2,700 research outputs found
Bis(2,2′-bipyridine)(5,5′-iminoditetrazolato)cadmium(II) 2,2′-bipyridine hemisolvate monohydrate
The title complex, [Cd(C2HN9)(C10H8N2)2]·0.5C10H8N2·H2O, was prepared under hydrothermal reaction conditions. The asymmetric unit contains the cadmium complex, half a 2,2′-bipyridine solvent molecule and a solvent water molecule. The CdII ion is coordinated by four N atoms from two 2,2′-bipyridine ligands and two N atoms from an HBTA− anion ligand [where H2BTA is N,N-bis(1H-tetrazol-5-yl)amine], forming an octahedral geometry. The complex is linked into a three-dimensional network by O—H⋯N and N—H⋯N hydrogen bonds and by the stacking interactions of rings, with distances of 3.5–3.7 Å between the atoms of two parallel 2,2′-bipyridine rings
Pemetrexed plus cisplatin/carboplatin in previously treated locally advanced or metastatic non-small cell lung cancer patients
<p>Abstract</p> <p>Background</p> <p>The objective of this study was to evaluate the efficacy and safety of pemetrexed plus cisplatin/carboplatin in locally advanced or metastatic non-small cell lung cancer (NSCLC) patients previously treated with platinum-based chemotherapy.</p> <p>Methods</p> <p>Fifty-three locally advanced or metastatic non-small cell lung cancer patients previously treated with platinum-based chemotherapy received pemetrexed 500 mg/m<sup>2 </sup>plus cisplatin 75 mg/m<sup>2 </sup>or carboplatin area under the curve (AUC) 5 every 21 days, with dexamethasone, folic acid and vitamin B12 being administered.</p> <p>Results</p> <p>Median age was 52 years. Eastern Cooperative Oncology Group (ECOG) performance status was 0-2. Thirty-eight patients had stage IV tumors. Thirty-seven patients had adenocarcinoma (including 6 alveolar carcinoma patients), and fourteen patients had squamous cell carcinoma. Thirty-four patients were treated in second line, 15 in third line, and 4 in fourth line. Seven patients (13.2%) showed partial response; Thirty-six (67.9%) had stable disease. The median progression free survival time was 6.0 months and the median overall survival time was 10.0 months. The 1-year survival rate was 40.9%. Five (9.4%) and four (7.5%) patients experienced grade 3 or 4 leukopenia and thrombocytopenia, respectively. Nonhematological toxicities included grade 3 nausea/vomiting in 1 patient (1.9%), grade 3 rash in 1 patient, grade 4 diarrhea in 1 patient (1.9%) and grade 4 creatinine increase in 1 patient (1.9%).</p> <p>Conclusion</p> <p>Locally advanced or metastatic NSCLC patients previously treated with platinum-based chemotherapy could benefit from pemetrexed plus cisplatin/carboplatin chemotherapy with tolerable adverse events.</p
Development, in vitro biocompatibility, and antitumor efficacy of acetic acid-modified Cordyceps sinensis polysaccharide nanoparticle drug delivery system
Docetaxel-loaded acetic acid conjugated Cordyceps sinensis polysaccharide (DTX-AA-CSP) nanoparticles were prepared through dialysis and their release rates in vitro, particle sizes, zeta potentials, drug loading capacities, and encapsulation efficiencies were characterized for the synthesis of AA-modified CSPs from traditional Chinese medicine Cordyceps sinensis (Berk.) Sacc. Then, the AA-modified CSPs were characterized by 1 H-NMR and FT-IR. Furthermore, the biocompatibility of the delivery carrier (AA-CSP nanoparticles) was assessed on human umbilical vein endothelial cells. In vitro antitumor activity studies on DTX-AA-CSP nanoparticles were conducted on the human liver (HepG2) and colon cancer cells (SW480). The DTX-AA-CSP nanoparticles were spherical and had an average size of 98.91±0.29 nm and zeta potential within the −19.75±1.13 mV. The encapsulation efficiency and loading capacity were 80.95%±0.43% and 8.09%±0.04%, respectively. In vitro, DTX from the DTX-AA-CSP nanoparticles exhibited a sustained release, and the anticancer activities of DTX-AA-CSP nanoparticles against SW480 and HepG2 were significantly higher than those of marketed docetaxel injection (Taxotere®) in nearly all the tested concentrations. The AA-CSP nanoparticles showed good biocompatibility. This study provided a promising biocompatible delivery system for carrying antitumor drugs for cancer therapy
Natural plant polyphenols for alleviating oxidative damage in man: Current status and future perspectives
The balance between oxidation and reduction is important for maintaining a healthy biological system. Oxidative stress results from an imbalance between excessive formation of reactive oxygen species (ROS) and/or reactive nitrogen species (RNS) and limited endogenous defense systems, and this imbalance can adversely alter lipids, proteins and DNA, causing a number of human diseases. Thus, exogenous antioxidants that can neutralize the effect of free radicals are needed to diminish the cumulative effects of oxidative damage over human life span. Current research reveals that phenolic compounds in plants possess high antioxidant activity and free radical scavenging capacity and can prevent the body from oxidative damage over human life span. This review focuses on the present understanding of free radicals and antioxidants and their importance in human health and disease. Information about the chemical features of free radicals as well as their deleterious effects on cell structures is reviewed. The chemical structure and anti-oxidative mechanisms of essential polyphenols and their potential health benefits are presented. In addition, the limitation of natural antioxidants and a perspective on likely future trends in this field are also discussed.Keywords: Free radicals, Oxidative stress, Natural antioxidants, Polyphenols, Health benefits, Reactive oxygen species, Reactive nitrogen specie
Reconfigurable Intelligent Surface Aided TeraHertz Communications Under Misalignment and Hardware Impairments
TeraHertz (THz) communications are envisioned to help satisfy the ever high
data rates demand with massive bandwidth in the future wireless communication
systems. However, severe path attenuation, transceiver antenna misalignment,
and hardware imperfection greatly alleviate the performance of THz
communications. To solve this challenge, we utilize the recently proposed
reconfigurable intelligent surface (RIS) technology and provide a comprehensive
analytical framework of RIS-aided THz communications. More specifically, we
first prove that the small-scale amplitude fading of THz signals can be exactly
modeled by the fluctuating two-ray distribution based on recent measurements.
Exact statistical characterizations of end-to-end signal-to-noise plus
distortion ratio (SNDR) and signal-to-noise ratio (SNR) are derived. Moreover,
we propose a novel method of optimizing the phase-shifts at the RIS elements
under discrete phase constraints. Finally, we derive analytical expressions for
the outage probability and ergodic capacity, respectively. The tight upper
bounds of ergodic capacity for both ideal and non-ideal radio frequency chains
are obtained. We provided Monte-Carlo simulations to validate the accuracy of
our results. It is interesting to find that the impact of path loss is more
pronounced compared to others, and increasing the number of elements at the RIS
can significantly improve the THz communication system performance
Increases in solar conversion efficiencies of the ZrO2 nanofiber-doped TiO2 photoelectrode for dye-sensitized solar cells
In this paper, in order to improve the efficiency of dye-sensitized solar cells, we introduced zirconia [ZrO2] nanofibers into a mesoporous titania [TiO2] photoelectrode. The photoelectrode consists of a few weight percent of ZrO2 nanofibers and a mesoporous TiO2 powder. The mixed ZrO2 nanofibers and the mesoporous TiO2 powder possessed a larger surface area than the corresponding mesoporous TiO2 powder. The optimum ratio of the ZrO2 nanofiber was 5 wt.%. The 5 wt.% ZrO2-mixed device could get a short-circuit photocurrent density of 15.9 mA/cm2, an open-circuit photovoltage of 0.69 V, a fill factor of 0.60, and a light-to-electricity conversion efficiency of 6.5% under irradiation of AM 1.5 (100 mW/cm2)
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