Efficacy of a Virtual 3D Simulation-Based Digital Training Module for Building Dental Technology Students' Long-Term Competency in Removable Partial Denture Design: Prospective Cohort Study

Background

Removable partial denture (RPD) design is crucial to long-term success in dental treatment, but shortcomings in RPD design training and competency acquisition among dental students have persisted for decades. Digital production is increasing in prevalence in stomatology, and a digital RPD (D-RPD) module, under the framework of the certified Objective Manipulative Skill Examination of Dental Technicians (OMEDT) system reported in our previous work, may improve on existing RPD training models for students.

Objective

We aimed to determine the efficacy of a virtual 3D simulation-based progressive digital training module for RPD design compared to traditional training.

Methods

We developed a prospective cohort study including dental technology students at the Stomatology College of Chongqing Medical University. Cohort 1 received traditional RPD design training (7 wk). Cohort 2 received D-RPD module training based on text and 2D sketches (7 wk). Cohort 3 received D-RPD module pilot training based on text and 2D sketches (4 wk) and continued to receive training based on 3D virtual casts of real patients (3 wk). RPD design tests based on virtual casts were conducted at 1 month and 1 year after training. We collected RPD design scores and the time spent to perform each assessment.

Results

We collected the RPD design scores and the time spent to perform each assessment at 1 month and 1 year after training. The study recruited 109 students, including 58 (53.2%) female and 51 male (56.8%) students. Cohort 1 scored the lowest and cohort 3 scored the highest in both tests (cohorts 1-3 at 1 mo: mean score 65.8, SD 21.5; mean score 81.9, SD 6.88; and mean score 85.3, SD 8.55, respectively; P<.001; cohorts 1-3 at 1 y: mean score 60.3, SD 16.7; mean score 75.5, SD 3.90; and mean score 90.9, SD 4.3, respectively; P<.001). The difference between cohorts in the time spent was not statistically significant at 1 month (cohorts 1-3: mean 2407.8, SD 1370.3 s; mean 1835.0, SD 1329.2 s; and mean 1790.3, SD 1195.5 s, respectively; P=.06) but was statistically significant at 1 year (cohorts 1-3: mean 2049.16, SD 1099.0 s; mean 1857.33, SD 587.39 s; and mean 2524.3, SD 566.37 s, respectively; P<.001). Intracohort comparisons indicated that the differences in scores at 1 month and 1 year were not statistically significant for cohort 1 (95% CI -2.1 to 13.0; P=.16), while cohort 3 obtained significantly higher scores 1 year later (95% CI 2.5-8.7; P=.001), and cohort 2 obtained significantly lower scores 1 year later (95% CI -8.8 to -3.9; P<.001).

Conclusions

Cohort 3 obtained the highest score at both time points with retention of competency at 1 year, indicating that progressive D-RPD training including virtual 3D simulation facilitated improved competency in RPD design. The adoption of D-RPD training may benefit learning outcomes.

Modelling enzyme inhibition toxicity of ionic liquid from molecular structure via convolutional neural network model

Deep learning (DL) methods further promote the development of quantitative structure-activity/property relationship (QSAR/QSPR) models by dealing with complex relationships between data. An acetylcholinesterase inhibitory toxicity model of ionic liquids (ILs) was established using a convolution neural network (CNN) combined with support vector machine (SVM), random forest (RF) and multilayer perceptron (MLP). A CNN model was proposed for feature self-learning and extraction of ILs. By comparing with the model results through feature engineering (FE), the model regression results based on the CNN model for feature extraction have been substantially improved. The results showed that all six models (FE-SVM, FE-RF, FE-MLP, CNN-SVM, CNN-RF, and CNN-MLP) had good prediction accuracy, but the results based on the CNN model were better. The hyperparameters of six models were optimized by grid search and the 10-fold cross validation. Compared with the existing models in the literature, the model performance has been further improved. The model could be used as an intelligent tool to guide the design or screening of low-toxicity ILs.

IS IT MEANINGFUL FOR SERUM MYOGLOBIN IN PATIENTS WITH COVID-19 DECREASED?

More than 3 years since cases were first reported, the COVID-19 pandemic remains an acute global emergency. As of April 12, the number of confirmed deaths worldwide was 6,897,025. Since January 8, 2023, based on the evaluation of the virus mutation, prevention, and control situation, according to the Infectious Diseases Prevention and Control Law, COVID-19 disease has been under Category B management in China. The number of COVID-19 cases in Chinese hospitals nationwide peaked (1.625 million) on January 5, 2023, and then decreased continually to 248,000 on January 23, 2023, with an 84.8% reduction from the peak. During the national COVID-19 pandemic in January 2023, we found that serum myoglobin reduced below the reference interval in 956 patients with COVID-19 who presented to the emergency department of our hospital from January 1 to January 31, 2023. So far, no articles specifically reporting the decrease of serum myoglobin in patients with COVID-19 have been retrieved. These 956 patients with low serum myoglobin were identified from 1142 COVID-19 patients who came to the emergency department of our hospital with symptoms of palpitations or chest tightness or chest pain. All 956 patients visited the hospital more than 2 weeks after the first symptoms appeared. The patient's initial symptoms were fever or cough but resolved before they arrived in the emergency department. There were 358 males and 598 females, aged from 14 to 90 years. Electrocardiogram showed no myocardial damage. Chest CT showed no signs of acute pulmonary infection. Cardiac enzymes and blood cell analysis were performed. The reference interval of serum myoglobin in our hospital is 28.0-72.0 ng/ml in males and 25.0-58.0 ng/ml in females. Patient data were obtained from a review of the electronic medical record system. What is the significance of serum myoglobin falling below the reference interval in patients with COVID-19? So far, no reports have been found in the literature. It may have the following implications: 1. Of cardiac biomarkers, an increase in myoglobin could efficiently predict COVID-19 severity in its early stages. Perhaps a decrease in myoglobin also predicts that COVID-19 patients will not have severe myocardial damage later in the disease. 2. Individuals differ widely in the clinical consequences of SARS-CoV-2 infection, from asymptomatic illness to death. Cong Chen et al. have indirectly demonstrated that SARS-CoV-2 can infect human cardiomyocytes. Most markers in the cardiac enzymes and blood cell analysis of 956 patients did not increase, indicating that the SARS-CoV-2 may not cause myocardial damage in these patients, but cardiac nerve function damage in the later stage of the disease, and then cause palpitations and other symptoms, but not serious cardiovascular disease. 3. It is possible that the virus resides somewhere in the body, such as the nerves of the heart, to cause lasting effects. 4. It may help in the research of drugs to treat COVID-19. The serum myoglobin of 956 patients was significantly decreased without myocardial damage, so we speculated that the symptoms of patients such as heart palpitations were caused by the damage of heart nerves caused by SARS-CoV-2. We further speculated that cardiac nerves were potential drug targets for the treatment of COVID-19. Echocardiography was not performed in 956 patients due to emergency department conditions and time constraints. These 956 patients were not hospitalized or followed up because they did not have myocardial injury or acute pneumonia. The emergency department also did not have adequate laboratory conditions for follow-up studies. We hope that the qualified researchers all over the world will continue to study this.

Ultrafast X-Ray Diffraction Visualization of B1-B2 Phase Transition in KCl under Shock Compression

The classical B1(NaCl)↔B2(CsCl) transitions have been considered as a model for general structural phase transformations, and resolving corresponding phase transition mechanisms under high strain rate shock compression is critical to a fundamental understanding of phase transition dynamics. Here, we use subnanosecond synchrotron x-ray diffraction to visualize the lattice response of single-crystal KCl to planar shock compression. Complete B1-B2 orientation relations are revealed for KCl under shock compression along ⟨100⟩_{B1} and ⟨110⟩_{B1}; the orientation relations and transition mechanisms are anisotropic and can be described with the standard and modified Watanabe-Tokonami-Morimoto model, respectively, both involving interlayer sliding and intralayer ion rearrangement. The current study also establishes a paradigm for investigating solid-solid phase transitions under dynamic extremes with ultrafast synchrotron x-ray diffraction.

LncRNA SNHG8 promotes cell migration and invasion in breast cancer cell through miR-634/ZBTB20 axis

OBJECTIVE

Small nucleolus RNA Host Gene 8 (SNHG8) belongs to a subgroup of long non-coding RNAs. SNHG8 is upregulated in many cancers, such as gastric cancer, liver cancer, and esophageal squamous cell cancer. However, whether SNHG8 is abnormally expressed in breast cancer and its biological functions remain unclear. Therefore, our research intended to determine the expression status of SNHG8 in breast cancer, explore the effects of SNHG8 on the development of breast cancer, and investigate the potential molecular mechanisms in cancer progression.

PATIENTS AND METHODS

The expression levels of SNHG8 were detected in tissue samples and cell lines via qRT-PCR. The effects of SNHG8 on viability of breast cancer cells were detected via CCK-8, EdU, transwell, and flow cytometry analyses.

RESULTS

qRT-PCR results showed that the expression level of SNHG8 was significantly upregulated in tumor tissues and cell lines. Gene functional studies showed that the downregulation of the expression level of SNHG8 significantly inhibited the breast cancer cells migration and invasion, and induced apoptosis. Meanwhile, we found that SNHG8 served as an inhibitor of miR-634 in tumor tissues. SNHG8 may participate in the malignancy of breast cancer by sponging the miR-634 to increase the expression level of ZBTB20.

CONCLUSIONS

The SNHG8-miR-634-ZBTB20 pathway may be a potential target for the treatment of breast cancers.

Multiscale measurements with adjustable x-ray spot size for in situ imaging and diffraction

A large field of view is normally desired for synchrotron x-ray imaging, while a small x-ray spot size is required for x-ray diffraction. A multiscale measurement system with an adjustable x-ray spot size is developed to accommodate different spot size requirements for in situ phase-contrast imaging and diffraction. The centers of a diffraction scintillator with a through-hole and an imaging scintillator are collinear with the x-ray beam. With the proof-of-principle experiments on a magnesium alloy under uniaxial tension, we demonstrate the feasibility of the multiscale measurement system for full azimuthal range diffraction measurements with improved resolution and large field of view strain field measurements via x-ray digital image correlation.

Corneal sub-basal whorl-like nerve plexus: a landmark for early and follow-up evaluation in transthyretin familial amyloid polyneuropathy

BACKGROUND AND PURPOSE

Small-fiber nerves are the first to be involved in transthyretin familial amyloid polyneuropathy (TTR-FAP) patients. In vivo corneal confocal microscopy (CCM) is a noninvasive technique to detect small-fiber polyneuropathy (SFN) by quantifying corneal nerve morphology. The characteristic whorl-like pattern of the corneal nerve provides a static landmark for observation. We aimed to evaluate whether CCM images of the whorl-like plexus can sensitively evaluate and monitor disease progression in FAP patients.

METHODS

Fifteen FAP patients and 15 controls underwent neurological evaluation and CCM observation. Corneal nerve fiber length (CNFL), corneal nerve fiber density (CNFD), corneal nerve branch density (CNBD) detected by conventional method and inferior whorl length (IWL), inferior whorl fiber density (IWFD), and inferior whorl branch density (IWBD) were compared in controls and patients. The Langerhans cell (LC) density in each image was calculated.

RESULTS

All CCM parameters were significantly reduced with disease progression. Preclinical patients had significantly lower IWL (P = 0.008) than age-matched controls. IWL (P = 0.006), CNFL (P = 0.005), CNBD (P = 0.008), and CNFD (P = 0.014) were significantly lower in early-phase patients. LC density was significantly increased around the central whorl in early-phase patients and was relatively lower in progressive patients. Both IWL and CNFL correlated with the severity of neuropathy, and IWL was more significantly reduced. The area under the receiver operating characteristic (ROC) curve for FAP with CNFL and IWL was 88.0% (95% CI, 70.9%-96.9%) and 89.3% (95% CI, 72.6%-97.6%), respectively, exceeding other parameters.

CONCLUSIONS

IWL is a more sensitive surrogate to detect preclinical SFN in FAP and can best discriminate patients from controls. The clustering of immature LCs at the inferior whorl area might reflect the inflammatory response of small-fiber nerves at the early stage.

MicroRNA-374b inhibits migration and invasion of glioma cells by targeting EGFR

OBJECTIVE

To investigate the expression level of microRNA-374b in glioma tissues and its influence on the invasive ability of glioma cells. Meanwhile, the regulatory mechanism of microRNA-374b in glioma was also explored.

PATIENTS AND METHODS

The expression level of microRNA-374b in 32 glioma tissues and para-cancerous tissues were detected by quantitative Real-time polymerase chain reaction (qRT-PCR). The relationship between microRNA-374b expression and clinical indicators of glioma was analyzed. Meanwhile, the expression of microRNA-374b in glioma cells was verified by qRT-PCR as well. Subsequently, microRNA-374b over-expression model was constructed in glioma cell lines, including U251 and U87. Next, the effect of microRNA-374b on cellular biological functions was analyzed using cell counting kit-8 (CCK-8) assay, Wound healing test and transwell invasion assay, respectively. Finally, the relationship between miRNA and epidermal growth factor receptor (EGFR) was explored.

RESULTS

QRT-PCR results showed that the expression level of microRNA-374b in glioma was significantly lower than that of adjacent tissues, and the difference was statistically significant. Compared with patients with higher expression of microRNA-374b, the occurrence rate of lymph node or distant metastasis was significantly higher in those with lower microRNA-374b expression. In addition, compared with NC group, the proliferation, invasion and migration abilities of cells in microRNA-374b mimics group was significantly decreased. Subsequently, results demonstrated that the expression of EGFR was significantly increased in glioma cells and tissues, which was negatively correlated with microRNA-374b expression. Subsequent cell recovery experiment indicated that microRNA-374b and EGFR had a mutual regulation and could affect the malignant progression of glioma all together.

CONCLUSIONS

MicroRNA-374b could inhibit the invasion and migration of glioma by regulating EGFR. Moreover, the expression of microRNA-374b was significantly associated with lymph node metastasis, distant metastasis and poor prognosis.

MiR-3662 suppresses cell growth, invasion and glucose metabolism by targeting HK2 in hepatocellular carcinoma cells

Hepatocellular carcinoma (HCC) is one of the most common malignancies with a rising incidence around the world. MicroRNAs (miRNAs) have been reported to play essential roles in the progression of HCC. However, the precise mechanism of miR-3662 in the HCC process remains poorly understood. This study was aimed to determine the regulatory network of miR-3662 and hexokinase 2 (HK2) in HCC. Quantitative real-time polymerase chain reaction (qRT-PCR) was performed to detect miR-3662 expression. Cell proliferation and invasion were measured by Cell Counting Kit-8 (CCK-8) assay and Transwell assay, respectively. Glucose consumption and lactate production assays were used to detect glucose metabolism activity in HCC cells. The potential binding sites between miR-3662 and HK2 were predicted by TargetScan online software and the relationship between miR-3662 and HK2 was verified by luciferase report assay. The protein expression of HK2 was measured by western blot analysis. A xenograft tumor model was established to confirm the role of miR-3662 and HK2 in vivo. miR-3662 expression was downregulated in HCC tissues and cells, and it was reduced in hypoxia-induced HCC cells in a time-dependent manner. Overexpression of miR-3662 or knockdown of HK2 inhibited cell proliferation, invasion, and glucose metabolism in HCC cells, which could be reversed by upregulating HK2. Besides, HK2 was a direct target of miR-3662 in HCC cells, and hypoxia upregulated the expression of HK2. In addition, the upregulation of HK2 could abolish miR-3662 overexpression-induced inhibitory effects on tumor growth and glucose metabolism in vivo.

[Effects of maslinic acid on isoproterenol-induced myocardial fibrosis in mice]

Objective: To investigate the effect of maslinic acid (MA) on isoproterenol (ISO)-induced myocardial fibrosis in mice. Methods: ISO was used to induce myocardial fibrosis in adult male C57BL/6 mice, and MA was administered for two weeks to detect the effects of MA on cardiac function and fibrosis. Molecular changes of fibrosis markers and signaling pathways were detected by RT-PCR and western blotting. Phosphate buffer saline (PBS), PBS+SB203580 (p38 MAPK inhibitor), PBS+MA, ISO, ISO+SB203580, ISO+MA were added to the primary cultured rat fibroblasts. Cells were collected after 48 h for subsequent detection. Results: In this study, the mouse model of myocardial fibrosis was successfully established. The left ventricular faction shortening (FS) and maximum rate of rise and maximum rate of fall of pressure in left ventricular chamber (±dp/dt) of the ISO+MA group were significantly higher than those of the ISO group ((35.1±1.8)% vs (28.5±2.6)%, (7 256±153) mmHg/s vs (6 402±240) mmHg/s, (7 156±163) mmHg/s vs (6 319±219) mmHg/s, all P<0.05). The levels of interstitial and perivascular collagen deposition in the ISO+MA group were higher than those in the ISO group (P<0.05), the relative mRNA levels of COL-1, COL-3 and TGF-β in the ISO+MA group were significantly lower than those in the ISO group, with the relative expression levels of 1.70±0.24 vs 3.69±0.34, 1.72±0.56 vs 4.84±0.82, 1.52±0.19 vs 2.64±0.29, respectively (all P<0.05). The phosphorylation levels of p38 MAPK, Smad3 and protein expression level of TGF-β1 in ISO+MA group were lower than those in ISO group (relative expression levels were 1.67±0.35 vs 2.61±0.58, 1.68±0.23 vs 2.52±0.19,1.56±0.15 vs 2.48±0.26, respectively, all P<0.05). The results of in vitro cell experiments showed that the mRNA levels of COL-1, COL-3 and TGF-β in the SB203580 and MA groups were significantly lower than those in the ISO group (relative expression levels were 2.25±0.51, 2.16±0.48 vs 5.29±1.21; 1.58±0.34, 1.69±0.29 vs 4.97±1.32; 1.41±0.31, 1.55±0.38 vs 3.53±0.56, respectively, all P<0.05). The phosphorylation levels of p38 MAPK and Smad3 in the SB203580 MA groups was significantly lower than those in the ISO group, and the protein expression level of TGF-β1 was lower than that in the ISO group (1.81±0.18, 1.77±0.16 vs 2.56±0.32; 1.85±0.21, 1.81±0.17 vs 2.48±0.37; 1.84±0.24, 1.72±0.17 vs 2.52±0.29, all P<0.05). Conclusion: Maslinic acid can inhibit the phosphorylation of p38 MAPK, thereby preventing the canonical TGF-β1/Smads fibrosis signaling pathway to achieve an anti-fibrosis role.

Molecular analysis and clinical diversity of distal hereditary motor neuropathy

BACKGROUND AND PURPOSE

Distal hereditary motor neuropathies (dHMNs) are a clinically and genetically heterogeneous group of disorders. The purpose of this study was to identify the genetic distribution of dHMNs in a large cohort of Chinese patients and provide insight into the underlying common pathophysiology of dHMNs.

METHODS

Multi-gene panel testing or whole-exome sequencing was performed in 70 index patients with clinically diagnosed dHMN between January 2007 and December 2018. The clinical features, Charcot-Marie-Tooth (CMT) neuropathy scores and electrophysiological data at diagnosis were recorded.

RESULTS

Twenty-four causative mutations were identified in 70 index patients with dHMN (34.3%). Mutation in the HSPB1 gene was the most common cause of dHMN. Some CMT genes (MPZ, SH3TC2, GDAP1) were found to be related to dHMN with minor sensory involvement. Patients with a dHMN-plus phenotype (distal motor neuropathy and additional neurological deficits) carried variants in genes related to hereditary spastic paraplegia, amyotrophic lateral sclerosis and spinal muscular atrophy (FUS, KIF5A, KIF1B, ZFYVE26, DNAJB2).

CONCLUSIONS

Comprehensive genetic testing of dHMN patients allows for identification of the pathogenic mutation in one-third of cases. Pure motor neuropathies and motor neuropathies with minor sensory involvement share many genes with CMT disease. Causes for dHMN-plus phenotypes overlap with motor neuron disease.

Charge inhomogeneity of carbon

Charge distribution on every atom of carbon matter in four dimension forms (cluster, fullerene, atomistic carbon chain, nanotube, graphene, surface and solid) was investigated by the first-principles calculation. It is found that the charge distribution in most of these materials is inhomogeneous, even in one certain solid phase. We found that if one atom in carbon has different surrounding environment from another one nearby, they always have electron transfer, that is, they have different charge. In round C₁₀ ring, C₂₄ and C₆₀ fullerenes, charge is zero, while charge is not zero in pentagon C₁₀ ring, C₃₀ and C₇₀ fullerenes. At the ends of atomistic chains, nanotube or on the edges of graphenes, carbon atoms have larger positive or negative charge, while almost zero in the central parts. Charge is zero in diamond and graphite, while it is not zero in the high pressure solid phase hexagonite or on some carbon surfaces. The non-zero charge in carbon possibly means its non-zero valence.

3D Printing of Large Areas of Highly Ordered Submicron Patterns for Modulating Cell Behavior

Fabricating large areas of geometrically complex and precisely controlled topographies is required for the studies of cell behavior on patterned surfaces. Direct laser writing (DLW) is an advanced 3D-fabrication technique, which facilitates the manufacturing of structures within various scales (from a few hundred nanometers to millimeters). However, this method requires improvements in the accuracy and reproducibility of the submicron and nanoscale features that are printed over a large area. Here, we present a scheme to both improve the uniformity of the printed submicron patterns and decrease the printing time. The effects of various processing parameters (e.g., laser power and writing field) on the dimensions and uniformity of submicron pillars as well as on their Young's modulus and surface wettability were assessed. Decreasing the writing field to 33 × 33 μm2 significantly improved the uniformity of submicron pillars that were printed over an area of 4 mm2 in a single-step process. Preosteoblast cells (MC3T3-E1) were used to assess the cytocompatibility of the used material (IP-L780 resin) with a focus on cell morphology, cell proliferation, cytoskeletal organization, and the elastic modulus of the cells. The cells cultured for 2 days on the submicron pillars showed a polarized shape and a higher Young's modulus of the area corresponding to the nucleus relative to those cultured on flat surfaces. Taken together, the results of the current study clearly show that the submicron patterns created using DLW are both cytocompatible and could modulate the morphology and mechanical properties of cells. This work paves the way for direct printing of submicron features with controlled Young's moduli over large areas in a single-step process, which is necessary for systematically studying how such patterns modulate cellular functions.

Capture Deformation Twinning in Mg during Shock Compression with Ultrafast Synchrotron X-Ray Diffraction

Deformation twinning plays a vital role in accommodating plastic deformation of hexagonal-close-packed (hcp) metals, but its mechanisms are still unsettled under high strain rate shock compression. Here we investigate deformation twinning in shock-compressed Mg as a typical hcp metal with in situ, ultrafast synchrotron x-ray diffraction. Extension twinning occurs upon shock compression along ⟨112[over ¯]0⟩ and ⟨101[over ¯]0⟩, but only upon release for loading along ⟨0001⟩. Such deformation mechanisms are a result of the polarity of deformation twinning, which depends on directionality and relative magnitude of resolved shear stress and may be common for Mg and its alloys in a wide range of strain rates.

A robotic Intelligent Towing Tank for learning complex fluid-structure dynamics

We describe the development of the Intelligent Towing Tank, an automated experimental facility guided by active learning to conduct a sequence of vortex-induced vibration (VIV) experiments, wherein the parameters of each next experiment are selected by minimizing suitable acquisition functions of quantified uncertainties. This constitutes a potential paradigm shift in conducting experimental research, where robots, computers, and humans collaborate to accelerate discovery and to search expeditiously and effectively large parametric spaces that are impracticable with the traditional approach of sequential hypothesis testing and subsequent train-and-error execution. We describe how our research parallels efforts in other fields, providing an orders-of-magnitude reduction in the number of experiments required to explore and map the complex hydrodynamic mechanisms governing the fluid-elastic instabilities and resulting nonlinear VIV responses. We show the effectiveness of the methodology of "explore-and-exploit" in parametric spaces of high dimensions, which are intractable with traditional approaches of systematic parametric variation in experimentation. We envision that this active learning approach to experimental research can be used across disciplines and potentially lead to physical insights and a new generation of models in multi-input/multi-output nonlinear systems.

INFLUENCE OF STATIC ELECTRICITY ON RADON MEASUREMENT USING PASSIVE DETECTORS

In order to investigate the influence of the static electricity on the measurement using passive radon detector, detectors were charged at the surface of chamber and its CR-39 elements respectively on purpose before the exposure in this study. The results of in-chamber experiments revealed that the static electricity would lead to critical influence on measurement especially when the CR-39 elements were negatively charged. The static charge would remain for several ten hours, which result in more significant influence on the short-term measurement.

Utility of Dynamic Susceptibility Contrast Perfusion-Weighted MR Imaging and 11C-Methionine PET/CT for Differentiation of Tumor Recurrence from Radiation Injury in Patients with High-Grade Gliomas

BACKGROUND AND PURPOSE

Both ¹¹C-methionine PET/CT and DSC-PWI could be used to differentiate radiation injury from recurrent brain tumors. Our aim was to assess the performance of MET PET/CT and DSC-PWI for differentiation of recurrence and radiation injury in patients with high-grade gliomas and to quantitatively analyze the diagnostic values of PET and PWI parameters.

MATERIALS AND METHODS

Forty-two patients with high-grade gliomas were enrolled in this study. The final diagnosis was determined by histopathologic analysis or clinical follow-up. PWI and PET parameters were recorded and compared between patients with recurrence and those with radiation injury using Student t tests. Receiver operating characteristic and logistic regression analyses were used to determine the diagnostic performance of each parameter.

RESULTS

The final diagnosis was recurrence in 33 patients and radiation injury in 9. PET/CT showed a patient-based sensitivity and specificity of 0.909 and 0.556, respectively, while PWI showed values of 0.667 and 0.778, respectively. The maximum standardized uptake value, mean standardized uptake value, tumor-to-background maximum standardized uptake value, and mean relative CBV were significantly higher for patients with recurrence than for patients with radiation injury. All these parameters showed a high discriminative power in receiver operating characteristic analysis. The optimal cutoff values for the tumor-to-background maximum standardized uptake value and mean relative CBV were 1.85 and 1.83, respectively, and corresponding sensitivities and specificities for the diagnosis of recurrence were 0.97 and 0.667 and 0.788 and 0.88, respectively. Areas under the curve for the tumor-to-background maximum standardized uptake value and mean relative CBV were 0.847 ± 0.077 and 0.845 ± 0.078, respectively. Combined assessment of the tumor-to-background maximum standardized uptake value and mean relative CBV showed the largest area under the curve (0.953 ± 0.031), with corresponding sensitivity and specificity of 0.848 and 1.0, respectively.

CONCLUSIONS

Both ¹¹C-methionine PET/CT and PWI are equally accurate in the differentiation of recurrence from radiation injury in patients with high-grade gliomas, and a combination of the 2 modalities could result in increased diagnostic accuracy.

Diaheliotropic leaf movement enhances leaf photosynthetic capacity and photosynthetic light and nitrogen use efficiency via optimising nitrogen partitioning among photosynthetic components in cotton (Gossypium hirsutum L.)

Phototropic leaf movement of plants is an effective mechanism for adapting to light conditions. Light is the major driver of plant photosynthesis. Leaf N is also an important limiting factor on leaf photosynthetic potential. Cotton (Gossypium hirsutum L.) exhibits diaheliotropic leaf movement. Here, we compared the long-term photosynthetic acclimation of fixed leaves (restrained) and free leaves (allowed free movement) in cotton. The fixed leaves and free leaves were used for determination of PAR, leaf chlorophyll concentration, leaf N content and leaf gas exchange. The measurements were conducted under clear sky conditions at 0, 7, 15 and 30 days after treatment (DAT). The results showed that leaf N allocation and partitioning among different components of the photosynthetic apparatus were significantly affected by diaheliotropic leaf movement. Diaheliotropic leaf movement significantly increased light interception per unit leaf area, which in turn affected leaf mass per area (LMA), leaf N content (N_A ) and leaf N allocation to photosynthesis (N_P ). In addition, cotton leaves optimised leaf N allocation to the photosynthetic apparatus by adjusting leaf mass per area and N_A in response to optimal light interception. In the presence of diaheliotropic leaf movement, cotton leaves optimised their structural tissue and photosynthetic characteristics, such as LMA, N_A and leaf N allocation to photosynthesis, so that leaf photosynthetic capacity was maximised to improve the photosynthetic use efficiency of light and N under high light conditions.

Does the laparoscopic treatment of paediatric hydroceles represent a better alternative to the traditional open repair technique? A retrospective study of 1332 surgeries performed at two centres in China

Purpose

To evaluate the safety, efficacy and merits of laparoscopic repair in children with hydroceles by comparing the outcomes of laparoscopic repair and the traditional open repair (OR) procedure. The outcomes of the following three laparoscopic percutaneous extra-peritoneal closure (LPEC) approaches were also compared: conventional two-port surgery, transumbilical single-site two-port surgery and single-port surgery.

Methods

We retrospectively compared the demographic, perioperative and follow-up data from the consecutive records obtained for 382 boys who underwent OR and 950 boys who underwent LPEC at two children’s medical centres in China. In the LPEC group, regardless of the hydrocele form, one of the three approaches with percutaneous aspiration was performed: conventional two-port surgery was performed in 387 cases, single-site two-port surgery was performed in 468 cases and single-port surgery was performed in 95 cases. The clinical data and complications were statistically analysed.

Results

Postoperative follow-up data were obtained for all the patients. The mean follow-up time was 36 months (24–48 months) in the OR group and 32.5 months (20–44 months) in the LPEC group. Significant differences in recurrence were not observed between the groups (five in the OR and 10 in the LPEC; P = 0.69). However, the operation time, postoperative hospital stay, incidence of scrotal oedema, incision infection and contralateral metachronous hernia or hydrocele were significantly higher in the OR group than those in the LPEC group (P < 0.01). Eighteen children (4.71%) had a negative exploration of the patent processus vaginalis (PPV) in the OR group. Fourteen children (1.47%) in the LPEC group had a closed internal ring and were converted to a scrotal procedure. Significant differences in the clinical data or complications were not observed between the two centres for the laparoscopic procedure (P > 0.05). Contralateral PPV (cPPV) was found in 18 patients in the single-port group (18.9%). Of the patients affected with cPPV, significant differences were observed between the single-port group and the two-port LPEC group (122 patients, 31.5%, P = 0.016) and the single-site two-port group (the 148 patients, 31.6%, P = 0.013). A contralateral metachronous hernia or hydrocele was found in zero, zero and two cases in these groups, respectively, and significant differences were observed (P < 0.01) between the single-site surgery and the other two laparoscopic approaches.

Conclusions

LPEC is safe, feasible and effective for treating hydroceles in children and has the same recurrence rate as OR. However, LPEC is superior in operation time, hospital stay, occurrence of scrotal oedema, incision infection and occurrence of metachronous hernia or hydrocele. The transumbilical single-site two-port procedure has the same cosmetic effect as the single-port LPEC. According to our experience, the two-port LPEC approach is better for diagnosing cPPV and reducing metachronous hernia or hydrocele than the single-port LPEC procedure.

High-mobility group box 1 regulates cytoprotective autophagy in a mouse spermatocyte cell line (GC-2spd) exposed to cadmium

BACKGROUND

Cadmium (Cd) is an environmental and industrial pollutant that induces a broad spectrum of toxicological effects, influences a variety of human organs, and is associated with poor semen quality and male infertility. Increasing evidence demonstrates that Cd induces testicular germ cell apoptosis in rodent animals. However, the specific effect of Cd exposure on autophagy in germ cells is poorly understood.

METHODS

We investigate the role of high-mobility group box 1 protein (HMGB1), a ubiquitous nuclear protein, on Cd-evoked autophagy in a mouse spermatocyte cell line (GC-2spd).

RESULTS

Our data have shown that autophagy was significantly elevated in GC-2spd cells exposed to Cd. Furthermore, there was a reduction in rapamycin (RAP)-mediated apoptosis. In addition, Cd exposure reduced cell viability, which is an effect that could be significantly inhibited by RAP treatment. These results indicate that autophagy appears to serve a positive function in reducing Cd-induced cytotoxicity. In addition, HMGB1 increased coincident with the processing of LC3-I to LC3-II. Thus, the upregulation of HMGB1 increases LC3-II levels.

CONCLUSIONS

Our data suggest that HMGB1-induced autophagy appears to act as a defense/survival mechanism against Cd cytotoxicity in GC-2spd cells.

Review article: the aetiology of primary Budd-Chiari syndrome - differences between the West and China

BACKGROUND

China may have the largest number of Budd-Chiari syndrome (BCS) cases in the world (at least 1914 original papers were published, and at least 20 191 BCS patients were reported). Considering the discrepancy in the clinical profiles and preferred treatment selection of primary BCS between the West and China, understanding its aetiology in these two different regions is very important.

AIM

To review the data from large cohort studies and meta-analyses to illustrate the epidemiology of risk factors for BCS in the West and China.

METHODS

Relevant papers were identified by major English- and Chinese-language databases, conference abstracts, and by manual search.

RESULTS

Risk factors reviewed include myeloproliferative neoplasms (MPNs) and their related gene mutations, anti-phospholipid syndrome, paroxysmal nocturnal haemoglobinuria (PNH), hyperhomocysteinaemia and 5,10-methylenetetrahydrofolate reductase (MTHFR) C677T mutation, factor V Leiden (FVL) and prothrombin G20210A mutations, inherited anti-thrombin, protein C and protein S deficiencies, pregnancy and puerperium, poverty, and family history.

CONCLUSIONS

We examined the differences in the aetiological distribution of BCS between the West and China. Several recommendations should be considered in Chinese BCS patients: (i) screening for hyperhomocysteinaemia and MTHFR mutation should be regularly performed; (ii) screening for MPNs, PNH, and anti-phospholipid syndrome should be selectively performed; (iii) inherited anti-thrombin, protein C, and protein S deficiencies should be actively explored; (iv) screening for FVL and prothrombin G20210A mutations may be unnecessary; and (v) the clinical significance of pregnancy and puerperium, poverty with bacterial infections and unsanitary environments, and family history as possible risk factors should never be neglected.

Comparison of clinicopathological features and prognosis of gastric cancer located in the lesser and greater curve

PURPOSE

Little is known about the features of gastric cancer located in the lesser and greater curve. This study aims to investigate the clinicopathological features and prognosis of gastric cancer located in the lesser and greater curve.

PATIENTS

From September 2008 to March 2015, 780 gastric cancer patients were enrolled in the present study. The associations between locations and features of patients were analyzed.

RESULTS

There were 571 male (73.2 %) and 209 female (26.8 %) patients. The median age was 56 years (ranged 21-86). There were 684 tumors located in the lesser curve (87.7 %) and 96 located in the greater curve (12.3 %). The incidence of melena was significantly lower in patients with tumors located in the lesser curve than that in the greater curve (8.5 vs 15.6 %, P = 0.024). The median size of tumors in the lesser curve was significantly larger than that in the greater curve (5.0 (0.3-15) vs 4.0 cm (0.5-15), P = 0.001). The remaining clinicopathological features were comparable between the two groups (all P > 0.05). Tumor location was not a risk factor for the prognosis of gastric cancer by univariate and multivariate analysis (both P > 0.05). The postoperative complications (all P > 0.05) and prognoses (P = 0.279) were comparable between tumors located in the lesser and greater curve.

CONCLUSIONS

The ratio of gastric cancer located in the lesser to greater curve was 7.1:1. Compared with tumors located in the greater curve, the incidence of melena was significantly lower and the tumor size was significantly larger in tumors located in the lesser curve. The prognoses were comparable between tumors located in the lesser and greater curve.

OCCUPATIONAL EXPOSURE TO RADON IN DIFFERENT KINDS OF NON-URANIUM MINES

For more accurate assessments of the occupational exposure to radon for miners, the individual monitoring was conducted by using an improved passive integrating (222)Rn monitor. A total of 120 miners in 3 different kinds of mines were monitored throughout a year. The results showed that the individual exposure to radon significantly varied with types of mines and work. Compared with the exposure to coal miners, the exposure to copper miners was much higher. Furthermore, it was found that the exposure might be overestimated if the environmental (222)Rn monitored by the passive integrating monitors was used for assessment. The results indicate that the individual monitoring of radon is necessary for an accurate assessment of radon exposure to miners, and radon exposure to non-uranium miners should also be assessed from the viewpoint of radiation protection.

Reversal of multidrug resistance of gastric cancer cells by down-regulation of ZNRD1 with ZNRD1 siRNA

The over-expression of a new zinc ribbon (ZNRD1) gene has been shown previously to promote a multidrug-resistant phenotype in gastric cancer cells through the up-regulation of permeability-glycoprotein (P-gp). In the present study, siRNA eukaryotic expression vectors of ZNRD1 are constructed and transfected into SGC7901/VCR cells to examine whether or not down-regulation of ZNRD1 increases cell sensitivity towards chemotherapeutic drugs. After transfection, ZNRD1 expression decreased dramatically in ZNRD1 siRNA transfectants compared with that in parental cells and empty vector control cells. Down-regulation of ZNRD1 significantly enhanced the sensitivity of SGC7901/VCR cells to vincristine, adriamycin and etoposide, but not to 5-fluorouracil and cisplatin. Cell capacity to efflux adriamycin decreased markedly in ZNRD1 siRNA transfectants, and correlation between ZNRD1 down-regulation and increased multidrug resistance 1 (MDR1) gene transcriptional activity was observed. These results suggest that the ZNRD1 siRNA constructs down-regulate the expression of ZNRD1 effectively and reverse the resistant phenotype of gastric cancer cells. Furthermore, ZNRD1 might influence transcription of the MDR1 gene and thus play an important role in multidrug resistance in gastric carcinoma.

Simultaneous, single-pulse, synchrotron x-ray imaging and diffraction under gas gun loading

We develop a mini gas gun system for simultaneous, single-pulse, x-ray diffraction and imaging under high strain-rate loading at the beamline 32-ID of the Advanced Photon Source. In order to increase the reciprocal space covered by a small-area detector, a conventional target chamber is split into two chambers: a narrowed measurement chamber and a relief chamber. The gas gun impact is synchronized with synchrotron x-ray pulses and high-speed cameras. Depending on a camera's capability, multiframe imaging and diffraction can be achieved. The proof-of-principle experiments are performed on single-crystal sapphire. The diffraction spots and images during impact are analyzed to quantify lattice deformation and fracture; fracture is dominated by splitting cracks followed by wing cracks, and diffraction peaks are broadened likely due to mosaic spread. Our results demonstrate the potential of such multiscale measurements for studying high strain-rate phenomena at dynamic extremes.

Macrodeformation Twins in Single-Crystal Aluminum

Deformation twinning in pure aluminum has been considered to be a unique property of nanostructured aluminum. A lingering mystery is whether deformation twinning occurs in coarse-grained or single-crystal aluminum at scales beyond nanotwins. Here, we present the first experimental demonstration of macrodeformation twins in single-crystal aluminum formed under an ultrahigh strain rate (∼10^{6}  s^{-1}) and large shear strain (200%) via dynamic equal channel angular pressing. Large-scale molecular dynamics simulations suggest that the frustration of subsonic dislocation motion leads to transonic deformation twinning. Deformation twinning is rooted in the rate dependences of dislocation motion and twinning, which are coupled, complementary processes during severe plastic deformation under ultrahigh strain rates.

Serum lipid profile in gynecologic tumors: a retrospective clinical study of 1,550 patients

BACKGROUND

The study was performed to characterize and compare the serum lipid profile in gynecologic cancers and benign diseases.

MATERIALS AND METHODS

A total of 1,550 age-matched females were included in this study: 760 patients with gynecologic cancers and 790 patients with benign diseases. Serum levels of triglycerides (TG), high density lipoprotein cholesterol (HDL-c), low density lipoprotein cholesterol (LDL-c), total cholesterol (TC), and lipoprotein (a) were measured.

RESULTS

Compared to gynecologic benign disease group, gynecologic cancer group was associated with higher level of TG (p = 0.0002), as well as lower level of HDL-c (p < 0.0001), LDL-c (p = 0.004) and TC (p = 0.003). Compared to benign ovarian tumor group, ovarian cancer group had significantly lower levels of HDL-c (p < 0.0001), LDL-c (p = 0.0009), and TC (p < 0.0001), as well as a trend of higher level of lipoprotein (a) (p = 0.10). Compared to endometriosis group, endometrial cancer group showed higher levels of TG (p < 0.0001) and lower levels of HDL-c (p = 0.002). There was no significant difference in any lipid parameters between cervical cancer group and uterine leiomyomas group.

CONCLUSION

In conclusion, compared with benign diseases, gynecologic cancers are associated with a disordered lipid profile characterized by higher TG and lipoprotein (a) levels, and lower HDL-c, LDL-c, and TC levels. The association is most conspicuous in ovarian cancers. Endometrial cancer is accompanied by alterations only in TG and HDL-c levels, while cervical cancer does not appear to be associated with disordered lipid profile.

Mechanism of periodic height variations along self-aligned VLS-grown planar nanostructures

In this study we report in-plane nanotracks produced by molecular-beam-epitaxy (MBE) exhibiting lateral self-assembly and unusual periodic and out-of-phase height variations across their growth axes. The nanotracks are synthesized using bismuth segregation on the GaAsBi epitaxial surface, which results in metallic liquid droplets capable of catalyzing GaAsBi nanotrack growth via the vapor-liquid-solid (VLS) mechanism. A detailed examination of the nanotrack morphologies is carried out employing a combination of scanning electron and atomic force microscopy and, based on the findings, a geometric model of nanotrack growth during MBE is developed. Our results indicate diffusion and shadowing effects play significant roles in defining the interesting nanotrack shape. The unique periodicity of our lateral nanotracks originates from a rotating nucleation "hot spot" at the edge of the liquid-solid interface, a feature caused by the relative periodic circling of the non-normal ion beam flux incident on the sample surface, inside the MBE chamber. We point out that such a concept is divergent from current models of crawling mode growth kinetics and conclude that these effects may be utilized in the design and assembly of planar nanostructures with controlled non-monotonous structure.

Novel zinc protease gene isolated from Dictyostelium discoideum is structurally related to mammalian leukotriene A4 hydrolase

The allantoicase (allC) gene of Dictyostelium discoideum allC RNAi mutant strain was silenced using the RNA interference technique. The mutant strain is motile, aggregated, and could not undergo further morphological development. The growth rate is high and the cells show a shortened cell cycle comparing with wild-type D. discoideum. However, the mechanisms regarding these actions remain unclear. mRNA differential display was used in this study to identify genetic differences. A novel D. discoideum gene (GenBank accession number: KC759140) encoding a new zinc protease was cloned. The amino acid sequence of the novel gene exhibited a conserved zinc-binding domain (HEX2HX18E) that allowed its classification into the M1 family of metallopeptidases. The gene encoded a 345-amino acid protein with a theoretical molecular mass of 39.69 kDa and a theoretical pI of 6.05. This protein showed strong homology with leukotriene A4 (LTA4) hydrolase of Homo sapiens (41% identity and 60% similarity at the amino acid level). By analyzing quantitative reverse transcription-polymerase chain reaction data, this zinc protease gene was more highly expressed in D. discoideum allC RNAi mutant type than in wild-type KAx-3 cells during the trophophase. The novel zinc protease gene may function as an LTA4 hydrolase and contribute to the shortening of the allC RNAi mutant cell cycle.

An improved electrostatic integrating radon monitor with the CR-39 as alpha-particle detector

In this study, based on the electrostatic integrating radon monitor (EIRM) developed by Iida et al., a new type of EIRM with the allyl glycol carbonate (CR-39) as alpha-particle detector was developed for outdoor radon measurements. Besides using the CR-39 to replace the cellulose nitrate film as alpha-particle detector, the electrode and the setting place of the CR-39 were also optimally designed based on the simulation results of the electric field and the detection efficiency. The calibration factor of the new EIRM was estimated to be 0.136±0.002 tracks cm(-2) (Bq m(-3) h)(-1), with the lower detection limit of 0.6 Bq m(-3) for a 2-month exposure. Furthermore, both the battery and the dry agent were also replaced to protect the environment. The results of intercomparison and field experiments showed that the performances of the new EIRM were much better than the original one. It suggests that the new type of ERIM is more suitable for large-scale and long-term outdoor radon surveys.

Association between DEFB103 gene copy number variation and ankylosing spondylitis: a case-control study

In this brief communication, we investigate the role of DEFB103 gene copy number variation (CNV) in ankylosing spondylitis (AS) susceptibility. A total of 807 Chinese individuals including 406 AS patients and 401 controls were enrolled. The DEFB103 copy number was measured by two sets of probes to obtain a stable result in a custom-by-design Multiplex AccuCopy(™) kit (Genesky Biotechnologies Inc., Shanghai, China) based on a multiplex fluorescence competitive polymerase chain reaction (PCR) principle. The copy number of DEFB103 ranged from 2 to 6 in both AS patients and controls. Mann-Whitney U test and chi-squared test were performed to analyze the difference of DEFB103 copy number between AS patients and controls while no statistical difference has been found. We considered the copy number of DEFB103 gene may not associate with susceptibility to AS.

Rap1 is indispensable for TRF2 function in etoposide-induced DNA damage response in gastric cancer cell line

The telomeric protein TRF2, involving in telomeric and extratelomeric DNA damage response, has been previously reported to facilitate multidrug resistance (MDR) in gastric cancer cells by interfering ATM-dependent DNA damage response induced by anticancer drugs. Rap1 is the TRF2-interacting protein in the shelterin complex. Complex formation between Rap1 and TRF2 is essential for their function in telomere and end protection. Here we focus on the effects of Rap1 on TRF2 function in DNA damage response induced by anticancer drugs. Both Rap1 and TRF2 expression were upregulated in SGC7901 and its MDR variant SGC7901/VCR after etoposide treatment, which was more marked in SGC7901/VCR than in SGC7901. Rap1 silencing by siRNA in SGC7901/VCR partially reversed the etoposide resistance. And Rap1 silencing partially reversed the TRF2-mediated resistance to etoposide in SGC7901. Rap1 silencing did not affect the TRF2 upregulation induced by etoposide, but eliminated the inhibition effect of TRF2 on ATM expression and ATM phosphorylation at serine 1981 (ATM pS1981). Furthermore, phosphorylation of ATM targets, including γH2AX and serine 15 (S15) on p53, were increased in Rap1 silencing cells in response to etoposide. Thus, we confirm that Rap1, interacting with TRF2 in the shelterin complex, also has an important role in TRF2-mediated DNA damage response in gastric cancer cells treated by etoposide.

Transient x-ray diffraction with simultaneous imaging under high strain-rate loading

Real time, in situ, multiframe, diffraction, and imaging measurements on bulk samples under high and ultrahigh strain-rate loading are highly desirable for micro- and mesoscale sciences. We present an experimental demonstration of multiframe transient x-ray diffraction (TXD) along with simultaneous imaging under high strain-rate loading at the Advanced Photon Source beamline 32ID. The feasibility study utilizes high strain-rate Hopkinson bar loading on a Mg alloy. The exposure time in TXD is 2-3 μs, and the frame interval is 26.7-62.5 μs. Various dynamic deformation mechanisms are revealed by TXD, including lattice expansion or compression, crystal plasticity, grain or lattice rotation, and likely grain refinement, as well as considerable anisotropy in deformation. Dynamic strain fields are mapped via x-ray digital image correlation, and are consistent with the diffraction measurements and loading histories.