ALL-ATOM MOLECULAR DYNAMICS SIMULATION OF SUBMICRON THICKNESS EHL OIL FILM

ABSTRACT All-atom molecular dynamics simulations of an elastohydrodynamic lubricating oil film have been performed to study the effect of the oil film thickness (large spatial scale; thickness: 430 nm, MD time: 25 ns) and the effect of pressure (long time scale; thickness: 10 nm, MD time: 50 ns, external pressure: 0.1 to 8.0 GPa). Fluid layers of n-hexane are confined between two solid Fe plates by a constant normal force. Traction simulations are performed by applying a relative sliding motion to the Fe plates. In a long spatial scale simulation, the mean traction coefficient was 0.03, which is comparable to the experimental value of 0.02. In a long time scale simulation, a transition of the traction behavior is observed around 0.5 GPa to 1.0 GPa which corresponds to a change from the viscoelastic region to the plastic-elastic region which have been experimentally observed. This phase transition is related to a suppressed fluctuation of the molecular motion. INTRODUCTION Machine elements in which large loads are transmitted such as a traction drive continuously variable transmission (CVT) work in the elastohydrodynamic lubrication (EHL) regime. The molecular dynamic behavior of the oil film under EHL is not well understood, since long trajectories of a ensembles of large number of fluid molecules are required to analyze the drastic phase transition induced by high pressur

Successful resection of liver metastasis detected by exacerbation of skin symptom in a patient with dermatomyositis accompanied by rectal cancer: a case report and literature review

Abstract Background Dermatomyositis (DM) is a rare syndrome that belongs to the group of idiopathic inflammatory myopathies. The association between DM and malignancy is well recognized, and the severity of DM symptoms has been linked to the progression of metastatic disease. Case presentation We report the case of a 42-year-old man that was diagnosed with dermatomyositis (DM) and rectal cancer. Proctectomy was performed, and DM symptoms were resolved postoperatively. One year and 9\ua0months after the surgery, liver metastasis occurred accompanied by the exacerbation of DM symptom. Partial resection of the liver was performed, and postoperative course was uneventful. DM symptoms improved postoperatively, and no evidence of cancer recurrence or DM symptoms was observed 2\ua0years after the second surgery. To date, few reports have described recurring cases of DM accompanied by colorectal cancer in detail. We reviewed four similar cases that were reported poor prognoses with treatment resistance. However, our case report demonstrates good long-term results with resection of metastatic lesion. Conclusions It is important to check the exacerbation of DM symptoms, as this symptom sometimes preceded cancer relapse during the follow-up of our patient with DM and colorectal cancer

Gravity sensing in plant and animal cells

Gravity determines shape of body tissue and affects the functions of life, both in plants and animals. The cellular response to gravity is an active process of mechanotransduction. Although plants and animals share some common mechanisms of gravity sensing in spite of their distant phylogenetic origin, each species has its own mechanism to sense and respond to gravity. In this review, we discuss current understanding regarding the mechanisms of cellular gravity sensing in plants and animals. Understanding gravisensing also contributes to life on Earth, e.g., understanding osteoporosis and muscle atrophy. Furthermore, in the current age of Mars exploration, understanding cellular responses to gravity will form the foundation of living in space

Decreased serum pyridoxal levels in schizophrenia : meta-analysis and Mendelian randomization analysis

Background: Alterations in one-carbon metabolism have been associated with schizophrenia, and vitamin B6 is one of the key components in this pathway. Methods: We first conducted a case–control study of serum pyridoxal levels and schizophrenia in a large Japanese cohort (n = 1276). Subsequently, we conducted a meta-analysis of association studies (n = 2125). Second, we investigated whether rs4654748, which was identified in a genome-wide association study as a vitamin B6-related single nucleotide polymorphism, was genetically implicated in patients with schizophrenia in the Japanese population (n = 10 689). Finally, we assessed the effect of serum pyridoxal levels on schizophrenia risk using a Mendelian randomization (MR) approach. Results: Serum pyridoxal levels were significantly lower in patients with schizophrenia than in controls, not only in our cohort, but also in the pooled data set of the meta-analysis of association studies (standardized mean difference –0.48, 95% confidence interval [CI] –0.57 to –0.39, p = 9.8 × 10–24). We failed to find a significant association between rs4654748 and schizophrenia. Furthermore, an MR analysis failed to find a causal relationship between pyridoxal levels and schizophrenia risk (odds ratio 0.99, 95% CI 0.65–1.51, p = 0.96). Limitations: Food consumption and medications may have affected serum pyridoxal levels in our cross-sectional study. Sample size, number of instrumental variables and substantial heterogeneity among patients with schizophrenia are limitations of an MR analysis. Conclusion: We found decreased serum pyridoxal levels in patients with schizophrenia in this observational study. However, we failed to obtain data supporting a causal relationship between pyridoxal levels and schizophrenia risk using the MR approach

Techniques of biliary drainage for acute cholecystitis: Tokyo Guidelines

The principal management of acute cholecystitis is early cholecystectomy. However, percutaneous transhepatic gallbladder drainage (PTGBD) may be preferable for patients with moderate (grade II) or severe (grade III) acute cholecystitis. For patients with moderate (grade II) disease, PTGBD should be applied only when they do not respond to conservative treatment. For patients with severe (grade III) disease, PTGBD is recommended with intensive care. Percutaneous transhepatic gallbladder aspiration (PTGBA) is a simple alternative drainage method with fewer complications; however, its clinical usefulness has been shown only by case-series studies. To clarify the clinical value of these drainage methods, proper randomized trials should be done. This article describes techniques of drainage for acute cholecystitis

Successful autologous stem cell transplantation for light chain proximal tubulopathy with severe kidney injury

Key Clinical Message Light chain proximal tubulopathy (LCPT) is a rare type of monoclonal gammopathy of renal significance. Clinicians should consider LCPT in the differential diagnosis of patients with renal or proximal tubular dysfunction with monoclonal gammopathy. They should confirm diagnosis by renal biopsy and initiate chemotherapy before disease progression

Effects of Anaerobically Digested Slurry on Meloidogyne incognita and Pratylenchus penetrans in Tomato and Radish Production

Since effective disposable way of anaerobically digested biogas slurry is expected, ADS was applied to soil to evaluate its effects on nematode damage. Damage index of tomato by root-knot nematode was significantly (<.05) lower and the growth better in pots applied with ADS (100 and 200 mg NH+4-N kg−1) than that in those with chemical fertilizer and control (no ADS). ADS was applied into radish cultivated fields infested with the root-lesion nematode: a single (100 kg NH+4-N ha−1) in 2007 and 2008 and multiple applications (25, 50, 25 kg NH+4-N ha−1 soil) in 2009. Damage to radish was 30% and 50% lower in ADS-treated fields than that in the control in 2007 and 2009, respectively, although not in 2008. These results suggest that application of ADS to fields might be feasible for mitigating nematode damage, but the rate and timing should be considered further for the best application way

Effects of Remimazolam and Propofol on Ca2+ Regulation by Ryanodine Receptor 1 with Malignant Hyperthermia Mutation

Background. We investigated the potential safety of remimazolam and propofol in malignant hyperthermia- (HM-) susceptible patients using ryanodine receptor 1- (RYR1-) expressing human embryonic kidney- (HEK-) 293 cells. Methods. We compared the enhanced responsiveness of HEK-293 cells expressing wild-type RYR1 with that of mutant RYR1 to caffeine following perfusion with remimazolam or propofol. Furthermore, we investigated whether RYR1 enhanced the responsiveness of cells to remimazolam or propofol and compared the median effective concentration (EC50; i.e., the concentration required to reach half-maximal activation) using an unpaired two-tailed t-test while a P<0.05 was considered significant. Results. Remimazolam and propofol did not promote the caffeine-induced increase in intracellular Ca2+ levels in HEK-293 cells expressing mutant RYR1 even with exposure to approximately 100-fold the clinically used concentration. In wild-type RYR1, EC50 values of remimazolam following refusion vs. nonperfusion were 2.86 mM vs. 2.75 mM (P=0.76) while for propofol perfusion vs. nonperfusion, they were 2.76 mM vs. 2.75 mM, respectively (P=0.83). In mutant RYR1, EC50 values of remimazolam refusion vs. nonperfusion were 1.58 mM vs. 1.71 mM, respectively (P=0.63) while for propofol perfusion vs. nonperfusion, they were 1.65 mM vs. 1.71 mM, respectively (P=0.73). Remimazolam and propofol increased intracellular Ca2+ levels in a concentration-dependent manner, but the effect was not enhanced by RYR1. EC50 values of remimazolam with non-RYR1 vs. wild-type RYR1 were 1.00 mM vs. 0.92 mM, respectively (P=0.91) while those of propofol were 1.09 mM vs. 1.05 mM, respectively (P=0.84). Conclusions. The increase in intracellular Ca2+ concentration caused by remimazolam or propofol was not considered an RYR1-mediated reaction. We conclude that remimazolam and propofol can be safely used as an anesthetic in MH-susceptible patients with RYR1-mutation without causing MH and may be safely substituted for an MH-triggering anesthetic when RYR1-mediated MH occurs

A small pancreatic hamartoma with an obstruction of the main pancreatic duct and avid FDG uptake mimicking a malignant pancreatic tumor: a systematic case review

Abstract Background Pancreatic hamartomas are extremely rare and may be misdiagnosed as malignant tumors. We report herein a case of a small, solid-type pancreatic hamartoma. Case presentation A 72-year-old female was incidentally detected pancreatic lesion by ultrasonography. Computed tomography and magnetic resonance imaging revealed a 2.0-cm solid lesion. The main pancreatic duct (MPD) was obstructed by the lesion in the head of the pancreas, and the upstream MPD was dilated. 18F-fluorodeoxyglucose (FDG) accumulated avidly in the lesion and increased in FDG intensity from the early to the delayed images. The histopathological studies confirmed the diagnosis of pancreatic hamartoma. Immunohistochemically, the cell membrane of the accessory glands and ducts showed homogeneous expression of glucose transporter type I and hexokinase II. Conclusion Pancreatic hamartomas causing dilatation of the MPD are extremely rare, and this appears to be the first case of a hamartoma to take up FDG avidly. It was a rare occurrence and should be noted that pancreatic hamartomas can cause an obstruction of the MPD and show avid FDG uptake, thereby mimicking malignant pancreatic tumors