Relaxation Behavior of Residual Stress on Deck-to-Rib Welded Joints by Fatigue Loading in an Orthotropic Bridge Deck

To accurately evaluate the influence of the actual tension and compression state and stress ratio at the deck-to-rib welding seam position on the fatigue life of a bridge deck, this paper establishes a coupled stress analysis model that considers the welding residual stress and vehicle stress. Taking the Jiangyin Bridge as an example, a qualitative analysis of the fatigue life under the vehicle load and residual stress field is carried out using the proposed method. A case analysis showed that when the residual tensile stress in the welding seam position is superimposed on the mainly tensile cyclic vehicle load stress, the longitudinal stress relaxation exceeds the peak vehicle load stress; significant longitudinal stress relaxation occurred, while the transverse stress relaxation is not significant. However, when the residual tensile stress is superimposed on the mainly compressive cyclic vehicle load stress, the relaxations of both the longitudinal and transverse stresses are not obvious. Compared with the stress state of the welding point under the action of only the vehicle stress, when the coupling effect of the residual stress and vehicle stress is considered, i.e., the loading condition, the fatigue stress state of the weld point has undergone an essential change under cyclic compressive stress, that is, the compressive stress state that does not require a fatigue check is changed to the tensile stress state. Although the fatigue state of the tensile stress cycle condition has not changed, the fatigue life is reduced by varying degrees under either the compressive or tensile condition

Surgical Management of Urolithiasis in Patients After Urinary Diversion

Objective: To present our experience in surgical management of urolithiasis in patients after urinary diversion. Patients and Methods: Twenty patients with urolithiasis after urinary diversion received intervention. Percutaneous nephrolithotomy, percutaneous based antegrade ureteroscopy with semi-rigid or flexible ureteroscope, transurethral reservoir lithotripsy, percutaneous pouch lithotripsy and open operation were performed in 8, 3, 2, 6, and 1 patients, respectively. The operative finding and complications were retrospectively collected and analyzed. Results: The mean stone size was 4.5±3.1 (range 1.5-11.2) cm. The mean operation time was 82.0±11.5 (range 55-120) min. Eighteen patients were rendered stone free with a clearance of 90%. Complications occurred in 3 patients (15%). Two patients (10%) had postoperative fever greater than 38.5°C, and one patient (5%) suffered urine extravasations from percutaneous tract. Conclusions: The percutaneous based procedures, including percutaneous nephrolithotomy, antegrade ureteroscopy with semi-rigid ureteroscope or flexible ureteroscope from percutaneous tract, and percutaneous pouch lithotripsy, provides a direct and safe access to the target stones in patients after urinary diversion, and with high stone free rate and minor complications. The surgical management of urolithiasis in patients after urinary diversion requires comprehensive evaluation and individualized consideration depending upon the urinary diversion type, stone location, stone burden, available resource and surgeon experience

Isospin dependence of projectile-like fragment production at intermediate energies

The cross sections of fragments produced in 140 $A$ MeV $^{40,48}$Ca + $^9$Be and $^{58,64}$Ni + $^9$Be reactions are calculated by the statistical abration-ablation(SAA) model and compared to the experimental results measured at the National Superconducting Cyclotron Laboratory (NSCL) at Michigan State University. The fragment isotopic and isotonic cross section distributions of $^{40}$Ca and $^{48}$Ca, $^{58}$Ni and $^{64}$Ni, $^{40}$Ca and $^{58}$Ni, and $^{48}$Ca and $^{64}$Ni are compared and the isospin dependence of the projectile fragmentation is studied. It is found that the isospin dependence decreases and disappears in the central collisions. The shapes of the fragment isotopic and isotonic cross section distributions are found to be very similar for symmetric projectile nuclei. The shapes of the fragment isotopic and isotonic distributions of different asymmetric projectiles produced in peripheral reactions are found very similar. The similarity of the distributions are related to the similar proton and neutron density distributions inside the nucleus in framework of the SAA model.Comment: 7 pages, 4 figures; to be published in Phys Rev

Effect of Thiazolidinedione Amide on Insulin Resistance, Creactive Protein and Endothelial Function in Young Women with Polycystic Ovary Syndrome

Purpose: To investigate the effect of thiazolidinedione amide (TZDA) treatment on high-sensitivity Creactive protein (hsCRP) levels and endothelial dysfunction in patients with polycystic ovary syndrome (PCOS).Methods: Twenty five women (mean age 24.7 ± 3.9 years; mean body mass index (BMI), 23.2 ± 4.0 kg/m2) with PCOS were treated with 15 μM TZDA daily for 12 months. Serum levels of testosterone, leutenizing hormone (LH), follicle stimulating hormone (FSH), sex hormone-binding globulin (SHBG), insulin and hsCRP were measured. BMI, hirsutism scores and insulin sensitivity indices were also calculated prior to and after TZDA treatment. Brachial artery responses to stimuli was used to measure arterial endothelium and smooth muscle function prior to and after the treatment.Results: TZDA treatment caused a significant (p < 0.05) decrease in serum testosterone from 93.1 ± 40.3 to 54.8 ± 19.5 ng/dl and fasting insulin concentration from 11.9 ± 6.8 to 9.23 ± 5.13 U/mL. Insulin resistance index significantly (p < 0.05) improved and hirsutism score decreased significantly from 11.6 ± 2.0 to 6.8 ± 2.0. BMI, waist circumference, serum total cholesterol, low-density lipoprotein (LDL)- cholesterol, FSH and LH levels remained almost unchanged. Twenty-four of the women reverted to regular menstrual cycles. SHBG levels showed a significant (p < 0.05) increase from 24.8 ± 9.5 to 49.1 ± 13.5 nmol/L after TZDA treatment. Serum hsCRP levels decreased (p < 0.05) from 0.25 ± 0.1 to 0.09 ± 0.02 mg/dL while endothelium-dependent vascular responses significantly improved (p < 0.05) following TZDA treatment (9.9 ± 3.9 vs 16.4 ± 5.1%).Conclusion: TZDA treatment improves insulin sensitivity, decreases androgen production and improves endothelial dysfunction in young women with PCOS.Keywords: Thiazolidinedione amide, Insulin sensitivity, Endothelial dysfunction, Polycystic ovary syndrom

Bilateral striatal necrosis due to homoplasmic mitochondrial 3697G\u3eA mutation presents with incomplete penetrance and sex bias

© 2019 The Authors. Molecular Genetics & Genomic Medicine published by Wiley Periodicals, Inc. Background: Heteroplasmic mitochondrial 3697G\u3eA mutation has been associated with leber hereditary optic neuropathy (LHON), mitochondrial encephalopathy, lactic acidosis and stroke-like episodes (MELAS), and LHON/MELAS overlap syndrome. However, homoplasmic m.3697G\u3eA mutation was only found in a family with Leigh syndrome, and the phenotype and pathogenicity of this homoplasmic mutation still need to be investigated in new patients. Methods: The clinical interviews were conducted in 12 individuals from a multiple-generation inherited family. Mutations were screened through exome next-generation sequencing and subsequently confirmed by PCR-restriction fragment length polymorphism. Mitochondrial complex activities and ATP production rate were measured by biochemical analysis. Results: The male offspring with bilateral striatal necrosis (BSN) were characterized by severe spastic dystonia and complete penetrance, while the female offspring presented with mild symptom and low penetrance. All offspring carried homoplasmic mutation of NC_012920.1: m.3697G\u3eA, p.(Gly131Ser). Biochemical analysis revealed an isolated defect of complex I, but the magnitude of the defect was higher in the male patients than that in the female ones. The ATP production rate also exhibited a similar pattern. However, no possible modifier genes on the X chromosome were identified. Conclusion: Homoplasmic m.3697G\u3eA mutation could be associated with BSN, which expanded the clinical spectrum of m.3697G\u3eA. Our preliminary investigations had not found the underlying modifiers to support the double hit hypothesis, while the high level of estrogens in the female patients might exert a potential compensatory effect on mutant cell metabolism