The element diffusion from the Ti–6Al–4V titanium alloy to WC/Co carbide tools (vice versa) at temperatures up to 800
°C was examined. The morphology of the diffusion couples was detected by SEM. Dry ...turning tests on Ti–6Al–4V alloy were carried out with WC/Co carbide tools. Results showed that W and Co elements did not greatly penetrate into the Ti–6Al–4V alloy at 400
°C; while at 600
°C, W and Co diffused a long way into the Ti–6Al–4V alloy, and the penetrating depth reached 20
μm at 800
°C. The hardness near the interface of the diffusion couples is lower than those far away from the interface owing to element diffusions. The element diffusion from the Ti–6Al–4V to the WC/Co carbide tools (vice versa) through the tool–chip interface in machining processes leads to a composition change of the tool substrate, which may accelerate the tool wear.
Summary
Objectives
Intestinal tuberculosis (ITB) remains prevalent and a big health hazard in China. The aim of this study was to retrospectively analyse its clinico‐pathological features.
Methods
...Retrospective study of 85 consecutive ITB patients in two tertiary hospitals in East China. Relevant clinical, laboratory examination, radiological, endoscopic and histopathological features of ITB were recorded.
Results
The mean age was 37.3 ± 16.0 years; 56 patients (65.9%) were male. 67.1% had ITB secondary to pulmonary tuberculosis. The overall median length of hospital stay was 28 days and was significantly longer in patients with intestinal complications (P = 0.003) and malnutrition (P = 0.042). Abdominal pain (88.2%) and weight loss (75.3%) were the commonest symptoms. The positive rate of the purified protein derivative (PPD) test was 88.2%; of the T‐spot, 85.7%. Histopathology revealed caseating granuloma in 70.6% and caseating necrosis in 24.7% of patients. The most commonly affected sites were the ileocecal valve (56, 65.9%), terminal ileum (40, 47.1%) and caecum (33, 38.8%). Only 17 (20%) patients were initially diagnosed as ITB, the other 68 patients were misdiagnosed. Six patients with caecum tuberculosis were misdiagnosed as appendicitis, four of whom had improper surgical procedures followed by post‐operative intestinal fistulas; two died due to MODS.
Conclusions
Diagnosis of ITB is often misdirected and delayed, which may lead to inappropriate treatment and high mortality. High diagnostic suspicion is necessary for patients with unexplained abdominal complaints. Diagnosis is not easy but could benefit coexisting pulmonary tuberculosis, T‐spot, CT imaging, colonoscopy, pathological features, acid‐fast bacilli and response to anti‐tuberculosis therapy (ATT).
Objectifs
La tuberculose intestinale (TBI) demeure répandue et représente un danger important pour la santé en Chine. Le but de cette étude était d'analyser rétrospectivement ses caractéristiques clinico‐pathologiques.
Méthodes
Etude rétrospective de 85 patients consécutifs atteints de TBI dans deux hôpitaux tertiaires dans l'est de la Chine. Les caractéristiques cliniques, de laboratoire, radiologiques, endoscopiques et histopathologiques pertinentes pour la TBI ont été enregistrées.
Résultats
L’âge moyen était de 37,3 ± 16,0 ans; 56 patients (65,9%) étaient masculins. 67,1% avaient une TBI secondaire à une tuberculose pulmonaire. La durée médiane globale de l'hospitalisation était de 28 jours et était significativement plus longue chez les patients présentant des complications intestinales (p = 0,003) et la malnutrition (p = 0,042). Les symptômes les plus communs étaient la douleur abdominale (88,2%) et la perte de poids (75,3%). Le taux positif du test tuberculinique était de 88,2% et 85,7% pour le test T‐SPOT. L'histopathologie a révélé un granulome de caséification chez 70,6% et une nécrose de caséation chez 24,7% des patients. Les sites les plus fréquemment touchés étaient la valvule iléo‐colique (56 à 69,9%), l'iléon terminal (40 à 77,1%) et le cæcum (33 à 38,8 %). Seuls 17 (20%) des patients avaient été initialement diagnostiqués avec TBI, les 68 autres patients avaient été mal diagnostiqués. 6 patients avec une tuberculose cæcale avaient été diagnostiqués à tort comme une appendicite, 4 d'entre eux ayant subi une intervention chirurgicale inappropriée suivie de fistules intestinales postopératoires; 2 sont décédés suite au syndrome de dysfonction de multiples organes.
Conclusions
Le diagnostic de la TBI est souvent mal guidé et retardé, ce qui peut entraîner un traitement inapproprié et une mortalité élevée. Une suspicion diagnostique élevée est nécessaire chez les patients présentant des problèmes abdominaux inexpliqués. Le diagnostic doit tenir compte de la tuberculose pulmonaire coexistante, du test T‐SPOT, de la radiographie, de la coloscopie, des caractéristiques pathologiques, des bacilles acido‐résistants et de la réponse au traitement antituberculeux.
Although there is numerous evidence on the epidemiological risk factors for insulin resistance (IR)-related metabolic diseases, there is still insufficient evidence to explore the non-linear ...association of Atherogenic Index of Plasma (AIP) with IR. Therefore, we aimed to elucidate the non-linear relationship between AIP and IR and type 2 diabetes (T2D).
This cross-sectional study was conducted in the National Health and Nutrition Survey (NHANES) from 2009 to 2018. A total of 9,245 participants were included in the study. The AIP was calculated as log10 (triglycerides/high-density lipoprotein cholesterol). The outcome variables included IR and T2D defined by the 2013 American Diabetes Association guidelines. The weighted multivariate linear regression, weighted multivariate logistic regression, subgroup analysis, generalized additive model, smooth fitting curve and two-part logistic regression were adopted to reveal the relationship of AIP with IR and T2D.
After adjustment for age, gender, race, education level, smoking status, alcohol consumption, vigorous/moderate physical activity, body mass index, waist circumference and hypertension, we found that AIP was positively associated with fasting blood glucose (β = 0.08, 95% CI: 0.06, 0.10), glycosylated hemoglobin (β = 0.04, 95% CI: 0.39, 0.58), fasting serum insulin (β = 4.26, 95% CI: 3.73, 4.79), and homeostasis model assessment of insulin resistance (β = 0.22, 95% CI: 0.18, 0.25). Further studies found that AIP was associated with increased risk of IR (OR = 1.29, 95% CI: 1.26-1.32) and T2D (OR = 1.18, 95% CI: 1.15-1.22). However, the positive association between AIP and IR or T2D was more significant in female than in male (IR: P for interaction = 0.0135; T2D: P for interaction = 0.0024). A non-linear and inverse L-shaped association was found between AIP and IR, while a J-shaped association was found between AIP and T2D. In patients with - 0.47 < AIP < 0.45, increased AIP was significantly associated with increased risk of IR and T2D.
AIP showed an inverse L-shaped association with IR and a J-shaped association with T2D, indicating that AIP should be reduced to a certain level to prevent IR and T2D.
Background/Aims: the pathogenesis of sepsis-associated encephalopathy (SAE) is multifactorial, involving neurotransmitter alterations, inflammatory cytokines, oxidative damage, mitochondrial ...dysfunction, apoptosis, and other factors. Mitochondria are major producers of reactive oxygen species, resulting in cellular injury. Omi/HtrA2 is a proapoptotic mitochondrial serine protease involved in caspase-dependent cell death; it is translocated from mitochondria to the cytosol after an apoptotic insult. We previously found that UCF-101, a specific inhibitor of Omi/HtrA2, has neuroprotective effects on cerebral oxidative injury and cognitive impairment in septic rats. In this study, the mechanisms and molecular pathways underlying these effects were investigated. Methods: Male Sprague–Dawley rats were subjected to cecal ligation and puncture (CLP) or sham-operated laparotomy and were administered vehicle or UCF-101 (10 µmol/kg). The hippocampus was isolated for subsequent analysis. Omi/HtrA2 expression in the mitochondria or cytosol was evaluated by immunofluorescence or western blotting. Terminal deoxynucleotidyl transferase dUTP nick end labeling staining was utilized to evaluate levels of apoptosis, and western blotting was used to evaluate apoptosis-related proteins, such as cleaved caspase-3, caspase-9, and poly (ADP-ribose) polymerase (PARP). Tight junction expression was assessed by immunofluorescence and western blotting. Mitochondrial function, inflammatory cytokines, and oxidative stress were also assayed. In addition, a wet/dry method was used to evaluate brain edema and Evans blue extravasation was used to evaluate blood–brain barrier (BBB) integrity. Results: After CLP treatment, the hippocampus exhibited a mild increase in Omi/HtrA2 expression; cytosolic Omi/HtrA2 expression increased significantly, whereas mitochondrial Omi/HtrA2 expression was reduced, indicating that CLP-induced oxidative stress resulted in the translocation of Omi/HtrA2 from mitochondria to the cytosol. Hippocampal cleaved caspase-3, caspase-9, and PARP levels were significantly higher in animals treated with CLP than in sham-operated animals, while XIAP expression was lower. Treatment with UCF-101 prevented the mobilization of Omi/HtrA2 from mitochondria to the cytosol, attenuated XIAP degradation, and decreased cleaved caspase-3, caspase-9, and PARP expression as well as apoptosis. UCF-101 also reversed the decreased mitochondrial complex I, II, and III respiration and the reduced ATP caused by CLP. In addition, UCF-101 treatment resulted in a significant improvement in BBB integrity, as demonstrated by increased occludin, claudin-5, and zonula occludens 1 levels and reduced Evans blue extravasation. No significant effects of UCF-101 on brain edema were found. Inflammatory cytokines and oxidative stress were significantly higher in the CLP-treated group than in the sham-operated group. However, the inhibition of Omi/HtrA2 by UCF-101 significantly alleviated these responses. Conclusion: Our data indicated that Omi/ HtrA2 regulates a mitochondria-dependent apoptotic pathway in a murine model of septic encephalopathy. Inhibition of Omi/HtrA2 by UCF-101 leads to neuroprotection by inhibiting the cytosolic translocation of Omi/HtrA2 and antagonizing the caspase-dependent apoptosis pathway. Therapeutic interventions that inhibit Omi/HtrA2 translocation or protease activity may provide a novel method to treat SAE.
Short bowel syndrome (SBS) is featured by impaired nutrients and fluids absorption due to massive small intestine resection. Gut dysbiosis has been implicated in SBS, this study aimed to characterize ...the metagenomic and metabolomic profiles of SBS and identify potential therapeutic targets.
Fecal samples from SBS and Sham rats (
= 8 per group) were collected for high-throughput metagenomic sequencing. Fecal metabolomics was measured by untargeted liquid chromatography-mass spectrometry.
We found that the species-level α-diversity significantly decreased in SBS rats, accompanied by altered microbiome compositions. The beneficial anaerobes from Firmicutes and Bacteroidetes were depleted while microorganisms from
,
,
, and
were enriched in faces from SBS rats. LEfSe analysis identified 17 microbial species and 38 KEGG modules that were remarkably distinct between SBS and Sham rats. In total, 1,577 metabolites with known chemical identity were detected from all samples, among them, 276 metabolites were down-regulated and 224 metabolites were up-regulated in SBS group. The typical signatures of SBS fecal metabolome comprised reduced short-chain fatty acids and products of amino acid metabolism (indole derivatives and p-cresol), as well as altered bile acid spectrum. We revealed 215 robust associations between representative differentially abundant microbial species and metabolites, the species with the same changing trend tended to have a similar correlation with some certain metabolites.
The fecal microbiome and metabolome significantly altered in SBS. Our findings may lay the foundation for developing new strategies to facilitate intestinal adaptation in SBS patients.
In this study, a Ti(C,N)-based cermet material was prepared through vacuum sintering. The research also investigates how holding time and maximum sintering temperature influence the material ...microstructure and mechanical properties. X-ray diffraction (XRD), energy dispersive spectroscopy (EDS) were used to analyze the composition of the cermet. The microstructure of the cermet was analyzed and examined using a scanning electron microscope (SEM). A Vickers hardness tester was used to test the mechanical properties of the materials. As indicated by testing results, the hardness of the material decreases as the temperature of sintering increases, and its fracture toughness increases gradually as holding time increases. Ti(C,N)-based cermet manifested the optimal mechanical properties when sintering was conducted under 1400 °C with 80 min of holding time. Moreover, the material microstructure is significantly affected by the sintering process. The grain size of Ti(C,N) cermets increases as the sintering temperature increases. The microstructure tends to be uniform and the complete core-rim structures are established as the holding time increases.
Cutting fluids are the most effective method to lower the cutting temperature and decrease the cutting tool wear. At the same time, the cutting fluids influence the corrosion resistance property of ...the machined surface. In this study, chlorinated paraffin (CP), which is a common additive in the cutting fluid, was selected as the research objective to study its corrosion resistance property. The passivation effect of CP with different concentrations on the machined surface of stainless steel was studied. Electrochemical measurements and surface morphology investigation were used to characterize the passivation effect of CP with different concentrations. The test results showed that the corrosion resistance of stainless steel in the cutting fluid was enhanced with the increase in CP additive. This reason is that the charge transfer resistance increases and the corrosion current density decreases with the increase in CP additive. The X-ray photoelectron spectroscopy (XPS) results show that the proportion of metal oxides on the processed surface of the stainless steel sample was increased from 20.4% to 22.0%, 32.9%, 26.6%, and 31.1% after adding 1 mL, 2 mL, 4 mL and 6 mL CP in the cutting fluid with a total volume of 500 mL, respectively. The oxidation reaction between CP and the stainless steel sample resulted in an increase in metal oxides proportion, which prevented the stainless steel sample from corrosion in cutting fluid.
Summary Background & aims Parenteral nutrition-associated liver disease (PNALD) complicates the treatment of patients with short bowel syndrome (SBS). Some studies have shown omega-3 polyunsaturated ...fatty acids (ω-3 PUFAs) have favorable effects in treating PNALD in children. We, therefore, investigate the effects of ω-3 PUFAs supplemented intravenous lipid emulsion (ILE) on PNALD in adults. Methods We performed an open-labeled study of a ω-3 PUFAs based ILE in 15 adults with SBS who developed cholestasis while receiving soybean oil-based ILE. Liver biopsies were performed before and after the initiation of ω-3 PUFAs to confirm the presence and improvement of cholestasis. Blood samples were collected every week for analysis of fatty acid composition and liver function. Results 12 of the 15 patients had their direct bilirubin normalized within 4 weeks and our data demonstrated a significant decrease in both DB ( P ≤ 0.001) and TB ( P ≤ 0.001) after 4 weeks compared to baseline. There were ameliorations of liver function and fatty acid patterns in all patients and serial liver biopsy specimens showed progressive histologic improvement. Conclusions Parenteral ω-3 PUFAs supplemented fat emulsions are safe and effective in the treatment of PNALD in adults.
It has already been proved that the Neuber method overestimates the notch root stresses and strains and the equivalent strain energy density（ESED） method underestimates those,that is,the upper limit ...and lower limit can be obtained by the above two methods.On the basis of the analysis of results of notch root subjected to biaxial loading,a modified calculation method is proposed based on Neuber method in order to make up it’s shortage.Meanwhile,in the case of plastic stage,the effect of the material constants of elastic modulus,yield stress and poisson’s ratio on the stresses and strains should be considered and the results calculated by modified method should locate between those by Neuber method and the equivalent strain energy density method.Taking the LD5 notch sample as an example,the notch root stresses and strains are calculated.Finally the calculation results using modified method are validated with those by the finite element method.
PDF
