66 research outputs found
Quarantine region scheme to mitigate spam attacks in wireless sensor networks
The Quarantine Region Scheme (QRS) is introduced to defend against spam attacks in wireless sensor networks where malicious antinodes frequently generate dummy spam messages to be relayed toward the sink. The aim of the attacker is the exhaustion of the sensor node batteries and the extra delay caused by processing the spam messages. Network-wide message authentication may solve this problem with a cost of cryptographic operations to be performed over all messages. QRS is designed to reduce this cost by applying authentication only whenever and wherever necessary. In QRS, the nodes that detect a nearby spam attack assume themselves to be in a quarantine region. This detection is performed by intermittent authentication checks. Once quarantined, a node continuously applies authentication measures until the spam attack ceases. In the QRS scheme, there is a tradeoff between the resilience against spam attacks and the number of authentications. Our experiments show that, in the worst-case scenario that we considered, a not quarantined node catches 80 percent of the spam messages by authenticating only 50 percent of all messages that it processe
Neuroprotective effect of magnesium on lipid peroxidation and axonal function after experimental spinal cord injury
Study design: An experimental study examining the neuroprotective effect of magnesium on axonal function and lipid peroxidation in a rat model of acute traumatic spinal cord injury. Objective: To determine the effectiveness of postinjury treatment with magnesium on evoked potentials and lipid peroxidation after spinal cord injury (SCI). Setting: Pamukkale University, Denizli, Turkey. Methods: Spinal cord injury occurred in 30 rats with an aneurysm clip at T9 and the rats were randomly assigned to undergo subcutaneous administration of one of the following at 1 h after injury: (1) Physiological saline (n = 10); (2) MgSO4, 300 mg/kg (n = 10) and (3) MgSO4, 600 mg/kg (n = 10). Spinal somatosensory evoked potentials (SSEPs) were recorded before injury, 30 min after injury and 3 h after injections. Rats were killed 24 h after the injury, and malondialdehyde (MDA) levels were measured. Results: Following SCI, there were significant decreases in the amplitudes of P1 and N1 (P 0.001) and only high-dose magnesium improved the SSEPs (P < 0.01). On the other hand, there was significant difference in lipid peroxide content between high-dose magnesium treated group and both of saline treated and low-dose magnesium treated groups (P < 0.01). Conclusion: These results suggest that magnesium has a dose-dependent neuroprotective effect on SSEPs and lipid peroxidation after experimental spinal cord injury
Rapid Recovery of Visual Acuity after Lumboperitoneal Shunt Operation in Malignant Idiopathic Intracranial Hypertension
Background. Idiopathic intracranial hypertension can cause rapid deterioration of visual acuity in some severe cases, and these cases are usually thought to have “malignant” form of this disease. Case. In this paper, we report on a 16-year-old girl who is a typical example for malignant idiopathic intracranial hypertension with a rapid recovery of visual acuity after lumboperitoneal shunt operation. Observations and Conclusions. Malignant form of idiopathic intracranial hypertension must be kept in mind in selected patients to avoid irreversible visual loss
Successful treatment of multidrug resistant Acinetobacter baumannii meningitis.
Acinetobacter baumannii is a major cause of nosocomial infections in many hospitals and appears to have a propensity for developing multiple antimicrobial resistance rapidly. We report two cases with post-surgical meningitis due to multidrug resistant A. baumannii which were successfully treated with high-dose intravenous meropenem therapy. Multidrug resistant Acinetobacter spp. in intensive care units are a growing concern. High-dose meropenem is used in the treatment of these infections
A study on marital relationship and marital life satisfaction with regard to values of marital couplesEvlilik içi ilişki ile evlilikteki yaşam doyumunun evli çiftlerin değerleri açısından incelenmesi
The aim of this study is to investigate the life satisfaction and marital relationships of married couples with regard to values of them. This study is based on relational scanning model. The scope of this study is composed of married couples living in Konya. The sample of this study consists of voluntarily adults, selected by convenience sampling approach. The sample of this study composed of totally 554 married couples, 377 females (68.1 %) and 177 males (31.9 %). Schwartz Value Survey, Marital Self-efficacy Scale and Marital Life Scale were used in this study. SPSS 16.00 was used to analyze the data. Pearson product moment correlation coefficient was also used to determine the relationships among marital relationships, marital life satisfaction and values of married couples. A multiple linear regression analysis was used to predict whether the value of married couples explains significantly marital relationships and marital life satisfaction. Results indicated that marital life satisfaction was found to positively and significantly correlate with power, stimulation, benevolence and security sub-dimensions of Schwartz Value Survey. Also, achievement, hedonism, stimulation, universalism, tradition and conformity sub-dimensions of Schwartz Value Survey predicted to marital life satisfaction. ÖzetBu araştırmanın amacı, evlilik içi ilişki ile evlilikte yaşam doyumunun evli çiftlerin değerleri açısından incelenmesidir. Araştırma, ilişkisel tarama modeline uygun olarak yapılmıştır. Araştırmanın evreni Konya da yaşayan evli çiftlerden oluşmaktadır. Örneklem grubu ise araştırmaya gönüllü olarak katılan yetişkinlerden uygun (convenience) örnekleme yöntemi ile seçilmiştir. Örneklem, 377’ si (%68.1) kadın ve 177’ü (%31.9.) erkek olmak üzere 554 evli yetişkinden oluşmaktadır. Araştırmada, Schwartz Değerler Listesi, Evlilikte Öz-yetkinlik Ölçeği ve Evlilik Yaşamı Ölçeği kullanılmıştır. Araştırmada uygulanan ölçeklerden elde edilen verilerin değerlendirilmesi SPSS 16.00 paket programı kullanılarak yapılmıştır. Evli çiftlerin, değerler ile evlilik yaşamı doyumu ve evlilik ilişkisi arasındaki ilişkinin ortaya konulmasında Pearson Momentler Çarpımı Korelasyonu tekniği kullanılmıştır. Evli çiftlerin değerlerinin, evlilik içi ilişki ile evlilikteki yaşam doyumunu anlamlı düzeyde açıklayıp açıklamadığı ise çoklu doğrusal regresyon analizi ile test edilmiştir. Araştırmadan elde edilen bulgulara bakıldığında, evlilik yaşamı doyumunun, değerler ölçeğinin alt boyutlarından güç, uyarılma, yardımseverlik ve güven ile pozitif yönde anlamlı bir ilişki bulunmuştur. Ayrıca değerler ölçeğinin başarı, hazcılık, uyarılma, evrensellik, geleneksellik ve uyum alt boyutlarının evlilik yaşamı doyumunu yordadığı görülmektedir
Visual acuity and intraocular pressure values in patients with phacomorphic glaucoma following phacoemulsification and intraocular lens implantation
Objectives: To evaluate the efficiency of phacoemulsificationand uncomplicated Intraocular Lens (IOL) implantationsurgery on visual prognosis and intraocular pressurecontrol on eyes with phacomorphic glaucoma.Materials and methods: Totally 17 eyes of 17 patientswith phacomorphic glaucoma who underwent cataractsurgery was evaluated retrospectively. Intraocular pressure(IOP), best corrected visual acuity, axial length, thicknessof the lens and anterior chamber depth of the caseswere measured preoperatively and postoperatively.Results: Ten cases (59 %) were male and 7 (41%) werefemale. The mean age of the cases was 63.8 ± 10.3 years(40-83). The average follow up period was 12.1 ± 6.7months (3-26). Preoperative average intraocular pressurewas 44.7 ± 10.02 mm Hg (30-70), and the average IOPin the last postoperative follow up was 12.8 ± 1.9 mm Hg(10-16). There was no IOP increase in any eye during followup. Decrease in IOP in the first postoperative day wasstatistically significant (p<0.001). Preoperative averageaxial length was 22.1 ± 0.7 mm (21.0 - 24.2) and averagelens thickness was 5.5 ± 0.2 mm (5.1 - 5.9). Preoperativeand postoperative average anterior chamber depthwere 1.5 ± 0.3 mm (0.9 - 2.1) and 2.6 ± 0.1 mm (2.4 - 2.9)(p<0.001). Significantly increases in visual acuity weredetermined postoperatively in 14 (82%) cases.Conclusion: It was concluded that in cases with phacomorphicglaucoma, uncomplicated phacoemulsificationand IOL implantation is safe and effective procedure inimproving visual acuity and controlling IOP
Spinal cord compression secondary to extramedullary hematopoiesis in thalassemia intermedia
Extramedullary hematopoiesis associated with thalassemia causing spinal cord compression is an extremely rare event in the course of the disease. Documentation with an imaging technique, such as MRI, is mandatory. A patient with thalassemia intermedia, who developed paraparesis in spite of transfusion, underwent surgical decompression. Rapid neurological improvement was observed postoperatively and this neurological condition was protected with adequate hemoglobin level. Management of these patients remains controversial. Various modes of therapy such as surgical decompression, radiotherapy, and transfusion are discussed and the related literature is reviewed
Investigation of efficacy of mitomycin-C, Sodium hyaluronate and human amniotic fluid in preventing epidural fibrosis and adhesion using a rat laminectomy model
Study Design: A retrospective study. Purpose: The aim of this study was to evalute the effects of mitomycin-C, sodium hyaluronate and human amniotic fluid on preventing spinal epidural fibrosis. Overview of Literature: The role of scar tissue in pain formation is not exactly known, but it is reported that scar tissue causes adhesions between anatomic structures. Intensive fibrotic tissue compresses on anatomic structures and increases the sensitivity of the nerve root for recurrent herniation and lateral spinal stenosis via limiting movements of the root. Also, neuronal atrophy and axonal degeneration occur under scar tissue. Methods: The study design included 4 groups of rats: group 1 was the control group, groups 2, 3, and 4 receieved antifibrotic agents, mitomycin-C (group 2), sodium hyaluronate (group 3), and human amniotic fluid (group 4). Midline incision for all animals were done on L5 for total laminectomy. Four weeks after the surgery, the rats were sacrificed and specimens were stained with hematoxylineosin and photos of the slides were taken for quantitive assesment of the scar tissue. Results: There was no significant scar tissue in the experimental animals of groups 2, 3, and 4. It was found that there was no significant difference between drug groups, but there was a statistically significant difference between the drug groups and the control group. Conclusions: This experimental study shows that implantation of mitomycin-C, sodium hyaluronate and human amniotic fluid reduces epidural fibrosis and adhesions after spinal laminectomy in rat models. Further studies in humans are needed to determine the complications of the agents researched. © 2013 by Korean Society of Spine Surgery
Spontaneous recovery of post-traumatic cerebrospinal fluid rhinorrhea following meningitis: A case report
The aim of the present report was to present the patient with an anterior cranial base fracture who developed post-traumatic cerebrospinal fluid rhinorrhea, which recovered after onset of meningitis complication. A 26-year-old male patient who had a traffic accident one week ago was sent to our clinic because of his rhinorrhea persisting for 4 days. On cranial computed tomography, fracture of the left frontal skull base and sinus walls, a fracture line on temporal bone, parenchymal bleeding in the vicinity of the frontal sinus, subarachnoidal bleeding and left temporal extradural hematoma were detected. Then he underwent sinus wall repair and extradural hematoma was drained through bifrontal craniotomy. However, rhinorrhea persisted which resulted a deterioration in consciousness and he entered into a deep somnolent state. When his symptoms of meningitis became apparent, rhinorrhea of the patient disappeared. The patient transferred in intensive care unit and re-connected to a lumbar drainage system. On cerebral magnetic resonance imaging, regression of contrast-enhanced lesions localized in the left anterotemporal and frontal and in the regions lateral to the right trigon and medial to the right thalamus and in the right posteroparietal regions was observed. Despite repair of the anterior cranial fracture and lumbar drainage, rhinorrhea may persist. Herein, development of meningitis caused disappearing of rhinorrhea symptoms without any need for surgical intervention
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