Abstract. Primary chylopericardium (CP) is a rare clinical condition in which chylous fluid containing high concentrations of triglyceride accumulates in the pericardial cavity. The present study reports a case of CP that was successfully treated by reconstruction surgery of thoracic duct. To improve the ability to diagnosis and treat this rare disease, the current study also systematically extracted 104 reported cases of primary or idiopathic CP from the past 60 years (January 1950 to December of 2015), and reviewed the clinical manifestation, etiology, diagnosis and treatment of these cases. The age at diagnosis varied between 6 weeks and 79 years with a mean age of 27.95±16.50 years. Asymptomatic patients accounted for 39.42% of cases, while the most common initial symptoms were dyspnea (44.23%) and coughing (10.58%). Jugular venous distention and distant heart sound was identified in 23 (22.12%) and 34 cases (32.69%), respectively. Cardiomegaly in X-ray scans was detected in the majority of patients (93.27%). In addition, lymphoscintigraphy and lymphangiography were helpful in identifying the source of chyle. Regarding the etiology, idiopathic cases accounted for 35.56% of the included cases in the present study. The most important cause of primary CP was abnormal connection or accumulation of lymph fluid in the pericardium (37.50%). Conservative therapy included low-fat or medium-chain triglyceride diet, as well as total parenteral nutrition. The majority of patients (71.2%) required surgery for definitive therapy, and thoracic duct ligation was the most preferred surgical procedure, performed in 44.23% of cases. Follow-up was reported in 64 cases, and all patients survived during the mean follow-up period of 12 months. Therefore, it is suggested that surgical management is the most successful treatment method and is associated with a favorable prognosis.

Background: Medical students are affected by high levels of general anxiety disorder. However, few studies have specifically focused on the applicability of universal anxiety screening tools in this sample. This study was aimed to evaluate the psychometric property of the 7-item Generalized Anxiety Disorder Scale (GAD-7) among Chinese medical university students.Methods: A questionnaire survey was conducted among 1,021 medical postgraduates from six polyclinic hospitals. Internal consistency and convergent validity of the GAD-7 were evaluated. Factor analyses were used to test the construct validity of the scale. An item response theory (IRT) framework was used to estimate the parameters of each item. Multi-group confirmatory analyses and differential item function analyses were used to evaluate the measurement equivalence of the GAD-7 across age, gender, educational status, and residence.Results: Cronbach's α coefficient was 0.93 and the intraclass correlation coefficients ranged from 0.71 to 0.87. The GAD-7 summed score was significantly correlated with measures of depression symptoms, perceived stress, sleep disorders, and life satisfaction. Parallel analysis and confirmatory factor analysis supported the one-factor structure of the GAD-7. Seven items showed appropriate discrimination and difficulty parameters. The GAD-7 showed good measurement equivalence across demographic characteristics. The total test information of the scale was 22.85, but the test information within the range of mild symptoms was relatively low.Conclusions: The GAD-7 has good reliability, validity, and measurement invariance among Chinese medical postgraduate students, but its measurement precision for mild anxiety symptoms is insufficient.

In addition to providing maneuverability, electrospun nanofibrous meshes can make excellent supports for constructing flexible cell sheets to regulate cell behavior by nanofiber features. With the target of bone regeneration, herein composite nanofibers with two different fiber arrangements (nestlike, random) were electrospun from a blend solution containing poly(l-lactide) (PLLA) and gelatin (1:1 in weight ratio). Unlike the non-woven morphology in a random nanofibrous mesh, PLLA/gelatin composite nanofibers in the nestlike nanofibrous mesh displayed both non-woven and parallel morphologies. Both kinds of nanofibrous mesh were ∼50 μm thick as-prepared, and shrank to ∼30 μm after seeding with bone mesenchymal stromal cells (BMSCs). After 7 days of in vitro culture, cell sheets could form on both meshes (CSM) and on the culture plate. It was found that application of nanofibrous mesh promoted the osteogenic differentiation of BMSC sheets compared with the control. The nestlike mesh displayed slight superiority over the random mesh in enhancing osteogenic differentiation, but their different fiber arrangements did not cause much difference in cell proliferation. Three-dimensional multi-layered CSM constructs were built by stacking four mono-layered CSMs together. The CSM constructs (based on a nestlike or random nanofibrous mesh) were incubated in vitro for 3 days before being implanted into rat cranial defects. In comparison with the control group, there was significant formation of new calcified bone in both CSM construct-filled groups at 12 weeks' post-operation. The nestlike group showed slightly better bone healing (based on both qualitative and quantitative analysis) than the random group, while showing insignificant differences. We showed that the concept of using a three-dimensional multi-layered CSM construct in enhancing bone regeneration was feasible. Future studies should take more nanofiber features (e.g. bioactive components) into account to further enhance osteogenesis.

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This paper presents a method to investigate the characteristics of a high-speed motorized spindle system. The geometric quality of high-precision parts is highly dependent on the dynamic performance of the entire machining system, which is determined by the interrelated dynamics of machine tool mechanical structure and cutting process. This performance is of great importance in advanced, high-precision manufacturing processes. The state-of-the-art in machine tool main spindle units is focus on motorized spindle units for high-speed and high performance cutting. This paper taking the high-speed milling motorized spindle of CX8075 produced by Anyang Xinsheng Machine Tool Co. Ltd. as an example, a finite element model of the high-speed motorized spindle is derived and presented. The model takes into account bearing support contact interface, which is established by spring-damper element COMBIN 14. Furthermore, the static analysis, modal analysis, harmonic response analysis and thermal analysis were done by means of ANSYS commercial software. The results show that the maximum rotating speed of the motorized spindle is far smaller than the natural resonance region speed, and the static stiffness of the spindle can meet the requirements of design. The static and dynamic characteristics of the motorized spindle accord with the requirements of high-speed machining. The thermal deformation of spindle is 6.56µm, it is too small to affect the precision of the spindle. The results illustrate the rationality of the spindle structural design.

Background. The association between lipoprotein-associated phospholipase A2 (Lp-PLA2) and stroke risk is inconsistent. We conducted a meta-analysis to determine whether elevated Lp-PLA2 is a risk factor for stroke. Methods. Studies were included if they reported Lp-PLA2 mass and/or activity levels and adjusted risk estimates of stroke. The primary outcome was overall stroke incidence. The combined results were shown as relative risks (RRs) with 95% confidence intervals (CI) for per 1 standard deviation (SD) higher value of Lp-PLA2 and the highest versus lowest Lp-PLA2 category. Results. Twenty-two studies involving 157,693 participants were included for analysis. After adjusting for conventional risk factors, the RRs for overall stroke with 1 SD higher Lp-PLA2 activity and mass were 1.07 (95% CI 1.02–1.13) and 1.11 (95% CI 1.04–1.19), respectively. The RRs of ischemic stroke with 1 SD higher Lp-PLA2 activity and mass were 1.08 (95% CI 1.01–1.15) and 1.11 (95% CI 1.02–1.22), respectively. When comparing the highest and lowest levels of Lp-PLA2, the RRs of stroke for Lp-PLA2 activity and mass were 1.26 (95% CI 1.03–1.54) and 1.56 (95% CI 1.21–2.00), respectively. Finally, when comparing the highest and lowest levels of Lp-PLA2, the pooled RRs of ischemic stroke for Lp-PLA2 activity and mass were 1.29 (95% CI 1.07–1.56) and 1.68 (95% CI 1.12–2.53), respectively. Conclusions. Elevated baseline Lp-PLA2 levels, detected either by activity or mass, are associated with increased stroke risk.

The controlling of robotic arms based on brain–computer interface (BCI) can revolutionize the quality of life and living conditions for individuals with physical disabilities. Invasive electroencephalography (EEG)-based BCI has been able to control multiple degrees of freedom (DOFs) robotic arms in three dimensions. However, it is still hard to control a multi-DOF robotic arm to reach and grasp the desired target accurately in complex three-dimensional (3D) space by a noninvasive system mainly due to the limitation of EEG decoding performance. In this study, we propose a noninvasive EEG-based BCI for a robotic arm control system that enables users to complete multitarget reach and grasp tasks and avoid obstacles by hybrid control. The results obtained from seven subjects demonstrated that motor imagery (MI) training could modulate brain rhythms, and six of them completed the online tasks using the hybrid-control-based robotic arm system. The proposed system shows effective performance due to the combination of MI-based EEG, computer vision, gaze detection, and partially autonomous guidance, which drastically improve the accuracy of online tasks and reduce the brain burden caused by long-term mental activities.

The importance of transmission of occult HBV infection (OBI) via transfusion, organ transplantation and hemodialysis has been widely recognized. However, data regarding the transmission of OBI through close contact remain limited. In this study, serum samples were obtained from a child and his parents. The child had received the standard vaccination regimen at birth and produced protective antibody. Sera were tested for HBV serological markers. Nested PCR assays were used to detect HBV DNA and the amplicons were cloned and their sequences subjected to phylogenetic analysis. The results showed that both parents had occult infections while the child had an overt infection. Twelve, eleven and nine clones, from the father, mother and son, respectively, were sequenced. Serotypes adrq+, ayw1, ayw and ayr were found in the father and ayw1, adw2 and adwq+ in the mother; adrq+ was the only serotype in son. Genotype B, subgenotype C2 and a recombinant were identified in the father and genotype B, subgenotype C5 and three recombinants were found in the mother. Subgenotype C2 was the only genotype identified in the child. A phylogenetic tree showed that all of the child’s sequences and most of the father’s sequences clustered together. However, none of mother’s sequences clustered with those of the child. The surface gene from the child and his father had the same amino acid substitution pattern (T118K, T123N and G145A). We concluded that the father was the source of the son’s HBV infection, suggesting that occult HBV infection may be transmitted through close contact and manifest as an overt infection.