21 research outputs found
Olfactory neuroblastoma: a case report and review of the literature
Malignant tumors of the nasal cavity are rare. We report the case of an elderly woman who consulted us with a 4-year history of progressive nasal obstruction, occasional epistaxis, facial pain, and watering of the eyes. A diagnosis of olfactory neuroblastoma was established by histopathology and confirmed by immunohistochemistry. On staging, the mass was classified as a Kadish stage B tumor. The mass was excised via a lateral rhinotomy approach, and the tumor was peeled away completely from the cribriform plate with endoscopes. The patient underwent postoperative radiation, and she was free of recurrence at follow-up 15 months later
Sinonasal teratocarcinosarcoma
Teratocarcinosarcoma is a rare, morphologically heterogeneous and highly malignant neoplasm. It is characterized by the presence of benign and malignant epithelial, mesenchymal and neural components. The carcinoma may be either squamous or adenocarcinoma and the mesenchymal component may manifest spindle, smooth, skeletal muscle, cartilage and bone features. Because of their infrequency, these lesions are often misdiagnosed, leading to management difficulties. In this case report we have shared our experience with sinonasal teratocarcinosarcoma in a 23 year old female and performed a brief review of literature
Granular Cell Myoblastoma of the Larynx
Granuloma cell myoblastoma ofthe larynx is a relatively uncommon tumor. A review of the literature reveals only 52 cases reported. The lesion is a benign growth which is often asymptomatic, though most commonly associated with hoarseness. The treatment of choice is local surgical excision. Four successfully treated cases are reported. All four patients are Negro — three females and one male
Frequency-Selective Surface-Based MIMO Antenna Array for 5G Millimeter-Wave Applications
In this paper, a radiating element consisting of a modified circular patch is proposed for MIMO arrays for 5G millimeter-wave applications. The radiating elements in the proposed 2 × 2 MIMO antenna array are orthogonally configured relative to each other to mitigate mutual coupling that would otherwise degrade the performance of the MIMO system. The MIMO array was fabricated on Rogers RT/Duroid high-frequency substrate with a dielectric constant of 2.2, a thickness of 0.8 mm, and a loss tangent of 0.0009. The individual antenna in the array has a measured impedance bandwidth of 1.6 GHz from 27.25 to 28.85 GHz for S11 ≤ −10 dB, and the MIMO array has a gain of 7.2 dBi at 28 GHz with inter radiator isolation greater than 26 dB. The gain of the MIMO array was increased by introducing frequency-selective surface (FSS) consisting of 7 × 7 array of unit cells comprising rectangular C-shaped resonators, with one embedded inside the other with a central crisscross slotted patch. With the FSS, the gain of the MIMO array increased to 8.6 dBi at 28 GHz. The radiation from the array is directional and perpendicular to the plain of the MIMO array. Owing to the low coupling between the radiating elements in the MIMO array, its Envelope Correlation Coefficient (ECC) is less than 0.002, and its diversity gain (DG) is better than 9.99 dB in the 5G operating band centered at 28 GHz between 26.5 GHz and 29.5 GHz
Frequency-selective surface-based MIMO antenna array for 5G millimeter-wave applications
In this paper, a radiating element consisting of a modified circular patch is proposed for MIMO arrays for 5G millimeter-wave applications. The radiating elements in the proposed 2 x 2 MIMO antenna array are orthogonally configured relative to each other to mitigate mutual oupling that would otherwise degrade the performance of the MIMO system. The MIMO array was fabricated on Rogers RT/Duroid high-frequency substrate with a dielectric constant of 2.2, a thickness of 0.8 mm, and a loss tangent of 0.0009. The individual antenna in the array has a measured impedance bandwidth of 1.6 GHz from 27.25 to 28.85 GHz for S11 less than or equal to -10 dB, and the MIMO array has a gain of 7.2 dBi at 28 GHz with inter radiator isolation greater than 26 dB. The gain of the MIMO array was increased by introducing frequency-selective surface (FSS) consisting of 7 x 7 array of unit cells comprising rectangular C-shaped resonators, with one embedded inside the other with a central crisscross slotted patch. With the FSS, the gain of the MIMO array increased to 8.6 dBi at 28 GHz. The radiation from the array is directional and perpendicular to the plain of the MIMO array. Owing to the low coupling between the radiating elements in the MIMO array, its Envelope Correlation Coefficient (ECC) is less than 0.002, and its diversity gain (DG) is better than 9.99 dB in the 5G operating band centered at 28 GHz between 26.5 GHz and 29.5 GHz
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Global burden of 288 causes of death and life expectancy decomposition in 204 countries and territories and 811 subnational locations, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021
BACKGROUND Regular, detailed reporting on population health by underlying cause of death is fundamental for public health decision making. Cause-specific estimates of mortality and the subsequent effects on life expectancy worldwide are valuable metrics to gauge progress in reducing mortality rates. These estimates are particularly important following large-scale mortality spikes, such as the COVID-19 pandemic. When systematically analysed, mortality rates and life expectancy allow comparisons of the consequences of causes of death globally and over time, providing a nuanced understanding of the effect of these causes on global populations. METHODS The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 cause-of-death analysis estimated mortality and years of life lost (YLLs) from 288 causes of death by age-sex-location-year in 204 countries and territories and 811 subnational locations for each year from 1990 until 2021. The analysis used 56 604 data sources, including data from vital registration and verbal autopsy as well as surveys, censuses, surveillance systems, and cancer registries, among others. As with previous GBD rounds, cause-specific death rates for most causes were estimated using the Cause of Death Ensemble model-a modelling tool developed for GBD to assess the out-of-sample predictive validity of different statistical models and covariate permutations and combine those results to produce cause-specific mortality estimates-with alternative strategies adapted to model causes with insufficient data, substantial changes in reporting over the study period, or unusual epidemiology. YLLs were computed as the product of the number of deaths for each cause-age-sex-location-year and the standard life expectancy at each age. As part of the modelling process, uncertainty intervals (UIs) were generated using the 2·5th and 97·5th percentiles from a 1000-draw distribution for each metric. We decomposed life expectancy by cause of death, location, and year to show cause-specific effects on life expectancy from 1990 to 2021. We also used the coefficient of variation and the fraction of population affected by 90% of deaths to highlight concentrations of mortality. Findings are reported in counts and age-standardised rates. Methodological improvements for cause-of-death estimates in GBD 2021 include the expansion of under-5-years age group to include four new age groups, enhanced methods to account for stochastic variation of sparse data, and the inclusion of COVID-19 and other pandemic-related mortality-which includes excess mortality associated with the pandemic, excluding COVID-19, lower respiratory infections, measles, malaria, and pertussis. For this analysis, 199 new country-years of vital registration cause-of-death data, 5 country-years of surveillance data, 21 country-years of verbal autopsy data, and 94 country-years of other data types were added to those used in previous GBD rounds. FINDINGS The leading causes of age-standardised deaths globally were the same in 2019 as they were in 1990; in descending order, these were, ischaemic heart disease, stroke, chronic obstructive pulmonary disease, and lower respiratory infections. In 2021, however, COVID-19 replaced stroke as the second-leading age-standardised cause of death, with 94·0 deaths (95% UI 89·2-100·0) per 100 000 population. The COVID-19 pandemic shifted the rankings of the leading five causes, lowering stroke to the third-leading and chronic obstructive pulmonary disease to the fourth-leading position. In 2021, the highest age-standardised death rates from COVID-19 occurred in sub-Saharan Africa (271·0 deaths [250·1-290·7] per 100 000 population) and Latin America and the Caribbean (195·4 deaths [182·1-211·4] per 100 000 population). The lowest age-standardised death rates from COVID-19 were in the high-income super-region (48·1 deaths [47·4-48·8] per 100 000 population) and southeast Asia, east Asia, and Oceania (23·2 deaths [16·3-37·2] per 100 000 population). Globally, life expectancy steadily improved between 1990 and 2019 for 18 of the 22 investigated causes. Decomposition of global and regional life expectancy showed the positive effect that reductions in deaths from enteric infections, lower respiratory infections, stroke, and neonatal deaths, among others have contributed to improved survival over the study period. However, a net reduction of 1·6 years occurred in global life expectancy between 2019 and 2021, primarily due to increased death rates from COVID-19 and other pandemic-related mortality. Life expectancy was highly variable between super-regions over the study period, with southeast Asia, east Asia, and Oceania gaining 8·3 years (6·7-9·9) overall, while having the smallest reduction in life expectancy due to COVID-19 (0·4 years). The largest reduction in life expectancy due to COVID-19 occurred in Latin America and the Caribbean (3·6 years). Additionally, 53 of the 288 causes of death were highly concentrated in locations with less than 50% of the global population as of 2021, and these causes of death became progressively more concentrated since 1990, when only 44 causes showed this pattern. The concentration phenomenon is discussed heuristically with respect to enteric and lower respiratory infections, malaria, HIV/AIDS, neonatal disorders, tuberculosis, and measles. INTERPRETATION Long-standing gains in life expectancy and reductions in many of the leading causes of death have been disrupted by the COVID-19 pandemic, the adverse effects of which were spread unevenly among populations. Despite the pandemic, there has been continued progress in combatting several notable causes of death, leading to improved global life expectancy over the study period. Each of the seven GBD super-regions showed an overall improvement from 1990 and 2021, obscuring the negative effect in the years of the pandemic. Additionally, our findings regarding regional variation in causes of death driving increases in life expectancy hold clear policy utility. Analyses of shifting mortality trends reveal that several causes, once widespread globally, are now increasingly concentrated geographically. These changes in mortality concentration, alongside further investigation of changing risks, interventions, and relevant policy, present an important opportunity to deepen our understanding of mortality-reduction strategies. Examining patterns in mortality concentration might reveal areas where successful public health interventions have been implemented. Translating these successes to locations where certain causes of death remain entrenched can inform policies that work to improve life expectancy for people everywhere. FUNDING Bill & Melinda Gates Foundation
If stones could speak : Echoes from the past
The most compressed and visually stunning pictorial tour of ancient civilizations and historical landmarks of the past. ‘If Stones Could Speak’ takes the readers on a fascinating journey in the form of 4 splendid sections, and every one of them retells the history through a dimension of power utilized by the religious rulers of these sites. These images show the shared commonalities between us and our ancestors, the complexities of societies and more captivating attributes which transcends the reader to a realm of pure mysticism. A preaching scholar’s dream journal and a history fanatic’s treasure, this book greatly captures the beauty and remarkability of famous locations with helpful descriptions and subtexts on the sides. The duo writers of this book ‘Iftikhar and Naseem Salahuddin’ elevate each other in terms of visual storytelling and it’s ever so transparent in this universal truth of a journey through history’s timeless monuments.https://ecommons.aku.edu/books/1108/thumbnail.jp
Experience with stapedectomy in a developing country: a review of 200 cases
Since stapedectomy was first performed in 1956, many innovations have been described. We retrospectively analyzed 200 cases of stapedectomy that had been performed with standard otologic instruments. Of the 200 patients, 54 (27.0%) had significant sensory deafness associated with footplate fixation. In most cases, the footplate was partially removed (stapedotomy group); in the remainder, the footplate was removed in its entirety or subtotally (stapedectomy group). Of the 200 patients, 163 were available for short-term follow-up. The air-bone gap was closed to within 10 dB in roughly 83% of both groups. Although long-term follow-up was possible in only a limited number of cases, we believe that an experienced otologist working with standard equipment and a basic operating microscope can obtain satisfactory stapedectomy results with minimal complications
Rhinocerebral invasive mycosis: Occurrence in immunocompetent individuals
We report the computed tomographic appearance of invasive fungal disease of the paranasal sinuses in 13 patients. Coronal and axial computed tomographic images were obtained in each patient and data were analysed. Eight patients had Aspergillus flavus infection, four had Mucormycosis, and one had mixed Candida and Mucor. Our experience was different from that of other workers in many respects. All of our patients were immunocompetent. On radiological imaging by computed tomography, ethmoid sinuses were involved in 85% of our patients. In previously reported series maxillary sinuses were most frequently affected. Calcification in the inflammatory mass was not encountered in any of our patients, whereas this feature was present in many reported cases. Features in our patients that were similar to other studies were contrast enhancement, extension of the disease into the orbit and cranial cavity and a high mortality. The clinical course and radiological features of invasive mycosis simulate malignancy. Certain features that may help to differentiate invasive fungal infection from malignancy are discussed. We conclude that invasive fungal infection can affect immunocompetent individuals and should be considered in the differential diagnosis in appropriate clinical settings
Tuberculous otitis media: two case reports and literature review
Tuberculous otitis media can be difficult to diagnose because it can easily be confused with other acute or chronic middle ear conditions. Compounding this problem is the fact that physicians are generally unfamiliar with the typical features of tuberculous otitis media. Finally, the final diagnosis can be difficult because it requires special culture and pathologic studies. To increase awareness of this condition, we describe two cases of tuberculous otitis media and we review the literature