Atypical respiratory distress in eastern Democratic Republic of the Congo prior to the COVID-19 pandemic. A case report

Background Predictions have been made that Africa would be the most vulnerable continent to the novel Coronavirus disease 2019 (COVID-19). Interestingly, the spread of the disease in Africa seems to have been delayed and initially slower than in many parts of the world. Here we report on two cases of respiratory distress in our region before the official declaration of the disease in December 2019, cases which in the present times would be suspect of COVID-19. Case presentation These two cases (one 55-year-old man and one 25-year-old woman) of acute respiratory distress secondary to atypical pneumonia were seen in Bukavu, in Eastern Democratic Republic of the Congo (DRC), between September and December 2019. One patient had returned from China and the other had close contacts with travellers from China in the 2 weeks prior to the onset of symptoms. In either case, the aetiology could not be accurately determined. However, the two cases presented a clinical picture (progressive dyspnoea, preceded by dry cough and fever) and laboratory changes (procalcitonin within the normal range, slight inflammation, and lymphopenia) compatible with a viral infection. The chest X-ray series of the first patient showed lesions (reticulations, ground glass, and nodules ≤6 mm) similar to those currently found in COVID-19 patients. In addition, unlike the 25-year-old female patient who had no comorbidity, the 55-year-old male patient who had hypertension as comorbidity, developed a more severe acute respiratory distress which progressed to death. Conclusion These cases bring to the attention the fact that COVID-19-like syndromes may have already been present in the region months before the official beginning of the pandemic. This also brings to question whether a prior presence of the disease or infections with related virus may account for the delayed and less extensive development of the pandemic in the region.

Appropriate abdominal imaging for the emergency department patient

Abdominal x-ray series (AXR) and abdominal CT scans (ACT) are commonly performed to aid in the diagnosis for patients who present to the emergency room with abdominal pain. Patients commonly receive both an AXR and ACT, due to a lack of knowledge regarding imaging appropriateness among healthcare professionals who order these exams. A primary simple retrospective data-analysis was performed to understand the prevalence of how often both exams were ordered in three Nova Scotia emergency departments. A literature review was also conducted to compare the diagnostic accuracy of each diagnostic imaging modality. Several articles showed that patients who have an AXR also have an ACT that demonstrates an abnormal finding. Emergency department physicians are not reassured when abdominal x-rays are negative and do not show abnormal findings, and as a result, a CT scan is also performed. Radiation dose must be considered when ordering multiple diagnostic imaging exams. A low-dose CT (LDCT) can be used to reduce the radiation exposure to the patient, while maintaining high diagnostic quality images. Image quality can be enhanced at a reduced radiation dose by using an image reconstruction technique such as adaptive statistical iterative reconstruction (ASIR). Understanding the most appropriate abdominal imaging modality for emergency department patients allows for fewer examinations being ordered and a reduction of radiation dose to the patient. When the most appropriate imaging is performed, a definitive diagnosis can be made and the best treatment can be provided to patients. This information can help to create an imaging appropriateness protocol for emergency departments.Additional research can help determine the cost differences between the two exams and the influence a protocol change could have on the emergency and diagnostic imaging departments.Keywords: AXR – Abdominal x-ray series, ACT – Abdominal computed tomography scan, CT – Computed tomography, SDCT – Standard-dose CT, LDCT – Low-dose CT, ASIR – Adaptative statistical iterative reconstruction FBP – Filtered back projection, CTDIvol – Volume computed tomography dose index

Noncompressed cylindrical layer shock loading in anisothermic conditions

На примере нескольких задач о нагружении упруговязкопластического и термоупругого цилиндрических слоёв с предварительными деформациями показаны основные моменты, на которые следует обратить внимание при комплексном моделировании отклика на существенно нестационарное воздействие термоупругой несжимаемой среды с вязкопластическими свойствами. Отмечены нюансы, касающиеся употребления соотношений теории больших упругопластических деформаций, применения метода лучевых рядов и использования специальных схем численных расчётов. Представлены зависимости скачков температуры и добавочного давления на плоскополяризованных поверхностях сильного разрыва, определены скорости волн нагрузки и круговой поляризации. The main points witch should be paid attention of modeling the response of thermoelastic incompressible medium with viscoplastic properties to the essentially unsteady effect are shown by the example of several problems on loading elastoviscoplastic and thermoelastic cylindrical layers with preliminary deformations. Some remarks were noted regarding to the use of the relations of the theory of finite elastoplastic deformations, the ray series method application and special numerical calculation schemes. The dependencies of temperature and additional pressure breaks on plane-polarized strong discontinuities surfaces, loading and circular polarized waves velocities are determined.

Requirement of HE-PIXE at High Z Elements in Charnockite Matrix Composition

The maximum of Proton Induced X-ray Emission analytical technique on metamorphic rocks in geology has used 3 MeV range proton beams for excitation of thick targets. Protons of such energies do not accurately excite K-X–rays for high Z elements in matrix geological compositions like charnockite. In this analysis, low-energy PIXE (LE-PIXE) uses K-X-rays of Low Z elements and L-X-ray series for high Z elements. The resulting spectra between K-X-rays of light elements and L-X-rays of heavy elements can require striping techniques to resolve overlap difficulties in matrix composition. The results high Z elements in charnockite are to be expected, as the cross section for K-shell ionization of high-Z elements have greater values in the proton energy range of greater than 3 MeV in case of charnockite matrix composition. It has been suggested that the overlap of these discrete, gamma-rays with the X-ray spectrum may be serious problem in charnockite high energy PIXE (HE-PIXE) work, sufficient to preclude its use as a viable analytical technique. The conclusion proves that for a very complex matrix charnockite material of unknown chemistry, a HE-PIXE analytical spectrum may contain various X-ray and gamma peaks, some of which may overlap, making the analysis of line identities and the evaluation of X-ray counts intractable. It does not however represent any intrinsic drawback in HE-PIXE, nor does it mean that HE-PIXE is any more or less intractable than many other nuclear analytical techniques. Alternatively, the same analytical tool use could be made of gamma-rays in HE-PIXE as in low energy analytical tools like PIGE, NRA or INAA to obtain the results of charnockite at high Z completely.