preventing its quenching from oxygen and water. To the best of our knowledge, this is a very rare example of an OLPL system that exhibits hour-level afterglow under ambient conditions. Finally, applications of m-CDs@CA in glow-in-the-dark paints for emergency signs and multicolored luminous pearls were preliminarily demonstrated. This work may provide new insights for the development of rare-earth-free and robust OLPL materials.

Green and Near-Infrared Dual-Mode Afterglow of Carbon Dots and Their Applications for Confidential Information Readout.

Near-infrared (NIR), particularly NIR-containing dual-/multi-mode afterglow, is very attractive in many fields of application, but it is still a great challenge to achieve such property of materials. Herein, we report a facile method to prepare green and NIR dual-mode afterglow of carbon dots (CDs) through in situ embedding o-CDs (being prepared from o-phenylenediamine) into cyanuric acid (CA) matrix (named o-CDs@CA). Further studies reveal that the green and NIR afterglows of o-CDs@CA originate from thermal activated delayed fluorescence (TADF) and room temperature phosphorescence (RTP) of o-CDs, respectively. In addition, the formation of covalent bonds between o-CDs and CA, and the presence of multiple fixation and rigid effects to the triplet states of o-CDs are confirmed to be critical for activating the observed dual-mode afterglow. Due to the shorter lifetime and insensitiveness to human vision of the NIR RTP of o-CDs@CA, it is completely covered by the green TADF during directly observing. The NIR RTP signal, however, can be readily captured if an optical filter (cut-off wavelength of 600 nm) being used. By utilizing these unique features, the applications of o-CDs@CA in anti-counterfeiting and information encryption have been demonstrated with great confidentiality. Finally, the as-developed method was confirmed to be applicable to many other kinds of CDs for achieving or enhancing their afterglow performances.

Band structure regulation in Fe-doped MgZnO by initial magnetic moments.

ZnO-based diluted magnetic semiconductors have high prospects in spintronics applications. In this study, the electronic and magnetic properties of Fe-doped MgZnO are studied by density functional theory calculations. The investigations of the band structure, total density of states, and projected density of states revealed a strong correlation between Mg and O atoms in addition to the magnetism and impurity level generated by the Fe atoms. In the spin charge density and band structure of 2.78% Fe-doped MgZnO, Fe atoms always cause paramagnetic coupling with oxygen atoms bonded around them, and when the initial magnetic moments were parallel, the band gap is broadened in the opposite channel. On the contrary, when the initial magnetic moments are anti-parallel, the band gap is narrowed in both the spin-up and spin-down channels. This shows that the initial magnetic moments have a great influence on the band structure, giving another way to tune the gap dynamically.

Reduced Stroke Risk among Patients with Atrial Fibrillation Receiving Chinese Herbal Medicines Treatment: Analysis of Domestic Data in Taiwan.

Background and objectives: Patients with atrial fibrillation (AF) reportedly have a much higher risk of death due to stroke. Faced with this heavy burden, it remains unclear if the Chinese herbal medicines (CHMs), the most common form complementary and alternative medicine, can lower the risk of stroke for them. This study aimed to evaluate the association of CHMs use with stroke risk among them. MATERIALS AND METHODS: From a nationwide database, 11,456 AF patients aged ≧ 20 years between 1998 and 2007 were identified. Afterwards, we enrolled 2670 CHMs users and randomly selected 2670 non-CHMs users using the propensity score method. The occurrence of stroke was recorded until the end of 2012. RESULTS: Within the follow-up period, 671 CHMs users and 900 non-CHMs users developed stroke, with incidence rates of 33.02 and 45.46 per 1000 person-years, respectively. CHMs use was associated with a 30% lower stroke risk, especially for those receiving CHMs for over two years. CONCLUSIONS: The findings of the present study suggest that adding CHMs to conventional therapy could decrease subsequent stroke risk for AF patients. It is also suggested that prospective randomized trials are needed to further clarify if the detected association revealed in this study supports a causal link, and to identify the specific CHMs that may be beneficial to AF patients.

Etomidate Suppresses Invasion and Migration of Human A549 Lung Adenocarcinoma Cells.

BACKGROUND/AIM: Etomidate, an intravenous anesthetic, has been shown to have anticancer effects, including induction of cell-cycle arrest and apoptosis. However, to our knowledge, there are no reports about the anti-metastasis effects of etomidate on A549 human lung adenocarcinoma cells. MATERIALS AND METHODS: The cell viability, cell adhesion, gelatin zymography assay, transwell migration and invasion assay, and western blotting analysis were used to investigate the effects of etomidate on A549 cells. RESULTS: In our study, etomidate showed low cytotoxicity, inhibited cell adhesion, and suppressed the migration and invasion in A549 cells. The activity of matrix metallopeptidase 2 (MMP2) was reduced by 48 h treatment of etomidate. Results of western blotting analysis indicated that etomidate down-regulated the expression of protein kinase C, MMP7, MMP1, MMP9, and p-p-38, but up-regulated that of RAS, phosphoinositide 3-kinase, and phosphor-extracellular-signal related kinase after 24 and 48 h treatment, in A549 cells. CONCLUSION: Etomidate suppressed the migration and invasion of lung adenocarcinoma A549 cells via inhibiting the expression of MMP1, MMP2, MMP7 and MMP9, and provides potential therapeutic targets for lung cancer treatment.

Norcantharidin-induced Apoptosis of AGS Human Gastric Cancer Cells Through Reactive Oxygen Species Production, and Caspase- and Mitochondria-dependent Signaling Pathways.

Norcantharidin (NCTD) was purified from mylabris, the dried body of the Chinese blister beetle. NCTD has been shown to exhibit anticancer activities in many human cancer cell lines, but there are no reports to show whether it induces apoptosis of human gastric cancer cells. Therefore, in the present study, we investigated NCTD-induced cell death and associated protein expression in human gastric cancer AGS cells in vitro. Cell morphological changes, viability and cell-cycle distribution were examined and analyzed by phase-contrast microscopy and flow cytometric assays. Flow cytometry was also used to measure the levels of reactive oxygen species (ROS), Ca2+, mitochondrial membrane potential (Ψm) and activity of caspases. The results indicated that NCTD induced cell morphological changes, reduced total viable cell number and induced G0/G1 phase arrest. NCTD also increased ROS production and reduced the Ψm and increased caspase-9 activity in AGS cells. Western blotting also found that NCTD increased the pro-apoptotic proteins such as BCL2-associated X protein (BAX) and BH3 interacting-domain death agonist (BID) and increased the release of cytochrome c, apoptosis inducing factor (AIF) and endonuclease G (Endo G) release from mitochondria in AGS cells. NCTD also significantly increased the expression of active forms of caspase-3 and -8 and -9 and reduced the expression of caspase-4 and -12 in AGS cells. Based on these observations, we suggest that NCTD-induced apoptotic cell death may be through mitochondria- and caspase-dependent pathways.

[Effective analysis of percutaneous reduction and Kirschner pin fixation for the treatment of intraarticular fractures of the calcaneus in children].

OBJECTIVE: To introduce and evaluate the clinical effects of percutaneous reduction and Kirschner pin fixation for the treatment of intraarticular fractures of the calcaneus in children. METHODS: From March 2001 to February 2009,12 patients with intraarticular calcaneal fractures were treated by percutaneous reduction and Kirschner pin fixation (13 feet). There were 8 males and 4 females,ranging in age from 3 to 14,with an average of 8.7 years. According to Essex-Lopresti classification, among 5 feet were tongue fractures and 8 feet were compressed fractures. According to Sanders classification, 9 feet were type II and 4 feet were type III. The Biihler angle and Gissane angle of the calcaneus were obtained before and after operation. All patients were evaluated according to Maryland Foot Score. RESULTS: All the patients were followed up for 16-71 months (means 35.9 months),and all the incisions were healed without complications and infection. The preoperative X-ray film showed that Böhler angle was (19.7+/-5.3) degrees, Gissane angle was (137.3+/-7.5) degrees. The postoperative X-ray film demonstrated that Böhler angle was (32.6+/-3.7) degrees, Gissane angle was (125.4+/-2.9) degrees. There was a significant difference between preoperative and postoperative (P<0.01). The average Maryland score was 96.3+/-2.4 (range, 92 to 100 points). CONCLUSION: Percutaneous reduction and Kirschner pin fixation is an effective minimally invasive way to treat intraarticular fractures of the calcaneus in children, it has many advantages such as minimal invasion, reliable fixation and satisfactory effects.

[Internal fixation with AO distal humerus plates for the treatment of distal humeral fractures in elderly osteoporotic patients].

OBJECTIVE: To study the clinical effects of AO distal humerus plate (DHP) for the treatment of distal humeral fractures in elderly osteoporotic patients. METHODS: From September 2008 to January 2010, 18 elderly osteoporotic patients with distal humeral fractures were treated with open reduction and internal fixation with DHP. There were 3 males and 15 females, ranging in age from 62 to 83 years (averaged, 71.4 years). According to AO classification, 1 patient was Type A2, 3 patients were Type A3; 2 patients were Type B1, 2 patients were Type B2; 3 patients were Type C1, 4 patients were Type C2, 3 patients were Type C3. The surgical approaches were either bilateral or via olecranon process of ulna. Early mobilization was initiated after surgery. Functional results were evaluated according to the Mayo elbow performance score (MEPS). RESULTS: The average duration of follow-up was 14.6 months (ranged from 11 to 24 months). All the patients had a complete healing of their fractures. There was no infection, hardware failure or loss of reduction after the operations. The average Mayo elbow performance score (MEPS) was (92.2 +/- 9.6) (65 to 100 points), among which the score of pain was (42.5 +/- 5.8) (30 to 45 points), the score of motion range was (19.2 +/- 1.9) (15 to 20 points), the score of stability was (9.2 +/- 1.9) (5 to 10 points), and the score of function was (21.4 +/- 2.9) (15 to 25 points). According to MEPS, 11 patients got excellent results, 5 good and 2 fair. CONCLUSION: Treatment of distal humeral fractures in elderly osteoporotic patients with AO distal humeral plates can obtain immediate stabilization which facilitates early mobilization of the elbow.

Morphometric comparisons between the pedicle and the pedicle rib unit in the immature Chinese thoracic spine: a computed tomographic assessment.

STUDY DESIGN: Morphology comparisons between the pedicle and pedicle rib unit in the immature spine were conducted through computed tomographic scans. OBJECTIVE: To establish reference data concerning the dimensions of the pedicle rib unit for normal children. SUMMARY OF BACKGROUND DATA: Until recently, studies on extrapedicular fixation were mostly based on adults. No published study has assessed the morphology of the pedicle rib unit in the normal immature population. Establishment of the basic morphometric characteristics may be beneficial in treating immature patients with spinal disorders. METHODS: Measurements were carried out on the chest computed tomography scans of the immature Chinese patients without any spinal disorder findings. The width, chord length, and transverse angle of the pedicle rib unit were obtained and compared with the corresponding pedicle index. Difference between sex groups was measured, and significant statistical correlations were carefully studied to determine potentially important clinical relationships. RESULTS: The mean values and the standard deviations obtained for each thoracic segment were determined. The width, chord length, and transverse angle of the pedicle rib unit were significantly larger than corresponding pedicle measurements at all levels. Significant difference for measurements between sexes was found at some segments. Compared with the sex, age seemed to have a more significant effect on the measurements. Linear pedicle and pedicle rib unit dimensions had good correlations with age, whereas the transverse angle seemed to change little with age. CONCLUSION: Compared with the dimensions of the immature pedicle, the significantly larger size of the corresponding pedicle rib unit provides a more ample space, which accommodates screws with larger diameters. Extrapedicular vertebral body fixation was anatomically feasible for the immature spine. The new procedure should be cautiously applied to avoid potential implant failures or a new deformity because of the growth of the immature spine.