Dynamics and stability of milling process Zhao, M.X.; Balachandran, B.
International journal of solids and structures,
03/2001, Letnik:
38, Številka:
10
Journal Article, Conference Proceeding
Recenzirano
Numerical and experimental investigations conducted into the dynamics and stability of a range of milling operations are presented in this article. A unified mechanics based model developed to study ...workpiece–tool system dynamics is used for the numerical studies. This model, which allows for both regenerative effects and loss of contact effects, can be used for studying partial-immersion, high-immersion, and slotting operations. Loss of stability of periodic motions associated with milling operations is assessed by using Poincaré sections, and the numerical predictions of stable and unstable motions are found to compare well with corresponding experimental data. Bifurcations experienced by the periodic motions with respect to parameters such as axial depth of cut are numerically examined and discussed. The sensitivity of dynamics to tooth passing period, feed rate, and feed direction is also discussed.
Abstract Visceral hyperalgesia is a multifactorial gastrointestinal disorder which featured with alterations of abdominal motility and/or gut sensitivity, and is believed to be triggered by ...environmental stressor or psychological factors. However, its etiology remains incompletely understood. In this study, we aimed to investigate whether nerve growth factor (NGF)-mediated neuronal plasticity is involved in neonatal maternal separation (NMS)-induced visceral hypersensitivity in adult rats, and whether NGF antagonist can attenuate or block such development. In our experiments, animals subjected to NMS were developed with visceral hyperalgesia at age of 8 weeks. The threshold for visceral pain among these NMS rats was remarkably lowered than that of the normal handling (NH) rats; however, the expression levels of NGF, c-fos , calcitonin gene-related peptide (CGRP), Substance P, and tyrosine kinases A (TrkA) were notably elevated in lumbosacral spinal cord and/or dorsal root ganglion (DRG) when comparing to those of the NH rats. Further, as intra-peritoneal administration of NGF (10 μl at 1 μg/kg/day) was given to NH rats during neonatal period, effects that comparable to NMS induction were observed in the adulthood. In contrast, when NMS rats were treated with NGF antagonist K252a (10 μl/day from postnatal days 2–14), which acts against tyrosine kinases, the neonatal stress-induced down-shifted visceral pain threshold was restored and neuronal activation, specifically NGF and neuropeptide production, was attenuated. In conclusion, our data strongly suggest that NGF triggers neuronal plasticity and plays a crucial role in NMS-induced visceral hypersensitivity in which NGF antagonism provides positive inhibition via blocking the tyrosine phosphorylation of TrkA.
Physical activity is beneficial for many aspects of health but is associated with a risk of injury. Studies that assess causal risk factors of injury and reinjury provide valuable information to help ...develop and improve injury prevention programs. However, the underlying assumptions of analytical approaches often used to estimate causal factors in injury and subsequent injury research are often violated. This means that ineffective or even harmful interventions could be proposed because the underlying analyses produced unreliable or invalid causal effect estimates. We describe an adapted version of the multistate framework multistate framework for the analysis of subsequent injury in sport (M‐FASIS) that makes investigator choices more transparent with respect to outcome and healing time. In addition, M‐FASIS incorporates all previous sport injury analytical frameworks and accounts for injuries or conditions that heal or do not heal to 100%, acute and overuse injuries, illnesses, and competing event outcomes.
Lacunes are associated with cognitive impairment. We sought to identify strategic lacune locations associated with mild cognitive impairment (MCI) and subtypes of MCI among older adults, and further ...to examine the role of white matter hyperintensities and perivascular spaces in the association.
This population-based cross-sectional study included 1230 dementia-free participants in the brain magnetic resonance imaging substudy (2018-2020) in MIND-China (Multimodal Interventions to Delay Dementia and Disability in Rural China). Lacunes were visually identified in frontal lobe, parieto-occipital lobe, temporal lobe, insula, basal ganglia, thalamus, cerebellum, and brainstem. MCI, amnestic MCI (aMCI), and nonamnestic MCI (naMCI) were defined following the Petersen's criteria. Data were analyzed using logistic regression models.
Of the 1230 participants (age, ≥60 years; mean age, 69.40; SD, 4.30 years; 58.5% women), lacunes were detected in 357 people and MCI was defined in 286 individuals, including 243 with aMCI and 43 with naMCI. Lacunes in the supratentorial area, internal capsula, putamen/pallidum, and insula was significantly associated with increased odds ratio of MCI (multivariable-adjusted odds ratio ranged 1.40-3.21;
<0.05) and aMCI (multivariable-adjusted odds ratio ranged 1.46-3.36;
<0.05), whereas lacunes in the infratentorial area and brainstem were significantly associated with naMCI (multivariable-adjusted odds ratio ranged 2.68-3.46;
<0.01). Furthermore, the associations of lacunes in insula and internal capsula with MCI and aMCI, as well as the associations of lacunes in infratentorial area and brainstem with naMCI were present independent of white matter hyperintensities volume and perivascular spaces number.
Lacunes in the internal capsula, putamen/pallidum, insula, and brainstem may represent the strategic lacunes that are independently associated with MCI, aMCI, or naMCI in Chinese older adults.
URL: https://www.chictr.org.cn; Unique identifier: ChiCTR1800017758.
In this study, we used a computational fluid dynamics (CFD)–discrete element method (DEM) model to analyze the triggering of sand movement below an offshore pipeline. The advantage of this CFD–DEM ...model is that it considers the motion and force applied to every individual particle, thereby facilitating detailed simulations of seepage flow and the breakdown of the water–sand mixture beneath the pipeline. The simulation results were similar to previous experimental studies, which showed that scouring occurs after the driving pressure beneath the pipe generates a floating gradient in the sand layer near the wake. Furthermore, the computed critical current velocity that leads to the onset of scour was in reasonable agreement with the observational data. Thus, we consider that CFD–DEM is a promising numerical tool for future investigations of the mechanism that underlies the onset of scour.
Chimeric antigen receptor (CAR)-engineered T cell therapies have been recognized as powerful strategies in cancer immunotherapy; however, the clinical application of CAR-T is currently constrained by ...severe adverse effects in patients, caused by excessive cytotoxic activity and poor T cell control. Herein, we harnessed a dietary molecule resveratrol (RES)-responsive transactivator and a transrepressor to develop a repressible transgene expression (RES
) device and an inducible transgene expression (RES
) device, respectively. After optimization, these tools enabled the control of CAR expression and CAR-mediated antitumor function in engineered human cells. We demonstrated that a resveratrol-repressible CAR expression (RES
-CAR) device can effectively inhibit T cell activation upon resveratrol administration in primary T cells and a xenograft tumor mouse model. Additionally, we exhibit how a resveratrol-inducible CAR expression (RES
-CAR) device can achieve fine-tuned and reversible control over T cell activation via a resveratrol-titratable mechanism. Furthermore, our results revealed that the presence of RES can activate RES
-CAR T cells with strong anticancer cytotoxicity against cells in vitro and in vivo. Our study demonstrates the utility of RES
and RES
devices as effective tools for transgene expression and illustrates the potential of RES
-CAR and RES
-CAR devices to enhance patient safety in precision cancer immunotherapies.
To build bridges between anti-α enolase antibody (anti-enolase 1 antibody, anti-ENO1 antibody) and common clinical and laboratory characteristics of systemic lupus erythematosus (SLE) and to analyze ...the role of anti-ENO1 antibody in the evaluation of SLE disease activity.
The SLE patients with retinopathy and without retinopathy were enrolled in the study, as well as healthy individuals whose gender and age matched with those of the SLE patients. Serum anti-ENO1 antibodies were measured using enzyme-linked immunosorbent assay (ELISA), presenting as intra-group positive rate and arbitrary units (AU) value. Clinical and laboratory data were obtained from medical records.
The SLE retinopathy patients represented various fundus abnormalities. Ranked by percentage, the top three retinopathies were retinal hemorrhage (14/32, 43.75%), cotton-wool spots (8/32, 25.00%) and retinal vein occlusion (3/32, 9.38%). Among the 32 SLE retinopathy patients, 13 (40.63%) suffered from two or more fundus abnormalities. The positi
SUMMARY
IgA deposition in glomerular mesangium and the interaction with mesangial cells may well be the final common pathway to IgA nephropathy (IgAN). Altered hinge‐region O‐glycosylation of IgA1 ...from patients with IgAN may predispose to mesangial deposition and activation of the mesangial cell (MC) by IgA1, via a novel IgA1 receptor, and may be a key event in the pathogensis of IgAN. The aim of this study was to investigate the binding capacity and biological effects of IgA1, from both patients with IgAN and healthy controls, on human mesangial cells (HMC). Serum IgA1 was isolated with jacalin affinity chromatography, heated to aggregated form (aIgA1) and labelled with 125I. Binding capacity of aIgA1 in vitro to cultured primary HMC was evaluated by a radioligand binding assay and the specificity of binding was determined by a competitive inhibition assay. Intracellular calcium release was studied by confocal analysis and phosphorylation of extracellular signal‐regulated kinase (ERK) was determined by Western blot analysis. Change of cell cycles was demonstrated by flow cytometry and HMC proliferation was evaluated by direct cell count. Expression of TGF‐β mRNA and production of supernatant fibronectin were tested by RT‐PCR and indirect competitive ELISA, respectively. aIgA1 from both the patients with IgAN and normal controls bound to HMC in a dose‐dependent, saturable manner, and was saturated at approximately 500 pmoles per 0·5 ml of aIgA1. aIgA1 from patients with IgAN, however, bound to HMC at a higher speed and Scatchard analysis revealed a Kd of (8·89 ± 2·1) × 10−8mversus (4·3 ± 1·2) × 10−7m for aIgA1 from healthy controls (P = 0·026).The binding was specific because it was only inhibited by unlabelled Mono‐IgA1 (mIgA1) and not by serum albumin or IgG. aIgA1 from patients with IgAN could induce release of intracellular calcium, phosphorylation of ERK, DNA synthesis, proliferation of HMC, expression of TGF‐βmRNA and secretion of fibronectin in HMC in a similar time‐dependent manner as aIgA1 from healthy controls, but the effects were much stronger and the durations were much longer (P < 0·05, respectively). We conclude that aIgA1 from patients with IgAN has a higher binding capacity to HMC and stronger biological effects than aIgA1 from healthy controls. This suggests that direct interaction between IgA1 and HMC and subsequential pathophysiological responses may play an important role in the pathogenesis for IgAN.
Bladder cancer is the most frequent tumor of the urinary system. Despite variety of new treatment options, bladder cancer remains a main global medical problem. Our purpose was to explore the ...potential molecular and therapeutic targets of bladder cancer diagnosis.
The qRT-PCR was used to assess the expression of miR-20a in tissues and cell lines. Counting Cell Kit-8 (CCK-8) assay was carried out to evaluate cell proliferation. Cell migration was calculated using the transwell assay.
The expression of miR-20a increased and PDCD4 decreased in bladder cancer tissues compared with normal tissues. Overexpression of miR-20a promoted T24 cell proliferation and migration, while miR-20a inhibitor suppressed cell proliferation and migration. MiR-20a targeted PDCD4 to regulate its expression in T24 cells. MiR-20a is inversely related to PDCD4 and PTENPL in bladder cancer tissues. Upregulation of PDCD4 suppressed T24 cell proliferation and migration.
The PTENP1/miR-20a/PTEN axis was involved in the progression of bladder cancer. Our study investigated the function of miR-20a in bladder cancer and provided new insights into the treatment of bladder cancer.
Unfortunately, there are errors that occurred in the name and manufacture of the growth hormone (GH) received by the patients in the GH group on page two, Table 1 and figure 1 on page three.
PDF
