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Objective: The outbreak of coronavirus disease (COVID‐19) coincided with the season of influenza A pneumonia, a common respiratory infectious disease. Therefore, this study compared ultrasonography and computed tomography (CT) for the diagnosis of the two diseases. Methods: Patients with COVID‐19 or influenza A infection hospitalized at our hospital were included. The patients were examined by ultrasonography every day. The CT examination results within 1 day before and after the day of the highest ultrasonography score were selected as the controls. The similarities and differences between the ultrasonography and CT results in the two groups were compared. Results: There was no difference between the ultrasonography and CT scores (P =.307) for COVID‐19, while there was a difference between ultrasonography and CT scores for influenza A pneumonia (P =.024). The ultrasonography score for COVID‐19 was higher than that for influenza A pneumonia (P =.000), but there was no difference between the CT scores (P =.830). For both diseases, there was no difference in ultrasonography and CT scores between the left and right lungs; there were differences between the CT scores of the upper and middle lobes, as well as between the upper and lower lobes of the lungs; however, there was no difference between the lower and middle lobes of the lungs. Conclusion: Ultrasonography is equivalent to the gold standard CT for diagnosing and monitoring the progression of COVID‐19. Because of its convenience, ultrasonography has important application value. Furthermore, the diagnostic value of ultrasonography for COVID‐19 is higher than that for influenza A pneumonia. [ABSTRACT FROM AUTHOR]

Background: Patients with human immunodeficiency virus (HIV) are at a significantly higher risk of cardiovascular disease (CVD) compared to HIV‐negative people. Left heart dysfunction is the most common cardiac complication in people living with HIV/acquired immune deficiency syndrome (PLWHA), and diastolic dysfunction is an important predictor of cardiovascular events. The aims of this study were (1) to detect changes in left cardiac structure and function in antiretroviral therapy (ART)‐naive PLWHA using echocardiography; and (2) to investigate the risk factors for the development of left ventricular diastolic dysfunction (LVDD) in ART‐naive PLWHA. Methods: We retrospectively included 105 ART‐naïve PLWHA and included 90 healthy subjects as controls to compare the differences in left heart structure and function between the two groups. Univariate and multifactorial logistic regression were employed to explore the risk factors of the development of LVDD in ART‐naive PLWHA. Results: The left ventricular end‐diastolic internal diameter (LVEDD), left ventricular mass index (LVMI), and left atrial volume index (LAVI) were significantly greater in PLWHA than in controls (p <.05). The E/A ratio, lateral e′ velocity, and mitral deceleration time were significantly lower in PLWHA than in controls (p <.05). Average E/e′ ratio was significantly higher in PLWHA than in controls (p <.05). Left ventricular ejection fraction (LVEF) and left ventricular fractional shortening (LVFS) were not significantly different between PLWHA and controls (p >.05). Multifactorial logistic regression analysis showed that age, body mass index (BMI), and CD4+ count <200 cells/μL were independent risk factors for LVDD in ART‐naive PLWHA (OR = 1.781, 1.228, 3.683, p <.05). Conclusions: Left ventricular systolic function did not differ between PLWHA and controls, and left ventricular diastolic function was lower in PLWHA than in controls. Age, BMI, and CD4+ count were independent factors affecting LVDD in ART‐naive PLWHA. [ABSTRACT FROM AUTHOR]

Background: An unexplained pneumonia occurred in Wuhan, China in December 2019, later identified and named coronavirus disease 2019 (COVID‐19). This study aimed to compare the ultrasonographic features of the lung between patients with COVID‐19 in Wuhan (the primary region) and those in Beijing (the secondary region) and to find the value of applying ultrasound in COVID‐19. Methods: A total of 248 COVID‐19 cases were collected, including long‐term residents in Wuhan (138), those who had a short‐term stay in Wuhan (72), and those who had never visited Wuhan (38). Ultrasound examination was performed daily; the highest lung ultrasound score (LUS) was the first comparison point, while the LUS of the fifth day thereafter was the second comparison point. The differences between overall treatment and ultrasonography of left and right lungs among groups were compared. Results: The severity decreased significantly after treatment. The scores of the groups with long‐term residence and short‐term stay in Wuhan were higher than those of the group that had never been to Wuhan. Conclusion: Ultrasonography is effective for dynamic monitoring of COVID‐19. The ultrasonographic features of patients in the Wuhan area indicated relatively severe disease. Thus, Wuhan was the main affected area of china. [ABSTRACT FROM AUTHOR]

Carbonate reservoirs are the main reservoir types in China, which occupy the large ratio of reserves and production at present. The high-efficiency development of carbonate reservoirs is of great significance to assure the stability of national energy supply. The Lower Paleozoic reservoir in Jingbian gas field and the Sinian reservoir in Anyue gas field are two typical carbonate gas reservoirs, and their successful development experiences can provide significant references for other similar carbonate gas reservoirs. For Jingbian gas field, it is a lithological-stratigraphic reservoir developed in a westward monocline and multiple rows of nose-fold structures, and is a stable craton basin with simple palaeognomy distribution and stable connectivity, which has complex gas-water distribution. However, for Anyue gas field, it is a lithological-structural reservoir with multiple tectonic high points and multiple fault systems, and is biological dune beach facies under extensional setting with highly differentiated inside of the block in palaeognomy characteristics, which has limited connectivity and tectonic side water is in a local area. The difference of gas reservoir characteristics leads to the diverse development strategies. For these two gas reservoirs, although there are some similar aspects, such as the screen of enrichment areas, the application of irregular well pattern and reservoir stimulation techniques, the criteria of enrichment areas, the well types, and the means of reservoir stimulation are absolutely different. In addition, due to the differences of control reserves and production capacity for these two kinds of reservoirs, the mode of stable production is also different. The effective development of Jingbian gas field can give some references to the future exploitation on the Sinian gas reservoir. Firstly, the sedimentary characteristics should be studied comprehensively. Secondly, the distribution pattern and distribution characteristics of the palaeognomy should be found and determined. Thirdly, the distribution of fracture system in the reservoir should be depicted finely. Finally, dynamic monitoring on the production performance should be strengthened, and the management for this gas field should be improved further. The findings of this study can help for better understanding of the Karst weathering-crust carbonate gas reservoir formation characteristics and the optimal development technologies that should be taken in practice. [ABSTRACT FROM AUTHOR]

CO2-alternating-water injection is an effective way of enhancing recovery for low-permeability oil reservoirs. The injection process is one of the essential issues that are facing severe challenges because of the low permeability and poor pore space connectivity. Previous researchers mentioned that water injection ability could be decreased by around 20% after the CO2-flooding; hence, it is necessary to quantify the water injectivity variation during an alternated injection process. In this paper, a CO2 convection-diffusion model is established based on the seepage law of CO2 and dissipation effect. The relationship between the width of miscible flooding and injection time is defined. Besides, an equivalent resistance method is introduced for developing a capillary bundle model for featuring an unequal diameter for CO2 water vapor alternate flooding. CO2-oil and CO2-water interactions are analyzed using the new model. The effects of oil viscosity, pore throat ratio, CO2 slug size, and equivalent permeability of the capillary bundle on water injection are analyzed. The result indicates that water injection ability increases with the rise of CO2 slug size and equivalent permeability of the capillary bundle and decreases with the increase of viscosity and pore throat ratio. [ABSTRACT FROM AUTHOR]

The article presents a study which analyzes problems and difficulties of existing production performance prediction models of stimulated reservoir volume(SRV)-fractured horizontal wells. The large effect of horizontal well SRV on stimulating effective reservoir volume and enhancing oil recovery is tackled. A summary of the theoretical advancement of horizontal well SRV fracturing productivity prediction is also revealed.

In the crystal structure of the title compound, C(5)H(6)N(6)S(4), the mol-ecules are linked by strong N-H⋯N hydrogen bonds into a two-dimensional network and an intra-molecular C-H⋯S inter-action also occurs.

In the title mononuclear complex, [Ni(C(4)H(5)O(2))(2)(C(10)H(9)N(3))]·1.5H(2)O, the Ni(II) ion is in a distorted square-planar coordination environment, formed by two O atoms from two methacrylate ligands and two N atoms from a bis-chelating dipyridylamine ligand. In the crystal structure, inter-molecular O-H⋯O and N-H⋯O hydrogen bonds link complex mol-ecules and water mol-ecules into one-dimensional chains.