Fluorescent supramolecular polymersomes based on pillararene/paraquat molecular recognition for pH-controlled drug release

Researchers have put significant efforts on developing versatile fluorescent polymeric systems due to their promising biological/biomedical labelling, tracking, monitoring, imaging, and diagnostic applications. However, complicated organic/polymeric synthesis or post-modification of these functionalized platforms is still a big obstacle for their further application and thereby provides clear motivation for exploring alternative strategies for the design and fabrication of easily available fluorescent systems. The marriage of supramolecular polymers and fluorescent imaging can provide a facile and dynamic manner instead of tedious and time-consuming synthesis due to the dynamic and reversible nature of noncovalent interactions. Herein, based on water-soluble pillararene/paraquat molecular recognition, we successfully prepare two amphiphilic polypseudorotaxanes which can self-assemble into supramolecular polymersomes in water. These polymersomes can be reversibly destroyed and reformed by tuning the solution pH. Attributed to the aggregation-induced emission of tetraphenylethylene groups, intense fluorescence can be introduced into the obtained supramolecular polymersomes. Furthermore, pH-triggered release of an encapsulated water-insoluble drug (doxorubicin) from the self-assembled fluorescent supramolecular polymersomes is also investigated

Lack of association between apolipoprotein C3 gene polymorphisms and risk of coronary heart disease in a Han population in East China

<p>Abstract</p> <p>Background</p> <p>Several polymorphisms in the apolipoprotein C3 (APOC3) gene have been found association with hypertriglyceridemia(HTG), but the link with coronary heart disease(CHD) risk between ethnicities was still controversial. Among them, reseachers paid more attentions to the promoter polymorphisms T-455C and C-482T because both of them located in insulin-responsive element (IRE) and insulin was thought to exert its action by down-regulating APOC3 gene expression. The aim of this study was to investigate the association of the two polymorphisms of APOC3 with CHD in a Han population in East China.</p> <p>Methods</p> <p>TaqMan SNP Genotyping Assays were carried out to detect the genotypes of APOC3 gene, including the T-455C and C-482T, in 286 subjects with CHD and 325 controls without CHD. The levels of serum lipid profiles were also detected by biochemical methods.</p> <p>Results</p> <p>There was no difference of genotype frequencies and allele frequencies between the CHD population and the controls(P > 0.05). Compared with the most common genotype -455TT or -482CC, the variants had neither significantly increased CHD risk, nor the lipid variables showed any statistically relevant differences in the research population. The adjusted OR of CHD were 5.67 [0.27-18.74] and 0.75 [0.20-2.73] in carriers of the APOC3 -455C and -482T variants, respectively(P > 0.05). There was also no significant difference in APOC3 haplotype distribution in CHD and controls, but there was a strong linkage disequilibrium between T-455C and C-482T with D' = 0.9293, 0.8881, respectively(P < 0.0001).</p> <p>Conclusions</p> <p>Our data did not support a relationship between the two polymorphisms of APOC3 gene and risk of CHD in the Han population in East China.</p

Consistency between ARPES and STM measurements on SmB6_6

Strongly correlated topological surface states are promising platforms for next-generation quantum applications, but they remain elusive in real materials. The correlated Kondo insulator SmB$_6$ is one of the most promising candidates, with theoretically predicted heavy Dirac surface states supported by transport and scanning tunneling microscopy (STM) experiments. However, a puzzling discrepancy appears between STM and angle-resolved photoemission (ARPES) experiments on SmB$_6$. Although ARPES detects spin-textured surface states, their velocity is an order of magnitude higher than expected, while the Dirac point -- the hallmark of any topological system -- can only be inferred deep within the bulk valence band. A significant challenge is that SmB$_6$ lacks a natural cleavage plane, resulting in ordered surface domains limited to 10s of nanometers. Here we use STM to show that surface band bending can shift energy features by 10s of meV between domains. Starting from our STM spectra, we simulate the full spectral function as an average over multiple domains with different surface potentials. Our simulation shows excellent agreement with ARPES data, and thus resolves the apparent discrepancy between large-area measurements that average over multiple band-shifted domains and atomically-resolved measurements within a single domain

New Insights Into Interactions of Presynaptic Calcium Channel Subtypes and SNARE Proteins in Neurotransmitter Release

Action potential (AP) induces presynaptic membrane depolarization and subsequent opening of Ca2+ channels, and then triggers neurotransmitter release at the active zone of presynaptic terminal. Presynaptic Ca2+ channels and SNARE proteins (SNAREs) interactions form a large signal transfer complex, which are core components for exocytosis. Ca2+ channels serve to regulate the activity of Ca2+ channels through direct binding and indirect activation of active zone proteins and SNAREs. The activation of Ca2+ channels promotes synaptic vesicle recruitment, docking, priming, fusion and neurotransmission release. Intracellular calcium increase is a key step for the initiation of vesicle fusion. Various voltage-gated calcium channel (VGCC) subtypes exert different physiological functions. Until now, it has not been clear how different subtypes of calcium channels integrally regulate the release of neurotransmitters within 200 μs of the AP arriving at the active zone of synaptic terminal. In this mini review, we provide a brief overview of the structure and physiological function of Ca2+ channel subtypes, interactions of Ca2+ channels and SNAREs in neurotransmitter release, and dynamic fine-tune Ca2+ channel activities by G proteins (Gβγ), multiple protein kinases and Ca2+ sensor (CaS) proteins

Plasma indoleamine 2,3-dioxygenase activity as a potential biomarker for early diagnosis of multidrug-resistant tuberculosis in tuberculosis patients

Purpose: Multidrug-resistant tuberculosis (MDR-TB) remains a challenge of global TB control, with difficulty in early detection of drug-sensitive tuberculosis (DS-TB). We investigate the diagnostic significance of IDO as a potential biomarker to discriminate MDR patients among the TB patients. Patients and methods: Plasma indoleamine 2,3-dioxygenase (IDO) was measured by the ratio of kynurenine (Kyn) to tryptophan (Trp) concentrations, using high performance liquid chromatography-mass spectrometry (LC-MS/MS). Chest computed tomography (CT) imaging signs from TB patients were collected and analyzed in 18 DS-TB patients, 16 MDR-TB patients, 6 lung cancer (LC) patients, and 11 healthy individuals. Lung imaging signs from TB patients were collected and analyzed. Results: We found that plasma IDO activity was significantly higher in the MDR-TB patients than in the DS-TB patients (p=0.012) and in the LC patients (p=0.003). We evaluated the diagnostic significance of plasma IDO activity in discriminating the MDR-TB group from the DS-TB group using a receiver operating characteristic (ROC) curve. With a cutoff level of 46.58 uM/mM, the diagnostic sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for IDO activity were 87.50%, 72.22%, 73.68%, and 86.67%, respectively. Plasma IDO activity was higher in cavity cases than in non-cavity cases (p=0.042), proving a positive correlation between lung cavity number and cavity size (p \u3c 0.05, separately) among all the TB patients studied. Conclusion: Our findings confirmed that plasma IDO activity might have an auxiliary diagnosis value for early discrimination of MDR-TB patients from DS-TB patients. Among the TB patients with cavitary lung lesions, higher plasma IDO activity can indicate a higher risk of MDR-TB

Transcriptional analysis of highly syntenic regions between Medicago truncatula and Glycine max using tiling microarrays

The comparative transcriptional analysis of highly syntenic regions in six different organ types between Medicago truncatula (barrel medic) and Glycine max (soybean), using nucleotide tiling microarrays, provides insights into genome organization and transcriptional regulation in these legume plants