DUHA SÜRESiNE DAİR SEBEB-İ NÜZÜLLERİN TAHLiLi

Kaynaklann zikrettiği rivayetlere göre Du ha süresi vahyin ilk yılında meydana gelen bir kesintiden sonra inmiştir. Aynı kaynaklar ilk inen vahiy metninden sonra da bir vahiy inkitasının var olduğunu ifade etmişlerdir. Söz konusu kaynaklar ilk vahiy metninden sonraki kesintinin süresinin takriben kırk gün-üç yıl. Duha süresinden önceki sürenin ise iki-üç gün olduğunu dile getirmişlerdir. ilk inen vahiy metninden sonraki kesintiyi müteakip inen vahiy metninin fasılasız vahyi başiattığını söyleyen aynı kaynaklar Duha süresinden önce ·de bir kesintinin vuku bulduğunu beyan ederek ihtilafa sebebiyet vermişlerdir. Söz konusu her iki kesintinin zikredildiği hadisler sahih olduğu için aralann ı tevil etme gayretleri olmuş, fakat çoğu müellif bu konuda ikna edici bir cevap verememiştir. Duha süresinden önceki kesintiyi müteakip süreçte insaniann Hz. Peygamberi terk edilmekle itharn etn:ıeleri sonucu sürenin indiği ifade edilmiştir. Bu rivayette ihtilafa sebebiyet veren husus, iki yıllık bir kesintiden sonra insanlardan her hangi bir •terk edilme· itharnı sadır olmamasına rağmen, iki üç günlük kesintiden hemen sonra terk edilme itharnının vuku bulmuş olmasıdır. SCırenin sebeb-i nüzülü olarak zikredilen diğer rivayetler ise zamansal olarak alakasız olmakla itharn edilmiş ve eleştirilmişlerdir. Makalede sadece sürenin nüzülüne vesile olduğu ifade edilen rivayetler değil. aynı zamanda sCırenin özel olarak ayetlerine mahsus zikredilmiş rivayetler de irdelenecektir

The assessment of slope stability and rock excavatability in a limestone quarry

The aim of this study is to evaluate the stability and excavatability of newly stripped rock slopes (slope 1 (SN–1), slope 2 (SN–2), and slope 3 (SN–3)) in a limestone quarry. These are new production sites with comparable geological formations along the southern part of the quarry where three planar failures were previously observed. For this reason, detailed fieldwork was performed to determine the properties (spacing, roughness, etc.) of the discontinuities of the rock slopes in the study area. The shear strength parameters of the discontinuities and the point load strength index (Is(5o)) and the uniaxial compressive strength (UCS) of rock samples obtained from the study area were tested in the laboratory. The stability of the slopes was assessed using kinematic analysis and an orientation–dependent and orientation–independent slope stability probability classification (SSPC) system. The results of the SSPC system analyses were compared with those of the slope mass rating (SMR). The kinematic analysis shows that planar, wedge and toppling failures are unlikely in the slopes of the study area. The orientation–dependent SSPC analysis revealed that SN–2 would experience sliding failure if its dip angle is greater than 66°. The slopes were shown to have a stability probability of ≥80%, provided that a pneumatic hammer or blasting methods are used for the excavation. However, the maximum slope height (Hmax) in blasting operations is required to be lower for durable slope faces. Furthermore, the SMR analysis has indicated that SN–1 and SN–2 will most likely lose their stability when blasting is used as an excavation method. The rock slopes could be excavated by pneumatic hammer because the category of excavatability of the rock was determined to be ‘easy ripping.’ Based on the kinematic, SSPC and SMR analyses, the angles for a safe slope are proposed to be 70°, 66° and 75° for SN–1, SN–2 and SN–3, respectively, with a slope height of 8 m. ResumenEl objeto de este estudio es evaluar la estabilidad y la medida de excavación de nuevas pendientes rocosas descubiertas (slope 1 (SN–1), slope 2 (SN–2), y slope 3 (SN–3)) en una cantera de caliza. Estos son nuevos sitios de producción con formaciones geológicas similares en la parte sur de la mina. Por esta razón se llevó a cabo un trabajo de campo detallado para determinar las propiedades (espaciado, irregularidades, etc.) de las discontinuidades en las pendientes rocosas del área de estudio. En un laboratorio se evaluaron los parámetros de fuerza de las discontinuidades, el índice de punto de carga (Is(5o)) y la fuerza de comprensión monoaxial (UCS) de las muestras de rocas tomadas en el área de estudio. La estabilidad de las pendientes fueron medidas a través de un análisis kinemático y de un sistema de clasificación de estabilidad probable (SSPC) en orientación-dependiente y orientación-independiente. Los resultados del análisis al sistema SSPC fueron cotejados con las clasificaciones de masa de las pendientes (SMR). El análisis kinemático muestra que las fallas planas, de bloque y de tope son improbables en las pendientes del área de estudio. Los análisis SSPC de orientación-dependiente muestran que la SN-2 podría presentar fallas de deslizamiento ya que el ángulo de la cuesta es mayor a 66°. Las pendientes evidencian una probabilidad estable de ≥80% si se utiliza un martillo neumático o métodos de explosión para la excavación. Sin embargo, la pendiente de máxima altura (Hmax) en operaciones de explosión debe ser menor para garantizar la duración de las fachadas de las pendientes. Además, los análisis SMR indicaron que la SN-1 y la SN-2 son más propensas a perder su estabilidad si se utilizan métodos de excavación con explosivos. Las pendientes rocosas podrán ser excavadas con martillo neumático ya que la medida de excavación de la roca fue determinada como de "fácil explotación". Basado en los análisis kinemático, SSPC y SMR, los ángulos propuestos para una pendiente segura son de 70°, 66° y 75° para las pendientes SN–1, SN–2 y SN–3, respectivamente, con una pendiente de altura de 8 m

Use of high-density paste bacfill for safe disposal of copper/zinc mine tailings

The safe environmental disposal of sulphide-rich copper/zinc mine tailings is fast becoming a major economic factor in determining the profitability of mining operations. There have been new approaches and better technologies practised in the recent years which allow the mining industries to reduce and/or eliminate the environmental impacts of harmful mine tailings. One of these approaches is the use of high-density paste backfill (HDPB) which is consisting mainly of a mix of solid particles (with the cement) and water, containing between 70% and 85% by dry weight of solids. The increased use of HDPB has improved the reliability, and has reduced the cost of the preparation and transportation systems. This paper focuses on the potential environmental benefits of using the HDPB when tailings are acid generating, and also provides a case study conducted in an underground copper/zinc mine in northeast Turkey in order to illustrate these benefits

Mandibular Prognathism and Genetic Transmission in Turkish Families

Objective:Mandibular prognathism (MP), defined as the difference in the size and relationship of maxilla and mandible, is the most serious anomaly in the practice of orthodontics. Incidence of MP varies among different populations; it is highest in Asian populations (15–23%) and lowest in Caucasian populations (0.48–4%). Genetic and environmental factors are suggested in the etiology of MP, but the contribution of these factors is not known. This study was designed to determine patients with MP in 3 generations of the families and to evaluate familial transmission of MP in Turkish families.Materials and Method:To reveal the effect of genetic factors on MP, we created pedigree charts for 99 subjects with severe skeletal Class III MP who planned to undergo or had undergone orthognathic surgery. Three generations of each patient's family was assessed on pedigree charts. The relatives of the probands were evaluated with photos and a detailed interview to confirm the prognathic phenotype.Results:The average ANB, SNA, and SNB angles in the probands were −2.65°, 79.92°, and 82.57°, respectively. A total of 1847 family members were examined, and 12.7% had MP. Men were slightly more affected than women. Most families (89%) had at least 1 member with MP other than the proband. The affected ratios of the first- and second-degree relatives were 20% and 7.3%, respectively. The affected ratio of fathers of probands (25.7%) was more than twice that of mothers of pronbands (9.9%), and siblings showed a 17.8% affected ratio.Conclusion:A high frequency of MP was seen in families of patients with skeletal Class III, suggesting a genetic transmission

Special education teachers’ knowledge about genetic disorders

Bu çalışmanın amacı özel eğitim öğretmenlerinin genetik hastalıklar konusunda bilgi düzeylerinin belirlenmesidir. Total olarak 83 özel eğitimde çalışan öğretmen çalışmaya dahil edilmiştir. Hücre bölünmesi katılımcılar arasında en fazla bilinen bilgi olarak tespit edilmiştir (33.7%). Bununla birlikte katılımcıların çoğu genetik danışmanlık (80.7%), prenatal genetik tanı (79.5%), polygenic kalıtım (72.3%), mitokondriyal kalıtım (71.1%), otozomal dominant and resesif genler (65.1% and 63,9% respectively) konusunda bilgilerinin olmadığını belirtmişlerdir. Katılımcıların büyük çoğunluğu Down sendromu (69.9%) Rh faktörü (31.3%), diabet (27.7%), kas distrofisi (24.1%) ve albinizm (24.1%) konularında bilgiye sahip olduklarını belirtmişlerdir. Sonuçlarımız katılımcıların büyük bir çoğunluğunun yeterli genetik bilgiye sahip olmadıklarını göstermiştir.The purpose of this work is to determine the knowledge level of the special education teachers about genetic disorders. A total of 83 teachers’ from working on special education centers were used. Knowledge of cell division was the highest among participants (33.7%). However, majority of the participants specified that they had no information about genetic counselling (80.7%), prenatal genetic diagnosis (79.5%), polygenic inheritance (72.3%), mitochondrial inheritance (71.1%), autosomal dominant and recessive genes (65.1% and 63,9% respectively). The majority of the participants were mostly aware of Down syndrome (69.9%) followed by Rh factor (31.3%), diabetes (27.7%), muscular dystrophy (24.1%) and albinism (24.1%). Our results showed that the majority of respondents were lack of adequately enough genetic knowledge

3-Year Follow-Up of Nonextraction Crowded Cases Treated With the Damon System

Objective:The aim of this retrospective study was to investigate treatment efficiency and 3-year follow-up stability of the Damon system by evaluating peer assessment rating (PAR) index, posteroanterior-lateral cephalometric changes, and the intercanine and intermolar widths.Materials and Methods:Fifty-five patients treated with a 0.022-inch slot Damon D3 MX bracket system were evaluated in this study. Cephalometric radiographs, dental models, and PAR scores were measured and evaluated pretreatment (T1), posttreatment (T2), and 3 years after treatment (T3). Repeated-measures analysis of variance (ANOVA)/paired t test were performed to evaluate the differences between the periods.Results:The mean PAR score of 34.75 at T1 was reduced to 3.35 and 3.05 at T2 and T3, respectively, succeeding in a 90.35% reduction with treatment. At T1–T2 and T1–T3, maxillary intercanine and intermolar width and mandibular intercanine width increased significantly. Although intercanine and intermolar widths decreased in both arches at T2–T3, only maxillary intercanine width showed a small, but statistically significant decrease (0.09 mm, p=0.001). Value of SNB angle, Md1-NB (mm), Md1-NB (degrees), and E plane-lower lip increased significantly at T1–T2 and T1–T3. Therefore, treatment resulted in mandibular incisor and lower lip proclination. All of the posteroanterior cephalometric changes were statistically significant except facial width changes at T1–T2.Conclusions:This study represented satisfactory results and a good follow-up stability with the Damon system. The Damon system can be used for nonextraction treatment in patients with moderate crowding

Immediate recovery of the left atrial and left ventricular diastolic function after transcatheter aortic valve implantation: A transesophageal echocardiography study

Background: Chronic increased afterload due to severe aortic stenosis (AS) results in com­pensatory concentric left ventricular (LV) hypertrophy and LV dysfunction. These in turn cause remodeling of the left heart. The aim of this study was to investigate the acute effect of transcatheter aortic valve implantation (TAVI) on left atrial (LA) mechanics and LV diastolic function. Methods: The study consisted of a total of 35 consecutive patients (mean age was 77.7 ± 5.0 years, 25 female) undergoing TAVI. All TAVI procedures have been performed under the transesophageal echocardiography (TEE) guidance. Before and 24 h after TAVI, all patients underwent transthoracic echocardiography (TTE) and mitral inflow velocities with pulsed-wave (PW) Doppler including early filling wave (E), late diastolic filling wave (A), and E/A ratio were obtained. LV diastolic function was also explored by pulsed tissue Doppler imaging (TDI). Early (E’) and late (A’) diastolic annular velocities, E’/A’ ratio and E/E’ ratio were obtained. In addition, during the procedure before and minutes after the valve implantation, the left atrial appendage-peak antegrade flow velocity (LAA-PAFV) was measured and recorded with TEE. Results: Compared with baseline, the mean mitral E, septal E’ and E’/A’ ratio increased significantly after TAVI. In addition, the LAA-PAFV increased significantly within minutes of TAVI (32.45 ± 10.7 cm/s vs. 47.6 ± 12.6 cm/s, p < 0.001). Conclusions: TAVI improves LV diastolic function and LA performance immediately

Impact of transcatheter aortic valve implantation in patients with reduced ejection fraction

Background: Aortic stenosis increases with age. According to guidelines, left ventricular systolic dysfunction is an indication for aortic valve replacement, even in asymptomatic patients. There is no clear data on the application of transcatheter aortic valve implantation (TAVI), which is a method showing continuous improvement in recent years, in patients with reduced ejection fraction (REF) having a poor prognosis for surgical aortic valve replacement. We therefore aimed to investigate the effect of TAVI on left ventricular ejection fraction (LVEF) and also its efficacy and safety in patients with REF. Methods and results: The study included 104 patients who underwent transfemoral TAVI in our clinic. The patients were divided into two groups: LVEF ≤ 45% (REF group, n = 28) and LVEF > 45% (preserved ejection fraction [PEF] group, n = 76). Follow-up measure­ments were performed at baseline, discharge, 1st, 6th and 12th months. No statistical difference was found between the groups with respect to complications and mortality rates. A statistically significant difference was detected in LVEF after TAVI, either in all patients (53.9 ± 14.6, 57.0 ± 11.4, 59.4 ± 8.4, 60.4 ± 6.8, 63.2 ± 3.9, respectively, at baseline, discharge, 1st, 6th and 12th months, p < 0.001) or in the groups separately. A statistically significant increase in LVEF (p < 0.001) was determined at discharge, 1st, 6th and 12th months, whereas LVEF increased in all follow-ups of the PEF group, however this elevation reached a statistical significance only at the 1st month (p = 0.04). Conclusions: Our study has shown the positive effect of TAVI on LVEF and its effective and safe applicability in patients with REF.

Reappraisal of the transthoracic echocardiographic algorithm in predicting pulmonary hypertension redefined by updated pulmonary artery mean pressure threshold

BACKGROUND: Although an adopted echocardiography algorithm based on tricuspid regurgitation jet peak velocity and suggestive findings for pulmonary hypertension has been utilized in the non-invasive prediction of pulmonary hypertension probability, the reliability of this approach for the updated hemodynamic definition of pulmonary hypertension remains to be determined. In this study, for the first time, we aimed to evaluate the tricuspid regurgitation jet peak velocity and suggestive findings in predicting the probability of pulmonary hypertension as defined by mean pulmonary arterial pressure > 20 mm Hg and > 25 mm Hg, respectively. METHODS: Our study group was comprised of the retrospectively evaluated 1300 patients (age 53.1 ± 18.8 years, female 62.1%) who underwent right heart catheterization with different indications between 2006 and 2018. All echocardiographic and right heart catheterization assessments were performed in accordance with the European Society of Cardiology/European Respiratory Society 2015 Pulmonary Hypertension Guidelines. RESULTS: Although tricuspid regurgitation jet peak velocity showed a significant relation with mean pulmonary arterial pressure in both definitions, suggestive findings offered a significant contribution only in predicting mean pulmonary arterial pressure ≥ 25 mm Hg but not for mean pulmonary arterial pressure > 20 mm Hg. In predicting the mean pulmonary arterial pressure > 20 mm Hg, tricuspid regurgitation jet peak velocity and suggestive findings showed an odds ratio of 2.57 (1.59-4.14, P 3.4 m/s were associated with 70% and 84% probability of mean pulmonary arterial pressure > 20 mm Hg and 60% and 76% probability of mean pulmonary arterial pressure ≥ 25 mm Hg, respectively. CONCLUSIONS: In contrast to those in predicting the mean pulmonary arterial pressure ≥ 25 mm Hg, suggestive findings did not provide a significant contribution to the probability of mean pulmonary arterial pressure > 20 mm Hg predicted by tricuspid regurgitation jet peak velocity solely. The impact of the novel mean pulmonary arterial pressure threshold on the echocardiographic prediction of pulmonary hypertension remains to be clarified by future studies