Time-dependent and clustering-induced phosphorescence, mechanochromism, structural-function relationships, and advanced information encryption based on isomeric effects and host-guest doping.

To explore the intrinsic mechanism of pure organic room temperature and clustering-induced phosphorescence and investigate mechanochromism and structural-function relationships, here, 4-(2-(9H-carbazol-9-yl)phenyl)-2-amino-6-methoxypyridine-3,5-dicarbonitrile (Lo-CzAD), 4-(3-(9H-carbazol-9-yl)phenyl)-2-amino-6-methoxypyridine-3,5-dicarbonitrile (Lm-CzAD), and 4-(4-(9H-carbazol-9-yl)phenyl)-2-amino-6-methoxypyridine-3,5-dicarbonitrile (Lp-CzAD) were designed and synthesized by choosing self-made carbazole and 3, 5-dicyanopyridine (DCP) unit as electron acceptor and electron donor in sequence. Compared with crystals Lm-CzAD and Lp-CzAD, crystal Lo-CzAD shows better room temperature phosphorescence (RTP) performance, with RTP lifetimes of 187.16 ms, as well as afterglows 1s, which are attributed to twisted carbazole unit and donor-acceptor (D-A) molecular conformation, big crystal density and spin orbit coupling constant ξ (S1 â†’ T1 and S1 â†’ T2), as well as intermolecular H type stacking and small ξ (S0 â†’ T1). By choosing urea and PPh3 as host materials and tuning doping ratio, four doping systems were successfully constructed, significantly improving RTP performance of Lo-CzAD and Lp-CzAD, as well as showing different fluorescence and RTP. The lifetimes and afterglows of pure organic Urea/Lo-CzAD and Urea/Lp-CzAD systems are up to 478.42 ms, 5 s, 261.66 ms and 4.5 s in turn. Moreover, Lo-CzAD and Lp-CzAD show time-dependent RTP in doping systems due to monomer and aggregate dispersion, as well as clustering-induced phosphorescence. Based on the different luminescent properties, multiple information encryptions were successfully constructed.

Clinical efficacy of transcrestal sinus floor augmentation, in comparison with lateral approach, in sites with residual bone height ≤6 mm: A systematic review and meta-analysis.

OBJECTIVE: This paper addressed two focused questions: Focused question 1 (Q1) "what is the clinical efficacy of transcrestal sinus floor augmentation (TSFA), as compared to lateral sinus floor augmentation (LSFA) in sites with residual bone height (RBH) ≤6 mm, in randomized clinical trials (RCTs) and controlled clinical trials (CCTs)?"; Focused question 2 (Q2) "what is the estimated effectiveness of TSFA for outcomes in Q1, in RCTs, CCTs or cohort studies?" MATERIALS AND METHODS: An electronic search (PubMed, EMBASE, The Cochrane Central Register of Controlled Trials) and hand search were conducted from January 1986 until December 2022. All eligible clinical studies expressly reporting TSFA in sites with RBH ≤6 mm were included. The data were extracted, and the risk of bias in individual studies was evaluated. Meta-analysis was performed whenever possible. RESULTS: Seven RCTs were included for Q1 and 25 studies (9 RCTs, 2 CCTs, 14 single arm cohort studies) for Q2. Q1: Meta-analysis did not show significant difference in the implant survival, sinus membrane perforation and marginal bone loss between TSFA and LSFA groups. Q2: Meta-analysis showed TSFA had a high implant survival rate (96.5%, 95% CI: 93.2%-98.9%) at least 1 year after surgery, and limited sinus membrane perforation (5.4%, 95% CI: 2.7%-8.8%). The results also presented higher patient satisfaction for TSFA. CONCLUSION: With the limitations of the present study (high risk of bias in individual studies), it can be concluded that there was no significant difference in implant survival, Schneiderian membrane perforation and MBL between two approaches in sites with RBH ≤6 mm.

Conversion of THz refractive index variation to detectable voltage change realized by a graphene-based Brewster angle device.

The Brewster effect has been previously reported as an essential mechanism for terahertz (THz) wave sensing application. However, generally in a sensing application, a complex rotation apparatus is required for detecting the slight change in Brewster angle. Here, we propose a graphene-based Brewster angle device operating at a specific terahertz frequency capable of sensing the refractive index at a fixed incident angle. In other words, our sensing device could avoid the impact of Brewster angle shift and eliminate the need for high-precision rotating equipment, which is usually required in traditional sensing applications. The conversion from the refractive index to a Volt-level detectable voltage roots from the tunability of graphene's Fermi level in the external electrical field. A linear correlation between the output voltage and the background refractive index is observed and theocratically analyzed. Furthermore, we present the improvement of our device in terms of sensing range and sensitivity by adjusting the permittivity of the dielectric substrate. As a demonstration of our proposed device, a detection range of 1.1-2.4 and a sensitivity of 20.06 V/RIU for refractive index is achieved on a high-resistance silicon substrate operating at 0.3 THz.

Light-activated PEG deshielding core-shell nanoparticles for enhanced chemo-photodynamic combination therapy.

Chemo-photodynamic combination therapy has attracted great attention as a promising cancer treatment strategy. However, the therapeutic efficacy has been limited by the low selectivity and penetration of therapeutic agents into the tumor. PEGylation is an effective strategy to enhance the stability and circulation times of nanoparticles, which improves the bioavailability of encapsulated drugs. However, such PEGylation nanomedicines also decrease cellular uptake efficiency. Herein, we developed a smart nano-drug delivery system with PEG deshielding and charge reversal performance triggered by external light irradiation, which can not only enhance tumor selectivity and tumor penetration but also combine photodynamic therapy and chemotherapy for better tumor treatment effects, contributed by the use of core-shell nanoparticles with positively charged complex Pt(IV) prodrugs and photosensitizers.

Chemometrics applied quantitative analysis of iron oxide mixtures by terahertz spectroscopy.

A quantitative analysis method for corrosion products based on terahertz spectroscopy is proposed in this paper. Mixture samples consisting of three major corrosion products (magnetite, hematite, and goethite) were prepared in 51 different concentrations. The refractive index spectra measured by terahertz time-domain spectroscopy were projected to the 2D score diagram by performing principal component analysis. The Euclidean distances between the mixtures and pure analyte on the diagram were used to build a concentration prediction model. The results indicate that the established model can precisely predict the concentration of magnetite, which is essential for a stability evaluation of the corrosion system.

Efficient Mining Multi-mers in a Variety of Biological Sequences.

Counting the occurrence frequency of each -mer in a biological sequence is a preliminary yet important step in many bioinformatics applications. However, most -mer counting algorithms rely on a given k to produce single-length -mers, which is inefficient for sequence analysis for different k. Moreover, existing -mer counters focus more on DNA and RNA sequences and less on protein ones. In practice, the analysis of -mers in protein sequences can provide substantial biological insights in structure, function and evolution. To this end, an efficient algorithm, called MulMer (Multiple-Mer mining), is proposed to mine -mers of various lengths termed multi-mers via inverted-index technique, which is orders of magnitude faster than the conventional forward-index methods. Moreover, to the best of our knowledge, MulMer is the first able to mine multi-mers in a variety of sequences, including DNARNA and protein sequences.

[Preliminary study on mechanisms of granulocyte macrophage-colony stimulating factor in enhancing impaired colonic anastomotic healing in rats treated with intraperitoneal oxaliplatin].

OBJECTIVE: To investigate the mechanisms of local application of granulocyte macrophage-colony stimulating factor (GM-CSF) on healing of colonic anastomoses impaired by intraperitoneal oxaliplatin in rats. METHODS: Sixty 10-week-old male Wistar rats were made the colonic anastomosis model and randomized into 3 groups, 20 rats in each. The rats received intraperitoneal injection of 5% dextrose in group A, and intraperitoneal injection of 5% dextrose and 10 mL oxaliplatin (25 mg/kg) in group B at 1 day; and 50 microg GM-CSF was injected into the perianastomotic area immediately after operation and 10 mL intraperitoneal oxaliplatin (25 mg/kg) was given at 1 day. The general situation of rats was observed after operation. Anastomotic healing was tested by measuring the bursting pressure in vivo at 2, 3, 5, 7 days. Anastomotic healing score was evaluated by histological staining. Immunohistochemical staining of the anastomotic site was used to determine the amount of collagen type I content. RESULTS: All animals survived to the experiment end. There was no significant difference in the bursting pressure among 3 groups at 2 and 3 days (P > 0.05); the bursting pressure of group B was significantly lower than that of groups A and C (P < 0.05). There was no significant difference in mononuclear cells infiltration, mucosal epithelialization, submucosa-muscle layer connection degree, and granulation tissue formation between groups A and C at different time points (P > 0.05); groups A and C were significantly better than group B in mucosal epithelialization and granulation tissue formation (P < 0.05). Groups A and C were significantly better than group B in mononuclear cells infiltration at 2 and 3 days, and in submucosa-muscle layer connection degree at 5 and 7 days (P < 0.05). There was no significant difference in collagen type I content among 3 groups at 2 and 3 days (P > 0.05); the content of collagen type I in groups A and C were significantly higher than that in group B (P < 0.05) at 5 and 7 days. CONCLUSION: Local administration of GM-CSF may enhance colonic anastomotic healing by early stimulating infiltration of macrophages and increasing collagen deposition.

Synthesis and structural characterization of two-coordinate low-valent 14-group metal complexes bearing bulky bis(amido)silane ligands.

A series of germylene, stannylene and plumbylene complexes [η(2)(N,N)-Me(2)Si(DippN)(2)Ge:] (3a), [η(2)(N,N)-Ph(2)Si(DippN)(2)Ge:] (3b), [η(2)(N,N)-Me(2)Si(DippN)(2)Sn:] (4), [η(2)(N,N)-Me(2)Si(DippN)(2)Pb:](2) (5a), and [η(2)(N,N)-Ph(2)Si(DippN)(2)Pb:] (5b) (Dipp = 2,6-iPr(2)C(6)H(3)) bearing bulky bis(amido)silane ligands were readily prepared either by the transamination of M[N(SiMe(3))(2)](2) (M = Sn, Pb) and [Me(2)Si(DippNH)(2)] or by the metathesis reaction of bislithium bis(amido)silane [η(1)(N),η(1)(N)-R(2)Si(DippNLi)(2)] (R = Me, Ph) with the corresponding metal halides GeCl(2)(dioxane), SnCl(2), and PbCl(2), respectively. Preliminary atom-transfer chemistry involving [η(2)(N,N)-Me(2)Si(DippN)(2)Ge:] (3a) with oxygen yielded a dimeric oxo-bridged germanium complex [η(2)(N,N)-Me(2)Si(DippN)(2)Ge(µ-O)](2) (6). All complexes were characterized by (1)H, (13)C, (119)Sn NMR, IR, and elemental analysis. X-ray single crystal diffraction analysis revealed that the metal centres in 3b, 4, and 5b are sterically protected to prevent interaction between the metal centre and the nitrogen donors of adjacent molecules while complex 5a shows a dimeric feature with a strong intermolecular Pb···N interaction.