Ultrasonographic findings in patients with abdominal symptoms or trauma presenting to an emergency room in rural Tanzania

BACKGROUND: Frequencies of ultrasonographic findings and diagnoses in emergency departments in sub-Saharan Africa are unknown. This study aimed to describe the frequencies of different sonographic findings and diagnoses found in patients with abdominal symptoms or trauma presenting to a rural referral hospital in Tanzania. METHODS: In this prospective observational study, we consecutively enrolled patients with abdominal symptoms or trauma triaged to the emergency room of the Saint Francis Referral Hospital, Ifakara. Patients with abdominal symptoms received an abdominal ultrasound. Patients with an abdominal or thoracic trauma received an Extended Focused Assessment with Ultrasound in Trauma (eFAST). RESULTS: From July 1st 2020 to June 30th 2021, a total of 88838 patients attended the emergency department, of which 7590 patients were triaged as 'very urgent' and were seen at the emergency room. A total of 1130 patients with abdominal symptoms received an ultrasound. The most frequent findings were abnormalities of the uterus or adnexa in 409/754 females (54.2%) and abdominal free fluid in 368 (32.6%) patients; no abnormality was found in 150 (13.5%) patients. A tumour in the abdomen or pelvis was found in 183 (16.2%) patients, an intrauterine pregnancy in 129/754 (17.1%) females, complete or incomplete abortion in 96 (12.7%), and a ruptured ectopic pregnancy in 32 (4.2%) females. In males, most common diagnosis was intestinal obstruction in 54/376 (14.4%), and splenomegaly in 42 (11.2%). Of 1556 trauma patients, 283 (18.1%) received an eFAST, and 53 (18.7%) had positive findings. A total of 27 (9.4%) trauma patients and 51 (4.5%) non-trauma patients were sent directly to the operating theatre. CONCLUSION: In this study, ultrasound examination revealed abnormal findings for the majority of patients with non-traumatic abdominal symptoms. Building up capacity to provide diagnostic ultrasound is a promising strategy to improve emergency services, especially in a setting where diagnostic modalities are limited

Electrical valley filtering in transition metal dichalcogenides

This work investigates the feasibility of electrical valley filtering for holes in transition metal dichalcogenides. We look specifically into the scheme that utilizes a potential barrier to produce valley-dependent tunneling rates, and perform the study with both a k.p based analytic method and a recursive Green's function based numerical method. The study yields the transmission coefficient as a function of incident energy and transverse wave vector, for holes going through lateral quantum barriers oriented in either armchair or zigzag directions, in both homogeneous and heterogeneous systems. The main findings are the following: 1) the tunneling current valley polarization increases with increasing barrier width or height, 2) both the valley-orbit interaction and band structure warping contribute to valley-dependent tunneling, with the former contribution being manifest in structures with asymmetric potential barriers, and the latter being orientation-dependent and reaching maximum for transmission in the armchair direction, and 3) for transmission ~ 0.1, a tunneling current valley polarization of the order of 10% can be achieved.Comment: 12 pages, 8 figure

Fotossíntese, relações hídricas e crescimento de cafeeiros jovens em relação à disponibilidade de fósforo

O objetivo deste trabalho foi avaliar de que maneira a alta disponibilidade de fósforo no solo afeta a fotossíntese e o crescimento de mudas de cafeeiro arábica (Coffea arabica). Mudas da cultivar Ouro Verde com aproximadamente quatro meses de idade, cultivadas com boa disponibilidade hídrica, foram submetidas a três tratamentos quanto à disponibilidade de fósforo: quantidade recomendada de P, na literatura (PA); duas vezes a dosagem utilizada em PA (P+); e sem adição de P ao solo (P-). Após 70 dias da aplicação dos tratamentos, foram avaliados: as trocas gasosas, a atividade fotoquímica, o potencial de água da folha, a condutância hidráulica da planta (K L), a partição de matéria seca na planta, os teores de pigmentos e carboidratos, e a composição química das folhas. O tratamento P- influenciou negativamente a fotossíntese, e levou à restrição do crescimento das plantas. As plantas do tratamento P+ apresentaram maior teor foliar de P (~1,9 g kg-1), com incrementos na assimilação de CO2, na eficiência instantânea de carboxilação e na atividade fotoquímica - maior eficiência do fotossistema II e maior transporte aparente de elétrons - em relação às plantas do tratamento PA. Houve aumento em K L, maior teor de carboidratos foliares e maior teor de clorofila nas plantas que receberam o dobro da dose recomendada de P, as quais apresentaram maior produção de matéria seca em relação às de PA e P-