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Registration between the baseline and follow-up lung computed tomography (CT) volumes plays an important role in computer-aided diagnosis and following-up care during adaptive radiotherapy. Diffeom...

Classification of benign and malignant pulmonary nodules can provide useful indicators for estimating the risk of lung cancer. In this study, an improved random forest (RF) algorithm is proposed for classification of benign and malignant pulmonary nodules in thoracic computed tomography images. First, an improved random walk algorithm is proposed to automatically segment pulmonary nodules. Then, intensity, geometric and texture features based on the grey-level co-occurrence matrix, rotation invariant uniform local binary pattern and Gabor filter methods are combined to generate an effective and discriminative feature vector. Mutual information is employed to reduce the dimensionality. Finally, an improved RF classifier is trained to classify benign and malignant nodules. An appropriate feature subset is selected by the bootstrap method and an effective combination method is introduced to predict a class label. The proposed classification method on the lung images dataset consortium dataset achieves a sensitivity of 0.92 and the area under the receiver-operating-characteristic curve of 0.95. An additional evaluation is performed on another dataset coming from General Hospital of Guangzhou Military Command. A mean sensitivity and a mean specificity of the proposed method are 0.85 and 0.82, respectively. Experimental results demonstrate that the proposed method achieves the satisfactory classification performance.

By employing in situ methylnicotinohydrazide dication (MNH(2+)) as an electron acceptor, we have constructed an iodocuprate(I) hybrid {[MNH][Cu2I3]2}n (1), which exhibits charge transfer (CT) thermochromism due to the intense absorption of CT and electron transfer (ET) photochromism with high photocoloration contrast and fast response to UV irradiation due to the synergetic effect of valence change of copper ions.

Objectives To systematically review the failure rate and complications of different framework designs of resin-bonded fixed dental prostheses (RBFDPs) in the anterior region. Methods A systematic search for clinical studies on RBFDPs published prior to December 2014 in Medline/PubMed, EMBASE, and Cochrane Library databases was conducted and complemented by a manual search. Randomized controlled trials (RCTs) as well as prospective and retrospective cohort studies that compared at least two RBFDP framework designs with a minimum of 2 years follow up were included in this review. The quality of the included studies were assessed using the Newcastle–Ottawa scale for cohort studies and Cochrane Handbook for RCT. Prostheses-based data on reported failure rate/survival rate, debonding, and fractures were analyzed by meta-analysis. Results Of 1010 screened articles, one RCT and 4 cohort studies fit the inclusion criteria and were included in the meta-analysis. All included articles have a high risk of bias. Failure rates of single-retainer cantilever RBFDPs were lower than two-retainer fixed–fixed RBFDPs (OR 0.42, 95% CI 0.19–0.94, P = 0.04). Metal-ceramic RBFDPs showed no difference of failure rates between cantilever RBFDPs and two-retainer fixed–fixed RBFDPs (OR 0.93, 95% CI 0.33–2.63, P = 0.89). Debonding was not significantly different between cantilever RBFDPs and two-retainer fixed–fixed RBFDPs (OR 0.61, 95% CI 0.23–1.60, P = 0.32). Metal-ceramic RBFDPs showed no difference of debonding between cantilever RBFDPs and two-retainer fixed–fixed RBFDPs (OR 0.81, 95% CI 0.28–2.34, P = 0.70,). Conclusions Within the limitations of the present study, cantilever RBFDPs demonstrate lower clinical failure than two-retainer RBFDPs in the anterior region. The failure of metal-ceramic RBFDPs is independent of the framework design, while the failure of all-ceramic RBFDPs with different designs has not been clear yet. Clinical significance Based on the principle of minimally invasive treatment, less number of retainers is recommended for RBFDPs.

Based on analyzing the features of transverse modes of LD beam and experiment with quartz cylindrical lenses of different diameters, using certain cylindrical lenses to compress the ellipse shaped LD beam in the direction of the fast axis can result in the best pumping efficiency. The research findings can be applied to the practical production to manufacture highly efficient Nd:YVO 4 /KTP optical-contact crystal lasers at a low cost.

In this paper, from detailed experiment-based research on how ambient temperature influences the output power of optical-contact crystal green laser, it is showed that the output power of optical-contact crystal laser is directly affected by ambient temperature, and individual difference exists in the optical-contact crystals. The negative effect caused by low ambient temperature can be eliminated by temperature control sleeves. Most optical-contact crystal lasers work well at room temperature.

To investigate the relationship between wedge-shaped defects and occlusal interference.Following examination from 46 patients, a total of 157 teeth were identified to have the criteria set for wedge-shaped defects and regarded as the experiment group. Also, 157 adjacent teeth exhibiting no such noncarious cervical lesions were randomly selected from the same group of patients and regarded as the control group. The distribution of occlusal force and time were examined with T-Scan II system in 46 patients with wedge-shaped defects in intercuspal occlusion position, protrusive movement and lateral movement. Occlusal interference and premature contact were evaluated and compared between the two groups.The proportion of the teeth with premature contact in experiment group was 6.37%, while the control group was 2.55%, there was no significant difference between the two groups (P0.05). The total proportion with occlusal interferences in experiment group was 23.57%, which was significantly higher than that of the control group (10.19%, P0.05), in experiment group the proportion with working side interferences was 15.92%, and in control group, the proportion was 3.82%, there was significant difference between the two groups (P0.01). At the same time, the teeth with occlusal interferences had more serious degree of the wedge-shape defects than those with no occlusal interference.The increased occlusal force has relation to the formation as well as severity of wedge-shaped defects.

To evaluate mechanical properties of zirconia toughened composite alumina (ZTCA) ceramic used for dental application, characterize the effect of different zirconia contents on mechanical properties of ZTCA.Dental alumina ceramic powder was prepared by sol-gel method, and four groups of ZTCA powders with different zirconia contents were prepared via surface-induced precipitation method. All five groups of powders were dry-pressed and then sintered to make standard specimens for mechanical tests. The flexural strength and fracture toughness of these specimens were evaluated, and the fractography was characterized by scanning electronic microscope (SEM). Phases of ZTCA were also determined using X-ray diffraction (XRD).It was found that the flexural strength of ZTCA ceramics increases with ZrO2 content up to 30%, and decreases thereafter. ZTCA specimens containing 30% ZrO2 show the highest flexural strength, and the corresponding fracture toughness was 1.85 MPa x m(1/2). The XRD results of ZTCA ceramics showed the phase constituents of alpha-Al2O3, t-ZrO2 and a small amount of m-ZrO2.The strengthening and toughening mechanisms of ZTCA depend on ZrO2 content. In the range of 15%-30% ZrO2, the stress-induced phase transformation toughening mechanism is dominant, while microcrack and deflection exist as the additional toughening mechanism when ZrO2 addition amount is above 30%.