A new method to calculate and counterbalance the inertia force of slider-crank mechanisms in high-speed mechanical presses was put forward. By analyzing the kinematic characteristics of a center-located slider-crank mechanism whose crank rotates at a constant angular velocity, the kinematic parameters of the slide, connecting rod and crank were formulated approximately. On the basis of the results above, three inertia forces and the input moment in the mechanism during its idle running were investigated and formulated by dynamic analysis. A verification experiment was performed on a slider-crank mechanism at a high-speed press machine. The forces derived from the established formulas were compared respectively with those obtained by the ADAMS software and the classical method of connecting rod mass substitution. It was experimentally found that the proposed formulas have an improved performance over related earlier techniques. By use of these results, a 1000 kN 1250 rpm four-point high-speed press machine was designed and manufactured. The slide of this press is driven by four sets of slider-crank mechanisms with symmetrical layout and opposite rotation directions to counterbalance the horizontal inertia forces. Four eccentric counterbalance blocks were designed to counterbalance the vertical force after their mass and equivalent eccentric radius were formulated. The high-speed press machine designed by the proposed counterbalance method has worked with satisfactory performance and good dynamic balance for more than four years in practical production.

Objective: This study aimed to determine the efficacy of a medium-chain triglyceride ketogenic diet on patients with drug-resistant epilepsy over a period of 1 year and 8 months. Methods: Patients with refractory epilepsy on a medium-chain triglyceride ketogenic diet were prospectively enrolled. Their clinical condition and the effectiveness of the ketogenic diet were followed-up every month for 1 year. Adverse events and the reasons for discontinuing the diet were recorded. Results: Fifty-three patients (27 males and 26 females) were enrolled. At the end of the study, 21 patients remained on the diet, 14 of whom were followed-up for 1 year. Among the 53 patients, 22.6% had a more than 50% reduction in seizure frequency, and 16.9% became seizure-free. Conclusions: After a 1-year follow-up, the use of a medium-chain triglyceride ketogenic diet for patients with drug-resistant epilepsy was found to be a safe and effective therapy, and may be considered to bean alternative for patients with difficult-to-control seizures in children as well as young adults.
Epilepsy

OBJECTIVETo investigate the antitumor immune efficiency of mouse dendritic cells (mDCs) by using adenovirus-mediated tumor necrosis factor-alpha (AdV-TNF-alpha) gene transfer.

METHODSMDCs infected with AdV-TNF-alpha and AdV-pLpA (no gene insert) at 100 multiplicity of infection (MOI) were analyzed by RNase protection assay for their cytokine secretion. Mixed lymphocyte reactions were also performed to analyze their capacity for alloantigen-presentation. C57BL/6 mice were challenged with R3LL tumor cells (Lewis lung carcinoma line) 10 days after vaccination with different engineered DCs and regular DCs as well.

RESULTSCompared to AdV-pLpA and mock-infected DCs, AdV-TNF-alpha-infected DCs displayed up-regulated expression of alpha tumor necrosis factor, interleukin-12 (IL-12), interleukin-18 (IL-18) and granulocyte macrophage colony stimulation factor (GM-CSF), and indicated stronger allogeneic T cell proliferative responses. Furthermore, vaccination of mice with dendritic cell tumor necrosis factor-alpha (DCTNF-alpha) pulsed with Mut1 peptide induced more efficient tumor-specific cytotoxic T lymphocyte (CTL) cytotoxicity against R3LL tumor cells in vitro and with efficient antitumor immunity in vivo.

CONCLUSIONThis type of engineered DCs could be applied in clinical settings of DC-based cancer vaccines.

Adenoviridae ; genetics ; Animals ; Cytokines ; biosynthesis ; Cytotoxicity, Immunologic ; Dendritic Cells ; immunology ; Gene Transfer Techniques ; Genetic Therapy ; Lymphocyte Activation ; Mice ; Mice, Inbred C57BL ; Neoplasms, Experimental ; immunology ; therapy ; T-Lymphocytes, Cytotoxic ; immunology ; Tumor Necrosis Factor-alpha ; genetics

Aim To investigate the protective effect of naringin ( NA) on diabetic cardiomyopathy by activating the large conduction Ca2+ activated K4 channels (Maxi K ).Methods SD rats were fed with high-fat diet combined with intraperitoneal injection of strepto- zotocin (STZ) to establish a diabetic rat model.Then the rats were randomly divided into model group ( DCM) , naringin group ( NA) and naringin + Maxi K-specific inhibitor group ( NA + PAX) , with 8 rats in each group.Hats in treatment group received administration for 12 weeks and blood glucose was monitored regularly during experiments.The changes of cardiac function, morphology and fibrosis were detected after the treatment.The changes of cx and (3 subunits of Maxi K in heart were detected.Results Cardiac ultrasound results showed that NA could partially restore the cardiac function of rats.However, the cardiac protec tive function of NA was significantly reduced in diabetic rats after Maxi K was specifically blocked.Fibrosis analysis showed that the expression of collagen and fi- bronectin in rats could be decreased after NA treatment, which could be partially reversed by PAX.Western blot results showed that the expression of Maxi K a and p-subunit decreased in DCM group, but there was no significant change after NA treatment.Conclusions NA has a cardioprotective effect on diabetic rats by promoting the opening of the Maxi K channel on the membrane surface rather than increasing its expression.

COVID-19 has been prevalent for three years. The virulence of SARS-CoV-2 is weaken as it mutates continuously. However, elderly patients, especially those with underlying diseases, are still at high risk of developing severe infections. With the continuous study of the molecular structure and pathogenic mechanism of SARS-CoV-2, antiviral drugs for COVID-19 have been successively marketed, and these anti-SARS-CoV-2 drugs can effectively reduce the severe rate and mortality of elderly patients. This article reviews the mechanism, clinical medication regimens, drug interactions and adverse reactions of five small molecule antiviral drugs currently approved for marketing in China, so as to provide advice for the clinical rational use of anti-SARS-CoV-2 in the elderly.