51 research outputs found

    Электропривод ротора буровой установки

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    Цель работы - разработка и исследование двухзонного электропривода ротора буровой установки В работе выбраны элементы силовой цепи, определены оптимальные параметры настройки регуляторов системы, рассчитаны статические и динамические характеристики, определены качественные показатели.Objective - development and research of electric double belt rig rotor in the selected elements of the power circuit, the optimum settings of the system regulators calculated static and dynamic characteristics determined quality indicators

    Clinical Characterization and the Caregiver Burden of Dementia in China

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    AbstractObjectivesThe prevalence of dementia in China is among the highest in the world, but systematic estimates of the rate of dementia subtypes and characterization of associated deficits are lacking. The primary aim of this study was to determine the clinical presentation of dementia and describe the caregiver burden in mainland China.MethodsA 3-month, open-enrollment, multicenter, cross-sectional study was conducted at 48 tier-3 hospitals. Caregivers who qualified for study entry (provided amount and duration of care information), had intimate knowledge of patient status, and accompanied enrolled patients to study sites were asked to participate in an interview about patient care and caregiver burden. Caregiver burden was assessed via the Chinese version of the validated Zarit Burden Interview.ResultsA total of 1425 caregivers completed the survey. Patients had mild to moderate dementia (mean Clinical Dementia Rating score of 1.67±0.79), and the most common dementia subtypes were Alzheimer disease (46.7%) and vascular dementia (28.7%). Among caregivers, 57% were females, 52% were patients’ spouses, and 67.3% had been caring for patients for 1 year or more. Most patients required family help and lived at home or with a family member. Caregiver awareness of dementia was limited. The mean total caregiver Zarit Burden Interview score was 26.6. Observations were similar across age, gender, education, dementia type, Clinical Dementia Rating score, and duration of care.ConclusionsChina faces multiple obstacles in preparing to care for its fast-growing dementia population. Better understanding of patients and caregivers may mitigate these challenges by improving awareness and education

    A clinical practice comparison of patients with chronic lymphocytic leukemia with and without deletion 17p receiving first-line treatment with ibrutinib

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    Among patients with chronic lymphocytic leukemia (CLL) with deletion 17p (del[17p]), evidence from clinical trials for the effectiveness of single-agent ibrutinib as first-line therapy is limited. This retrospective analysis compared real-world clinical outcomes among patients with CLL, with and without del(17p), treated with first-line ibrutinib monotherapy. Overall survival, time to next treatment, time to treatment discontinuation, and reasons for ibrutinib discontinuation were evaluated. Using data from a real-world database, patients included were aged ≥18 years, had been diagnosed with CLL between January 1, 2011 and December 31, 2019, had undergone cytogenetic testing, and had received first-line ibrutinib monotherapy. A total of 1,069 patients were included in the analysis (62.7% male; median age 69 years); 23.8% (n=254) had del(17p). The median overall survival was significantly shorter in patients with del(17p) than in patients without (57.7 months vs. not reached; P=0.0006). Similar results were observed for median time to next treatment (49.4 months vs. not reached, P=0.0330). The median time to treatment discontinuation was non-significantly shorter in the group of patients with del(17p) (32.5 months vs. 42.9 months, P=0.3370). Results of an adjusted Cox proportional hazards model showed that the group with del(17p) was at significantly higher risk of death than was the group without del(17p) (hazard ratio=1.70, P=0.0031). Event rates for switching to new treatment and discontinuation were higher but not statistically significantly so. The most common reason for discontinuing ibrutinib treatment in both groups was toxicity, but discontinuation due to progression was significantly more frequent among patients with del(17p) (20% vs. 6%; P<0.0001). This study identifies an unmet need for more effective first-line therapeutic options in patients with CLL/small lymphocytic lymphoma and del(17p), despite the advent of ibrutinib

    Fractional Vegetation Cover Estimation of Different Vegetation Types in the Qaidam Basin

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    The estimation of fractional vegetation cover (FVC) by using remote sensing images has become feasible. Based on Landsat8-OLI images and field data obtained from an unmanned aerial vehicle, we established an empirical model (EM) and a pixel decomposition model (PDM) of FVC in the desert vegetation region, steppe vegetation region, meadow vegetation region and mixed vegetation region (the three vegetation region types) of the Qaidam Basin, and the inversion accuracies of the models were compared. The results show the following: (1) Vegetation classification inversion (VCI) provides a promising approach for FVC estimation. The accuracy of FVC by VCI was obviously better than that achieved using vegetation mixed inversion (VMI); (2) Differences were observed in the FVC estimation between VCI and VMI by the EM in areas with relatively high-density vegetation cover (FVC &gt; 60%). The FVC in some parts of steppe region in the basin was slightly overestimated by VMI of the EM; 3) VCI estimated by the PDM resulted in lower inversion values for extremely low-density vegetation cover (FVC &#8804; 10%) and higher inversion values for high-density vegetation cover (FVC &gt; 80%). The FVC inversion was underestimated by the PDM in steppe and meadow regions with FVC &gt; 15% in the basin. The application of VCI in different models can provide new ideas for the sustainable study of vegetation in arid regions

    Topology design and analysis of a novel 3-translational parallel mechanism with analytical direct position solutions and partial motion decoupling

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    International audienceAccording to the topological design theory and method of parallel mechanism (PM) based on position and orientation characteristic (POC) equations, this paper design a novel 3-translation (3T) PM that has three advantages, i.e., ① it consists on three actuated prismatic joints, ② the PM has analytical direct position solutions, and ③ the PM is of partial motion decoupling property. Firstly, the main topological characteristics such as the POC, degree of freedom and coupling degree are calculated for kinematics modelling. Due to the special constraint feature of the 3-translation, the analytical direct position solutions of the PM can be directly obtained without needing to use one-dimensional search method. Further, the conditions of the singular configuration of the PM, as well as the singularity location inside the workspace are analyzed according to the inverse kinematics

    Whole exome sequencing analysis for sebaceous carcinoma of the parotid gland

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    Objective To analyze potential pathogenic gene mutations related to sebaceous carcinoma (SC) of the parotid gland by whole exome sequencing (WES). Methods One sample from a patient pathologically diagnosed with SC of the parotid gland and 1 sample from 1 patient with sebaceous adenoma (SA) of scalp were collected and prepared for WES by Illumina Hiseq 2500 platform. Suspicious single nucleotide variation sites were selected for mutation conservation and functional analysis. SciClone software was used to track subclone evolution and clonal map information was obtained for each tumor sample. The high-frequency significant gene mutations in the tumor samples were screened by MutSigCV software, and compared with the known driver genes. Results There were 57 driver genes harboring mutations in SC of the parotid gland compared to those of SA of the scalp. Conclusion SC of the parotid gland yields gene mutations and mutation patterns different from malignant tumors

    Scientific visualization for advanced deep-sea exploration equipment and underwater automatic manipulation

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    Scientific visualization is important in modern technological activities and engineering exploration. Due to the dark and high-pressure characteristics of deep sea, it is difficult to visualize the entire operation of deep-sea equipment. Thus, it is of great necessity to use virtual simulation technology to help people understand the operation process of some deep-sea exploration equipment on the sea floor. In this paper, science, art, and new media are combined through artistic rendering, visual processing, and the technology of virtual reality (VR) and holography, which makes the exploration of the latest deep-sea lander and intelligent submersible named “Luling” look more intuitive and smart and have more visual impact and expression. Apart from that, automatic manipulation videos of the rover robot in the deep sea captured by the Luling are effectively nested to realize the goal of virtual and real presentation. The designed scientific visualization of deep-sea equipment can not only adapt to the display output of VR, mobile phones, TV, 360° showcase, and other platforms, but also achieve immersive experience and virtual simulation learning through HTC Vive VR equipment. The technology and design way of scientific visualization in this paper is universal and suitable to the same kind of engineering simulation
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