Use of Radiomics Models in Preoperative Grading of Cerebral Gliomas and Comparison with Three-dimensional Arterial Spin Labelling.

AIMS: To build machine learning-based radiomics models to discriminate between high- (HGGs) and low-grade gliomas (LGGs) and to compare the effectiveness of three-dimensional arterial spin labelling (3D-ASL) to evaluate which is a better method. MATERIALS AND METHODS: We retrospectively analysed the magnetic resonance imaging T1WI-enhanced images of 105 patients with gliomas that were pathologically confirmed in our hospital. We divided the patients into a training group and a verification group at a ratio of 8:2; 200 patients from the Brain Tumour Segmentation Challenge 2020 were selected as the test group for image segmentation, feature extraction and screening. We constructed models using multilayer perceptron (MLP), support vector machine, random forest and logistic regression and evaluated their predictive performance. We obtained the mean maximum relative cerebral blood flow (rCBFmax) value from 3D-ASL of 105 patients from the hospital to evaluate its efficacy in discriminating between HGGs and LGGs. RESULTS: In machine learning, the MLP classifier model exhibited the best performance in discriminating between HGGs and LGGs; the areas under the curve obtained by MLP and rCBFmax were 0.968 versus 0.815 (verification group) and 0.981 versus 0.815 (test group), respectively. The machine learning-based MLP classifier model performed better in discriminating between HGGs and LGGs than 3D-ASL. CONCLUSION: In our study, we found that machine learning-based radiomics models and 3D-ASL were valuable in discriminating between HGGs and LGGs and between them, the machine learning-based MLP model had better diagnostic performance.

Multiplexed Imaging Strategy to Distinguish Indeterminant Biliary Strictures: An Ex Vivo Study.

Introduction: Indeterminant biliary strictures can be either malignant or benign. Biliary intraepithelial neoplasia (BilIN) is the precursor lesion to cholangiocarcinoma, a deadly bile duct cancer. Current diagnostic methods are limited by inadequate amounts of cells and tissues collected. Aim: We aim to demonstrate use of fluorescently-labeled peptides specific for EGFR, claudin-1, and ErbB2 to perform multiplexed imaging of biliary neoplasia. Methods: Formalin fixed and paraffin embedded specimens resected from human biliary strictures were sectioned. A gastrointestinal pathologist used standard criteria to score immunohistochemistry from biliary neoplasia and adjacent normal epithelium from the same specimen. Peptides specific for EGFR, claudin-1, and ErbB2 were fluorescently-labeled with FITC, Cy5, and IRDye800, respectively. The fluorophores were chosen to provide spectral separation to distinguish the individual targets. Immuno fluorescence images were collected using confocal microscopy. Results: Target expression was validated using immunohistochemistry. Staining was visualized on the surface of biliary duct epithelial cells and not in the stroma. Greater fluorescence intensity was observed for peptide binding to biliary neoplasia by comparison with normal. The mean ratio for neoplasia-to-normal was 1.4, 1.7, and 1.6, respectively, and the average intensities were significantly greater for neoplasia than normal for each peptide. Peptides and antibody binding co-localized with correlation of ρ=0.64, 0.51 and 0.62, respectively. Conclusions: A panel of fluorescently-labeled peptides can distinguish BilIN and cholangiocarcinoma from normal biliary epithelium, and may be used for multiplexed imaging of indeterminant biliary strictures.

Large-Displacement Vertical Electrostatic Microactuator Dynamics using Duty-Cycled Softening/Stiffening Parametric Resonance.

Electrostatic microactuators with large vertical scanning range (several hundred microns) at high frequency (hundreds to thousands of hertz) and chips sizes compatible with endoscopic microscopy have recently been demonstrated based on parametric resonance. This paper examines the use and modeling of mixed softening/hardening dynamics to help produce large ranges of motion in this class of mirrors. Origin of spring stiffening behavior in actuator design is described, followed by non-dimensional analysis of actuator motion trends. Experimental results are presented for a sample actuator design with up to 480 µm displacement at 1225 Hz and 60 V. Comparison to predicted trends and comments on benefits and limitations of modeling are provided.

[Research advances in dentin biomimetic remineralization].

With similar characteristic as nature dentin in structure and function, regenerated dentin is considered to be the ideal material for detected dentin restoration. Accordingly, dentin regeneration is a key issue in oral medicine and biomaterial science. Biomimetic mineralizatioin and remineralization are thus considered as strategies in dentin regeneration. This review is about the research advances of dentin biomimetic remineralization.

In vivo fluorescence imaging of hepatocellular carcinoma xenograft using near-infrared labeled epidermal growth factor receptor (EGFR) peptide.

Minimally-invasive surgery of hepatocellular carcinoma (HCC) can be limited by poor tumor visualization with white light. We demonstrate systemic administration of a Cy5.5-labeled peptide specific for epidermal growth factor receptor (EGFR) to target HCC in vivo in a mouse xenograft model. We attached a compact imaging module to the proximal end of a medical laparoscope to collect near-infrared fluorescence and reflectance images concurrently at 15 frames/sec. We measured a mean target-to-background ratio of 2.99 ± 0.22 from 13 surgically exposed subcutaneous human HCC tumors in vivo in 5 mice. This integrated imaging methodology is promising to guide laparoscopic resection of HCC.

Nutritional status of the elderly in rural North China: a cross-sectional study.

OBJECTIVES: This study aimed to describe the nutritional status of elderly people living in a rural area of North China. DESIGN: Community-based, cross-sectional prevalence survey. SETTING: 3 rural towns of Lvliang City, Shanxi Province, China. PARTICIPANTS: A sample of 1845 community residents (29.1% of those eligible) 55 years or older (birth before 1958-01-01). MEASUREMENTS: The participants were assessed regarding demographic characteristics, height, weight, as well as having a physical examination and blood sampling for serum cholesterol, total homocysteine (tHcy), folate, and vitamin B12 levels. RESULTS: 991 (53.7%) were female and 139 (7.5%) did not complete the anthropometric measurement. Prevalence of underweight and obesity was 3.5% and 24.9% in men and 6.7% and 31.0% in women (P = 0.003, P = 0.005, respectively). Prevalence of hypercholesterolemia and hypocholesterolemia was 13.5% and 52.6% in men and 25.0% and 34.3% in women (P < 0.001, P < 0.001, respectively). Prevalence of high LDL-c concentrations was 8.8% in men and 16.8% in women (P < 0.001). The mean serum tHcy in men (28.8 ± 20.1 µmmol/l) was significantly higher than in women (21.0 ± 15.1 µmmol/L, P < 0.001). Prevalence of hyperhomocysteinemia (defined as > 15µmmol/L) was 79.7% in men and 65.5% in women (P < 0.001). Prevalence of low folate (defined as < 11 nmol/L) and vitamin B12 levels (defiend as < 185 pmol/L) was 70.8 % and 76.8% in men and 56.5% and 72.6% in women (P < 0.001, P = 0.036, respectively). Correlation coefficients between tHcy, folate, and vitamin B12 indicated an inverse linear correlation (r = -0.21, P < 0.001, r = -0.35, P < 0.001, respectively). CONCLUSIONS: As China's economic climate has developed, the nutritional status of elderly people in the rural parts of the country has improved in some aspects. However, the trend toward obesity will lead to a shift in the burden of obesity-related chronic diseases. In addition, rurally-located elderly people are at high risk of death that may be associated with abnormal serum cholesterol. The data also suggest that severe deficiencies in folate and vitamin B12 levels exist, as well as there being a high prevalence of hyperhomocysteinemia. Folate and vitamin B12 supplementation are necessary to prevent related diseases.

Amplifying transmission and compact suspension for a low-profile, large-displacement piezoelectric actuator.

A low-profile, piezoelectrically-driven microactuator is presented that achieves very large stroke lengths within size constraints suitable for certain endoscopic microscopy applications. The actuator utilizes a transmission consisting of lever arm and chevron-beam structures to amplify high-force, low-displacement motion of a ceramic lead-zirconate-titanate (PZT) brick into large displacement of a translational platform. For ±120 V input, a full range of 486 µm of motion is achieved, with natural frequency greater than 500 Hz. This corresponds to an anticipated In addition, the lateral translational platform is supported by a redesign of common folded silicon flexures to provide large transverse and vertical stiffness when the width of the actuator is limited.

[Nasal dorsal augmentation]. / Augmentation des Nasenrückens.

The present article describes the anatomy, surgical technique and outcomes for nasal dorsal augmentation. The various materials available for augmentation are outlined, including polytetrafluoroethylene (PTFE), autogenous costal cartilage graft and irradiated costal cartilage. In addition, appropriate surgical guidelines for successful augmentation are given. The correct height of the nasal dorsum is determined according to the position of the nasion and the nasal tip, whereby the desired height may also be influenced by the sex of the patient as well as his/her notion of an aesthetic ideal. Access is chosen according to the extent of the planned correction; external access is advisable in the case of extensive correction. Osteotomies should only be undertaken where unavoidable, e. g. in the case of concomitant nasal misalignment. Patient results, complications and future directions are presented.

Thermal waveguide OPO.

We report a mid-infrared, CW singly resonant optical parametric oscillator (OPO) with a thermally induced waveguide in its gain crystal. We measured a numerical aperture of 0.0062 for the waveguide at 80-W intracavity power at 3.2 microm. This thermal-guiding effect benefits to the stable operation of an OPO and improves the parametric conversion efficiency by more than a factor of two when compared with that without thermal guiding.

Fiber-laser-pumped CW OPO for red, green, blue laser generation.

We report a CW, watt-level, red, green, and blue (RGB) laser pumped by an economical multimode (1-nm linewidth) Yb-fiber laser at 1.064 mum. A singly resonant optical parametric oscillator at 1.56 mum has two intracavity sum-frequency generators for red and blue laser generation. An extracavity second harmonic generator converts the residual pump power into green laser radiation. At 25-W pump power, the laser generated 3.9, 0.456, and 0.49 W at 633, 532, and 450 nm, respectively. The multimode pump laser offers a large temperature bandwidth for operating the RGB OPO without the need of a precision crystal temperature stabilizer.

Endoscopic evaluation of esophago-gastro-jejunostomy in rat model of Barrett's esophagus.

Endoscopy can be used to monitor the onset of metaplastic transformation and to observe the progression of neoplasia in small animal models of Barrett's esophagus. By avoiding animal sacrifice, the natural history of this disease can be studied in a longitudinal fashion. We aim to characterize the endoscopic features of esophageal mucosa at various stages of the metaplasia-dysplasia-carcinoma sequence in a rat reflux model of Barrett's for comparison with histology. Acid and bile reflux was produced by introducing a side-to-side esophago-gastro-jejunostomy in Sprague-Dawley rats. Endoscopic examination of the distal esophagus was performed in 24 surgically altered and 4 control rats, between weeks 24 and 36 after the operation in 4-week intervals, and all rats were biopsied and sacrificed at 36 weeks. Endoscopic images were classified based on the surface mucosal patterns of the distal esophagus and then compared with histology. The endoscopic appearance was classified as: (i) normal, characterized by a smooth surface; (ii) intestinal metaplasia, defined as elevated plaques/ridges, deep grooves, and thin linear folds; (iii) dysplasia, indicated by coarse folds/grooves, meshlike villi, and foveolar appearance; and (iv) carcinoma, suggested by irregular-shaped mass lesions with ulcerations. The endoscopic criteria for intestinal metaplasia yielded a sensitivity of 100% in comparison with histology. Intestinal metaplasia with high-grade dysplasia was found in two rats and with low-grade dysplasia in three rats. Both focally invasive squamous cell carcinoma and invasive adenocarcinoma were found in one rat. Small animal endoscopy in a rat model of Barrett's esophagus can be used to perform surveillance, classify mucosal patterns, observe the onset of intestinal metaplasia, and monitor the progression of neoplastic transformation, representing a useful tool for studying the natural history of this disease.

Low-threshold, narrow-line THz-wave parametric oscillator with an intra-cavity grazing-incidence grating.

We report a low-threshold, narrow-line THz-wave parametric oscillator with an intra-cavity grazing-incidence grating and a 1-mm thick, 45-mm long lithium-niobate planar waveguide. When pumped by an actively Q-switched Nd:YAG laser, the threshold energy and intensity of the parametric oscillator were about 2.2 mJ and 70 MW/cm(2), respectively. The linewidths of the output THz wave were 12 and 134 GHz with and without the intra-cavity grating, respectively.

Forward and backward terahertz-wave difference-frequency generations from periodically poled lithium niobate.

We report terahertz-wave generation in the wavelength range of 190 - 210 and 457 - 507 microm from forward and backward difference frequency generations, respectively, in a 3.2-cm long multi-grating periodically poled lithium niobate (PPLN) crystal. The grating period of the PPLN crystal varies form 63 to 70 microm in 1-microm increments. The extraordinary refractive index of lithium niobate in the THz-wave range was precisely deduced from the quasi-phase-matching condition of the difference frequency generations.

Mammary gland expression of antibacterial peptide genes to inhibit bacterial pathogens causing mastitis.

As a step toward prevention of bovine mastitis, a plasmid-mediated gene transfer technique was used to enable mammary cells to synthesize and secrete bovine lactoferricin and bovine tracheal antibacterial peptides. For this purpose, a series of mammary tissue-specific expression vectors, harboring the antibacterial peptide gene, the 5'-flanking regulation sequence of goat beta-casein, and the bovine growth hormone polyadenylation signal sequence, were constructed using a eukaryotic expression vector pIRES1-neo. The mammary gland tissue-specific expression vector carrying the antimicrobial peptide genes dissolved in physiologic saline was injected directly into the lactating mammary glands of goats. The milk samples after injection were checked by Tricine-SDS-PAGE and bacterium inhibition zone assay. The results of these tests showed that the mammary gland tissue-specific expression vector driven by the goat beta-casein gene promoter could efficiently direct the expression of antibacterial peptides in goat milk; the expression of antibacterial proteins lasted for 3 to 6 d. All of the milk samples collected from the mammary glands that had been injected with different vectors harboring the antibacterial peptide gene(s) exhibited bacteriostatic activity against different bacterial pathogens. These results demonstrated that the mammary gland tissue-specific expression vector could be used to introduce antibacterial peptide gene into the goat mammary gland, enabling secretion of a bioactive form of antibacterial peptide in the milk. This successful expression of antibacterial peptides in goat mammary glands provided a possible method to prevent mastitis in ruminants.

Diagnostic accuracy of tissue Doppler echocardiography for patients with acute heart failure.

BACKGROUND: Acute heart failure leads to high mortality and morbidity rates. The symptom of acute dyspnoea is non-specific and the diagnostic tools of acute heart failure are still not satisfactory. Tissue Doppler echocardiography is accurate in evaluating cardiac function; however, its efficacy in diagnosing patients with acute dyspnoea in emergency departments remains unclear. METHODS: Patients with acute dyspnoea were included prospectively while visiting the emergency department. Tissue Doppler echocardiography was carried out and the ratios of peak early diastolic transmitral blood flow velocity (E) to the peak early diastolic tissue velocity over mitral annulus (Ea) were recorded. The sensitivity, specificity and accuracy of tissue Doppler parameters and the receiver-operating characteristic curves for diagnosing acute heart failure were also evaluated. RESULTS: A total of 92 patients were enrolled. The ratio E:Ea was found to be a good diagnostic test to estimate the diagnostic performances of tissue Doppler echocardiography using receiver-operating characteristic curves in cases of acute heart failure in patients with preserved left ventricular systolic function (mean (SD) area under the curve = 0.875 (0.049); p<0.001; cut-off value = 11) and with left ventricular systolic dysfunction (mean (SD) area under the curve = 0.903 (0.061); p = 0.003; cut-off value = 16). E:Ea was an independent predictor of acute heart failure in multiple logistic regressions. For patients with a B-type natriuretic peptide level between 100 and 500 pg/ml, E:Ea provided an accuracy of 90.9% (p = 0.015) for diagnosing acute heart failure. CONCLUSIONS: Tissue Doppler echocardiography is accurate in diagnosing patients with acute heart failure in emergency departments. It can be a useful supplementary diagnostic tool for patients with inconclusive blood B-type natriuretic peptide level.

Enhanced terahertz-wave parametric generation and oscillation in lithium niobate waveguides at terahertz frequencies.

We observed parametric-generation efficiency of 1.61% from 1064 to 1071 nm and at 162 microm in a 0.5 mm thick, 45 mm long z-cut congruent lithium niobate waveguide with a pump energy of 2.2 mJ and a pump pulse width of 5.8 ns. We also measured an ultralow-threshold intensity of 70 MW/cm2 for a 1064 nm pumped parametric oscillator resonating at 1071 nm and emitting at 162 microm with a 1 mm thick, 45 mm long lithium niobate waveguide.

Distributed-feedback optical parametric oscillation by use of a photorefractive grating in periodically poled lithium niobate.

We report a demonstration of distributed-feedback (DFB) optical parametric oscillation (OPO) by writing photorefractive gratings in periodically poled lithium niobate (PPLN). The photorefractive DFB structures were fabricated by illumination of PPLN with UV light through a photomask and by writing of PPLN with UV-light gated interfering laser beams at 532 nm. Evidence of OPO was observed from the spectral narrowing at the 1438.8- and the 619.3-nm signal wavelengths from 1064- and 532-nm-pumped PPLN crystals with the DFB grating periods phase matched to the 4084.5- and 3774-nm idler wavelengths, respectively.

Local flaps in scar revision.

Local and regional skin flaps provide the foundation for reconstructive surgery of the face. When planned and executed properly, local skin flaps provide rapid reconstruction using donor tissue with excellent color and texture match, and a reliable, adequate blood supply. The majority of local skin flaps are utilized for reconstruction after superficial cancer extirpation, however, unfavorable scars from previous trauma, burns, or reconstruction efforts provide the motivated patient and surgeon another opportunity to restore form and function. This article reviews techniques commonly used to reconstruct the face and provides several cases where these techniques were successfully employed.

Efficacy of cholesterol levels and ratios in predicting future coronary heart disease in a Chinese population.

In this study, we assessed the efficacy of various lipid and lipoprotein measurements at baseline for predicting the risk for coronary heart disease (CHD) and determined the associated risk of CHD in subgroups stratified by different lipid and lipoprotein screening strategies to evaluate the adequacy of current total and low-density lipoprotein (LDL) cholesterol-based approaches in lipid management. We analyzed data from the Chin-Shan Community Cardiovascular Cohort study, a Chinese population-based prospective cohort study that began in 1990. During an 8-year follow-up period, 213 of 3,159 participants (6.7%) without CHD (aged > or =35 years) developed CHD. The total cholesterol/high-density lipoprotein (HDL) cholesterol ratio was the most powerful lipoprotein predictor of future CHD (hazard ratio 1.21 for a 1.0 increment in ratio; p <0.001). Subjects with "high-risk" LDL cholesterol levels (>160 mg/dl) and low total cholesterol/HDL cholesterol ratios (< or =5) had an incidence of CHD similar to those with low levels of both LDL cholesterol (< or =130 mg/dl) and total cholesterol/HDL cholesterol ratios (4.9% vs 4.6%). In contrast, subjects with "low-risk" LDL cholesterol levels (< or =130 mg/dl) and high total cholesterol/HDL cholesterol ratios (>5) had a 2.5-fold higher incidence of CHD than those with similar LDL cholesterol levels but low total cholesterol/HDL cholesterol ratios (p <0.001). Compared with using an LDL cholesterol level of 130 mg/dl as the cut-off point, using a total cholesterol/HDL cholesterol ratio of 5 was associated with superior specificity (73% vs 59%, p <0.001) and accuracy (72% vs 58%, p <0.001), and similar sensitivity (50% vs 53%). Our data indicate that current guidelines for lipid management may misclassify subjects with high levels of HDL and LDL cholesterol as well as those with low levels of HDL and LDL cholesterol. Using the ratio of total to HDL cholesterol as the initial screening tool can obviate this discrepancy.

Increased levels of tissue plasminogen activator antigen and factor VIII activity in nonvalvular atrial fibrillation: relation to predictors of thromboembolism.

INTRODUCTION: Given that nonvalvular atrial fibrillation (AF)-associated stroke can be either cardioembolic or atherothrombotic, we investigated the relationships between nonvalvular AF and hemostatic factors reflecting intrinsic thrombogenic and atherogenic potentials (tissue plasminogen activator [t-PA] antigen, plasminogen activator inhibitor-1, and factor VIII activity). We also evaluated the clinical applicability of these hemostatic factors by examining whether AF subjects with established clinical or echocardiographic predictors of thromboembolism had higher levels of these factors. METHODS AND RESULTS: Of the 3,212 participants of a Chinese population-based study, 53 subjects (1.7%) with AF were identified. Among the hemostatic factors measured, t-PA antigen (median 12.8 vs 8.1 ng/mL; P < 0.01) and factor VIII activity (median 155% vs 133%; P < 0.05) were significantly higher in AF subjects after adjustment for age and sex. In multivariate analysis, features independently associated with t-PA antigen levels were AF, sex, body mass index, systolic blood pressure, total cholesterol, triglycerides, and left ventricular systolic dysfunction. Features independently associated with factor VIII activity levels included AF, age, and total cholesterol. Levels of both t-PA antigen and factor VIII activity were primarily elevated in AF subjects with predictors of thromboembolism (age > 75 years, hypertension, diabetes, and left ventricular systolic dysfunction), whereas in AF subjects with no thromboembolic predictors, plasma levels of hemostatic factors examined were similar to those without AF. CONCLUSION: We demonstrated that nonvalvular AF was independently associated with increased peripheral levels of t-PA antigen and factor VIII activity. Levels of both hemostatic factors were primarily elevated in AF subjects with predictors of thromboembolism. Whether these hemostatic factors are independently predictive of future thromboembolic events in AF patients requires further investigation.