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The incidence of colorectal cancer is constantly increasing. With the improvement of residents' health need and the continuous development of surgery, more and more patients with colorectal cancer have a history of abdominal surgery. Complex abdominal adhesions put forward higher requirements for surgeons. The use of Veress puncture needle to establish pneumoperitoneum in laparoscopic-assisted colorectal cancer surgery leads to an increased incidence of puncture side injury.Open laparoscopy is an effective method to reduce puncture damages, but there are still some limitations. Combined with the fact that most laparoscopic assisted colorectal cancer operations require auxiliary incisions, advance incision seems to be a reasonable solution. Its application is not limited to patients with previous surgical history, but also can be routinely applied to all patients with colorectal cancer. Its efficacy and safety need to be verified by further clinical studies.

Overexpression is one of the classical approaches to study pleiotropic functions of genes of interest. To achieve overexpression, we often increase the transcription by introducing genes on exogenous vectors or by using the CRISPR/dCas9-based transcriptional activation system. To date, the most efficient CRISPR/dCas9-based transcriptional activator is the Synergistic Activation Mediator (SAM) system whereby three different transcriptional activation domains are directly fused to dCas9 and MS2 phage Coat Protein (MCP), respectively, and the system in Drosophila is named flySAM. Here we describe the effective and convenient transcriptional activation system, flySAM, starting from vector construction, microinjection, and transgenic fly selection to the phenotypic analysis.

Introduction β-thalassemia is a severe hereditary hemolytic anemia. Due to the diversity of mutations spectrum, β-thalassemia manifests a highly heterogeneous clinical severity. We noted that a previous report characterized HBB:c.313delA, at the end of exon 2, as a β-thalassemia trait rather than dominant β-thalassemia, the classification given to similar mutations. We further explored the impact of this functional variant on globin structure through larger pedigree analysis and in vitro studies. Methods Hematological analysis and molecular genotyping were conducted on the proband and his family members. We evaluated functional effects of the variant on β-globin gene in the proband's nucleated erythrocytes and transfected HEK-293T cells. Three-dimensional construction of protein structure was carried out in silico to demonstrate amino acid changes. Results The thalassemia major proband was identified as a compound heterozygote of HBB:c.313delA and HBB:c.126_129delCTTT. Three family members with heterozygotes of HBB:c.313delA displayed microcytic hypochromic anemia. Molecular characterization demonstrated that the frameshift mutation could give rise to retro-positioning of the termination codon, resulting in an elongated β-globin chain with an extension of 10 amino acids. Clinical phenotype and functional experiments indicated that HBB:c.313delA led to β0 -thalassemia phenotype. Conclusion We concluded that the phenotype of HBB:c.313delA was mainly related to the stability of mutant mRNA, the degradation of mutant proteins, and production of inclusion bodies according to a systematic description of clinical phenotype and a series of molecular experiments.

The flySAM/CRISPRa system has recently emerged as a powerful tool for gain-of-function studies in Drosophila melanogaster. This system includes Gal4/UAS-driven dCas9 activators and U6 promoter-controlled sgRNA. Having established dCas9 activators superior to other combinations, to further enhance the efficiency of the targeting activators we systematically optimized the parameters of the sgRNA. Interestingly, the most efficient sgRNAs were found to accumulate in the region from -150bp to -450bp upstream of the transcription start site (TSS), and the activation efficiency showed a strong positive correlation with the GC content of the sgRNA targeting sequence. In addition, the target region is dominant to the GC content, as sgRNAs targeting areas beyond -600bp from the TSS lose efficiency even when containing 75% GC. Surprisingly, when comparing the activities of sgRNAs targeting to either DNA strand, sgRNAs targeting to the non-template strand outperform those complementary to the template strand, both in cells and in vivo. In summary, we define criteria for sgRNA design which will greatly facilitate the application of CRISPRa in gain-of-function studies.

The HECT domain-containing UPL3 ligase plays critical roles in plant development and stress protection, but its mechanism of action remains limited. To globally identify its targets in Arabidopsis thaliana, we conducted proteomic analyses of ubiquitinated proteins in upl3 mutants via label-free mass spectrometry. In 6-week-old plants, a landscape of UPL3-dependent ubiquitinated proteins is constructed based on correlated datasets of ubiquitome, proteome, and transcriptome. Preferential ubiquitination of proteins related to carbon fixation represented the largest set of proteins with increased ubiquitination in the upl3 plant, while a small set of proteins with reduced ubiquitination caused by the upl3 mutation were linked to cysteine/methionine synthesis and protein translation processes. Furthermore, the upl3 mutation led to an increase in ubiquitination of some of proteins including chromatin remodeling ATPase (BRM), histone proteins, and most of carbon metabolic enzymes, but decreased the ubiquitination of hexokinase 1 (HXK1), phosphoenolpyruvate carboxylase 2 (PPC2), ribosomal protein S5, and H1/H5 domain proteins. Notably, ubiquitin hydrolase 12 (UBP12), BRM, and PPC2 were identified as the UPL3-interacting partners by both GFP-nanotrap-Mass-Spectrometry analyses and yeast two-hybrid assay. Characterization of upl3, brm, and ubp12 mutant plants and transcriptome analysis suggested that UPL3 fine-tunes carbon metabolism mediating cellular senescence by interacting with UBP12, BRM, and PPC2 in the nucleus. Our results highlight an important function of UPL3 as a hub of regulator on proteolysis-independent regulation and proteolysis-dependent degradation.

The HECT-type UPL3 ligase plays critical roles in plant development and stress protection, but understanding of its regulation remains limited. Here, the multi-omics analyses of ubiquitinated proteins inupl3mutants were performed. A landscape of UPL3-dependent ubiquitinated proteins is constructed: Preferential ubiquitination of proteins related to carbon fixation represented the largest set of proteins with increased ubiquitination in theupl3plant, including most of carbohydrate metabolic enzymes, BRM, and variant histone, whereas a small set of proteins with reduced ubiquitination caused by theupl3mutation were linked to cysteine/methionine synthesis, as well as hexokinase 1 (HXK1) and phosphoenolpyruvate carboxylase 2 (PPC2). Notably, ubiquitin hydrolase 12 (UBP12), BRM, HXK1, and PPC2 were identified as the UPL3-interacting partners in vivo and in vitro. Characterization ofbrm,upl3,ppc2,gin2, andubp12mutant plants and proteomic and transcriptomic analysis suggested that UPL3 fine-tunes carbohydrate metabolism, mediating cellular senescence by interacting with UBP12, BRM, HXK1, and PPC2. Our results highlight a regulatory pattern of UPL3 with UBP12 as a hub of regulator on proteolysis-independent regulation and proteolysis-dependent degradation.

Notch signaling and epigenetic factors are known to play critical roles in regulating tissue homeostasis in most multicellular organisms, but how Notch signaling coordinates with epigenetic modulators to control differentiation remains poorly understood. Here, we identify heterochromatin protein 1c (HP1c) as an essential epigenetic regulator of gut homeostasis in Drosophila. Specifically, we observe that HP1c loss-of-function phenotypes resemble those observed after Notch signaling perturbation and that HP1c interacts genetically with components of the Notch pathway. HP1c represses the transcription of Notch target genes by directly interacting with Suppressor of Hairless (Su(H)), the key transcription factor of Notch signaling. Moreover, phenotypes caused by depletion of HP1c in Drosophila can be rescued by expressing human HP1γ, suggesting that HP1γ functions similar to HP1c in Drosophila. Taken together, our findings reveal an essential role of HP1c in normal development and gut homeostasis by suppressing Notch signaling.

The Transgenic RNAi Project (TRiP), a Drosophila melanogaster functional genomics platform at Harvard Medical School, was initiated in 2008 to generate and distribute a genome-scale collection of RNA interference (RNAi) fly stocks. To date, it has generated >15,000 RNAi fly stocks. As this covers most Drosophila genes, we have largely transitioned to development of new resources based on CRISPR technology. Here, we present an update on our libraries of publicly available RNAi and CRISPR fly stocks, and focus on the TRiP-CRISPR overexpression (TRiP-OE) and TRiP-CRISPR knockout (TRiP-KO) collections. TRiP-OE stocks express single guide RNAs targeting upstream of a gene transcription start site. Gene activation is triggered by coexpression of catalytically dead Cas9 fused to an activator domain, either VP64-p65-Rta or Synergistic Activation Mediator. TRiP-KO stocks express one or two single guide RNAs targeting the coding sequence of a gene or genes. Cutting is triggered by coexpression of Cas9, allowing for generation of indels in both germline and somatic tissue. To date, we have generated >5000 TRiP-OE or TRiP-KO stocks for the community. These resources provide versatile, transformative tools for gene activation, gene repression, and genome engineering.

In this article, eight enhanced single tubes and two smooth single tubes are selected for condensing and evaporating experiments with R134a. Heat transfer performance is compared under different test conditions. The heat transfer coefficients of small diameter enhanced tube are greater than those of large diameter tube in condensing test, while in evaporating test, the coefficients are approximately the same. The pressure drop of small diameter enhanced tube is greater than that of large diameter enhanced tube under same water flow velocity inside tube. Based on the experimental study result, a simulation model is proposed to evaluate small diameter tube replacement. The limit values of the theoretical simulation of STRPE (small tube replacement performance evaluation) are 1.257, 1.304, 1.286, 1.292 and 1.295 for tubes 1#, 2#, 3#, 4#, and 5#, respectively, for which replacement by a small diameter tube with the same enhanced fin configuration yields the same pressure drop and material consumption. According to the simulation model, the material reduction can be achieved directly for selected tubes. The study provides a reference for heat exchanger design in terms of cost reduction.

The activity of electrocatalysts exhibits a strongly dependence on their electronic structures. Specifically, for perovskite oxides, Shao-Horn and co-workers have reported a correlation between the oxygen evolution reaction activity and the eg orbital occupation of transition-metal ions, which provides guidelines for the design of highly active catalysts. Here we demonstrate a facile method to engineer the eg filling of perovskite cobaltite LaCoO3 for improving the oxygen evolution reaction activity. By reducing the particle size to ∼80 nm, the eg filling of cobalt ions is successfully increased from unity to near the optimal configuration of 1.2 expected by Shao-Horn's principle. Consequently, the activity is significantly enhanced, comparable to those of recently reported cobalt oxides with eg∼1.2 configurations. This enhancement is ascribed to the emergence of spin-state transition from low-spin to high-spin states for cobalt ions at the surface of the nanoparticles, leading to more active sites with increased reactivity., The activity of electrocatalysts exhibits a strong dependence on their electronic structures. Here, the authors manipulate the eg filling of perovskite cobaltite LaCoO3 nanoparticles by changing particle size and show improved oxygen evolution activity with increased numbers of surface high-spin cobalt ions.

Oxygen vacancies (Ov) on CeO2 surfaces create polarons, involving both electron localization on Ce ions and local geometry distortions. The relative positions of reduced Ce(III) and Ov affect the energies. We use trivalent doping to study the factors affecting the Ov formation energy on the CeO2(111) surfaces. We find that it is easier to form an Ov adjacent to the dopant with a smaller radius for Al, Ga, In, Tl, Sc, and Y doped cases, and on the second nearest neighbor O to the dopant with a larger radius (La and Ac). It is ascribed to that the smaller dopant could give more space to relax when the Ce(III) is sharing neighboring O to it, while the larger ones not. The Ce(III) could also be considered as a case of trivalent doping, following the same trend varying with dopant radius. Compared with the other trivalent dopants, the reduced Ce(III) produces a new occupied 4f state in the band gap, increases the Ov formation energy, and would be more easily oxidized and favorable for the redox cycle. This study gives a theoretical view of the Ov formation process and takes us closer to the physical nature of the doped ceria system.

In this study, the coating process on the copper surface with titanium dioxide (TiO2) has been introduced. The coated surface exhibits extremely high affinity for water and the solid–liquid contact angle decreases nearly to zero by exposing the surface to ultra-violet light. This superhydrophilic characteristic was applied to nucleate boiling heat transfer of water jet impingement on a flat heated plate. By making use of this special heat transfer surface, the nucleate boiling heat transfer and the critical heat flux (CHF) of a bar water jet impingement on a large flat superhydrophilic surface was experimentally investigated. The experimental data were measured in a steady state. The purified water was employed as the working liquid. Three main influencing factors, i.e., subcooling, impact velocity and the surface coating condition, were changed and their effects on the nucleate boiling heat transfer and the CHF were investigated. The empirical correlations were obtained for predicting the CHF of steady boiling for a small round water jet impingement on a large flat superhydrophilic surface. The experimental results show that the CHF on the superhydrophilic surface is about 30% higher than that on conventional copper surface by decreasing the solid–liquid contact angle.

There has been huge research interest in the energy gap problem of monolayer and bilayer graphene due to their great potential in practical applications. Herein, based on first-principles calculations, we report a promising way to open a large band gap in bilayer graphene (BLG) by sandwiching it between two substrates, although this is not usually expected to occur due to the weak interlayer interactions dominated by van der Waals forces. Taking surface-functionalized boron-nitrides as substrates, we predict from first-principles calculations that BLG can have energy gaps ranging from 0.35 eV to 0.55 eV, depending on the substrates and stacking order. Compared to other methods of band-gap manipulation in BLG, the structural integrity of BLG is well-preserved in our study, and the predicted energy gap is suitable for electric devices. Since the proposed method is easily realized in experiments, our results will hopefully accelerate the application of graphene in semiconductor devices and promote the development of graphene technology.