Investigation of Load Bearing Capacities of Grouted Rock Bolts with New Auxetic Head Designs

Within this study, new bolt heads were designed to be able to expand in drill holes as the load applied on the bolt shank increases. The heads of newly designed rock bolts include a conic part and split rings encircling them. To determine load bearing capacities of new rock bolts with varying angles of the conic parts and expansion properties, a series of deformation controlled pull-out tests were carried out by using bolt samples grouted in rock blocks. In addition to the experimental studies, numerical modelling analyses were performed to better understand the support properties of newly designed rock bolts. Because of a negative Poisson’s ratio effect supplied by the head part expansion with the tension of the shank, new bolt heads are suggested to be defined as auxetic. According to the results of this study, the new head designs significantly improve the load bearing and energy absorption capacities of grouted rock bolts

Hand hygiene compliance of health care workers in a neonatal intensive care unit: a prospective observation study

Background: We aimed to determine hand hygiene (HH) compliance of the healthcare workers (HCW’s) and evaluate if there is an epidemiological relation between the microorganisms isolated from the hands of HCWs and patients clinical materials in the neonatal intensive care unit (NICU).Methods: HH compliance was observed in two unannounced phases in March and in August within the scope of 5 indications determined by WHO. Between two phases personnel was trained to improve HH by educational sessions and introduction of Semmelweis system hand in scan (HIS, Sysmex) in the unit.  A total of 22 nurses, 11 physicians and 5 staff was working in the NICU. Hand samples taken from HCW by glove juice method were inoculated quantitatively in culture plates and colonies were identified by MALDI-TOF MS. Epidemiological relation between clinical isolates and hand samples was investigated with arbitrary primed PCR.Results: Although overall compliance remained only 50%, a significant increase in compliance was detected in August prior to aseptic procedures and after contact with patients and body fluids. Alcohol scrub was preferred as 60.4% in March and 75.2% in August. HH efficacy reached to 72% by implementing HIS. During this period, 10.7% of 607 patient’s samples revealed clinically significant growth. Potential pathogens were isolated in 5.2% of 144 hand samples, but any epidemiological correlation with patient isolates was detected.Conclusions: HH compliance observations should be done at regular intervals and current technology could be utilized in trainings to overcome hospital related infections

Heavy metal profiles of agricultural soils in Sakarya, Turkey

Sakarya is famous for cucurbit productions in Turkey and cucurbits can grow as big as 560 kg of weight per fruit in its agricultural areas. There is no or limited information about contaminant levels and profiles of the agricultural fields in Sakarya. The purpose of this study is to investigate the levels of polycyclic aromatic hydrocarbons (PAHs) (naphthalene, phenanthrene, pyrene, and fluoranthene) and heavy metal (As, Cd, Cu, Cr, Ni, Pb, Zn) concentrations of the selected fields. Total 33 soil samples were collected from 12 counties of Sakarya where both cucurbits have been produced and organochlorine pesticides have been applied to the fields for more than 30 y during the historical plantation periods. Heavy metal and PAH contents in the soil samples were measured by an Inductively Coupled Plasma Emission Spectroscopy and a Gas Chromatography-Mass Spectrometry. The highest phenanthrene, pyrene, and fluoranthene concentrations were measured as 63.50 ng/g, 134.34 ng/g, 140.0 ng/g, respectively in the soil samples from Geyve County. Cu, Ni, and Cr concentrations were measured as 108.2 mg/kg, 219.9 mg/kg, and 173.1 mg/kg, respectively in Geyve's samples which were also the highest and 2-7 times more than the limit values given in the Turkish Soil Pollution Control Regulation. Precautions need to be taken for Sakarya's agricultural fields which are an important milestone of Turkey's cucurbit and fruit productions since the contaminants can be accumulated in the fruits and edible parts of the plants

The Relationship Between Structural Measurements of the Corpus Callosum and Disability in Patients with Multiple Sclerosis

Abstract Purpose: The corpus callosum (CC) is the largest commissural pathway connecting both cerebral cortices. Materials and Methods: Forty MS patients and 40 healthy controls were included in this research, which was planned as a prospective and case-control study. Disability was evaluated with the expanded disability rating scale. The number of attacks, disease duration, and MS disease subtype were determined. CC genu, truncus, splenium, and anterior-posterior diameters were measured in brain magnetic resonance imaging TSE/T1 sagittal sequence, and the corpus callosum index (CCI) was calculated using these measurements. The relationship of all these parameters with each other was examined. Results: There were 40 patients (29 females, 11 males) with a mean age of 36.47±11.14 years in the study. In the CC morphometric measurements of the patients, the genu (mean±SD) was 11.46±1.60, truncus (median, min-max) 5.29 (4.6-6.52), splenium 11.09±1.82, anterior-posterior diameter 65.20 (63.64-67.22) and CCI was determined as 0.43±0.05 millimeters. The anterior-posterior diameter was smaller in MS patients (p=0.022). A negative correlation was determined between CCI and disease duration, the number of attacks, and EDSS scores in MS patients (p<0.05; r=-0.319; r=-0.316; r=-0.349; respectively). In the severe disability group, CC splenium, AP diameter, and CCI were lower (p=0.007; p=0.020; p=0.046; respectively). Conclusion: In MS disease, the CC structure is affected, as in many central nervous system regions. The study results revealed that changes in the corpus callosum could be examined as a parameter in evaluating the disease process in MS patients. Keywords: Multiple sclerosis; corpus callosum; morphometry; disability

Mechanotransduction is a context-dependent activator of TGF-β signaling in mesenchymal stem cells

We previously found that surface topographies induce the expression of the Scxa gene, encoding Scleraxis in tenocytes. Because Scxa is a TGF-β responsive gene, we investigated the link between mechanotransduction and TGF-β signaling. We discovered that mesenchymal stem cells exposed to both micro-topographies and TGF-β2 display synergistic induction of SMAD phosphorylation and transcription of the TGF-β target genes SCX, a-SMA, and SOX9. Pharmacological perturbations revealed that Rho/ROCK/SRF signaling is required for this synergistic response. We further found an activation of the early response genes SRF and EGR1 during the early adaptation phase on micro-topographies, which coincided with higher expression of the TGF-β type-II receptor gene. Of interest, PKC activators Prostratin and Ingenol-3, known for inducing actin reorganization and activation of serum response elements, were able to mimic the topography-induced TGF-β response. These findings provide novel insights into the convergence of mechanobiology and TGF-β signaling, which can lead to improved culture protocols and therapeutic applications

Assessment of the requisites of microbiology based infectious disease training under the pressure of consultation needs

<p>Abstract</p> <p>Background</p> <p>Training of infectious disease (ID) specialists is structured on classical clinical microbiology training in Turkey and ID specialists work as clinical microbiologists at the same time. Hence, this study aimed to determine the clinical skills and knowledge required by clinical microbiologists.</p> <p>Methods</p> <p>A cross-sectional study was carried out between June 1, 2010 and September 15, 2010 in 32 ID departments in Turkey. Only patients hospitalized and followed up in the ID departments between January-June 2010 who required consultation with other disciplines were included.</p> <p>Results</p> <p>A total of 605 patients undergoing 1343 consultations were included, with pulmonology, neurology, cardiology, gastroenterology, nephrology, dermatology, haematology, and endocrinology being the most frequent consultation specialties. The consultation patterns were quite similar and were not affected by either the nature of infections or the critical clinical status of ID patients.</p> <p>Conclusions</p> <p>The results of our study show that certain internal medicine subdisciplines such as pulmonology, neurology and dermatology appear to be the principal clinical requisites in the training of ID specialists, rather than internal medicine as a whole.</p

Determination of Cohesion values of Rock Materials using Double Shear Jaws

WOS: 000459908800006In this study, experimental and numerical analyses were carried out for determination of cohesion values of different types of rock materials using double shear jaws (DSJ) which can be practically used with the conventional compressive test equipment, to make shear planes in the rock core specimens. Effects of various parameters like jaw dimensions, gaps between triple blocks of the DSJ and contact conditions of the jaw on the results and validity of the cohesion test were investigated considering failure mechanisms of rock core specimens. Instead of a failure induced due to the shear stresses, tensile failures are mostly seen from conventional shear testing conditions. For a valid failure under the control of shear stresses, a DSJ design was suggested to be used in cohesion determination tests according to the results obtained from this study

Monitorization of the effects of spinal anaesthesia on cerebral oxygen saturation in elder patients using near-infrared spectroscopy

OBJECTIVE: Central blockage provided by spinal anaesthesia enables realization of many surgical procedures, whereas hemodynamic and respiratory changes influence systemic oxygen delivery leading to the potential development of series of problems such as cerebral ischemia, myocardial infarction and acute renal failure. This study was intended to detect potentially adverse effects of hemodynamic and respiratory changes on systemic oxygen delivery using cerebral oxymetric methods in patients who underwent spinal anaesthesia. METHODS: Twenty-five ASA I-II Group patients aged 65-80 years scheduled for unilateral inguinal hernia repair under spinal anaesthesia were included in the study. Following standard monitorization baseline cerebral oxygen levels were measured using cerebral oximetric methods. Standardized Mini Mental Test (SMMT) was applied before and after the operation so as to determine the level of cognitive functioning of the cases. Using a standard technique and equal amounts of a local anaesthetic drug (15 mg bupivacaine 5%) intratechal blockade was performed. Mean blood pressure (MBP), maximum heart rate (MHR), peripheral oxygen saturation (SpO2) and cerebral oxygen levels (rSO2) were preoperatively monitored for 60 min. Pre- and postoperative haemoglobin levels were measured. The variations in data obtained and their correlations with the cerebral oxygen levels were investigated. RESULTS: Significant changes in pre- and postoperative measurements of haemoglobin levels and SMMT scores and intraoperative SpO2 levels were not observed. However, significant variations were observed in intraoperative MBP, MHR and rSO2 levels. Besides, a correlation between variations in rSO2, MBP and MHR was determined. CONCLUSION: Evaluation of the data obtained in the study demonstrated that post-spinal decline in blood pressure and also heart rate decreases systemic oxygen delivery and adversely effects cerebral oxygen levels. However, this downward change did not result in deterioration of cognitive functioning