514 research outputs found

    Dynamic Optimal Pricing Strategies for Knowledge-Sharing Platforms

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    The sharing economy is a fast-growing business model, and the sharing resources have crept from physical assets (e.g., vehicles and houses) to intangible assets (e.g., skills and knowledge). Online knowledge-sharing platforms allow sharers to offer knowledge products in various forms and can generate revenue through charging users subscription and/or transaction fees. How to charge bilateral users is an essential and complex decision-making problem that puzzles knowledge-sharing platforms. This study proposes a dynamic optimal pricing model that involves multiple development stages based on the optimal control theory. In addition, the inherent features of knowledge products and sharers’ social capitals are considered. The applicability and utility of the proposed model is verified through numerical experiments on an empirical dataset from the China’s largest knowledge-sharing platform named Zhihu. The results reveal that the platform can adjust its pricing strategies to achieve different optimization goals and this is conducive to its sustainable development

    Clematis chinensis Extract Protects against Diabetic Nephropathy in Rats

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    Purpose: To study the effect of Clematis chinensis extract (CCE) on diabetic nephropathy in rats.Methods: Eight-week old male Wistar rats were injected with streptozotocin to induce diabetes. The effects of CCE(250 or 500 mg/kg) on renal function index, fasting blood glucose (FBG), blood fat, oxidation index, and pathological kidney changes for 3 weeks were compared to those of the positive control drug, captopril.Results: At 12 weeks, CCE(500 mg/kg) treatment had significantly decreased serum blood urea nitrogen (BUN, 12.61 ± 1.42 mmol/L), serum creatinine (SCr, 84.64 ± 6.37 μmol/L), creatinine clearance (CCr, 0.88 ± 0.10 mmol/L), interleukin-6 (IL-6, 297.56 ± 19.62 pg/mL), urinary albumin, urinary albumin excretion rate (UAER, 11.68 ± 0.97 μg/min), kidney hypertrophy index (kidney weight/body weight, 0.58 ± 0.03%) and FBG (11.51 ± 0.96 mmol·L-1). It significantly decreased triglyceride (TG, 0.26 ± 0.05 mmol/L), total cholesterol (TC, 1.52 ± 0.06 mmol/L) and low-density lipoprotein cholesterol (LDL-c, 0.71 ± 0.06 mmol/L) levels and increased high density lipoprotein-cholesterol (HDL-c, 0.65 ± 0.05 mmol/L). CCE treatment also significantly decreased malondialdehyde (MDA, 16.14 ± 1.24 nmol/mgprot) levels and increased superoxide dismutase (SOD, 95.17 ± 4.06 U/mgprot) and glutathione peroxidase (GSHPx, 154.33 ± 11.76 mmol/L) (both p < 0.05). Finally, CCE reduced the degree of glomerular basement membrane and renal tubular thickening and swelling in diabetic rats.Conclusion: CCE has a significant inhibitory effect on diabetic nephropathy-induced renal injury in rats.Keywords: Clematis chinensis, Diabetic nephropathy, Renal function, Pathological morpholog

    Mediastinal Lymph Node Metastases in Thyroid Cancer: Characteristics, Predictive Factors, and Prognosis

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    Background. Mediastinal lymph node metastases (MLNM) have not been extensively studied. The aim of this study is to investigate the characteristics, predictive factors, and prognosis of MLNM in thyroid cancer. Methods. This is a retrospective study based on the thyroid cancer patients with MLNM at our institution from 2008 to 2015. Results. In total, 73 thyroid cancer patients with positive MLNM were included in this study. It contained sixty patients (82.2%) with papillary thyroid carcinoma (PTC), twelve (16.4%) with medullary thyroid carcinoma, and one (1.4%) with anaplastic thyroid carcinoma. Forty-eight patients had the surgery as initial treatment. Fifty-three (72.6%) patients remained disease-free, and fifteen (20.5%) developed a regional recurrence. Distant metastases occurred in four (5.5%) patients and five (6.8%) patients died. Five-year overall survival rate and disease-free survival (DFS) rate of the PTC patients for initial treatment are 95.4% and 77.2%, respectively. Extrathyroidal extension and multiple lymph nodes involved were associated with DFS in PTC patients. Conclusions. Initial therapeutic control is very important for the thyroid cancer patients. Extrathyroidal extension and multiple mediastinal lymph nodes involved were the influence factors of prognosis in the thyroid cancer patients with MLNM

    A new nursing pattern based on ERAS concept for patients with lumbar degenerative diseases treated with OLIF surgery: A retrospective study

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    ObjectiveThe purpose of this study was to introduce enhanced recovery after surgery (ERAS) concept into patients with lumbar degenerative diseases who were treated with oblique lumbar interbody fusion (OLIF), and to assess whether it could increase clinical efficacy, reduce perioperative complications, shorten length of hospital stay (LHS), decrease readmission rate, and improve patient satisfaction.MethodsThe study included patients with lumbar degenerative diseases (LDDs) who underwent OLIF between July 2017 and October 2018 (non-ERAS group), and between November 2018 and July 2020 (ERAS group). The two groups were compared according to the demographic and clinical characteristics.ResultsThere was no significant difference in descriptive characteristics and concomitant diseases between the two groups. The preoperative Oswestry disability index (ODI) score (P = 0.191), lumbar visual analogue scale (VAS) score (P = 0.470), and leg VAS score (P = 0.657) did not significantly different. Most of the ERAS measures were also well implemented after surgery, except for early delivery (74.2%), early catheter removal (63.9%), and multimodal analgesia (80.6%). The LHS in the ERAS group was significantly shorter than that in the non-ERAS group (P = 0.004). Besides, Hamilton Anxiety Rating Scale (HAMA) score at 3 days after surgery showed a significant difference between the two groups (P = 0.019). The patient satisfaction in ERAS group was significantly higher than that in the non-ERAS group (P = 0.001).ConclusionThe new nursing pattern combined with ERAS in patients with LDDs who underwent OLIF did not improve the short-term prognosis of surgery, while it could effectively reduce postoperative complications, shorten the LHS, and improve patient satisfaction, and did not lead to additional adverse events

    Ultraquantum magnetoresistance in Kramers Weyl semimetal candidate β\beta-Ag2Se

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    The topological semimetal β\beta-Ag2Se features a Kramers Weyl node at the origin in momentum space and a quadruplet of spinless Weyl nodes, which are annihilated by spin-orbit coupling. We show that single crystalline β\beta-Ag2Se manifests giant Shubnikov-de Haas oscillations in the longitudinal magnetoresistance which stem from a small electron pocket that can be driven beyond the quantum limit by a field less than 9 T. This small electron pocket is a remainder of the spin-orbit annihilatedWeyl nodes and thus encloses a Berry-phase structure. Moreover, we observed a negative longitudinal magnetoresistance when the magnetic field is beyond the quantum limit. Our experimental findings are complemented by thorough theoretical band structure analyses of this Kramers Weyl semimetal candidate, including first-principle calculations and an effective k*p model.Comment: A new version based on arXiv:1502.0232

    帕金森病认知功能损害的中医药治疗

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    Parkinson’s disease (PD) is a degenerative disease of the central nervous system that involves many other systems. Cognitive impairment is one of the major presentations of non-motor symptoms of PD. Mild cognitive impairment in Parkinson’s disease (PD-MCI), a predictive factor of the transformation of PD to dementia is a common cognitive defect in PD patients. The effects of traditional Chinese Medicine on cognitive impairment in Parkinson’s disease were valued at home and abroad. Traditional Chinese Medicine has less toxic and side effects, treatment based on syndrome differentiation, and adjustment the balance of Yin and Yang for patients. Combination of Chinese and western medicine treatment could not only reduce the amount of dopamine agents but also counteract the toxic and side effects induced by dopamine agents. Meanwhile, combination of Chinese and western medicine treatment could delay the occurrence and development of cognitive impairment, and has broad application prospect.帕金森病(PD)是一种累及多系统的中枢神经系统变性病。认知功能障碍是PD非运动症状的重要表现形式,大多数PD患者均伴有认知功能损害并最终发展成为痴呆。中医药在帕金森病治疗中的作用越来越受到国内外的重视。中药具有毒副作用小且通过辨证论治、从整体调节患者阴阳平衡的特点,中西医结合治疗既能减少多巴胺制剂用量,又能有效拮抗和治疗西药所引起的毒副作用,延缓认知障碍的发生和发展,具有广阔应用前景

    Evidence synthesis of Chinese medicine for monkeypox: Suggestions from other contagious pox-like viral diseases

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    Background: Monkeypox, a zoonotic disease caused by an Orthopoxvirus, presents an etiology similar to smallpox in humans. Currently, there are no licensed treatments for human monkeypox, so clear and urgent research on its prophylaxis and treatment is needed. Objective: The purpose of this study was to explore the evidence of Chinese medicine for contagious pox-like viral diseases and provide suggestions for the multi-country outbreak management of monkeypox. Methods: The review was registered on INPLASY (INPLASY202270013). Ancient classics in China and clinical trials involving randomized controlled trials , non-RCTs, and comparative observational studies of CM on the prevention and treatment of monkeypox, smallpox, measles, varicella, and rubella were retrieved from the Chinese Medical Code (fifth edition), Database of China Ancient Medicine, PubMed, the Cochrane Library, China National Knowledge Infrastructure, Chongqing VIP, Wanfang, Google Scholar, International Clinical Trial Registry Platform, and Chinese Clinical Trial Registry until 6 July 2022. Both quantitative and qualitative methods were applied to present the data collected. Results: The use of CM to control contagious pox-like viral diseases was traced back to ancient Chinese practice cited in Huangdi’s Internal Classic, where the pathogen was recorded nearly two thousand years back. There were 85 articles (36 RCTs, eight non-RCTs, one cohort study, and 40 case series) that met the inclusion criteria, of which 39 studies were for measles, 38 for varicella, and eight for rubella. Compared with Western medicine for contagious pox-like viral diseases, CM combined with Western medicine showed significant improvements in fever clearance time (mean difference, −1.42 days; 95% CI, −1.89 to −0.95; 10 RCTs), rash/pox extinction time (MD, −1.71 days; 95% CI, −2.65 to −0.76; six RCTs), and rash/pox scab time (MD, −1.57 days; 95% CI, −1.94 to −1.19; five RCTs). When compared with Western medicine, CM alone could reduce the time of rash/pox extinction and fever clearance. Chinese herbal formulas, including modified Yinqiao powder, modified Xijiao Dihaung decoction, modified Qingjie Toubiao decoction, and modified Shengma Gegen decoction, were frequently applied to treat pox-like viral diseases and also showed significant effects in shortening the time of fever clearance, rash/pox extinction, and rash/pox scabs. Compared with Western medicine (placental globulin) or no intervention, eight non-randomized trials and observational studies on the prevention of contagious pox-like viral diseases showed a significant preventive effect of Leiji powder among high-risk populations. Conclusion: Based on historical records and clinical studies of CM in managing contagious pox-like viral diseases, some botanical drugs could be an alternative approach for treating and preventing human monkeypox. Prospective, rigorous clinical trials are urgently needed to confirm the potential preventive and treatment effect of Chinese herbal formulas

    Alternating Current Electrohydrodynamic Printing of Microdroplets

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    This paper discusses the technology of orderly printing of microdroplets by means of electrohydrodynamic print (EHDP) with alternating current (AC). The AC electric field induces charges to reciprocate in the electrohydrodynamic charged jet and generates periodic alternation of electric field force, which facilitates the breakup of charged jets and injection of microdroplets. Microdroplets with a diameter of 100~300 μm can be printed with a frequency of 5~25 Hz via AC EHDP. Effects of process parameters on the microdroplet injection behaviors were investigated. A higher frequency of applied AC voltage led to a higher deposition frequency, but smaller diameters of printed droplets. Deposition frequency and droplet diameters increased with the increase of duty cycle and solution supply rate. AC pulse voltage has provided a novel way to study the control technology in EHDP, which would accelerate the application of inkjet printing in the field of micro/nanosystem production
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