Genetic Basis of Virulence Attenuation Revealed by Comparative Genomic Analysis of Mycobacterium tuberculosis Strain H37Ra versus H37Rv

Tuberculosis, caused by Mycobacterium tuberculosis, remains a leading infectious disease despite the availability of chemotherapy and BCG vaccine. The commonly used avirulent M. tuberculosis strain H37Ra was derived from virulent strain H37 in 1935 but the basis of virulence attenuation has remained obscure despite numerous studies. We determined the complete genomic sequence of H37Ra ATCC25177 and compared that with its virulent counterpart H37Rv and a clinical isolate CDC1551. The H37Ra genome is highly similar to that of H37Rv with respect to gene content and order but is 8,445 bp larger as a result of 53 insertions and 21 deletions in H37Ra relative to H37Rv. Variations in repetitive sequences such as IS6110 and PE/PPE/PE-PGRS family genes are responsible for most of the gross genetic changes. A total of 198 single nucleotide variations (SNVs) that are different between H37Ra and H37Rv were identified, yet 119 of them are identical between H37Ra and CDC1551 and 3 are due to H37Rv strain variation, leaving only 76 H37Ra-specific SNVs that affect only 32 genes. The biological impact of missense mutations in protein coding sequences was analyzed in silico while nucleotide variations in potential promoter regions of several important genes were verified by quantitative RT-PCR. Mutations affecting transcription factors and/or global metabolic regulations related to in vitro survival under aging stress, and mutations affecting cell envelope, primary metabolism, in vivo growth as well as variations in the PE/PPE/PE-PGRS family genes, may underlie the basis of virulence attenuation. These findings have implications not only for improved understanding of pathogenesis of M. tuberculosis but also for development of new vaccines and new therapeutic agents

Siam-DWENet: Flood inundation detection for SAR imagery using a cross-task transfer siamese network

Emergency management agencies must address the challenges presented by frequent flooding events. Remote sensing imagery provides a means for timely monitoring of rapidly changing water bodies during flooding events; but manual analysis of remote sensing (RS) images however, is labor intensive and time consuming. Automated methods are effective, but the post-classification comparison method for flood inundation detection is subject to error accumulation, and the direct change detection method is limited by the accuracy of flood mapping and the difficulty of obtaining training samples. To overcome these challenges, a flood inundation detection network (Siam-DWENet) that achieves high-accuracy inundation detection is proposed. In Siam-DWENet, an innovative cross-task transfer learning strategy incorporates an attention mechanism and multi-scale pyramid structure based on Siamese architectures. This approach realizes a priori knowledge transfer-based flood inundation detection with a limited number of training samples. Comparative experiments on Siam-DWENet and other methods using two flooding SAR datasets to evaluate the accuracy of flood detection. The experimental results indicate that Siam-DWENet outperforms other change detection methods and makes the inundation area edge more accurate when dealing with complex backgrounds, achieving an average OA of 0.887 and F1 of 0.865 in flood inundation detection tasks

Influence of enhanced recovery after surgery programs on laparoscopy-assisted gastrectomy for gastric cancer: a systematic review and meta-analysis of randomized control trials

Abstract Background This meta-analysis is aimed to evaluate the feasibility and safety of enhanced recovery after surgery (ERAS) programs in gastric cancer patients undergoing laparoscopy-assisted gastrectomy (LAG). Methods We performed a meta-analysis of randomized control trials involving either enhanced recovery after surgery (ERAS)/fast track surgery (FTS) for patients underwent LAG. EMBASE, Pubmed, Web of science, and Cochrane Library were searched. Primary outcomes included the length of postoperative hospital stay, cost of hospitalization, postoperative complications, and readmission rate. Results Five randomized control trials were eligible for analysis. There were 159 cases in FTS group and 156 cases in conventional care group. Compared with conventional care group, FTS group relates to shorter postoperative hospital stay (WMD − 2.16; 95% CI − 3.05 to − 1.26, P < 0.00001), less cost of hospitalization (WMD − 4.72; 95% CI − 6.88 to − 2.55, P < 0.00001), shorter time to first flatus (WMD − 9.72; 95% CI − 13.75 to − 5.81, P < 0.00001), lower level of C-reaction protein on postoperative days 3 or 4 (WMD − 19.66; 95% CI − 28.98 to − 10.34, P < 0.00001), higher level of albumin on postoperative day 4 (WMD 3.45; 95% CI 2.01 to 4.89, P < 0.00001), and postoperative day 7 (WMD 5.63; 95% CI 1.01 to 10.24, P = 0.02). Regarding postoperative complications, no significant differences were observed between FTS group and conventional care group (OR 0.63, 95% CI 0.37 to 1.09, P = 0.10). The readmission rate of FTS group was comparable to conventional care group (WMD 3.14; 95% CI 0.12 to 81.35, P = 0.49). Conclusions Among patients undergoing LAG, FTS is associated with shorter postoperative hospital stay, rapid postoperative recovery, and decreased cost without increasing complications or readmission rate. The combined effects of the two methods could further accelerate clinical recovery of gastric cancer patients

Study on Tool Path Optimization in Multi-axis NC Machining

This paper presents a new generation algorithm for tool path based on the optimization of traditional algorithms. Then, the tool path on an impeller is generated with UG software, and it is used to make contrasts and verifications for the effect of optimization. Finally, VERICUT software with the function of the simulating on the whole manufacturing process is utilized to verify the feasibility of the optimized algorithm

Study on Tool Path Optimization in Multi-axis NC Machining

This paper presents a new generation algorithm for tool path based on the optimization of traditional algorithms. Then, the tool path on an impeller is generated with UG software, and it is used to make contrasts and verifications for the effect of optimization. Finally, VERICUT software with the function of the simulating on the whole manufacturing process is utilized to verify the feasibility of the optimized algorithm

Solid-state composite electrolyte LiI/3-hydroxypropionitrile/SiO2 for dye-sensitized solar cells

A new compound, LiI(3-hydroxypropionitrile)2, is reported here. According to its single-crystal structure (C2/c), this compound has 3-D transporting paths for iodine. Further ab initio calculation shows that the activation energy for diffusion of iodine (0.73 eV) is much lower than that of lithium ion (8.39 eV) within the lattice. Such a mono-ion transport feature is favorable as solid electrolyte to replace conventional volatile organic liquid electrolytes used in dye-sensitized solar cells (DSSC). LiI and 3-hydroxypropionitrile (HPN) can form a series of solid electrolytes. The highest ambient conductivity is 1.4 × 10-3 S/cm achieved for LiI(HPN)4. However, it tends to form large crystallites and leads to poor filling and contact within porous TiO2 electrodes in DSSC. Such a drawback can be greatly improved by introducing micrometer-sized and nanosized SiO2 particles into the solid electrolyte. It is helpful not only in enhancing the conductivity but also in improving the interfacial contact greatly. Consequently, the light-to-electricity conversion efficiency of 5.4% of a DSSC using LiI(HPN)4/15 wt % nano-SiO2 was achieved under AM 1.5 simulated solar light illumination. Due to the low cost, easy fabrication, and relatively high conversion efficiency, the DSSC based on this new solid-state composite electrolyte is promising for practical applications

Enhanced light absorption of thin perovskite solar cells using textured substrates

Thin perovskite layers are crucial for fabricating semitransparent perovskite solar cells and tandem devices. However, this will reduce the light absorption of the device, resulting in low efficiency. To overcome this dilemma, we use textured fluorine doped SnO2 (FTO) substrates to trap light and enhance light absorption in thin perovskite solar cells. Both optical simulation and experimental demonstration show the successful application of this new strategy in enhancing the efficiency. In the meantime, the transmittance of the full cell beyond the perovskite absorption range is not sacrificed, which is pivotal for fabricating semitransparent perovskite solar cells and tandem devices

Spatiotemporal transcriptomic atlas reveals the dynamic characteristics and key regulators of planarian regeneration

Abstract Whole-body regeneration of planarians is a natural wonder but how it occurs remains elusive. It requires coordinated responses from each cell in the remaining tissue with spatial awareness to regenerate new cells and missing body parts. While previous studies identified new genes essential to regeneration, a more efficient screening approach that can identify regeneration-associated genes in the spatial context is needed. Here, we present a comprehensive three-dimensional spatiotemporal transcriptomic landscape of planarian regeneration. We describe a pluripotent neoblast subtype, and show that depletion of its marker gene makes planarians more susceptible to sub-lethal radiation. Furthermore, we identified spatial gene expression modules essential for tissue development. Functional analysis of hub genes in spatial modules, such as plk1, shows their important roles in regeneration. Our three-dimensional transcriptomic atlas provides a powerful tool for deciphering regeneration and identifying homeostasis-related genes, and provides a publicly available online spatiotemporal analysis resource for planarian regeneration research