Clinical characteristics and outcomes of pregnant women with COVID-19 and comparison with control patients: A systematic review and meta-analysis.

In a large-scale study, 128176 non-pregnant patients (228 studies) and 10000 pregnant patients (121 studies) confirmed COVID-19 cases included in this Meta-Analysis. The mean (confidence interval [CI]) of age and gestational age of admission (GA) in pregnant women was 33 (28-37) years old and 36 (34-37) weeks, respectively. Pregnant women show the same manifestations of COVID-19 as non-pregnant adult patients. Fever (pregnant: 75.5%; non-pregnant: 74%) and cough (pregnant: 48.5%; non-pregnant: 53.5%) are the most common symptoms in both groups followed by myalgia (26.5%) and chill (25%) in pregnant and dysgeusia (27%) and fatigue (26.5%) in non-pregnant patients. Pregnant women are less probable to show cough (odds ratio [OR] 0.7; 95% CI 0.67-0.75), fatigue (OR: 0.58; CI: 0.54-0.61), sore throat (OR: 0.66; CI: 0.61-0.7), headache (OR: 0.55; CI: 0.55-0.58) and diarrhea (OR: 0.46; CI: 0.4-0.51) than non-pregnant adult patients. The most common imaging found in pregnant women is ground-glass opacity (57%) and in non-pregnant patients is consolidation (76%). Pregnant women have higher proportion of leukocytosis (27% vs. 14%), thrombocytopenia (18% vs. 12.5%) and have lower proportion of raised C-reactive protein (52% vs. 81%) compared with non-pregnant patients. Leucopenia and lymphopenia are almost the same in both groups. The most common comorbidity in pregnant patients is diabetes (18%) and in non-pregnant patients is hypertension (21%). Case fatality rate (CFR) of non-pregnant hospitalized patients is 6.4% (4.4-8.5), and mortality due to all-cause for pregnant patients is 11.3% (9.6-13.3). Regarding the complications of pregnancy, postpartum hemorrhage (54.5% [7-94]), caesarean delivery (48% [42-54]), preterm labor (25% [4-74]) and preterm birth (21% [12-34]) are in turn the most prevalent complications. Comparing the pregnancy outcomes show that caesarean delivery (OR: 3; CI: 2-5), low birth weight (LBW) (OR: 9; CI: 2.4-30) and preterm birth (OR: 2.5; CI: 1.5-3.5) are more probable in pregnant woman with COVID-19 than pregnant women without COVID-19. The most prevalent neonatal complications are neonatal intensive care unit admission (43% [2-96]), fetal distress (30% [12-58]) and LBW (25% [16-37]). The rate of vertical transmission is 5.3% (1.3-16), and the rate of positive SARS-CoV-2 test for neonates born to mothers with COVID-19 is 8% (4-16). Overall, pregnant patients present with the similar clinical characteristics of COVID-19 when compared with the general population, but they may be more asymptomatic. Higher odds of caesarean delivery, LBW and preterm birth among pregnant patients with COVID-19 suggest a possible association between COVID-19 infection and pregnancy complications. Low risk of vertical transmission is present, and SARS-CoV-2 can be detected in all conception products, particularly placenta and breast milk. Interpretations of these results should be done cautiously due to the heterogeneity between studies; however, we believe our findings can guide the prenatal and postnatal considerations for COVID-19 pregnant patients.

Innovative solution to enhance the Helmholtz resonator sound absorber in low-frequency noise by nature inspiration.

Sound absorbing elements commonly used to make quieter spaces are very desirable for high-frequency noise control. It is more attractive if it is possible to produce sound absorbing structures that perform well for a wide frequency range, especially in low-frequencies. In this regard, Helmholtz resonator array is a well-known structure but the maximum performance of each resonator unit in an array panel can only be achieved at resonance frequency that is dependent on its size. Therefore, a resonator array panel with equal size units has insufficient performance in a wide frequency range. Hence, the consideration of suitable sizes for each resonator in an array panel consisting of unequal size units is a key point to widen the frequency range of sound absorption. On the other hand, it seems that engineering science can be developed by nature inspiration. In addition, Fibonacci sequence is a famous mathematical model which describes the shape/ratio of different phenomena which exist in nature. In this paper, Fibonacci sequence is utilized to investigate Helmholtz resonator arrangement to increase both the amount of sound absorption coefficient and frequency bandwidth of absorption without changing the total volume of resonator array with equal size units. Analytical solutions based on the modified equivalent electrical circuit theory is used to calculate the sound absorption coefficient of the proposed panel with numerical experiments in MAPLE and COMSOL Multiphysics softwares to validate the proposed overall approach. Results show that the Fibonacci sequence is an optimum candidate to design a resonator-based sound absorber in low-frequency noise.

Conservative Management of Asymptomatic Pneumoperitoneum; Report of Two Cases.

Peptic ulcer disease is a common gastrointestinal disorder, the prevalence of which has reduced in recent years due to effective new treatments. Peptic ulcer perforation is an emergent life-threatening condition that causes pneumoperitoneum and septic shock. It often requires surgical procedures. We describe two cases of peptic ulcer perforation with only mild discomfort on the epigastric region since several months before. The patients were treated with a high dose proton pump inhibitor and conservative treatment without surgical procedures. Weekly follow up of the cases showed that the clinical condition of patients remained stable without any new signs and symptoms. This report shows that noninvasive treatment alone can be effective in some cases with mild symptoms.