Cervical Spondylotic Myelopathy, Be Vigilant of Miscellaneous Presentations: A Case Series

Background: Cervical spondylotic myelopathy (CSM) is the result of prolonged compression of the central spinal canal. Clinical and radiological manifestations of CSM could be misleading and physicians need to be vigilant while evaluating patients with neurologic complaints otherwise delay in diagnosis and management would happen that could finally lead to a poor outcome. The aim of this study was to report our series of patients with CSM to reiterate that CSM could have diverse manifestations, and it can be only identified if the physicians are aware and do a thorough investigation. The progressive nature of CSM makes its early diagnosis and subsequent appropriate management vital to avoid further complications.Methods: A total of 10 patients who had diagnosed with CSM and undergone surgical treatment at our  institute evaluated according to the pre-operative and post-operative Nurrick classification and also pre-operative history and physical examination findings and elecrodiagnostic examination.Conclusions: Because of progressive nature CSM and wide range of clinical manifestation, high index of suspicion, early diagnosis and early treatment prior to permanent spinal cord injury is recommended

How Reactivation of SARS-CoV-2 in Astronauts with Dysregulated Immune Systems Can Negatively Affect the Odds of Success in Future Space Missions

We have previously reported that during future space missions the risk of severe COVID-19 infection will be a cardinal issue that needs careful attention. Our studies show that even with the most reliable pre-mission screening and quarantine strategies, astronauts with a latent (hidden, inactive, or dormant) SARS-CoV-2 infection might be sent to space. Given this consideration, an asymptomatic individual with dormant SARS-CoV-2 infection may successfully pass all the pre-launch medical tests. Then during a space mission such as a journey to Mars or beyond, when the immune system of these astronauts starts to weaken, the dormant infection may progress to a severe infection that possibly affects the chance of the mission’s success. The effects of microgravity and the elevated space radiation are two key factors that should be evaluated. Furthermore, the limited size of the spacecraft, the proximity of crew members during flight operations, spacecraft atmospheric composition, limited exercise capability, effects of viral response to space radiation, and uncertainty in the likelihood of the virus to mutate and evolve during a space mission merit additional study

The Accuracy of Magnetic Resonance Imaging in the Diagnosis of Meniscal and Cruciate Ligament Tears of the Knee

Background: During the past decade, magnetic resonance imaging (MRI) has been accepted as the ideal approach for primary diagnosis of traumatic knee intra-articular lesion. Despite this, the overall diagnostic accuracy of MRI has been carefully scrutinized in Iran. The purpose of this investigation was to scrutinize the diagnostic accuracy of MRI of the knee in identifying traumatic intra-articular knee lesions.Methods: We compared MRI findings with subsequent arthroscopic findings (as the gold standard) in 107 patients (107 knees) with a clinical diagnosis of traumatic intra-articular knee lesion. The sensitivity, specificity, positive predictive value, negative predictive value, and the accuracy of MRI were calculated based on arthroscopic findings for menisci and cruciate ligaments.Results: MRI showed the following results for medial meniscus: sensitivity 83%; specificity 37%; positive predictive value 46%; negative predictive value 77%; and accuracy 55%. For lateral meniscus it showed the following results: sensitivity 43%; specificity 86%; positive predictive value 40%; negative predictive value 87%; and accuracy 79%. MRI showed the following results for anterior cruciate ligament (ACL): sensitivity 62%; specificity 90%; positive predictive value 71%; negative predictive value 66%; and accuracy 75%. In addition, it showed the following results for posterior cruciate ligament (PCL): sensitivity 60%; specificity 94%; positive predictive value 42%; negative predictive value 98%; and accuracy 94%. The overall accuracy of MRI was 62.5%. We compared MRI accuracy in two time periods to investigate if there was any improvement over time. Our data showed a significant increase in the accuracy of detection of ACL injuries by MRI in more recent patients; however, there was no improvement in the diagnosis of other internal knee derangements. In addition, overall MRI accuracy was the same in patients from different age groups.Conclusions: We concluded that the overall accuracy of MRI in diagnosing intra-articular lesions of the knee in Iran is comparable with other published studies in the literature. However, it could be improved; if radiologists and orthopedists work together to find possible flaws, their cooperation would result in optimal use of this diagnostic modality

Evaluating the Strength of a Hypothesis on How Terrestrial Organisms Overcame the Loss of Water’s Protective Shield

Evaluating the Strength of a Hypothesis on How Terrestrial Organisms Overcame the Loss of Water’s Protective Shield Evaluating the Strength of a Hypothesis on How Terrestrial Organisms Overcame the Loss of Water’s Protective Shield Evaluating the Strength of a Hypothesis on How Terrestrial Organisms Overcame the Loss of Water’s Protective Shield Evaluating the Strength of a Hypothesis on How Terrestrial Organisms Overcame the Loss of Water’s Protective Shiel

Ammonites albiennes et cénomaniennes de la bordure orientale du bloc de Lut (E Iran)

Upper Albian and Lower Cenomanian ammonites occur on the eastern margin of the Lut block in eastern Iran. The ammonite assemblages described herein are from the Nimbolook and Kerch sections located west of Qayen. The following taxa are described: Mantelliceras mantelli (J. Sowerby, 1814), Mantelliceras saxbii (Sharpe, 1857), Mantelliceras sp. 1, Mantelliceras sp. 2, Mantelliceras sp. 3, Sharpeiceras laticlavium (Sharpe, 1855), Sharpeiceras schlueteri (Hyatt, 1903), Puzosia (Puzosia) mayoriana (Orbigny, 1841), Hyphoplites costosus C.W. Wright & E.V. Wright, 1949, Mortoniceras (Mortoniceras) cf. fallax (Breistroffer, 1940), Mantelliceras cf. mantelli (J. Sowerby, 1814), Calycoceras (Gentoniceras) aff. gentoni (Brongniart, 1822), Idiohamites fremonti (Marcou, 1858), Mariella (Mariella) sp., Mariella (Mariella) dorsetensis (Spath, 1926), and Turrilites costatus Lamarck, 1801. The ammonite assemblages clearly indicate a late Albian-middle Cenomanian age for the Nimbolook section and late Albian-early Cenomanian age for the Kerch section.Des ammonites de l'Albien supérieur et du Cénomanien inférieur sont présentes sur la bordure orientale du bloc de Lut dans la partie orientale de l'Iran. Les associations ammonitiques décrites ici proviennent des coupes de Nimbolook et de Kerch, toutes deux situées à l'ouest de Qayen. Les taxons suivants sont décrits : Mantelliceras mantelli (J. Sowerby, 1814), Mantelliceras saxbii (Sharpe, 1857), Mantelliceras sp. 1, Mantelliceras sp. 2, Mantelliceras sp. 3, Sharpeiceras laticlavium (Sharpe, 1855), Sharpeiceras schlueteri (Hyatt, 1903), Puzosia (Puzosia) mayoriana (Orbigny, 1841), Hyphoplites costosus C.W. Wright & E.V. Wright, 1949, Mortoniceras (Mortoniceras) cf. fallax (Breistroffer, 1940), Mantelliceras cf. mantelli (J. Sowerby, 1814), Calycoceras (Gentoniceras) aff. gentoni (Brongniart, 1822), Idiohamites fremonti (Marcou, 1858), Mariella (Mariella) sp., Mariella (Mariella) dorsetensis (Spath, 1926), et Turrilites costatus Lamarck, 1801. Les associations ammonitiques indiquent clairement un âge Albien supérieur-Cénomanien moyen pour la coupe de Nimbolook et un âge Albien supérieur-Cénomanien inférieur pour celle de Kerch

Development of New Material Models for Thermal Behavior of Cold-Formed G-450 and G-550 Steels in OpenSees Software

In this study, new steel material classes were added to the OpenSees 3.0.0 library to model their behavior within cold-formed profiles under high temperatures. The new material classes that were added are capable of modeling G-450 and G-550 grade galvanized steels under mechanical and thermal loads. Gypsum panel, a nonstructural material within walls, significantly contributed to the lateral resistance of cold-formed structures. For the first time, the relevant material class was added to OpenSees. First, heat transfer analysis was performed to determine the temperature distribution within different parts of the frame structure. Second, the structure was analyzed under gravity loads, followed by thermal loads. Results from the first step were applied to the structure, and a transient thermomechanical analysis was performed. The output of this analysis included the deformation and force of the members of the structure. The behavior of each new material class was compared with the experimental results to determine the accuracy of the developed OpenSees scripts. Moreover, the results related to modeling with this material class were compared with those of the material classes available in OpenSees. The results exhibited high accuracy with the new material class, and the difference in the results obtained with the current material classes in OpenSees was significant

Family History of Alzheimer’s Disease Increases the Risk of COVID-19 Positivity: A SUMS Employees Cohort-based Study

Background: Substantial data indicate that genetic and environmental factors play a key role in determining the risk of Alzheimer’s disease (AD). Moreover, it is known that having relatives with AD increases the risk of developing this disease.Objective: This study is aimed at investigating whether having a family history of AD, may increase the risk of COVID-19 in a cohort-based study.Material and Methods: Participants of this retrospective cohort study were previously enrolled in the SUMS Employees Cohort (SUMSEC). All participants including those whose SARS-CoV-2 infection was confirmed by positive PCR test and chest CT scan were requested to respond to interviewer-administered questionnaires. Moreover, AD was diagnosed via memory and thinking impairment, concentration problems, confusion with location, and problems in finishing daily tasks.Results: The total numbers of female and male participants with a family history of AD were 463 and 222 individuals, respectively. When all types of family history of AD were considered, a 51.3% increase was found in the relative frequency of the participants with both family history of AD and confirmed COVID-19 compared with those only with a family history of AD. Conclusion: Despite the limitations of our study, and from a broader perspective, our findings can further support the concept that AD risk haplotypes including APOE are linked to the same morbidities from cardiovascular disease and obesity that increase vulnerability to COVID-19. Given this consideration, millions of APOE ε4 carriers around the globe should be advised to take additional precautions to prevent life-threatening diseases such as COVID-19

Comparison of thermal performance of steel moment and eccentrically braced frames

Eccentrically braced frames (EBFs) are typically employed in seismic design because they integrate the benefits of concentrically braced frames and moment-resisting frames, providing both high elastic stiffness and high ductility. However, the effect of fire on the structural stability of EBFs has not been well documented. Object-oriented techniques used in software program development have become popular in recent years, primarily because of their ability in addressing various complexity issues. Software developed based on an object-oriented approach is more robust than conventional software. Using the abovementioned approach, additional codes can be incorporated, thereby simplifying testing, refining, maintenance, and software extension. Furthermore, the object-oriented approach can be used for finite element analysis. This paper presents the further development of OpenSees software with the inclusion of other parameters:thermal parallel material, thermal spring element, thermal spring section, as well as beam with hinges and thermal elements subjected to fire loading. In contrast to the routine creation of fire-specific applications, these modifications improve the existing finite-element codes, thereby facilitating multi-hazard analysis (e.g., post-earthquake fire). OpenSees is considered in this study as it is an open-source application and suitable for object-oriented design. The abovementioned elements, particularly spring elements, are used extensively in structural simulations (e.g., the modeling of a link beam in an EBF); however, owing to the lack of thermal functions for these elements in OpenSees, the thermal performance of structures that involve these elements cannot be evaluated. Herein, the aforementioned new elements are introduced for the first time; furthermore, the behavior of an EBF system is investigated under thermal loads using open-source software. The thermal performance of EBFs subjected to realistic fire is evaluated in this study based on an analytical modeling of a three-story building. Finally, several compartment fire scenarios are simulated for both EBFs and gravity framing bays. Results show that the EBFs improve the fire performance of the system by extending the time to collaps

Implementation of new elements and material models in OpenSees software to account for post-earthquacke fire damage

Post-earthquake fire (PEF) damage in buildings is a hazard, which is usually not taken into consideration during structural design in buildings. Past instances of PEF events have led to severe damage and loss of lives, often higher than those experienced during the earthquake event. PEF is a complex phenomenon that requires special treatment, one that can be pursued via OpenSees– an efficient structural modeling software. Despite recent advancements in OpenSees, the latest edition still lacks constitutive thermal and mechanical models for spring element, spring section, parallel material, and beam elements with hinges. For this, carrying out a global thermal analysis of structures with the aforementioned element/member characteristics has been a daunting task,. To overcome this knowldeg gap, this work presents the development of constitutive models to be used in OpenSees to enable engineers from conducting a reaslitic and practical engineering simulation of a PEF event. A further development of OpenSees, introducing a New UserMat function, has also been carried out. Lastly, a series of case studies were explored using numerical implementations of the proposed models and validated based on hand calculations and new OpenSees material developmen