ABSTRACT
Objective: The aim of this study was to quantify the changes that occurred in the surgical services of children during the COVID-19 pandemic from the perspective of a low/middle-income country. Design: A case-control study was conducted at a large referral centre in Bangladesh among patients aged ≤12 years. Comparisons were made between cases admitted during a period of 'April to September 2020' (Pandemic period) and controls during a similar period in 2019 (Reference period). The number of admissions and outpatient department (OPD) attendances, age and sex distribution, diagnosis, number and types of surgeries performed (elective vs emergency), variations in treatment of acute appendicitis, types of anaesthesia and mortality were compared. Results: Admissions were only 41% of previous year (635 vs 1549), and OPD attendances were only 28% of previous year (603 vs 2152). Admission of children reduced by 65.8%, but neonatal admission reduced only by 7.6%. The median age of the admitted patients was significantly lower during the pandemic period (3 vs 4 years, p<0.01). Acute appendicitis (151, 9.8%) and trauma (61, 9.6%), respectively, were the the most common causes of admission during the reference and the pandemic period. Elective surgeries were only 17% and emergency surgeries were 64% of previous year (p<0.01). Appendectomy (88, 9.1%) and laparotomy (77, 17.6%), respectively, were the most common surgeries performed during the reference and the pandemic period. Conservative treatment of acute appendicitis was more during the pandemic period (47.5% vs 28.5%, p=0.01), but patients who underwent appendectomies had more complicated appendicitis (63.3% vs 42.1%, p=0.01). In all, 90.4% of surgeries were performed by resident doctors. There were no COVID-19- related deaths. Conclusion: Trauma became the most common cause of admission during the pandemic, and neonatal surgical conditions remained almost unchanged with high mortality rates. Elective procedures and laparoscopy remained low and resident doctors played a major role in providing surgical services.
Subject(s)
COVID-19 , Pandemics , Case-Control Studies , Child , Child, Preschool , Government , Humans , Infant, Newborn , Retrospective Studies , SARS-CoV-2 , Tertiary Care CentersABSTRACT
In this work, optical properties of epitaxial CaxBa1-xNb2O6, CBN (x = 0.28) thin film based waveguides are studied at 1550 nm optical communications wavelength. CBN thin films are deposited epitaxially on MgO substrates using Pulsed Laser Deposition and characterized by prism coupling to extract the refractive index and propagation loss. It is shown that the 2 µm-thick epitaxial CBN thin films have a refractive index close to the bulk form and the CBN planar waveguides have a propagation loss of 4.3 ± 0.5 dB/cm. 1 cm-long rib waveguide structures were fabricated using a high density plasma etching. Their propagation losses were measured by the cutback method at 8.4 ± 0.6 dB/cm.
ABSTRACT
We demonstrate photo-patternable ion gel-gated graphene transistors and inverters on plastic substrates. The photo-patternable ion gel can be used as a negative photoresist for the patterning of underlying graphene as well as gate dielectrics. As a result, an extra graphene-patterning step is not required, which simplifies the device fabrication and avoids a side effect arising from the photoresist residue. The high capacitance of ion gel gate dielectrics yielded a low voltage operation (~2 V) of the graphene transistor and inverter. The graphene transistors on plastic showed an on/off-current ratio of ~11.5, along with hole and electron mobilities of 852 ± 124 and 452 ± 98 cm(2) V(-1) s(-1), respectively. In addition, the flexible graphene inverter was successfully fabricated on plastic through the potential superposition effect from the drain bias. These devices show excellent mechanical flexibility and fatigue stability.