Subcellular localization and expression analysis of the BmDSCLP protein from silkworm, Bombyx mori

Leucine-rich repeat (LRR) proteins play important roles in the transduction of cellular signals and activation of defense responses. By scanning the cDNA library of silkworm (Bombyx mori) pupae constructed in our laboratory, we identified a 1557 bp gene that encodes a protein homologous to the death-associated small cytoplasmic leucine-rich protein, which was named as BmDSCLP. The full-length gene (GenBank accession no. FJ602779) contained a 642 bp open reading frame (ORF) encoding 213 amino acid residues. The ORF of this gene was inserted into the prokaryotic expression vector pET-28a(+) to construct a recombinant expression plasmid and the fusion protein was expressed in Escherichia coli BL21(DE3) cells. The fusion protein was purified by Ni-affinity chromatography and fast protein liquid chromatography (FPLC) and its size was then, determined by liquid chromatography-mass spectrometry (LC/MS/MS) and found to be 27.74 kD. Polyclonal antibodies were raised by subcutaneous injection of the recombinant protein into New Zealand white rabbits and the titer reached 1:12800. Analysis of the subcellular localization of the BmDSCLP protein revealed that, the protein was localized in both the cytoplasm and nucleus, but the amount in the former was slightly higher than that in the latter. In addition, real-time fluorescence quantification polymerase chain reaction studies were conducted to investigate BmDSCLP transcription at different developmental stages and in different tissues of the fifth instar larva. The results indicated that, BmDSCLP is widely transcribed in different stages and tissues of the silkworm. Analysis of stage-specific transcription patterns indicated that, the transcriptional level of BmDSCLP was highest in adults and lowest in eggs. Analysis of tissue-specific transcription patterns revealed that, the transcriptional level of BmDSCLP was highest in genital organs and lowest in silk glands. These results suggest that BmDSCLP plays important roles in the reproductive development of B. mori.Keywords: Bombyx mori, death-associated small cytoplasmic leucine-rich protein, prokaryotic expression, fluorescence quantification polymerase chain reactio

Structure-Based Virtual Screening for Drug Discovery: a Problem-Centric Review

Structure-based virtual screening (SBVS) has been widely applied in early-stage drug discovery. From a problem-centric perspective, we reviewed the recent advances and applications in SBVS with a special focus on docking-based virtual screening. We emphasized the researchers’ practical efforts in real projects by understanding the ligand-target binding interactions as a premise. We also highlighted the recent progress in developing target-biased scoring functions by optimizing current generic scoring functions toward certain target classes, as well as in developing novel ones by means of machine learning techniques

Study on Overburden Structure Characteristics and Induced Scour Mechanisms of Horizontal Sublevel Mining in Steep and Extra-Thick Coal Seams

In order to study the space–time evolution law and the induced impact mechanism of overburden breaking in the tangential horizontal sublevel during the fully mechanized mining of extra-thick and steep coal seams, we took the Yaojie No. 3 mine as an example. Through the establishment of an overburden breaking mechanical model, the structural characteristics of hinged rock beams after overburden breaking and the space–time evolution law of overburden structure instability were analyzed, the static and dynamic load conditions that induce rockbursts were analyzed, and the induced impact mechanism of dynamic and static load superposition was revealed. Our research showed that, due to the asymmetry of the roof and floor, the coal body in the working face is in the strong shear stress zone at the end of the air inlet roadway, which easily produces shear failure. The lateral support pressure and the shear stress of the coal body in the goaf are the static load sources of the rockburst in the steep coal seam; after the roof overburden is broken, a hinge-bearing structure is formed under the support of the sliding force of the fault block and the floating gangue in the goaf. When the coal is mined in the lower section, the strong dynamic load formed by the impact of the fault block on the topmost coal is the main dynamic load source of the impact on the working face. Under the superpositions of the dynamic load and static load, the coal and rock lose stability and release energy in a large range, generating dynamic and static superimposed rockbursts. Furthermore, the internal mechanism of the occurrence of rockbursts during the mining of steep and extra-thick coal seams in the Yaojie No. 3 coal mine was revealed. The static load of the coal body comes from the clamping actions of the roof and floor, and the dynamic impact load comes from the clamping structure’s instability. The reason for the occurrence of rockbursts in the mining of steep and extra-thick coal seams in the Yaojie No. 3 coal mine was reasonably explained

Dynamic Analysis of Shearer Traction Unit Considering the Longitudinal Swing

Shearer traction failure occurs frequently, which seriously restricts the safe and efficient mining of coal. However, the influence of the shearer’s posture on traction has not been fully considered in the existing research. To improve traction reliability: the dynamic model of the traction unit is established considering longitudinal swing; the walking characteristics of the shearer and the dynamics of the traction unit are analyzed; and the influences of traction velocity, drum load cutting arm angle, and depression angle are discussed. The results show that the longitudinal swing is reciprocating and the positive swing is more serious. With the increase of the traction velocity, the walking stability of the shearer decreases while the contact force increases, especially the support slipper. The longitudinal swing increases with the increase of lateral load, but the supporting force of the support slipper decreases with the increase of cutting load. The forces of the walking wheel and the support slipper show an increasing trend with the increase of cutting arm angle. When the depression angle is 5–10°, the load distribution of the contact components of the traction unit is more balanced. The results provide a reference for the structure optimization of the shearer and the layout of coalface

Control of Water Inrush from Longwall Floor Aquifers Using a Division Paste Backfilling Method

Aiming at the problem of the safety mining problems of longwall paste filling working face under buildings on high confined water in the Daizhuang Coal Mine, the paste filling mining method was used. A series of theoretical analyses, numerical simulations, and field measurements were applied. The results showed that when the filling interval of the working face increases from 1.2 m to 3.6 m, no significant change is found in the depth of the perforated plastic zone of the floor strata. According to the types of water-conducting cracks in the floor strata of the working face 11607, the floor strata are divided into the floor intact area, the structure developed area, and the floor weak area. Based on that, the measures for preventing and controlling the floor failure in the paste filling working face are proposed. Furthermore, the failure depth of the floor of the test working face was detected by the on-site water injection method, and the results showed that the maximum failure depth of the floor of the test working face was about 3 m

Damage characterization and numerical simulation of shear experiment of plain woven glass-fiber reinforced composites based on 3D geometric reconstruction

The investigation on the effect of defects on the mechanical properties of composites is vital to explain the failure mechanism of materials. A computer tomography (CT) scanning in-situ shear test is designed to obtain u-CT images of plain weave glass-fiber reinforced composites. The images are then applied to reconstruct the samples by using image processing techniques. Damage evolution characterization of the plain weave glass-fiber composites under in-situ shear experiment are realized by visualizing damages in three dimension. The damage evolution process is compared with the numerical simulation results to verify the materials failure mode

Determination of Narrow Coal Pillar Width and Roadway Surrounding Rock Support Technology in Gob Driving Roadway

In order to determine the rational width of coal pillars and study the surrounding rock control technology of gob side entry driving with a narrow coal pillar, this paper first calculates the width of narrow coal pillar according to limit equilibrium theory; after that, the lateral support pressure and plastic zone development of the goaf is analyzed by numerical simulation to determine the rational width of reserved coal pillar; finally, through the ring breaking deformation regulation of surrounding rock of the gob side entry, the deformation and failure characteristics of the gob-side roadway during excavation and the influence of mining on the deformation and failure of the gob-side roadway are analyzed. The research results show that, combined with theoretical analysis and numerical simulation, the width of narrow coal pillar is decided to be 10 m; the deformation of the coal pillar side of the gob side roadway is much bigger than the roof subsidence, the deformation of the solid coal wall and the floor deformation; after the bolt support design of the gob side roadway, the deformation and damage of the gob side roadway during the driving period is small; during mining, the deformation of the narrow coal pillar wall is the key factor to determine the stability of the gob roadway; under the bolt support scheme, the overall deformation and failure of surrounding rock of the goaf roadway is small, and the control effect of the surrounding rock of the goaf roadway is good

Research advances on molecular mechanism and natural product therapy of iron metabolism in heart failure

Abstract The progression of heart failure (HF) is complex and involves multiple regulatory pathways. Iron ions play a crucial supportive role as a cofactor for important proteins such as hemoglobin, myoglobin, oxidative respiratory chain, and DNA synthetase, in the myocardial energy metabolism process. In recent years, numerous studies have shown that HF is associated with iron dysmetabolism, and deficiencies in iron and overload of iron can both lead to the development of various myocarditis diseases, which ultimately progress to HF. Iron toxicity and iron metabolism may be key targets for the diagnosis, treatment, and prevention of HF. Some iron chelators (such as desferrioxamine), antioxidants (such as ascorbate), Fer-1, and molecules that regulate iron levels (such as lactoferrin) have been shown to be effective in treating HF and protecting the myocardium in multiple studies. Additionally, certain natural compounds can play a significant role by mediating the imbalance of iron-related signaling pathways and expression levels. Therefore, this review not only summarizes the basic processes of iron metabolism in the body and the mechanisms by which they play a role in HF, with the aim of providing new clues and considerations for the treatment of HF, but also summarizes recent studies on natural chemical components that involve ferroptosis and its role in HF pathology, as well as the mechanisms by which naturally occurring products regulate ferroptosis in HF, with the aim of providing reference information for the development of new ferroptosis inhibitors and lead compounds for the treatment of HF in the future