bluuebunny/crossref_metadata_2025 huggingface dataset:
Bright optical spatial solitons in a photovoltaic photorefractive waveguide exhibiting the two photon photorefractive effect
Authors: Katti Aavishkar
Published: March 2023

We investigate for the first time, photorefractive solitons in a two photon photorefractive waveguide which also exhibits the bulk photovoltaic effect. The dynamical evolution equation of such solitons has been obtained under the paraxial ray approximation along with the Wentzel-Kramers-Brilluoin Jefferys (WKBJ) approximation. The existence curve for the solitons is derived and four distinct regions of power have been identified in the absence of waveguiding depending upon the threshold power for self trapping. Bistable states have been observed to be present. We have studied the effect of the planar waveguide and found that it enhances the self trapping nonlinearity and hence results in a reduction of the threshold power required for formation of the soliton. The propagation of the light beam is studied for various different strengths of the waveguide. A beam which would not have normally been self trapped can now become a soliton by virtue of the planar waveguide structure. Finally, we investigate the linear stability of these solitons by both, the Lyapunov method and numerical simulations.
Green chemistry synthesis and structural and optical study of Dy2(CO3)3→ Dy2O3 transition
Authors: Portillo Oscar , Chavez Portillo M. , Juarez Santiesteban H. , Serrano de La Rosa L. , Alvarado Pulido J. , Ramos Reynoso Y.
Published: March 2023

This paper presents preliminary results of Dy2(CO3)3→Dy2O3 transition have been successfully obtained by Chemical Bath Deposition technical and subsequent thermal annealing temperature at ~600 °C. Two different temperatures of ~20°C and ~90 °C ± 2 °C are chosen to carry out the nanocrystalline growth. The crystalline phase is investigated by applying X-Ray Diffraction (XRD) and some optical properties; Transmittance, Reflectivity, Normalized Absorbance, real (n) and imaginary (k) parts refractive index. The crystalline phase of these inorganic nanomaterials for Dy2(CO3)3 is orthorhombic phase, while for Dy2O3 it is cubic. Grain size average values located at ranged ~2.8-3.4 nm for Dy2(CO3)3 and ~6.5-9.6 nm for Dy2O3. Vibrational modes are identified by Raman spectroscopy, modes at ~150-1800 cm-1 frequency range assigned to internal vibrations of  ion: v1-symmetric stretching (~1098 cm-1) v3-asymmetric -C-O stretching situated at ∼1063 cm-1, were observed corresponding to orthorhombic crystalline phase. The Fg+ Ag and A1g modes, corresponding to cubic phase Dy2O3. Multiple absorption bands with different relative intensities are observed at UV-Vis-NIR region, assigned to 4fs→4fs intra-electronic transitions and band gap energy. Absorption measurement were assigned to the transitions from ground state (6H15/2) to different excited states such as 4I13/2→4F7/2, 4I15/2, 6F3/2, 6F5/2, 6F7/2→6H5/2, 6F9/2→6H7/2, 6F11/2→6H9/2 and 6H11/2 of Dy3+ cation. Tauc’s plot reveals band gap situated at range ~4.66-5.17 eV for Dy2(CO3)3 and ~4.26-4.80 eV for Dy2O3 respectively.
Seasonal characterization of tropospheric ozone fluctuation in Mexico City
Authors: Matias Gutierres Sergio , Garcia-Otamendi Edgar Israel , Morales Ruíz Leobardo , Palacios Luengas Leonardo
Published: March 2023

The air pollution due to tropospheric ozone (O3) is one of the most serious problems of large industrialized cities in the world. The excessive increase in O3 has a negative impact on the population health. Consequently, researchers have focused their efforts establishing measures to characterize the statistical analysis of spatio-temporal data. This work shows a study based on seasonal analysis of spatio-temporal data through second order structure function to and the scale behavior in power law by using the Hurst exponent (H) and analyzing the trend of fluctuations associated with O3 pollution concentration records at four monitoring stations in the Metropolitan Area of Mexico City (MAMC) considering the four season of the year. The records were consulted from the database of the Automatic Atmospheric Monitoring Network (AAMN) in Mexico City from 2010 to 2018. The results show the differences in behavior of ozone according to the seasons of the year in this megacity. The behavior of statistical persistence predominates in spring, with 63.89% of occurrence over the total of the samples analyzed. In winter, the observed regime is antipersistent, with 80.56%. The three regimes: persistence, randomness and antipersistence were observed in summer and autumn, with a similar proportion of occurrence of 33% ± 3%. Given the above, the climatological characteristics of each season could be associated with the regimes of persistent, random and antipersistent behavior of the fluctuation of the concentration of the pollutant O3
Simbolismo y nostalgia
Authors: Hernández Perla Ileana , Montalvo Ramos
Published: February 2023

La arquitectura de remesas en San Simeón Xipetzinco, Tlaxcala, es una representaciónsimbólica que evoca nostalgia para sus migrantes establecidos en la región de JacksonHall, Wyoming, quienes se esfuerzan por mostrar éxito económico. El objetivo del trabajoes mostrar el sentir de migrantes quienes no quieren ser olvidados por el pueblo que losvio nacer y alejarse a una nueva vida, haciéndose presentes a través de majestuosas

construcciones que buscan el reconocimiento de la comunidad para ellos y su familia.

La arquitectura de remesas, mezcla la frialdad de una casa nueva con el calor de las emociones ysentimientos de migrantes como Paula y Emilio, quienes después de 20 años de esfuerzo ytrabajo dejaron México a cambio de una mejor calidad de vida en otro país.
Nuevos centros de urbanidad para Lima* Parque zonal Flor de Amancaes, Villa María del Triunfo. Parque zonal Santa Rosa, Santa Rosa
Authors: Facho Aldo
Published: February 2023

Escribo este artículo a siete años de la convocatoria a concurso nacional de ideas para el nuevo parque zonal Flor de Amancaes por parte del Servicio de Parques de Lima (SERPAR), y cuatro años desde la finalización de las obras. Más que realizar una descripción del mismo, me interesa compartir las lecciones que aprendí del proceso de gestión y concreción. En el año 2012 SERPAR convocó a un concurso para un nuevo parque zonal que se proyectaba construir en el distrito de Villa María del Triunfo, el mismo que ganamos junto a Ana Ábalos y Pablo Llopis de abalosllopis arquitectos. Este proyecto se enmarcaba en el Plan de Inversiones 2011-2014 que incluía la creación de dos nuevos parques y la implementación y remodelación de otros tres, con el objetivo de dotar a la población de equipamientos y servicios culturales, deportivos y recreacionales de alta calidad.
REOLOGÍA FISICOQUÍMICA DEL JARABE DE FRUTA (MIEL) PARA TURRÓN
Authors: Marín-Machuca Olegario , Iannacone José , Alvarado-Zambrano Fredy Aníbal , Vásquez-Aranda Ahuber Omar , Candela-Diaz José Eduardo , Quispe-Quispe Alexander
Published: February 2023

Las propiedades reológicas de los distintos alimentos líquidos y especialmente de los jarabes a base de frutas dependen de distintos aspectos, dentro de los cuales están la composición y la temperatura. Uno de los aspectos que influyen en mayor grado es el contenido de agua del jarabe y, en general cuando el contenido de humedad se incrementa la viscosidad del jarabe de frutas disminuye. El objetivo de este trabajo fue determinar la reología fisicoquímica del jarabe de fruta (miel) para el turrón peruano de “doña pepa”, para así obtener el mejor porcentaje de sinergismo de las gomas de xantan y de tara, y la más adecuada formulación para el jarabe de frutas. Para las dos gomas fueron determinadas seis concentraciones de 0,60 %, 0,80 %, 1,00 %, 1,20%, 1,40 % y 1,60%. En cada uno de estos porcentajes se determinó la viscosidad aparente, llegando a caracterizar el comportamiento de flujo del producto. Los resultados de pH, sólidos solubles y viscosidad dinámica de la fase continua para el tratamiento temperatura concentración (TZ), son mostrados tabulados. La viscosidad más idónea del jarabe de fruta para el turrón de Doña pepa a diferentes porcentajes de goma (xantan y tara) fue determinado a una temperatura de 22°C y a una concentración de 84°Brix.  Se ha concluye que las gomas xantan y tara son excelente espesantes para este tipo de productos.
NUEVOS REGISTROS PARA LA ICTIOFAUNA DE LOS HUMEDALES DE PUERTO VIEJO (LIMA, PERÚ)
Authors: García-Pio José Martín , Torres-Zevallos Uriel , Huamaní-Japan Mauro
Published: February 2023

Los humedales costeros son ecosistemas con alta diversidad de especies, considerándose de importancia estratégica en la conservación de la biodiversidad. La presente investigación tiene como fi nalidad hacer un registro de la ictiofauna entre los meses de noviembre y diciembre de 2019 en los humedales de Puerto Viejo, Perú. Se emplearon artes de pesca pasiva a través del uso de nasas. Se calculó la abundancia relativa por familia y especie, asimismo, los índices de diversidad alfa: riqueza específica (S), índice de Menhinick (DMn ), índice de Shannon (H’) e índice de Simpson (D). Un total de 201 especímenes fueron colectados pertenecientes a cinco géneros y siete especies: Bryconamericus peruanus (Müller & Troschel, 1845); Andinoacara stalsbergi Musilová, Schindler & Staeck, 2009; Amatitlania nigrofasciata (Günther, 1867); Oreochromis niloticus (Linnaeus, 1758); Poecilia reticulata Peters, 1859; Poecilia velifera (Regan, 1914) y Poecilia latipinna (Lesueur, 1821). La mayor diversidad se encontró en la laguna 1 (S = 4; H’ = 1,14; D = 0,65) y laguna 6 (S = 4; H’ = 1; D = 0,51). Bryconamericus peruanus, especie nativa para la vertiente del Pacífico, representó más del 50% de especímenes colectados, seguido de P. reticulata con 27,36% del total de peces. Fue hallado un espécimen de la especie endémica A. stalsbergi; se reporta la presencia de P. latipinna para humedales de Lima. A pesar de la fuerte presión antropogénica, los humedales de Puerto Viejo conservan una parte representativa de la ictiofauna continental de la costa peruana.
Media labs: journalistic innovation, evolution and future according to experts
Authors: Herrera-Damas Susana , Satizábal-Idárraga Christian-Camilo
Published: March 2023

At the current crossroads at which both the media and journalism find themselves, innovation emerges not as a “nice to have” but as an absolute, urgent, and pressing necessity. In this context, labs are presented as a structured and –in a certain way– privileged space to do so. However, since there are also voices that are critical of these spaces, we ask to what extent they contribute to journalistic innovation and also what future these spaces may have. To find out, we conducted semistructured interviews with a nonprobabilistic sample of 18 experts in this field, because they are both associated with a lab and are qualified experts in journalistic innovation or they are academic researchers. The results show that labs can bring a media outlet both tangible and intangible benefits, ranging from increased audience, audience loyalty, and revenue to increased prestige and reputation. However, today their future is uncertain owing to a variety of factors, including the funding necessary but also the utopian nature of the idea that the DNA of innovation can permeate the entire media outlet when there is no space specifically dedicated to designing, generating, and disseminating it to the newsroom as a whole.
ANALISIS EFEKTIFITAS PENGENDALIAN SISTEM SEPEDA LISTRIK MENGGUNAKAN GPS TRACKER BERBASIS APLIKASI ANDROID
Authors: Matsuani Matsuani Matsuani
Published: March 2023

Permasalahan jumlah kasus Pencurian Kendaraan Bermotor pada tahun 2017 terdapat 35226 kasus, tahun 2018 sebanyak 27731 kasus dan tahun 2019 terdapat 23476 kasus (Data BPS RI 2020). Masih tingginya tingkat pencurian sepeda listrik di indonesia. Mudah dirusaknya pengaman sepeda listrik bawaan pabrik dengan menggunakan kunci T atau cairan kimia. Pengaman konversional pada sepeda listrik yang digunakan belum bisa mencegah tindakan pencurian, sebatas hanya menghambat. Informasi yang kurang lengkap menyebabkan kesulitan dalam proses pencarian sepeda listrik yang telah dicuri. Tujuan analisis sistem pengaman GPS tracker pada sepeda listrik, Pengujian fitur-fitur yang dimiliki modul GPS tracker. Mengetahui titik lokasi kendaraan pada aplikasi GPS di smartphone android. Mengetahui koordinat garis bujur dan garis lintang pada aplikasi GPS. Perbandingan hasil titik koordinat dari aplikasi GPS dengan google maps. Menghitung tingkat keakuratan pada modul GPS tracker. Atas dasar permasalahan yang ada maka dikembangkan alat pengaman sepeda listrik yang menggunakan teknologi GPS dan smartphone android. Pengaman yang dapat melacak, menemukan, memonitor dan mengontrol sepeda listrik secara realtime dan live tracking menggunakan aplikasi berbasis android. Sistem pelacak kendaraan menggunakan GPS tracker dan GSM ini bertujuan untuk mengetahui posisi kendaraan pengguna, mematikan dan menghidupkan kendaraan yang dapat diatur menggunakan aplikasi dari perangkat smartphone android dan hasil pengujian perbandingan titik koordiant aplikasi GPS dengan google maps memiliki beberapa selisih angka yang berbeda. Tetapi tidak terlalu mempengaruhi lokasi sepeda listrik. Dari hasil perhitungan keakuratan koordinat modul GPS tracker dapat melacak koordinat GPS tracker dengan baik. Namun masih memiliki toleransi  keakuratan dengan rata-rata 10 meter. Hasil tersebut masih baik karena dari keakurasian GPS yaitu 3-12 meter.

 

Kata kunci: Efektifitas Pengendalian Sistem Sepeda Listrik, GPS Tracker, Aplikasi Android.
Pengaruh Kualitas Pelayanan, Kepercayaan, dan Harga terhadap Kepuasan Konsumen Pengguna Go-Ride di Kota Tangerang Selatan Pada Masa Pandemi Covid-19
Authors: Vindiana Afina Putri
Published: March 2023

Pandemi Covid-19 telah mempengaruhi berbagai sektor, salah satunya sektor transportasi berbasis online. Agar tetap bertahan pada masa pandemi, analisis mengenai kepuasan pelanggan dapat dilakukan oleh penyedia layanan jasa, khususnya transportasi berbasis online. Penelitian ini bertujuan untuk menganalisis pengaruh kualitas pelayanan, kepercayaan, dan harga terhadap kepuasan konsumen Go-Ride dimasa pandemi Covid-19 di Kota Tangerang Selatan menggunakan metode Structural Equation Modeling (SEM) dengan pendekatan Partial Least Square (PLS) dan menggunakan Software SmartPLS3. Responden berjumlah 114 orang yang merupakan pengguna Go-Ride di Kota Tangerang Selatan. Hasil penelitian menunjukkan: 1).Kualitas pelayanan berpengaruh signifikan terhadap kepuasan konsumen Go-Ride dimasa pandemi Covid-19 dengan nilai 0.152 dan P value 0.001. 2). Kepercayaan berpengaruh kuat dan sgnifikan terhadap kepuasan konsumen Go-Ride dimasa pandemi Covid-19 dengan nilai 0.211 dan P value 0.021. 3). Harga yang diberikan oleh Go-Ride berpengaruh sgnifikan terhadap kepuasan konsumen Go-Ride dimasa pandemi Covid-19 dengan nilai 0.589 dan P value 0.000. 4). Hasil GoF dalam penelitian ini menunjukkan bahwa model dapat dinyatakan kuat dan memiliki kecocokan dengan variabel yang diteliti dengan nilai 0.452.
Proses Scale Up Pembuatan Sabun Mandi Sekali Pakai dari Palm Cooking Oil (PCO) dengan Penambahan Berbagai Jenis Parfum
Authors: Handayani Sri
Published: March 2023

Sabun mandi sekali pakai merupakan sabun yang dibuat dalam bentuk yang kecil hanya sekitar 1-2 gram dan akan habis dalam sekali pemakaian. Pembeda utama antara sabun mandi sekali pakai dan sabun padat biasa adalah penambahan plasticizer untuk membuat sabun agar tidak menempel satu sama lain. Pada penelitian sebelumnya asam lemak yang digunakan berasal dari VCO (Virgin Coconut Oil)  dan polivinil alcohol 5% (sebanyak 15 gram) sebagai plasticizer. Pada penelitian ini digunakan          asam lemak yang berasal dari Palm Cooking Oil (PCO), dan dilakukan proses scale up dari formula yang telah ada serta dilakukan penambahan berbagai jenis parfum untuk mempelajari sifat fisik sabun mandi sekali pakai yang dihasilkan. Dari keempat formula yang ada, formula ke-3 yaitu sabun dengan 2% parfum Melona adalah formula yang paling baik dengan hasil analisa kadar air 15%, pH 9,9, kestabilan busa 90 dan kadar alkali bebas sebesar 0,02%.
Recommandations formalisées d’experts pour la prise en charge des pneumothorax spontanés primaires
Authors: Jouneau S. , Ricard J.-D. , Seguin-Givelet A. , Bigé N. , Contou D. , Desmettre T. , Hugenschmitt D. , Kepka S. , Le Gloan K. , Maître B. , Mangiapan G. , Marchand-Adam S. , Mariolo A. , Marx T. , Messika J. , Noël-Savina E. , Oberlin M. , Palmier L. , Perruez M. , Pichereau C. , Roche N. , Garnier M. , Martinez† M.
Published: March 2023

Introduction: Le pneumothorax spontané primaire (PSP) est un épanchement gazeux dans la cavité pleurale, survenant hors traumatisme et pathologie respiratoire connue. Des recommandations formalisées d'experts sur le sujet sont justifiées par les pluralités de moyens diagnostiques, stratégies thérapeutiques et disciplines médicochirurgicales intervenant dans leur prise en charge.

Méthodes: Revue bibliographique, analyse de la littérature selon méthodologie GRADE (Grading of Recommendation Assessment, Development and Evaluation) ; propositions de recommandations cotées par experts, patients et organisateurs pour obtenir un consensus. Seuls les avis d'experts avec accord fort ont été retenus.

Résultats: Un décollement sur toute la hauteur de la ligne axillaire et supérieur ou égal à 2 cm au niveau du hile à la radiographie thoracique de face définit la grande abondance. La stratégie thérapeutique dépend de la présentation clinique : exsufflation en urgence pour PSP suffocant ; en l'absence de signe de gravité : prise en charge conservatrice (faible abondance), exsufflation ou drainage (grande abondance). Le traitement ambulatoire est possible si organisation en amont de la filière. Les indications, procédures chirurgicales et l'analgésie périopératoire sont détaillées. Les mesures associées, notamment le sevrage tabagique, sont décrites.

Conclusion: Ces recommandations sont une étape de l'optimisation des stratégies de traitement et de suivi des PSP en France.
‘Need’ and ‘Desire’ in Shakespeare's Sonnets and Mawlana's Ghazals
Authors: Mortazavi Seyedeh Sahar , Ladani Zahra Jannessari , Pirnajmuddin Hossein
Published: February 2023

This article aims at a comparative reading of a selection of Shakespeare's sonnets and Mawlana's ghazals from a Levinasian perspective. We will argue how Shakespeare and Mawlana (Rumi) both represent an ethical relationship with the Other in their poems, where the needs and demands of the Other are prioritised. We will also contend that although Shakespeare's sonnets are not exclusively concerned with secular love or eroticism, they are closer to the Levinasian notion of desire or a-satiable desire in which transcendence becomes possible through need. On the other hand, Mawlana's ghazals in which need and erotic feelings are disparaged also warn about satiable desire and need. This is not to suggest that the results of this comparison can be extended to Shakespeare's sonnets and Mawlana's ghazals in general, but that a similar Levinasian reading is occasionally possible and might shed new light on connections between English and Persian lyric poetry.
Single-institution comparative analysis for odontoid resection: posterior transaxis versus anterior transnasal approach
Authors: Doğan İhsan , Bayatli Eyüp , Eray Halit Anil , Erdogan Koral , Terzi Macit , Hasimoglu Savas , Tekneci Ozan , Beton Suha , Eroglu Umit , Ozgural Onur , Kahilogullari Gokmen , Caglar Yusuf Sukru
Published: March 2023

OBJECTIVE

The resection of an upwardly migrated odontoid is most widely performed via an anterior endoscopic endonasal approach after the addition of posterior occipitocervical instrumentation. In patients with craniovertebral junction (CVJ) anomalies like basilar invagination (BI), surgery is usually achieved in two separate stages. However, the authors have recently introduced a novel posterior transaxis approach in which all the therapeutic goals of the surgery can be safely and effectively accomplished in a single-stage procedure. The aim of the current study was to compare the widely used anterior and the recently introduced posterior approaches on the basis of objective clinical results in patients who underwent odontoid resection for BI.

METHODS

Patients with BI who had undergone odontoid resection were retrospectively reviewed in two groups. The first group (n = 7) consisted of patients who underwent anterior odontoidectomy via the standard anterior transnasal route, and the second group (n = 6) included patients in whom the novel transaxis approach was performed. Patient characteristics, neurological conditions, and modified Rankin Scale (mRS) scores at admission were evaluated. Operative time, changes in intraoperative neurophysiological monitoring, blood loss during surgery, odontoid resection rate, postoperative complications, and mortality were compared between the patient groups.

RESULTS

Data were retrospectively reviewed for 13 patients who underwent odontoid resection, posterior CVJ decompression, and occipitocervical instrumentation at the Ankara University School of Medicine Department of Neurosurgery between 2009 and 2022. In the first group (n = 7), patients who underwent anterior odontoidectomy via the standard endonasal route, two serious complications were observed, pneumocephaly and basilar artery injury. In the second group (n = 6), patients in whom the novel transaxis approach was performed, only one complication was observed, occipital plate malposition.

CONCLUSIONS

This study represents the results of what is to the authors’ knowledge the first comparison of a novel approach with a widely used surgical approach to odontoid resection in patients with BI. The preliminary data support the successful utility of the transaxis approach for odontoid resection that meets all the operative therapeutic demands in a single-stage operation. Considering the diminished surgical risks and operative time, the transaxis approach may be regarded as a primary approach for the treatment of BI.
Reappraisal of intradural findings in Chiari malformation type I
Authors: Shao Belinda , Wojcik Daniel , Ma Kevin L. , Amaral-Nieves Natalie , Poggi Jonathan A. , Leary Owen P. , Klinge Petra M.
Published: March 2023

OBJECTIVE

Management of Chiari malformation type I (CM-I) requires the functional restoration of an obstructed cisterna magna. In posterior fossa decompression with duraplasty (PFDD), various intradural pathologies are suggested to alter CSF flow at the craniocervical junction and require surgical correction. However, reports of the spectrum of intraoperative intradural findings and their nuances are scarce, especially those characterizing rarer findings pertaining to the vascular structures and vascular compression.

METHODS

The authors conducted a retrospective cohort analysis of adults and children who underwent first-time PFDD for CM-I (2011–2021), with and without syringomyelia. The surgical reports and intraoperative videos were reviewed, and the frequency and nature of the intradural observations in regard to the tonsils, arachnoid, and vasculature were analyzed along with the clinical findings and surgical outcomes.

RESULTS

All 180 patients (age range 1–72 years; median [interquartile range] 24 (14–38) years; 37% of patients were children < 21 years of age) exhibited multiple intradural findings, with a median of 7 distinct concurrent observations in each patient. Novel findings not previously reported included posterior inferior communicating artery (PICA) branches compressing the neural elements at the cervicomedullary junction (26.7%). Other common findings included arachnoid adhesions (92.8%), thickening (90.6%), webs at the obex (52.2%), tonsillar gliosis (57.2%), tonsillar hypertrophy (18.3%), adhesions obstructing the foramen of Magendie (FoM) (62.2%), PICA obstruction of the FoM (17.2%), and dural scarring (87.8%). Tonsillar gliosis and intertonsillar adhesions obstructing the FoM were more common in children than adults. Tonsillar gliosis and arachnoid webs were more common among syringomyelia patients. After multivariable adjustment, none of the observed findings were independently associated with syringomyelia, preoperative symptoms, or postoperative improvement. The vast majority of patients improved postoperatively. The complication rate was low: 1.2% of patients required revision PFDD at > 3 years postoperatively, 3.6% experienced other operative complications, and 0% had CSF leaks.

CONCLUSIONS

The diversity of intradural findings and observations revealed in this study suggests that obstructive and compressive structural anomalies may be more common than previously reported among CM-I patients, both those patients with and those without syringomyelia and especially those with obstructive and compressive PICA branches. Although the authors cannot conclude that all these findings are necessarily pathological, further study may determine how they contribute to CM-I pathology and symptomatology in the setting of a compromised cisterna magna.
Risk factors for clinical and radiological worsening following Chiari malformation type I surgery in the pediatric population
Authors: Fatima Nida , Swift Dale M. , Montgomery Eric Y , Weprin Bradley E. , Price Angela V. , Whittemore Brett A. , Braga Bruno P.
Published: March 2023

OBJECTIVE

Foramen magnum (FM) decompression with or without duraplasty is considered a common treatment strategy for Chiari malformation type I (CM-I). The authors’ objective was to determine a predictive model of risk factors for clinical and radiological worsening after CM-I surgery.

METHODS

A retrospective review of electronic health records was conducted at an academic tertiary care hospital from 2001 to 2019. A multivariable Cox proportional hazards regression model was used to determine the risk factors. The Kaplan-Meier estimate was plotted to delineate outcomes based on FM size. FM was measured as the preoperative distance between the basion and opisthion and dichotomized into < 34 mm and ≥ 34 mm. Syrinx was measured preoperatively and postoperatively in the craniocaudal and anteroposterior directions using a T2-weighted MRI sequence.

RESULTS

A total of 454 patients (231 females [50.9%]) with a median (range) age of 8.0 (0–18) years were included in the study. The median duration of follow-up was 21.0 months (range 3.0–144.0 years). The model suggested that patients with symptoms consisting of occipital/tussive headache (HR 4.05, 95% CI 1.34–12.17, p = 0.01), cranial nerve symptoms (HR 3.46, 95% CI 1.16–10.2, p = 0.02), and brainstem/spinal cord symptoms (HR 3.25, 95% CI 1.01–11.49, p = 0.05) had higher risk, whereas those who underwent arachnoid dissection/adhesion lysis had 75% lower likelihood (HR 0.25, 95% CI 0.10–0.64, p = 0.004) of clinical worsening postoperatively. Similarly, patients with evidence of brainstem/spinal cord symptoms (HR 7.9, 95% CI 2.84–9.50, p = 0.03), scoliosis (HR 1.04, 95% CI 1.01–2.80, p = 0.04), and preoperative syrinx (HR 16.1, 95% CI 1.95–132.7, p = 0.03) had significantly higher likelihood of postoperative worsening of syrinx. Patients with symptoms consisting of occipital/tussive headache (HR 5.44, 95% CI 1.86–15.9, p = 0.002), cranial nerve symptoms (HR 2.80, 95% CI 1.02–7.68, p = 0.04), and nonspecific symptoms (HR 6.70, 95% CI 1.99–22.6, p = 0.002) had significantly higher likelihood, whereas patients with FM ≥ 34 mm and those who underwent arachnoid dissection/adhesion lysis had 73% (HR 0.27, 95% CI 0.08–0.89, p = 0.03) and 70% (HR 0.30, 95% CI 0.12–0.73, p = 0.008) lower likelihood of reoperation, respectively. The Kaplan-Meier curve showed that patients with FM size ≥ 34 mm had significantly better clinical (p = 0.02) and syrinx (p = 0.03) improvement postoperatively when the tonsils were resected.

CONCLUSIONS

These results showed that preoperative and intraoperative factors may help to provide better clinical decision-making for CM-I surgery. Patients with FM size ≥ 34 mm may have better outcomes when the tonsils are resected.
Intraoperative neuromonitoring for pediatric Chiari decompression: when is it useful?
Authors: Sen Rajeev D. , Martinez Vicente , Eaton Jessica , Holdefer Robert N. , Ellenbogen Richard G.
Published: March 2023

OBJECTIVE

Surgical treatment for symptomatic Chiari I malformation involves surgical decompression of the craniovertebral junction. Given the proximity of critical brainstem structures, intraoperative neuromonitoring (IONM) is employed for safe decompression in some institutions. However, IONM adds time and cost to the operation, and the benefit to the patient has not been defined. Given the diversity in surgical practices, there is no evidence-based standard of care regarding when to use IONM and which modalities are most helpful. The purpose of this study was to review a single-surgeon experience with IONM in order to determine the sensitivity, specificity, and predictive values of various IONM modalities routinely used in pediatric Chiari I decompression; to examine the associations between patient, clinical, and radiographic characteristics and IONM alerts; and to obtain data regarding the usefulness of these modalities during the surgical process to improve patient outcomes.

METHODS

A retrospective review was performed for 300 consecutive pediatric patients who underwent suboccipital craniectomy and C1 laminectomy for Chiari decompression performed by a single surgeon over a 15-year period. Clinical, radiographic, and IONM data were collected. Radiographic measurements of the skull base morphological abnormalities, including clival angle, Chamberlain’s line, and Grabb-Oakes line, were compared between patients with and without true IONM signal changes.

RESULTS

A total of 291 cases were included, with an age range of 6 months to 19 years. Among 291 cases, somatosensory evoked potentials (SSEPs) were monitored in 291, motor evoked potentials (MEPs) in 209, cranial nerve spontaneous electromyography (sEMG) in 290, and brainstem auditory evoked potentials (BAEPs) in 110. Sensitivity, specificity, positive predictive value, and negative predictive value, respectively, were as follows: 1.00, 1.00, 1.00, and 1.00 for SSEPs; 1.00, 0.99, 0.67, and 1.00 for MEPs; 0.00, 0.88, 0.00, and 1.00 for sEMG; and not appliable, 1.00, not applicable, and 1.00 for BAEPs. Six patients had true IONM signal changes. These patients had radiographic evidence of more severe concomitant craniocervical instability and basilar invagination, with steeper clival angles (124° vs 146°, p = 0.02) and larger Grabb-Oakes lines (10.1 mm vs 6.7 mm, p = 0.02), when compared with the patients without any true IONM changes.

CONCLUSIONS

Intraoperative neuromonitoring may be best utilized for patients who show radiographic features of abnormal skull base morphology, defined as a clival angle < 135° or Grabb-Oakes line > 9 mm. When IONM is employed, SSEP and MEP monitoring are the most useful modalities.
Tobacco Smoking among the Online Respondent Dental Students of a Dental College: A Descriptive Cross-sectional Study
Authors: Thakur Deepak , Kaur Navpreet , Chahar Monika , Barman Nitul , Gupta Roopali , Sharma Vivek
Published: March 2023

Introduction: Smoking tobacco is most common nowadays among dental students due to stress induced by practical workloads and exams. There is limited data regarding tobacco smoking among dental students. The aim of this study was to determine the prevalence of tobacco smoking among online respondent dental students of a dental college.
Methods: This was a descriptive cross-sectional study conducted on dental students from 15 July 2021 to 15 August 2021. Ethical approval was obtained from the Institutional Review Committee of K.D. Dental College and Hospital (Reference number: KDDC/Admin/2021/9990A). Data was collected through a structured questionnaire and responses were gathered using an online Google form survey with informed consent. A convenience sampling method was used. Point estimate and 95% confidence interval were calculated.
Results: Among 60 online respondents, the prevalence of tobacco smoking was found to be 11 (18.33%) (17.04-24.56, 95% Confidence Interval). The percentage of participants who wanted to stop smoking now was 11 (18.33)%.
Conclusions: The prevalence of tobacco smoking among the online dental respondents of a dental college was similar to the other studies done in similar settings.
Early Canities among Undergraduate Medical Students of a Medical College: A Descriptive Cross-sectional Study
Authors: Chaudhary Sonam , Mahotra Narayan Bahadur
Published: March 2023

Introduction: Early canities are the premature greying of hair before the age of 25 years in Asians. The condition is a matter of concern for young adults aesthetically. This study aimed to find out the prevalence of early canities among undergraduate medical students of a medical college.
Methods: A descriptive cross-sectional study was carried out from 1 December 2021 to 30 June 2022 among undergraduate medical students at a medical college. The study was conducted after receiving ethical approval from the Institutional Review Committee [Reference number: 146(6-11)C-2 078/079]. The participants with ages less than 25 years without a history of vitiligo, intake of chemotherapeutic drugs, progeria, pangeria and recent dyeing of hair were enrolled. A convenience sampling method was used. Point estimate and 95% Confidence Interval were calculated.
Results: Out of 235 students, 95 (40.42%) (34.15-46.69, 95% Confidence Interval) had early canities. The most prevalent premature greying was grade I early canities i.e.79 (83.15%) of participants. Among the participants with early canities, 56 (58.94%) were male, 41 (43.15%) had a positive family history for early canities, 67 (70.52%) had normal body mass index and 38 (40%) had O+ve blood group.
Conclusions: The prevalence of early canities among undergraduate medical students was lower than in other studies done in similar settings. The grade I early canities was seen more among the participants with premature greying of hair.
Positive Pivot Shift Test among Patients with Displaced Anterior Tibial Spine Fractures Undergoing Arthroscopic Fixation in a Tertiary Care Centre: A Descriptive Cross-sectional Study
Authors: Joshi Amit , Shrestha Sabin , Regmi Subhash , Basukala Bibek , Sharma Rajiv , Bista Rohit , Singh Nagmani , Pradhan Ishor
Published: March 2023

Introduction: Understanding of displaced anterior tibial spine fractures has evolved over the years and is now considered to be anterior cruciate ligament avulsion injuries rather than intra-articular fractures. However, there are very few studies available evaluating the presence or absence of a pivot shift test, which is specific in diagnosing anterior cruciate ligament insufficiency, in patients with anterior tibial spine fractures. This study aimed to find out the prevalence of the positive pivot shift test among patients with displaced anterior tibial spine fractures undergoing arthroscopic fixation in a tertiary care centre.
Methods: A descriptive cross-sectional study was conducted among patients presented with displaced anterior tibial spine fractures undergoing arthroscopic fixation. The data were collected between 1 January 2020 and 30 May 2022. Ethical approval was obtained from the Institutional Review Committee (Reference number: IRC_2019_11_09_1). All patients who presented with displaced anterior tibial spine fractures undergoing arthroscopic fixation were included in the study and those who did not provide consent were excluded. The pivot test was performed under anaesthesia. Point estimate and 90% Confidence Interval were calculated.
Results: Among 48 patients, pivot shift was positive in 36 (75%) (64.75-85.25, 90% Confidence Interval). The mean age of the participants was 28.97±11.16 years, 21 (58.33%) were males and 15 (41.66%) were females.
Conclusions: The prevalence of positive pivot shift test under anaesthesia in patients with displaced anterior tibial spine fractures undergoing arthroscopic fixation was higher than other studies done in similar settings.
Colostrum Feeding among Newborns Visiting the Outpatient Department of Pediatrics of a Tertiary Care Centre: A Descriptive Cross-sectional Study
Authors: Acharya Sharda , Thapa Bibechan , Dhakal Ajaya Kumar , Singh Saurav Kumar
Published: March 2023

Introduction: Colostrum is the thick yellowish breast milk that is produced during the first 3-5 days of childbirth. Feeding colostrum protects the newborn from various diseases, thus promoting the overall well-being of the newborn. The objective of this study was to find out the prevalence of colostrum feeding among newborns visiting the Department of Pediatrics in a tertiary care centre.
Methods: A descriptive cross-sectional study was done among infants presenting to the Department of Pediatrics in a tertiary care centre. Ethical approval was taken from the Institutional Review Committee (Reference number: 2078/079/107). The duration of study was six month from 12 February 2022 to 12 August 2022. A pre-designed questionnaire was used for face-to-face interviews. Convenience sampling was done. Point estimate and 95% Confidence Interval were calculated.
Results: Among 350 newborns, colostrum was fed to 305 (87.14%) (83.63-90.65, 95% Confidence Interval) newborns. A total of 180 (59.02%) were breastfed within 1 hour of delivery.
Conclusions: The prevalence of colostrum feeding was higher in our study than in other studies done in similar settings.
Hysteroscopy among Patients Attending the Outpatient Department of Gynaecology in a Tertiary Care Centre: A Descriptive Cross-sectional Study
Authors: Ghimire Asmita , Ghimire Sailaja , Shrestha Asmita , Pant Samridhha Raj , Subedi Nilam , Pant Padam Raj
Published: March 2023

Introduction: Hysteroscopy is a procedure used widely for diagnostic and therapeutic purposes. Hysteroscopy enables visualisation of the endometrial cavity and if possible treatment in the same setting avoiding invasive procedure. The objective of the study was to find out the prevalence of hysteroscopy among gynaecological patients attending the outpatient department of Obstetrics and Gynaecology in a tertiary care centre.
Methods: A descriptive cross-sectional study was done among gynaecological patients from 1 January 2016 to 1 January 2020 visiting the outpatient Department of Obstetrics and Gynaecology in a tertiary care centre after ethical approval from the Institutional Review Committee (Registration number: 029/2021). Convenience sampling was used. Data regarding demographic parameters, hysteroscopy findings, procedures performed, histopathological findings and complications were retrieved from the electronic database of the hospital. Point estimate and 95% Confidence Interval were calculated.
Results: Among 319 gynaecological patients, hysteroscopy was done in 72 (22.57%) (17.98-27.16, 95% Confidence Interval) patients.
Conclusions: The prevalence of hysteroscopy among gynaecological patients was higher to the studies done in similar settings.
A Large Follicular Adenomatoid Odontogenic Tumor Occupying the Maxillary Sinus: A Case Report
Authors: Maharjan Leison , Gurung Urmila , Pradhan Bibhu
Published: March 2023

Adenomatoid odontogenic tumour is a rare benign, odontogenic tumour with uncertain histogenesis. Whether it is a hamartoma or a neoplasm is still a controversial topic. It is usually associated with an unerupted maxillary canine. Here, we discuss a follicular adenomatoid odontogenic tumour in a young girl with uncommon features such as it arose from two unerupted teeth and partial resorption of the roots of other normal teeth. The tumour was large enough to completely occupy the maxillary sinus. It was treated with enucleation and curettage by lateral rhinotomy approach.
A Transitional Experience: Basic Science to Clinical Rotation
Authors: Pradhan Bishal , Rokaha Prerana Singh , Lama Ashmina
Published: March 2023

Bachelor of Medicine and Bachelor of Surgery is a roller coaster journey that is educational yet emotional. Because of how the context and responsibilities change throughout time, learning is exciting. Nevertheless, the exposure to basic science during this course teaches us to be diligent, committed, and compassionate, and it also gets us ready for the next stage of clinical practice. For us as students, the primary areas that change as a result of this transformation are professional networking, workload, patient interaction, time management, leadership, and communication skills. In this journey, the transition is inevitable so we need to adapt to change seamlessly. Additionally, extracurricular activities play a significant role in this journey.
Myopia among Medical Undergraduates of a Medical College: A Descriptive Cross-sectional Study
Authors: Shrestha Tina , Kushwaha Dilip Kumar , Tiwari Saurabh , Sah Umesh Kumar , Raj Risu , Rajak Siddharth , Lamsal Anukram , Joshi Sahasra , Dulal Aliza , Chaudhary Aashutosh
Published: March 2023

Introduction: Myopia is defined as a refractive error in which rays of light entering the eye parallel to the optic axis are brought to focus in front of the retina when accommodation is relaxed. Globally, myopia prevalence is on the rise for unknown reasons. The aim of the study was to find out the prevalence of myopia among undergraduates of a medical school.
Methods: A descriptive cross-sectional study was conducted among medical undergraduates of a medical school between 2 May 2022 to 3 August 2022 after receiving ethical approval from the Institutional Review Committee of the same institute (Reference number: 21/20). A proforma was distributed among the medical undergraduates and data from known myopic students were collected. A convenience sampling method was used. Point estimate and 95% Confidence Interval were calculated.
Results: Among 279 medical undergraduates, myopia was seen in 119 (42.65%) (36.85-48.45, 95% Confidence Interval). The mean age of the myopic undergraduates was 21±1.47 years.
Conclusions: The prevalence of myopia among undergraduates was found to be lower than the other studies done in similar settings.
Undermined Skin Lesion Emerged as Tubercular Meningitis: A Case Report
Authors: Yadav Dhirendra , Khan Javed Ahmad
Published: March 2023

Cutaneous tuberculosis is a rare type of extrapulmonary tuberculosis and it is uncommon even in places where tuberculosis is widespread. A 32-year-old female presented with fever and headache along with prior history of an ulcer in her leg which was treated as cellulitis at another centre. The neck rigidity, and the Kernig and Budzinski sign were also positive. There were also features of increased intracranial pressure. The non-contrast computed tomography showed bilateral hydrocephalus and hypodense areas. She was managed for increased intracranial pressure and anti-tubercular therapy for disseminated tuberculosis. Biopsy of non-healing wounds should be checked for lupus vulgaris.
Chronic Liver Disease among Patients Admitted in the Department of Internal Medicine of a Tertiary Care Centre: A Descriptive Cross-sectional Study
Authors: Poudel Sujan Chandra , Acharya Abishkar , Maharjan Sujata , GC Saroj , Shrestha Reshika , Thapa Suraksha , Poudel Shekhar
Published: March 2023

Introduction: Chronic liver disease with cirrhosis is a significant cause of morbidity and mortality not only in developed but also in developing countries. Many patients already develop complications before hospital admission and require intensive medical care during hospital treatment. The main objective of the study was to find out the prevalence of the chronic liver disease among patients admitted in the Department of Internal Medicine of a tertiary care centre.
Methods: A descriptive cross-sectional study was conducted among patients admitted to the Department of Internal Medicine of a tertiary care centre from 1 January 2022 to 31 March 2022. Ethical approval was obtained from the Ethical Review Board (Reference number: 2211202105). The patient admitted in the Department during the study period was included and those who do not gave consent were excluded. Convenience sampling method was used. Point estimate and 95% Confidence Interval were calculated.
Results: Out of 447 patients, the prevalence of chronic liver disease was 93 (20.8%) (17.04-24.56, 95% Confidence Interval). The mean age of the patients was 49.69±10.94 years and among them, males were 64 (68.82%).
Conclusions: The prevalence of the chronic liver disease among patients admitted to the Department of Internal Medicine of a tertiary care centre was lower than in other studies conducted in similar settings.
Dengue Fever in a Neonate: A Case Report
Authors: Bhattarai Chaitanya Darshan , Yadav Birendra Kumar , Basnet Rabin , Karki Manish , Chauhan Shanta
Published: March 2023

Dengue is one of the most common viral infections affecting the general population in endemic areas annually. However, it is barely reported in newborns owing to a widespread belief that they are protected from severe viral infections in the first six months of life by the presence of maternal antibodies. Here we present a case of a 23-day-old male infant born to primigravida with dengue fever with the post-natal transmission of infection. He presented with complaints of fever for three days. On general examination, red-coloured pinpoint macular rashes were observed bilaterally on lower limbs. No significant findings were present on systemic examination. On routine sepsis workup, thrombocytopenia was present. Acknowledging the endemicity and expanding dengue cases, NS1 antigen and antibody IgM and IgG of the baby were tested which came positive for antigen and IgM antibody. Even so, the mother was asymptomatic with NS1 antigen, IgG and IgM antibodies negative with a normal range of platelet count.