Camera Resectioning from Image Edges with the L∞L_\infty-Norm Using Linear Programming

This paper discusses how to resection camera using image edges extracted from projected polyhedron, with noise caused by shadows and occlusions etc. First, we propose a definition of the distance between two line segments in a 2D plane, which is an essential concept in computer vision. Based on it, the problem can be recast as a quasi-convex optimization problem in a famous and successful framewrok. Different from [8], our solution uses linear programming (LP) with the residual error defined by Euclidean distance, instead of using Second Order Cone Programming (SOCP) often utilized by most previous problems. Most related work makes use of the point to point correspondences. Intuitively, people may consider line segment correspondences should be more complex to handle than those of points. In fact, this paper shows that the problem can be simplified on the contrary.Computer Science, Artificial IntelligenceCPCI-S(ISTP)

Risk factors associated with prolonged viral clearance in patients with a refractory course of COVID-19: a retrospective study

Background This study aimed to characterize a cohort of patients with a refractory course of COVID-19, and to investigate factors associated with the duration of viral clearance (DoVC). Materials & Methods A total of 65 patients with refractory COVID-19 were retrospectively enrolled from Huoshenshan Hospital. Univariate analysis and multivariate analysis were performed to examine the potential association between clinicopathologic characteristics and the DoVC. Results The median DoVC in the overall study cohort was 48 days (ranged from 21 to 104 days). Multivariate analysis indicated that fever at illness onset (Hazard ratio (HR) = 4.897, 95% CI [1.809–13.260], p = 0.002), serum level of aspartate aminotransferase (AST) > 21.8 IU/L (HR = 3.010, 95% CI [1.195–7.578], p = 0.019), and titer of SARS-CoV-2 IgG > 142.09 AU/ml (HR = 3.061, 95% CI [1.263–7.415], p = 0.013) were the three independent risk factors associated with delayed viral clearance. Conclusion The current study suggested that clinical characteristics such as fever at illness onset, a high serum level of AST or SARS-CoV-2 IgG were associated with delayed viral clearance. Patients with these characteristics might need a more individualized treatment strategy to accelerate their recovery from the refractory COVID-19

Left ventricular long-axis ultrasound strain (GLS) is an ideal indicator for patients with anti-hypertension treatment

Background Primary hypertension is one of the most well-known risk factors for cardiovascular disease. Currently, there is still no ideal indicator for left ventricular end-diastolic pressure. Methods 73 hypertension patients and 37 healthy people were enrolled in this study. Each member was examined with conventional echocardiography including multiple indicators such as Peak mitral valve flow velocity (E, A), E/A, left atrial volume index (LAVl), tissue Doppler (PW-TDI) peak velocities during early and late diastolic mitral valve flow (e ‘), E/e ‘, and GLS. We have collected clinical data from all enrolled members. The above cardiac ultrasound indicators were obtained before the antihypertensive treatment, one month and three months after treatment. Results Left ventricular end-diastolic pressure (LVEDP) was positively correlated and negatively correlated with GLS (r = 0.638, P < .01) and E/e’ (r = −0.578, P < .05), respectively. The hypertensives had lower e’ value and higher values of GLS, E/e’, and LAVI than the control group (P < .05). GLS and E/e’ were significantly lower in hypertension group than those in the Control group after one month and three months of treatment (P < .05). The improvement rate of GLS was significantly higher than those in the improvement rate of e’, E/e’, LAVI after treatment (p < .05). Conclusion The GLS improvement rate was significantly higher than those of e’, E/e’ after one and three-month treatment. Therefore, GLS might be a potential ideal index for patients with anti-hypertension treatment. The results obtained in this study provide useful information for further study

Chiral Sulfur Nanosheets for Dual-Selective Inhibition of Gram-Positive Bacteria

Elemental sulfur is the oldest known antimicrobial agent. However, conventional sulfur in the clinic suffers from poor aqueous solubility and limited antibacterial activity, greatly hindering its practical use. Herein, we report a reform strategy coupling dimension engineering with chirality transfer to convert conventional 3D sulfur particles into chiral 2D sulfur nanosheets (S-NSs), which exhibit 50-fold improvement of antibacterial capability and dual-selective inhibition against Gram-positive bacteria. Benefiting from the inherent selectivity of S-NSs and chirality selectivity from decorated d-histidine, the obtained chiral S-NSs are proven to precisely kill Gram-positive drug-resistant bacteria, while no obvious bacterial inhibition is observed for Gram-negative bacteria. Mechanism studies reveal that S-NSs produce numerous reactive oxygen specipoes and hydrogen sulfide after incubation with bacteria, thus causing bacterial membrane destruction, respiratory chain damage, and ATP production inhibition. Upon spraying chiral S-NSs dispersions onto MRSA-infected wounds, the skin healing process was greatly accelerated in 8 days due to metabolism inhibition and oxidative damage of bacteria, indicating the excellent treatment efficiency of MRSA-infected wounds. This work converts the traditional well-known sulfur into modern antibacterial agents with a superior Gram-selectivity bactericidal capability

Optimization of Critical Factors Affecting Dynamic Membrane Formation in a Gravity-Driven Self-Forming Dynamic Membrane Bioreactor towards Low-Cost and Low-Maintenance Wastewater Treatment

Self-forming dynamic membrane (SFDM) formation is affected by a variety of operating conditions. However, previous studies have only focused on individual influencing factors and a systematic analysis of important factors is lacking. In this study, an aerobic self-forming dynamic membrane bioreactor (SFDMBR) was developed for the treatment of domestic wastewater with the critical factors that affect the effective formation of SFDM optimized, and the operational performances under optimized formation conditions confirmed. The results indicated that SFDM could be formed within 5 min using 48 μm stainless-steel mesh as the supporting material at a sludge concentration of 5–6 g/L and a gravity waterhead of 15 cm. And the SFDM formed could maintain a stable flux of 30–50 LMH, and the removals of COD, SCOD, and NH4+-N were 93.28%, 82.85%, and 95.46%, respectively. Furthermore, the cake layer resistance (reversible fouling) contributed to 95.93% of the total filtration resistance, thus a simple physical cleaning can effectively restore the flux indicating a low-maintenance requirement. This study provides valuable insights into the optimization and application of the SFDMBR process

Different doping behaviors of silicon in zinc blende and wurtzite GaAs nanowires : implications for crystal-phase device design

Crystal-phase engineering between zinc blende (ZB) and wurtzite (WZ) structures is becoming an important method in designing unique optoelectronic and electronic semiconductor devices. Doping to engineer their electric properties is thus of critical importance, but a direct experimental comparison in doping these two crystal structures is still missing. Nanowires (NWs) allow the coexistence of both structures due to their special growth mode. The differences in dopant incorporation between the two phases are studied here in GaAs NW shells that are coherently grown around the NWs, hence maintaining the crystal structure of the core. The Si dopant is observed to have a higher incorporation efficiency into the WZ structure due to a 2 times lower incorporation energy compared with that of the ZB structure. Besides, it can also be predicted that Si is more inclined toward Ga sites in both structures. Indeed, the As-site doping energy of the WZ structure is several orders of magnitude higher than that of Ga sites, allowing a lower doping compensation effect. This work provides useful information for doping control and hence designing crystal-phase devices