Synthesis, Properties, and Reaction Behavior of Cobalt and Copper Organometallic Complexes with Chelating Ligands

Several cobalt complexes with tripodal chelating ligands Tp and Tp* (Tp = tris(pyrazolyl)borate; Tp* = tris(3,5-dimethyl-pyrazolyl)borate) were synthesized by treating the homoscorpionates of the first generation with CoBr2 under different conditions. These complexes were characterized with X-ray crystallographic determination as well as IR, NMR, MS, and UV-vis spectroscopies. Reaction of KTp with CoBr2 in THF afforded an unprecedented trinuclear Co(II) complex [TpCo(Hpz)Br]2(CoBr2) (1) with Tp as terminal ligands, as well as an oxidized side-product (Tp2Co)(Co2Br6) (2). The terminal Co(II) centers of (1) are octahedrally coordinated while the Co(II) in the bridging unit has a distorted tetrahedral geometry, holding a neighboring Co···Co distance of 3.472 Å. Reaction of KTp* with CoBr2 afforded half-sandwich Tp*CoBr (4) with pseudotetrahedrally coordinated Co(II) center, which is accessible to other donors. Mononuclear Tp*CoSPh (7) and dinuclear (Tp*Co)2O2(pz)2 (8) were prepared through ligand exchange reactions of LiSPh and Li(pz) with (4), respectively. (8) contains two octahedral Co(III) centers bridged by two pyrazolyl and a peroxide groups, in which the Co···Co distance is 3.591 Å. Reaction of (dppf)Cu(NCMe) (dppf = 1,1’-bis(diphenylphosphino)ferrocene) with chloranilate dianion (CA2-) afforded tetranuclear complex (dppf)2Cu2(CA) (9). Single crystal X-ray diffraction revealed that the Cu(I) centers are coordinated by dppf and CA2- in a distorted-tetrahedral manner. The two Cu(I) centers are located almost in the same plane of the bridging ligand with the Cu···Cu separation of 7.940 Å. In its UV-Vis spectrum, the π−π∗ and n−π∗ absorptions of CA2- bridge are shown at 297.1 nm and 480.4 nm, respectively. Irreversible reduction waves were illustrated in the cyclic voltammogram of (9), which were attributed to an ECE process during the measurement

Solid lipid nanoparticle suspension enhanced the therapeutic efficacy of praziquantel against tapeworm

Hydatid disease caused by tapeworm is an increasing public health and socioeconomic concern. In order to enhance the therapeutic efficacy of praziquantel (PZQ) against tapeworm, PZQ-loaded hydrogenated castor oil solid lipid nanoparticle (PZQ-HCO-SLN) suspension was prepared by a hot homogenization and ultrasonication method. The stability of the suspension at 4°C and room temperature was evaluated by the physicochemical characteristics of the nanoparticles and in-vitro release pattern of the suspension. Pharmacokinetics was studied after subcutaneous administration of the suspension in dogs. The therapeutic effect of the novel formulation was evaluated in dogs naturally infected with Echinococcus granulosus. The results showed that the drug recovery of the suspension was 97.59% ± 7.56%. Nanoparticle diameter, polydispersivity index, and zeta potential were 263.00 ± 11.15 nm, 0.34 ± 0.06, and −11.57 ± 1.12 mV, respectively and showed no significant changes after 4 months of storage at both 4°C and room temperature. The stored suspensions displayed similar in-vitro release patterns as that of the newly prepared one. SLNs increased the bioavailability of PZQ 5.67-fold and extended the mean residence time of the drug from 56.71 to 280.38 hours. Single subcutaneous administration of PZQ-HCO-SLN suspension obtained enhanced therapeutic efficacy against tapeworm in infected dogs. At the dose of 5 mg/kg, the stool-ova reduction and negative conversion rates and tapeworm removal rate of the suspension were 100%, while the native PZQ were 91.55%, 87.5%, and 66.7%. When the dose reduced to 0.5 mg/kg, the native drug showed no effect, but the suspension still got the same therapeutic efficacy as that of the 5 mg/kg native PZQ. These results demonstrate that the PZQ-HCO-SLN suspension is a promising formulation to enhance the therapeutic efficacy of PZQ

Variational Wasserstein Barycenters for Geometric Clustering

We propose to compute Wasserstein barycenters (WBs) by solving for Monge maps with variational principle. We discuss the metric properties of WBs and explore their connections, especially the connections of Monge WBs, to K-means clustering and co-clustering. We also discuss the feasibility of Monge WBs on unbalanced measures and spherical domains. We propose two new problems -- regularized K-means and Wasserstein barycenter compression. We demonstrate the use of VWBs in solving these clustering-related problems

“What should be computed” for supporting post-pandemic recovery policymaking?:A life-oriented perspective

The COVID-19 pandemic has caused various impacts on people’s lives, while changes in people’s lives have shown mixed effects on mitigating the spread of the SARS-CoV-2 virus. Understanding how to capture such two-way interactions is crucial, not only to control the pandemic but also to support post-pandemic urban recovery policies. As suggested by the life-oriented approach, the above interactions exist with respect to a variety of life domains, which form a complex behavior system. Through a review of the literature, this paper first points out inconsistent evidence about behavioral factors affecting the spread of COVID-19, and then argues that existing studies on the impacts of COVID-19 on people’s lives have ignored behavioral co-changes in multiple life domains. Furthermore, selected uncertain trends of people’s lives for the post-pandemic recovery are described. Finally, this paper concludes with a summary about “what should be computed?” in Computational Urban Science with respect to how to catch up with delays in the SDGs caused by the COVID-19 pandemic, how to address digital divides and dilemmas of e-society, how to capture behavioral co-changes during the post-pandemic recovery process, and how to better manage post-pandemic recovery policymaking processes.</p

Synthesis of Stereoscopic Views from Monocular Endoscopic Videos

Abstract Recent studies have shown that 3D imaging provides some unique advantages over traditional 2D imaging for minimal invasive surgery. However, most existing endoscopes still use single-lens cameras, and the use of duallens 3D imaging techniques is still limited. This paper proposes an approach to enabling 3D imaging from a singlelens endoscope by automatically synthesizing stereoscopic views from monocular images captured by the endoscope. We first formulate the problem by introducing the notion of normalized disparity, based on which we show that affine reconstruction is sufficient for stereoscopic view synthesis. With this formulation and exploiting other domain-specific constraints, we then propose a robust structure-from-motion algorithm for a sparse set of feature points and a fast, linear interpretation algorithm for creating a dense disparity field for synthesizing stereoscopic views from original monocular video. Both synthetic images and real endoscopic videos are used to evaluate the proposed method. The results demonstrate the feasibility and effectiveness of the proposed method

“What should be computed” for supporting post-pandemic recovery policymaking?:A life-oriented perspective

The COVID-19 pandemic has caused various impacts on people’s lives, while changes in people’s lives have shown mixed effects on mitigating the spread of the SARS-CoV-2 virus. Understanding how to capture such two-way interactions is crucial, not only to control the pandemic but also to support post-pandemic urban recovery policies. As suggested by the life-oriented approach, the above interactions exist with respect to a variety of life domains, which form a complex behavior system. Through a review of the literature, this paper first points out inconsistent evidence about behavioral factors affecting the spread of COVID-19, and then argues that existing studies on the impacts of COVID-19 on people’s lives have ignored behavioral co-changes in multiple life domains. Furthermore, selected uncertain trends of people’s lives for the post-pandemic recovery are described. Finally, this paper concludes with a summary about “what should be computed?” in Computational Urban Science with respect to how to catch up with delays in the SDGs caused by the COVID-19 pandemic, how to address digital divides and dilemmas of e-society, how to capture behavioral co-changes during the post-pandemic recovery process, and how to better manage post-pandemic recovery policymaking processes.</p

Effect of implant placement depth on the peri-implant bone defect configurations in ligature-induced peri-implantitis : an experimental study in dogs

The subcrestal placement of implant platform has been considered a key factor in the preservation of crestal bone, but the influence of implant placement depth on bone remodeling combined with peri-implantitis is not fully understood. The aim of this study was to assess the effect of the crestal or subcrestal placement of implants on peri-implant bone defects of ligature-induced peri-implantitis in dogs. Eight weeks after tooth extraction in six beagle dogs, two different types of implants (A: OsseoSpeed?, Astra, Mölndal, Sweden; B: Integra-CP?, Bicon, Boston, USA) were placed at either crestal or subcrestal (-1.5 mm) positions on one side of the mandible. Ligature-induced peri-implantitis was initiated four weeks after the installation of the healing abutment connections. After 12 weeks, tissue biopsies were processed for histological analyses. Supra-alveolar bone loss combined with a shallow infrabony defect was observed in crestal level implants while deep and wide infrabony defects were present in subcrestal level groups. Subcrestal groups showed significantly greater ridge loss, depths and widths of infrabony defects when compared to crestal groups (P<0.001). Within the limitations of the animal study, it can be stated that the implants at subcrestal position displayed greater infra-osseous defect than implants at crestal position under an experimental ligature-induced peri-implantitis