3D Dynamic Motion Planning for Robot-Assisted Cannula Flexible Needle Insertion into Soft Tissue

In robot-assisted needle-based medical procedures, insertion motion planning is a crucial aspect. 3D dynamic motion planning for a cannula flexible needle is challenging with regard to the nonholonomic motion of the needle tip, the presence of anatomic obstacles or sensitive organs in the needle path, as well as uncertainties due to the dynamic environment caused by the movements and deformations of the organs. The kinematics of the cannula flexible needle is calculated in this paper. Based on a rapid and robust static motion planning algorithm, referred to as greedy heuristic and reachability-guided rapidly-exploring random trees, a 3D dynamic motion planner is developed by using replanning. Aiming at the large detour problem, the convergence problem and the accuracy problem that replanning encounters, three novel strategies are proposed and integrated into the conventional replanning algorithm. Comparisons are made between algorithms with and without the strategies to verify their validity. Simulations showed that the proposed algorithm can overcome the above-noted problems to realize real-time replanning in a 3D dynamic environment, which is appropriate for intraoperative planning. © 2016 Author

Inhibitory effect of reduced graphene oxide-silver nanocomposite on progression of artificial enamel caries

The use of antimicrobial agents is an efficient method to prevent dental caries. Also, nanometric antibacterial agents with wide antibacterial spectrum and strong antibacterial effects can be applied for prevention of dental caries. Objectives: The aim of this study was to evaluate the inhibitory effect of reduced graphene oxide-silver nanoparticles (rGO/Ag) composite on the progression of artificial enamel caries in a Streptococcus mutans biofilm model. Material and Methods: Enamel specimens from bovine incisors were divided into eight treatment groups (n=13), as follows: group 1 was inoculated with S. mutans grown in Brain Heart Infusion containing 1% sucrose (1% BHIS), as negative control; groups 2–4 were inoculated with S. mutans grown in the presence of different rGO/Ag concentrations (0.08, 0.12, 0.16 mg/mL) + 1% BHIS; group 5–7 were inoculated with S. mutans grown in the presence of different agents (0.16 mg/mL reduced graphene oxide, 0.16 mg/mL silver nanoparticles, 10 ppm NaF) + 1% BHIS; group 8 was mixed with 1% BHIS, without inoculation. Artificial enamel carious lesions were produced by S. mutans biofilm model for 7 days. Confocal laser scanning microscopy and atomic force microscopy were used to analyze roughness and morphology of the enamel surface. Polarized light microscopy and confocal laser scanning microscopy were employed to measure the lesion depth and the relative optical density (ROD) of the demineralized layer. Results: Compared with the control groups, the rGO/Ag groups showed: (a) reduced enamel surface roughness; (b) much smoother and less eroded surfaces; (c) shallower lesion depth and less mineral loss. Conclusion: As a novel composite material, rGO/Ag can be a promising antibacterial agent for caries prevention

Online monitoring instantaneous 2D temperature distributions in a furnace using acoustic tomography based on frequency division multiplexing

The online and accurate capture of dynamic changes in furnace temperature distribution is crucial for production efficiency improvement and international environmental policy compliance in power plants. To achieve this, a measurement system with a reliable online reconstruction capability and high temporal resolution is necessary. This paper presents a novel technique that can improve the temporal resolution of the currently existing acoustic tomography (AT) system using frequency division multiplexing (FDM). This method allows for concurrent transmissions of acoustic signals in several different frequency bands instead of a sequential manner, which leads to more efficient channel utilization and allows all acoustic signals to be acquired at the same time, so that a better temporal uniformity of multipath acoustic signals can be realized. Theoretical analysis and experiments have been conducted to verify the effectiveness of this technique. The results prove that the proposed method can significantly improve the temporal resolution of the AT system while maintaining the accuracy and robustness of the reconstruction

Streptococcus Mutans Membrane Vesicles Enhance Candida albicans Pathogenicity and Carbohydrate Metabolism

Streptococcus mutans and Candida albicans, as the most common bacterium and fungus in the oral cavity respectively, are considered microbiological risk markers of early childhood caries. S. mutans membrane vesicles (MVs) contain virulence proteins, which play roles in biofilm formation and disease progression. Our previous research found that S. mutans MVs harboring glucosyltransferases augment C. albicans biofilm formation by increasing exopolysaccharide production, but the specific impact of S. mutans MVs on C. albicans virulence and pathogenicity is still unknown. In the present study, we developed C. albicans biofilms on the surface of cover glass, hydroxyapatite discs and bovine dentin specimens. The results showed that C. albicans can better adhere to the tooth surface with the effect of S. mutans MVs. Meanwhile, we employed C. albicans biofilm-bovine dentin model to evaluate the influence of S. mutans MVs on C. albicans biofilm cariogenicity. In the S. mutans MV-treated group, the bovine dentin surface hardness loss was significantly increased and the surface morphology showed more dentin tubule exposure and broken dentin tubules. Subsequently, integrative proteomic and metabolomic approaches were used to identify the differentially expressed proteins and metabolites of C. albicans when cocultured with S. mutans MVs. The combination of proteomics and metabolomics analysis indicated that significantly regulated proteins and metabolites were involved in amino acid and carbohydrate metabolism. In summary, the results of the present study proved that S. mutans MVs increase bovine dentin demineralization provoked by C. albicans biofilms and enhance the protein and metabolite expression of C. albicans related to carbohydrate metabolism

A stability and spatial-resolution enhanced laser absorption spectroscopy tomographic sensor for complex combustion flame diagnosis

A novel stable laser absorption spectroscopy (LAS) tomographic sensor with enhanced stability and spatial resolution is developed and applied to complex combustion flame diagnosis. The sensor reduces the need for laser collimation and alignment even in extremely harsh environments and improves the stability of the received laser signal. Furthermore, a new miniaturized laser emission module was designed to achieve multi-degree of freedom adjustment. The full optical paths can be sampled by 8 receivers, with such arrangement, the equipment cost can be greatly reduced, at the same time, the spatial resolution is improved. In fact, 100 emitted laser paths are realized in a limited space of 200mm×200 mm with the highest spatial resolution of 1.67mm×1.67 mm. The stability and penetrating spatial resolution of the LAS tomographic sensor were validated by both simulation and field experiments on the afterburner flames. Tests under two representative experiment states, i.e., the main combustion and the afterburner operation states, were conducted. Results show that the error under the main combustion state was about 4.32% and, 5.38% at the afterburner operation state. It has been proven that this proposed sensor can provide better tomographic measurements for combustion diagnosis, as an effective tool for improving performances of afterburners

High psychological stress levels related to delivery can increase the occurrence of postpartum mental disorders

ObjectiveThe study sought to explore the relationship between high psychological stress levels related to delivery and postpartum mental disorders.MethodsA total of 284 parturients were included in the study from July 2021 to January 2022. The stress level at 1 month postpartum was assessed by the Impact of Event Scale-Revised (IES-R). Parturients with an IES-R score ≤ 9 were included in the low psychological stress level group, and those with an IES-R score > 9 were included in the high psychological stress level group. The Edinburgh Postnatal Depression Scale (EPDS), Union Physio-Psycho-Social Assessment Questionnaire (UPPSAQ-70), Symptom Checklist-90 (SCL-90) and Mini-International Neuropsychiatric Interview (M.I.N.I.) were conducted at 42 ± 7 days postpartum to assess the mental health of parturients.The parturients’ mental health after birth was assessed by the EPDS, UPPSAQ-70, and SCL-90. Semi-structured diagnostic interviews were conducted at 42 ± 7 days postpartum by using the M.I.N.I.ResultsThe incidence rate of postpartum mental disorders was 20.42% (58/284), the incidence rates of postpartum depression, anxiety disorders, obsessive-compulsive disorder and posttraumatic stress disorder were 17.96% (51/284), 11.97% (34/284), 4.58% (13/284) and 1.41% (4/284), respectively, and the comorbidity rate was 58.62% (34/58). A history of mental disorders and pregnancy complications were risk factors for postpartum depression (p = 0.028, p = 0.040, respectively); a history of mental disorders, a lack of physical exercise, partner violence and pregnancy complications were risk factors for postpartum anxiety disorders (p = 0.003, p = 0.007, p = 0.031, p = 0.048, respectively); and the delivery of female infants was a risk factor for postpartum obsessive-compulsive disorder (p = 0.022).The risk of postpartum depression, anxiety disorders and obsessive-compulsive disorder was 9.125 times (95% CI = 3.900 ~ 21.349, p < 0.01), 7.310 times (95% CI = 2.588 ~ 20.649, p < 0.01) and 6.259 times (95% CI = 1.347 ~ 29.093, p < 0.01) higher in postpartum women with high psychological stress levels related to delivery than in those with low psychological stress levels, respectively.ConclusionThe incidence of postpartum mental disorders is high and has a positive correlation with the level of psychological stress. This may lead to a new perspective of the effect of psychological stress on postpartum mental disorders and attract more attention to other mental disorders in addition to postpartum depression

Cost-effectiveness analysis of nivolumab combination therapy in the first-line treatment for advanced esophageal squamous-cell carcinoma

ObjectiveWe aimed to investigate the cost-effectiveness of nivolumab plus chemotherapy and nivolumab plus ipilimumab versus chemotherapy in the first-line treatment for advanced esophageal squamous-cell carcinoma (ESCC) patients from a healthcare system perspective in China.MethodsOn the basis of the CheckMate 648 trial, a partitioned survival model was constructed to estimate economic costs and health outcomes among overall and PD-L1-positive advanced ESCC patients over a 10-year lifetime horizon. The health-related costs and utilities were obtained from the local charges and published literature. The lifetime costs, life-years, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratio (ICER) were measured. One-way and probabilistic sensitivity analyses (PSA) were performed to assess the robustness of the model.ResultsIn the base-case analysis, in overall and PD-L1-positive advanced ESCC patients, the ICERs were $415,163.81/QALY and$216,628.00/QALY for nivolumab plus chemotherapy, and$430,704.11/QALY and$185,483.94/QALY for nivolumab plus ipilimumab, respectively, compared with chemotherapy. One-way sensitivity analyses revealed that patients’ weight was the most influential parameter on ICER. The PSA demonstrated that the probability of nivolumab combination therapy being cost-effective was 0% over chemotherapy at the current price and willingness-to-pay threshold ($38,351.20/QALY). When the price of nivolumab and ipilimumab decreased 80%, the cost-effective probability of nivolumab plus ipilimumab increased to 40.44% and 86.38% in overall and PD-L1-positive advanced ESCC patients, respectively.ConclusionNivolumab combination therapy could improve survival time and health benefits over chemotherapy for advanced ESCC patients, but it is unlikely to be a cost-effective treatment option in China

UTR introns, antisense RNA and differentially spliced transcripts between Plasmodium yoelii subspecies

Additional file 1. Evaluation of RNA quality from the two NSM parasite samples in agarose gel (a), and a flow chart of data processing and analysis (b)

Weldable and closed-loop recyclable monolithic dynamic covalent polymer aerogels

Owing to their low density, high porosity and unique micro-nanostructures, aerogels are attractive for application in various fields; however, they suffer from shrinkage and/or cracking during preparation, mechanical brittleness, low production efficiency and non-degradation. Herein, we introduce the concept of dynamic covalent polymer chemistry to produce a new class of aerogels&mdash;referred to as DCPAs. The resulting lightweight DCPAs have the potential to be prepared on a large scale and feature high porosity (90.7%&ndash;91.3%), large degrees of compression (80% strain) and bending (diametral deflection of 30 mm) without any cracks, as well as considerable tensile properties (an elongation with a break at 32.7%). In addition, the DCPAs showcase the emergent characteristics of weldability, repairability, degradability and closed-loop recyclability that are highly desirable for providing versatile material platforms, though hardly achieved by traditional aerogels. Taking advantage of their robust porous structures, we demonstrate the potential of DCPAs for applications in thermal insulation and emulsion separation. These findings reveal that the dynamic covalent bond strategy would be generalized for the production of a new generation of aerogels with customized features for functioning in the field of intelligent and sustainable materials. &nbsp;</p