Crystal structure of 5,15-dihexyl-5,15-dihydrobenzo[2,1-b:4,3-c′]dicarbazole hexane 0.375-solvate

The title compound, C38H40N2·0.375C6H14, crystallizes in the monoclinic space group P21/c and has a host–guest structure with the helicene molecules forming a porous structure and molecules of hexane inserted into the holes. The dihedral angles between the two carbazole sections of the right- and left-handed helicenes are 27.44 (3) and 25.63 (3)°, respectively. There are no classical π–π interactions or hydrogen-bonding interactions present between adjacent molecules in the crystal structure. The hexane solvent molecule shows positional disorder

Antisense Overexpression of Gγ Subunit CsGG3.1-2 Reduces Soluble Sugar Content and Chilling Tolerance in Cucumber

Plant G protein γ subunits have multiple functions in growth and development processes and in abiotic stress responses. Few functions of Gγ in horticultural crops have been revealed thus far. In this study, the potential function of CsGG3.1-2, one of the two alternative splice variants of Gγ gene CsGG3.1 in cucumber (Cucumis sativus L.), was investigated using transgenic plants overexpressing antisense CsGG3.1-2 under the control of the 35S promoter. The tolerance to chilling stress in transgenic plants was significantly decreased. Cold stress-related physiological parameters and the expression of CBFs and their downstream target genes were then measured. Compared with WT, the maximum efficiency of photosystem II (Fv/Fm), antioxidative enzymes activities, soluble protein, and proline accumulation decreased significantly in transgenic plants treated with cold stress, whereas the malonaldehyde (MDA) content increased. However, the overexpression of antisense CsGG3.1-2 did not affect the induction of cold-inducible genes. Quantitative real-time PCR (qPCR) analysis showed the increased expression of CBF genes and their downstream target genes in transgenic plants, suggesting that CsGG3.1-2 affects cold responses via CBF-independent pathways in cucumber. At the same time, the sucrose and fructose contents decreased in transgenic plants under both normal and cold conditions. These findings suggest that soluble sugar deficiency is associated with chilling sensitivity in transgenic plants, and CsGG3.1-2 may have a role in regulating carbohydrate metabolism in cucumber

Therapeutic strategies against bacterial biofilms

The emergence of multi-drug resistance makes bacterial infection a major threat to public health and economy. The formation of bacterial biofilms is one of the main reasons of bacterial resistance. The complexity of chemical composition and physical structure makes the elimination of mature biofilms a difficult problem. The highly antibiotic resistant property of biofilms urgently calls for potent antimicrobial agents and novel antibiofilm strategies. Researchers have made a lot of efforts in this field. Here we review the current strategies to eliminate mature biofilms and progress in related drug delivery nanosystems, with the aim of inspiring researchers to design new antibiofilm systems

Host-Defense-Peptide-Mimicking β-Peptide Polymer Acting as a Dual-Modal Antibacterial Agent by Interfering Quorum Sensing and Killing Individual Bacteria Simultaneously

Host defense peptides (HDPs) are one of the potentially promising agents for infection diseases due to their broad spectrum and low resistance rate, but their clinical applications are limited by proteolytic instability, high-cost, and complicated synthesis process. Here, we report a host-defense-peptide-mimicking β-peptide polymer that resists proteolysis to have enhanced the activity under physiological conditions, excellent antimicrobial efficiency even at high density of bacteria, and low cost for preparation. The β-peptide polymer demonstrated quorum sensing (QS) interference and bactericidal effect against both bacterial communities and individual bacterium to simultaneously block bacterial communication and disrupt bacterial membranes. The hierarchical QS network was suppressed, and main QS signaling systems showed considerably down-regulated gene expression, resulting in excellent biofilm eradication and virulence reduction effects. The dual-modal antibacterial ability possessed excellent therapeutic effects in Pseudomonas aeruginosa pneumonia, which could inhibit biofilm formation and exhibit better antibacterial and anti-inflammatory efficiency than clinically used antibiotics, levofloxacin. Furthermore, the β-peptide polymer also showed excellent therapeutic effect Escherichia coli pyogenic liver abscess. Together, we believed that the β-peptide polymer had a feasible clinical potential to treat bacterial infection diseases

Defective UiO-66-NH₂ (Zr) for Simultaneous Adsorption of Phosphate and Pb²⁺ for Hydrogen Peroxide Purification

Removal of hetero ions from the hydrogen peroxide solution is a crucial step in purifying electronic-grade H2O2. Conventional adsorption materials are challenged to meet the need for the simultaneous adsorption of both anions and cations in solvents. UiO-66 (Zr) modified by acetic acid and amino group for simultaneous adsorption of phosphate and Pb2+ in H2O2 purification was fabricated in this work. The as-prepared defective UiO-66-NH2 (Zr) demonstrated a significant increase in specific surface area and porosity, along with more exposed sites for phosphate and Pb2+ adsorption. The adsorption capacity of De-UiO-66-NH2 for phosphate and Pb2+ in H2O2 solution was 52.28 mg g–1 and 35.4 mg g–1, which is 1.19 times and 1.88 times that of unmodified UiO-66 (Zr), respectively. The trace simultaneous adsorption with both 100 ppb phosphate and Pb2+ showed removal rates of 94.0% and 88.7%, respectively, confirming the practicality of MOF materials in the purification of electronic chemicals. This work highlights the potential of Zr-based MOFs as anionic and cationic simultaneous adsorbents for highly efficient purification of electronic-grade solvents

A Common Polymorphism near the ESR1 Gene Is Associated with Risk of Breast Cancer: Evidence from a Case-Control Study and a Meta-Analysis

<div><h3>Background</h3><p>Genome-wide association studies have reported that a polymorphism near the estrogen receptor gene (ESR1) (rs2046210) is associated with a risk of breast cancer, with the A allele conferring an increased risk. However, considering the controversial results from more recent replicated studies, we conducted a case-control study in an independent Chinese Han population and a meta-analysis to clarify the association of this polymorphism with breast cancer risk.</p> <h3>Method and Findings</h3><p>A hospital-based case-control study including 461 cases and 537 controls from a Chinese Han population was conducted initially, and this study showed that the rs2046210 A allele was significantly associated with breast cancer risk, with an OR of 1.32 (95% CI  = 1.10–1.59). Subsequently, a meta-analysis integrating the current study and previous publications with a total of 53,379 cases and 55,493 controls was performed to further confirm our findings. Similarly, a significant association between this polymorphism and breast cancer risk was also observed in the overall population especially among Asians, with ORs for per A allele of 1.14 (95% CI  = 1.10–1.18) in the overall population and 1.27 (95% CI  = 1.23–1.31) in the Asian population.</p> <h3>Conclusion</h3><p>Our results provide strong evidence to support that the common polymorphism near the ESR1 gene, rs2046210, is associated with an increased risk of breast cancer in Asian and European populations but not in Africans, although the biological mechanisms need to be further investigated.</p> </div

Meta-analysis of the rs2046210 in association with breast cancer risk under different genetic models.

a<p>Included a study that only offered the adjusted ORs for AG vs. GG, AA vs. GG and dominant model, both crude and adjusted ORs were combined.</p>b<p>Compared to cases with ER positive cancer, crude OR(95% CI) for ER negative cancer was 1.11(1.06–1.15) for the model of A VS. G (<i>P</i> = 8.27×10⁻⁷).</p>c<p>Compared to premenopausal cases, crude OR(95% CI) for postmenopausal cases was 0.99(0.95–1.04) for the model of A VS. G (<i>P</i> = 0.706).</p

Characteristics of the study population.

<p>Abbreviations: ER, estrogen receptor; PR, progesterone receptor.</p>a<p><i>P</i> value was calculated by the <i>t</i> test.</p>b<p><i>P</i> value was calculated by the <i>χ²</i> test.</p

Sensitivity analysis of allelic model.

<p>Sensitivity analysis of allelic model.</p