Linear Friction Welding of an AZ91 Magnesium Alloy and the Effect of Ca Additions on the Weld Characteristics

Solid-state welding offers distinct advantages for joining reactive materials, such as magnesium (Mg) and its alloys. This study investigates the effect of linear friction welding (LFW) on the microstructure and mechanical properties of cast AZ91 (Mg–9Al–1Zn) and AZ91–2Ca alloys, which (to the best knowledge of the authors) has not been reported in the literature. Using the same set of LFW process parameters, similar alloy joints—namely, AZ91/AZ91 and AZ91–2Ca/AZ91–2Ca—were manufactured and found to exhibit integral bonding at the interface without defects, such as porosity, inclusions, and/or cracking. Microstructural examination of the AZ91/AZ91 joint revealed dissolution of the Al-rich second phase in the weld zone, while the Mn containing phases remained and were refined. In the AZ91–2Ca/AZ91–2Ca joint, the weld zone retained Ca- and Mn-rich phases, which were also refined due to the LFW process. In both joint types, extensive recrystallization occurred during LFW, as evidenced by the refinement of the grains from ~1000 µm in the base materials to roughly 2–6 µm in the weld zone. These microstructural changes in the AZ91/AZ91 and AZ91–2Ca/AZ91–2Ca joints increased the hardness in the weld zone by 32%. The use of digital image correlation for strain mapping along the sample gage length during tensile testing revealed that the local strains were about 50% lower in the weld zone relative to the AZ91 and AZ91–2Ca base materials. This points to the higher strength of the weld zone in the AZ91/AZ91 and AZ91–2Ca/AZ91–2Ca joints due to the fine grain size, second phase refinement, and strong basal texture. Final fracture during tensile loading of both joints occurred in the base materials.     

A rare form of urinary bladder cancer metastasis to lung

Sixty-seven year old male patient has attended with cough and sputum complaint. He had been operated because of transitional cell urinary bladder carcinoma four years ago. He had previous medical history of pulmonary tuberculosis 27 years ago. In chest X-ray, multiple cavitary appearances were present. In computerized tomography (CT) of the thorax, bilateral multiple cavities were seen. Sputum smear examinations for acido resistant bacilli (ARB) were negative for nine times. CT guided fine needle aspiration biopsy was performed and he was diagnosed as "pulmonary metastasis of transitional cell urinary bladder cancer". This patient is presented because of the interesting radiological appearance and rare presentation of the case.     

Treatment results for acetabulum fractures using the modified Stoppa approach

Objectives

The aim of this study was to evaluate the clinical and radiological results of the surgical treatment of acetabular fractures using modified Stoppa approach.

The alteration of retinal nerve fibre layer thickness with repetitive transcranial magnetic stimulation in patients with treatment resistant major depression

Objective: The nerves and axons of the retinal nerve fibre layer (RNFL) are similar to those in the brain and therefore retina is considered as the extension of the brain. We aimed to evaluate the RNFL thickness in the treatment-resistant major depressive patients before and after repetitive transcranial magnetic stimulation (rTMS) treatment and at least 6 months later after rTMS treatment using optical coherence tomography (OCT).

Methods: Thirty patients with treatment resistant major depression and 24 healthy controls were included in the study. rTMS was applied to the left dorsolateral prefrontal cortex (DLPFC) of the patients.

Results: rTMS was initiated in 28 patients. OCT assessments were performed in 24 patients at baseline and after rTMS treatment and in 19 patients at least sixth months after the rTMS treatment. We found significant increase in RNFL thickness compared with controls at the baseline and further increase in RNFL thickness after rTMS treatment. Although there was a decreasing trend in RNFL thickness 6?months after rTMS treatment, 6?months later RNFL thickness was still higher compared with controls.

Conclusions: RNFL thickness is increased in treatment resistant major depression and rTMS over the left DLPFC further increases RNFL thickness in treatment resistant major depressive patients.     

Concurrent assay for four bacterial species including alloiococcus otitidis in middle ear, nasopharynx and tonsils of children with otitis media with effusion: a preliminary report

Objectives

To detect the prevalences of Alloiococcus otitidis, as well as Haemophilus influenzae, Streptococcus pneumoniae, and Moraxella catarrhalis in children with chronic otitis media with effusion (OME) and to simultaneously investigate the colonization of these bacteria in the nasopharynx and palatine tonsils of these patients.

Methods

The study included 34 pediatric patients with OME, and 15 controls without OME. In the study group, A. otitidis, H. influenzae, S. pneumoniae, and M. catarrhalis were investigated in the samples obtained from middle ear effusions (MEE), nasopharyngeal swabs (NPS) and tonsillar swabs (TS), using multiplex polymerase chain reaction (PCR) and conventional culture methods. Only the samples obtained from NPS and TS were studied with the same techniques in the control group.

Results

A. otitidis was isolated only in MEE and only with multiplex PCR method. A. otitidis, S. pneumoniae, M. catarrhalis, H. influenzae were identified in 35%, 8.8%, 8.8%, and 2.9%, respectively, in 34 MEE. A. otitidis was not isolated in NPS or TS of the study and the control groups.

Conclusion

The prevalence of A.otitidis is high in children with OME and A.otitidis doesn''t colonize in the nasopharynx or tonsil.     

Executive dysfunction in Turkish children at high risk for schizophrenia

Objective  To explore different aspects of executive function (i.e. sequencing, set shifting and mental flexibility) in children who are at high risk for schizophrenia by comparing them with normal controls. Method  The high risk (HR) group consisted of 30 children whose parents were diagnosed as schizophrenia. As the control group (CG) 30 children, whose parents did not meet any DSM IV diagnostic criteria for any psychiatric disorder, participated. They were age and sex matched with the HR group. For the evaluation of different domains of cognitive functions Wechsler intelligence scale for children-revised (WISC-R), and a group of neuropsychological tests, including Trail Making A-B Tests, Color Form Test, and Progressive Figures Test were administered. Behavioral problems were assessed using Hacettepe Adjustment Scale. Results  The subjects in the high risk group had significantly lower scores on Trail Making A-B, Color Form, Progressive Figures Tests, as well as subtests and scores of WISC-R (Information, Comprehension, Similarities, Picture Completion, Block Design, Object Assembly and Coding subtests, Verbal, Performance and Full Scale IQ scores). There is no significant difference between the two groups in the frequency and severity of behavioral problems. Conclusion  Children of parents with schizophrenia displayed significantly greater number of difficulties in several areas of executive function, such as sequencing, set shifting, and mental flexibility, when compared to their controls.     

Anti-CCP antibodies in rheumatoid arthritis and psoriatic arthritis

Our aim is to assess the prevalence and associated clinical features of anti-CCP (cyclic citrullinated peptide) antibodies for RF (rheumatoid factor)-positive and RF-negative rheumatoid arthritis (RA) and psoriatic arthritis (PsA). In a prospective, cross-sectional, multi-centre study, we determined the titres of anti-CCP antibodies in 208 RA patients (129 RF-positive, 79 RF-negative), 56 PsA patients and 39 healthy controls (HC). Clinical parameters including disease activity (disease activity score 28-DAS28), physical disability (health assessment questionnaire-HAQ), functional capacity (functional class) and radiological erosions were investigated in patients with RA. In PsA patients, clinical and radiological features were determined. Anti-CCP2 antibodies were measured using a second-generation anti-CCP enzyme-linked immunosorbent assay (Euro-Diagnostica, Netherlands). One-hundred four of 129 RF-positive RA (81%), 16 of 79 RF-negative RA (20%), seven of 56 PsA patients (12.5%) and none of the HC had anti-CCP antibodies. RA patients with anti-CCP antibodies had significantly higher disease activity, greater loss of function and more frequent erosive disease than anti-CCP antibody-negative group. In subgroup analysis, anti-CCP antibodies in RF-negative patients were also associated with erosive disease. All PsA patients with anti-CCP antibodies had symmetric arthritis with higher number of swollen joints. The prevalence of anti-CCP antibodies in RF-positive RA patients was significantly higher than in RF-negative RA and PsA patients. Anti-CCP antibodies were also associated with erosive disease in RF-negative RA patients. Both anti-CCP and RF tests were negative in 30% of the patients. Anti-CCP positivity was a frequent finding in PsA and associated with symmetrical polyarthritis.     

Ultrasound-guided versus 'blind' intraparotid injections of botulinum toxin-A for the treatment of sialorrhoea in patients with Parkinson's disease

OBJECTIVE: To investigate the efficacy and safety of intraparotid botulinum toxin-A (BTX-A) injections into parotid gland using ultrasound-guided versus nonguided techniques for the treatment of sialorrhoea in patients with Parkinson's disease (PD). METHODS: 15 patients with PD and sialorrhoea were included and divided into two groups. Group A patients (n=8) were injected with BTX-A using ultrasound guidance. Group B patients (n=7) were injected with BTX-A without ultrasound guidance. Saliva secretion was assessed quantitatively at baseline and at weeks 1, 4, and 12. Patients and/or caregivers also assessed the saliva secretion using visual analog scale (VAS). RESULTS: All patients except one reported subjective improvement in sialorrhoea at the first week. Group A patients showed significantly higher rate of saliva reduction at the first week, whereas in Group B the reduction was not statistically significant from baseline at the first week (P>0.05). Comparisons of quantitative saliva assessments at each follow-up visit also showed that ultrasound-guided injections were superior to blind injections for saliva reduction. VAS scores showed an improvement in the mean rate of saliva secretion in each group at first week (P<0.05). Two patients suffered from dry mouth in mild severity lasting 1 month. CONCLUSION: Intraparotid BTX-A injections using ultrasound guidance may be an effective, easy, and safe treatment for parkinsonian sialorrhoea.