Biomedical subjects

Zhen Chen

Publications and source records attributed to Zhen Chen.

At least 19 recordsLinked to original sources

PubMed2026

Worldwide Innovative Network Consortium: Building a Common Global Cancer Database.

This review shares the ongoing work of the global Worldwide Innovative Network (WIN) Consortium for Precision Medicine to synthesize emerging cancer treatment data and to define the requirements for a common global cancer database that can truly support precision oncology. We performed a narrative review of emerging cancer treatment data, molecular profiling technologies, and existing clinicogenomic databases, focusing on how tumors are characterized, how subgroups are defined, and how demographic, lifestyle, and environmental factors are captured. The growth in molecular profiling technologies and the development of new targeted therapies are transforming cancer care. Tumors, regardless of tissue origin, are increasingly defined as composites of multiple, often rare, subgroups, each with distinct biology and likely response to specific therapies, based on multidimensional profiling of the tumor and its microenvironment. The solution lies in building vast databases that capture racial and ethnic diversity, reflected in genomic data, as well as diet and lifestyle factors that may have epigenetic impact on gene expression and post-translational modifications. A truly inclusive and informative data set must reflect global diversity, and there are multiple examples of demography-dependent differences in genomic signals. With members caring for and studying patients with cancer across five continents, WIN is actively exploring pathways to create a global cancer database, rich in clinical and molecular detail, granular enough for precise analysis, and large enough to power artificial intelligence-driven insights, provided appropriate data quality, validation, and governance frameworks are in place. This review surveys the current landscape and outlines practical paths forward to achieve this goal.

Humans↗

PubMed2026

Multi-omics integration uncovers adaptive responses of stomach and pyloric ceca to artificial feed in mandarin fish (Siniperca chuatsi).

The mandarin fish, as an obligate piscivore, is highly dependent on live bait, which restricts its intensive aquaculture. Although domestication has enabled it to partially accept formulated diets, the tissue-specific molecular adaptation mechanisms of its digestive tract to artificial feed remain unclear. In this study, we conducted an integrated analysis of mandarin fish fed with live bait or artificial diet for three weeks, combining growth performance evaluation, gastric histology, and paired transcriptomic and metabolomic analyses of the stomach and pyloric ceca. AD feeding significantly improved growth performance, while histological examination revealed marked hyperplasia of the gastric mucosa and disorganized fold structures. Transcriptomic analysis identified 5065 and 3381 differentially expressed genes in the stomach and pyloric ceca, respectively. In the stomach, the artificial diet induced a glutathione-dependent antioxidant response, accompanied by glycolytic reprogramming and coordinated upregulation of genes in the extracellular matrix (ECM)-receptor interaction signaling pathway, including those encoding collagen, laminin, and integrin. In the pyloric ceca, the tricarboxylic acid (TCA) cycle and oxidative phosphorylation were broadly suppressed, whereas glycosaminoglycan degradation and lysosomal pathways were activated. Metabolomic analysis showed that gastric metabolites were enriched in vascular and inflammatory mediator pathways, while metabolites in the pyloric ceca were enriched in peroxisome proliferator-activated receptor (PPAR) signaling, sphingolipid signaling, and steroid hormone biosynthesis pathways. Following artificial diet feeding, integrated multi-omics analysis of the stomach revealed significant enrichment of pathways such as phospholipase D signaling, sphingolipid signaling, and arachidonic acid metabolism, accompanied by the accumulation of key metabolites including sphingosine-1-phosphate, 20-hydroxyeicosatetraenoic acid, and cellobiose. Integrated analysis of the pyloric ceca identified significantly altered pathways, including sphingolipid metabolism, alpha-linolenic acid metabolism, and glutathione metabolism, along with elevated levels of sphingosine-1-phosphate, sphingosine galactoside, and 9-hydroxy-12-oxo-10,15-octadecadienoic acid, as well as decreased glutathionylspermidine. These findings systematically unveil the tissue-specific molecular adaptation characteristics of the mandarin fish digestive tract in response to artificial feed, providing an important basis for understanding the molecular mechanisms of dietary adaptation in carnivorous fish and for optimizing artificial feed formulations.

Animals↗

PubMed2026

Efficient homologous replacement and deletion of large genomic fragments through template-jumping prime editing in rice.

Homologous replacement of genomic sequences with large DNA fragments (> 100 bp) holds great potential for crop breeding, yet an efficient method to achieve such edits is lacking in plants. Here, in rice, we developed template-jumping prime editing (TJ-PE), a recently reported PE strategy for large targeted insertion, as an efficient tool for homologous replacement with DNA fragments ranging from dozens to hundreds of base pairs, and using TJ-PE, we replaced genomic fragments of up to 340 bp with homologous fragments of the same length. In addition, our TJ-PE tool also enabled precise deletion of 944- to 2024-bp fragments in rice, with efficiencies of up to 34.6% for c. 2000-bp precise deletions. Collectively, this study expands the editing scope of PE in rice and establishes TJ-PE as a generalist tool for precise deletion and replacement of large DNA fragments.

Oryza↗

PubMed2026

Non-telomeric function deficiency of TERT enhances pressure overload-induced mouse cardiac remodeling by activation of CNBP-mediated THBS3/ITGB1 pathway.

Recent studies show that telomerase reverse transcriptase (TERT) possesses important new biological functions in gene transcription regulation, signal transduction, tumorigenesis, vascular development and mitochondrial DNA protection independent of the maintenance of telomere length. In this study we investigated the role and mechanisms of TERT in regulating the gene expression and signal transduction during pressure overload-induced cardiac remodeling. The first-generation TERT knockout (Tert-/-) and wild-type littermate control (Tert+/+) male mice were subjected to transverse aortic constriction (TAC) surgery to establish a pressure overload-induced cardiac remodeling model. We showed that pressure overload significantly increased TERT expression in the hearts at 8 weeks after TAC, whereas TERT deficiency remarkably exacerbated pressure overload-induced cardiac dysfunction, cardiac hypertrophy and fibrosis, and reduced the survival rate of the mice. In contrast, TERT overexpression reversed phenylephrine (PE)-stimulated cardiomyocyte hypertrophy and fibrosis in neonatal rat ventricular myocytes (NRVMs). Ttranscriptomic and proteomic analyses revealed that extracellular matrix (ECM)-receptor interaction was a key Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway regulated by TERT in hemodynamic overload-induced cardiac remodeling. TERT knockdown greatly enhanced, while TERT overexpression inhibited the activation of the THBS3/ITGB1 signaling pathway, in which transcription factor cellular nucleic acid-binding protein (CNBP) played a pivotal mediating role by interacting with TERT. In conclusion, the non-telomeric function of TERT in gene transcription regulation and signaling transduction plays an important role during pressure overload-induced myocardial remodeling via modulating CNBP-mediated THBS3/ITGB1 signaling pathway, which provides new targets and strategies for the prevention and treatment of pressure overload-induced cardiac remodeling.

Animals↗

PubMed2025

Worldwide Innovative Network (WIN) Consortium in Personalized Cancer Medicine: Bringing next-generation precision oncology to patients.

The human genome project ushered in a genomic medicine era that was largely unimaginable three decades ago. Discoveries of druggable cancer drivers enabled biomarker-driven gene- and immune-targeted therapy and transformed cancer treatment. Minimizing treatment not expected to benefit, and toxicity-including financial and time-are important goals of modern oncology. The Worldwide Innovative Network (WIN) Consortium in Personalized Cancer Medicine founded by Drs. John Mendelsohn and Thomas Tursz provided a vision for innovation, collaboration and global impact in precision oncology. Through pursuit of transcriptomic signatures, artificial intelligence (AI) algorithms, global precision cancer medicine clinical trials and input from an international Molecular Tumor Board (MTB), WIN has led the way in demonstrating patient benefit from precision-therapeutics through N-of-1 molecularly-driven studies. WIN Next-Generation Precision Oncology (WINGPO) trials are being developed in the neoadjuvant, adjuvant or metastatic settings, incorporate real-world data, digital pathology, and advanced algorithms to guide MTB prioritization of therapy combinations for a diverse global population. WIN has pursued combinations that target multiple drivers/hallmarks of cancer in individual patients. WIN continues to be impactful through collaboration with industry, government, sponsors, funders, academic and community centers, patient advocates, and other stakeholders to tackle challenges including drug access, costs, regulatory barriers, and patient support. WIN's collaborative next generation of precision oncology trials will guide treatment selection for patients with advanced cancers through MTB and AI algorithms based on serial liquid and tissue biopsies and exploratory omics including transcriptomics, proteomics, metabolomics and functional precision medicine. Our vision is to accelerate the future of precision oncology care.

Humans↗

PubMed2024

Comprehensive Proteomic Analysis Reveals Distinct Features and a Diagnostic Biomarker Panel for Early Pregnancy Loss in Histological Subtypes.

Early pregnancy loss (EPL) is a common event in human reproduction and is classified into histological subtypes such as hydropic abortion (HA) and hydatidiform moles, including complete hydatidiform moles (CHMs) and partial hydatidiform moles (PHMs). However, accurate diagnosis and improved patient management remain challenging due to high rates of misdiagnosis and diverse prognostic risks. Therefore, diagnostic biomarkers for EPL are urgently needed. Our study aimed to identify biomarkers for EPL through comprehensive proteomic analysis. Ten CHMs, six PHMs, ten HAs, and 10 normal control products of conception were used to obtain a proteomic portrait. Parallel reaction monitoring-targeted proteomic and regression analyses were used to verify and select the diagnostic signatures. Finally, 14 proteins were selected and a panel of diagnostic classifiers (DLK1, SPTB/COL21A1, and SAR1A) was built to represent the CHM, PHM, and normal control groups (area under the receiver operating characteristic curve = 0.900, 0.804/0.885, and 0.991, respectively). This high diagnostic power was further validated in another independent cohort (n = 148) by immunohistochemistry (n = 120) and Western blot analyses (n = 28). The protein SPTB was selected for further biological behavior experiments in vitro. Our data suggest that SPTB maintains trophoblast cell proliferation, angiogenesis, cell motility, and the cytoskeleton network. This study provides a comprehensive proteomic portrait and identifies potential diagnostic biomarkers. These findings enhance our understanding of EPL pathogenesis and offer novel targets for diagnosis and therapeutic interventions.

Humans↗

PubMed2007

Cytokine response is lower after lung volume reduction through bilateral thoracoscopy versus sternotomy.

BACKGROUND: Lung volume reduction surgery performed through bilateral video-assisted thoracoscopy (BVATS) was associated in the National Emphysema Treatment Trial with a statistically significant reduction in intensive care unit days, failure to wean, hospital stay, and cost, and earlier recovery compared with median sternotomy. Studies comparing other minimally invasive techniques with "open" procedures, including pulmonary lobectomy, have demonstrated reduced serum proinflammatory mediators postoperatively. We measured these levels after lung volume reduction surgery through BVATS and sternotomy. METHODS: Serum cytokine levels were measured by radioimmunoassay in 9 consecutive, steroid-free patients undergoing sternotomy and lung volume reduction surgery and 6 undergoing BVATS and lung volume reduction surgery. The groups were not statistically different with respect to age, partial pressure of arterial carbon dioxide, percent forced expiratory volume in 1 second, percent residual volume, percent total lung capacity, diffusion capacity of the lung for carbon monoxide, 6-minute walk, or apical perfusion fraction. Proinflammatory interleukin 6 and interleukin 8 and antiinflammatory interleukin 10 were evaluated preoperatively and postoperatively on days 1, 4, and 5. Clinical data were prospectively collected. RESULTS: There were no major postoperative complications or deaths. Interleukin 6 levels were lower in the BVATS than the sternotomy group (p = 0.016 by repeated measures analysis of variance). Interleukin 8 levels were lower in the BVATS group at most postoperative time points, but there were no significant differences in interleukin 8 or interleukin 10 levels between the sternotomy and BVATS groups at any individual time point or by analysis of variance. CONCLUSIONS: Use of a BVATS approach to lung volume reduction surgery is associated with reduced postoperative release of proinflammatory cytokines compared with a sternotomy approach. This may account for the reduction in recovery time and some measures of postoperative morbidity seen with the BVATS approach.

Aged↗

PubMed2006

Two novel C29-5beta-sterols from the stems of Opuntia dillenii.

Two novel C29-5beta-sterols, opuntisterol [(24R)-24-ethyl-5beta-cholest-9-ene-6beta,12alpha-diol] (1) and opuntisteroside [(24R)-24-ethyl-6beta-[(beta-d-glucopyranosyl)oxy]-5beta-cholest-9-ene-12alpha-ol] (2), together with nine known compounds, beta-sitosterol (3), taraxerol (4), friedelin (5), methyl linoleate (6), 7-oxositosterol (7), 6beta-hydroxystigmast-4-ene-3-one (8), daucosterol (9), methyl eucomate (10) and eucomic acid (11), were isolated from the stems of Opuntia dillenii collected in Guizhou Province, China. Their structures were elucidated mainly by spectroscopic analysis. The absolute configuration of 1 were deduced from comparative 1H NMR data of the (S)- and (R)-methoxyphenyl acetate derivatives. Compounds 6-8, 10 and 11 were isolated from O. dillenii for the first time.

Hydrolysis↗

PubMed2006

Cholesterol loading increases the translocation of ATP synthase beta chain into membrane caveolae in vascular endothelial cells.

Caveolae and its structural protein caveolin-1 (Cav-1) are abundant in vascular endothelial cells (ECs) and have been suggested to contribute to cell signaling and cholesterol trafficking. This study investigated the effect of cholesterol on the movement of caveolae-related proteins in human umbilical vein ECs with use of caveolae functional proteomics. After cholesterol exposure to ECs for 2 to 4 h, caveolae were isolated and separated on 2-D protein gels. Among 40 protein spots revealed in caveolae fractions, the ATP synthase beta subunit (ATPS-beta), one of the 3 proteins enriched by cholesterol in caveolae, was confirmed by western blotting and confocal microscopy. Further, cholesterol exposure increased the level of ATPS-beta, along with Cav-1 and cholesterol in caveolae. These effects could be blocked by cytochalasin B, an actin cytoskeleton disruptor. ATPS-beta was physically associated with Cav-1, as demonstrated by co-immunoprecipitation and GST-Cav-1 fusion protein pull-down assay. Cholesterol increased the extracellular ATP release mediated by ATPS-beta, since this action could be blocked by piceatannol or oligomycin, ATPS inhibitors. Thus, the ectopic localization of ATPS-beta may participate in the energy balance of cells in response to the change in intracellular cholesterol levels.

Caveolae↗

PubMed2006

Antioxidative function and biodistribution of [Gd@C82(OH)22]n nanoparticles in tumor-bearing mice.

Oxidative stress is considered to be one of the important mechanisms involved in carcinogenesis. In our previous study, gadolinium endohedral metallofullerenol ([Gd@C82(OH)22]n nanoparticles) have shown high inhibitory activity on hepatoma cell (H22) growth in mice. To explore the antioxidative functions of nanoparticles, we investigated the biodistribution of [Gd@C82(OH)22]n nanoparticles, the changes of blood coagulation profiles, the metabolism of reactive oxygen species (ROS) in the tumor-bearing mice as well as the possible relationships between nanoparticles treatment and ROS production in this paper. The activities of hepatic superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), glutathione S-transferase (GST) and catalase (CAT) as well as the levels of reduced glutathione (GSH), protein-bound thiols and malondialdehyde (MDA) were compared between the tumor-bearing mice and normal mice. Transplanted tumors were grown in mice by subcutaneous injection of murine hepatoma cells in the mice. The comparison of the above parameters between nanoparticles and cyclophosphamide (CTX) therapy were also investigated. [Gd@C82(OH)22]n administration can efficiently restore the damaged liver and kidney of the tumor-bearing mice. All the activities of enzymes and other parameters related to oxidative stress were reduced after [Gd@C82(OH)22]n treatment and tended closely to the normal levels. The results suggest that [Gd@C82(OH)22]n nanoparticle treatment could regulate ROS production in vivo.

Animals↗

PubMed2006

Outcomes after 151 extended transcervical thymectomies for myasthenia gravis.

BACKGROUND: The ideal operative technique for thymectomy in myasthenia gravis (MG) remains controversial. We present the largest series of extended transcervical thymectomy to provide outcomes data to compare with transsternal procedures. METHODS: A retrospective chart review/interview was made of 164 patients operated upon from 1992 to 2004. Complete remission (CR) was defined as asymptomatic off medication for 6 months or asymptomatic on low-dose single-drug therapy (< or = 10 mg/d prednisone or < or = 150 mg/d azathioprine). A modified Osserman classification based upon the Myasthenia Gravis Foundation of America quantitative disease severity score was employed. RESULTS: The overall complication rate was 7.3%, and nearly all procedures were outpatient. Mean age at surgery was 43 years, and mean preoperative Osserman class was 2.3 (21% class 1; 39% class 2; 28% class 3; 12% class 4). Mean length of follow-up was 53 months. Mean postoperative Osserman class was 1.0. Nineteen percent of patients failed to improve. The crude cumulative CR rate was 37% (n = 58). Kaplan-Meier estimates of CR were 43% and 45% at 3 and 6 years, respectively. On multivariate analysis, only preoperative disease severity was significantly (inversely) associated with Kaplan-Meier CR rates. Longer-term follow-up (83 months) of only the earlier patients shows preserved CR rates (46%). CONCLUSIONS: This largest series of extended transcervical thymectomy for MG confirms that the 5-year Kaplan-Meier CR rate is comparable with that obtained after transsternal procedures. Patients with less severe disease have higher CR rates. Complete responses are durable, as the CR rate remains stable with extended follow-up.

Adolescent↗

PubMed2006

A potential outcomes approach to developmental toxicity analyses.

Estimating the effects of a toxin on fetal development in animal models such as mice can be problematic, because the number of pups that develop and survive until birth may simultaneously affect developmental outcomes such as birth weight and be affected by the introduction of a toxin into the fetal environment. Also, comparing pups that survived until birth at a high dose of the toxin with pups that survived at low doses may underestimate the effect of the toxin, because the lower dose means include the less healthy pups that would not survive if exposed to a higher level of toxin. We consider this problem in a potential outcomes framework that defines the effect of the dose on the outcome as the difference between what the outcome would have been for a pup had the dam in which the pup develops been exposed to dose level Z=z* rather than dose level Z=z. To disentangle the direct effect of dose from the effect of litter size, we focus on effects defined within principal strata that are a function of the survival status of the pups at each of the possible dose levels. A unique contribution to the potential outcomes literature is that we allow the outcome for a subject to be dependent on the principal stratum to which other subjects within a cluster belong.

Animals↗

PubMed2006

ZNRD1 mediates resistance of gastric cancer cells to methotrexate by regulation of IMPDH2 and Bcl-2.

We previously showed that downregulation of a transcription-associated gene (ZNRD1) could reverse the resistant phenotype of gastric cancer cells through regulation of the transcription of multidrug resistance gene 1 (MDR1). In the present study, we determined both known and novel differentially expressed genes in VCR-induced multidrug resistant gastric cancer cell SGC7901/VCR transfected with ZNRD1 siRNA or empty vector control. Screening was performed using the Human Cancer Xpro(tm) HC-III plus arrays, containing 3072 cancer-related cDNAs. Ten genes, involved in cell cycle control, nucleic acid binding, and protein phosphorylation, among other functions, underwent more than 5-fold change. Of the downregulated genes we chose Inosine monophosphate dehydrogenase 2 (IMPDH2) for further validation by quantitative RT-PCR. In vitro and in vivo drug sensitivity analyses revealed that inhibition of ZNRD1 and IMPDH2 activity sensitized SGC7901/VCR cells to methotrexate. Additionally, inhibition of ZNRD1 could suppress adriamycin-induced apoptosis and significantly downregulate the expression of Bcl-2, but it did not alter the expression of the glutathione-S-transferase, or intracellular glutathione content. Taken together, the findings suggest that ZNRD1 could act as a modulator of methotrexate chemotherapy in gastric cancer cells through the regulation of IMPDH2 and Bcl-2.

Antimetabolites, Antineoplastic↗

PubMed2006

[Effects of ethanol extracts of Panax notoginseng on liver metastasis of B16 melanoma grafted in mice].

OBJECTIVE: To observe the effects of ethanol extracts of Panax notoginseng on the tumor and the liver metastasis in experimental mice grafted with B16 melanoma. METHODS: B16 melanoma was transplanted in the spleen of C57BL/6 mice. The effects of different doses of ethanol extracts of Panax notoginseng on the inhibition rate of spleen tumors and the liver metastasis were observed respectively. RESULTS: The high-, medium-, and low-doses of the extracts and the interferon-alpha (IFN-alpha) can improve the quality of life of the experimental mice. The weights of spleen tumor were lower in the low- and medium-dose extracts-treated groups and the IFN-alpha-treated group than that in the normal saline (NS)-treated group (P<0.05 or P<0.01). The liver metastasis was less in the low- and medium-dose extracts-treated groups and the IFN-alpha-treated group than that in the NS-treated group (P<0.01). CONCLUSION: The ethanol extracts of Panax notoginseng can improve the quality of life of the experimental mice and inhibit the growth of tumor and the liver metastasis.

Animals↗

PubMed2006

[Clinical observation on electric stimulation of Yongquan (KI 1) for prevention of nausea and vomiting induced by Cisplatin].

OBJECTIVE: To search for an effective method for controlling nausea and vomiting induced by chemotherapy. METHODS: Eighty-eight cases of hepatic cancer with interventional therapy of Cisplatin were randomly divided into a treatment group and a control group, 44 cases in each group. The treatment group were treated with an antiemetic and electroacupuncture at Yongquan (KI 1), and the control group only with the antiementic. The controlling rates for nausea and vomiting were compared between the two groups. RESULTS: The controlling rates for acute nausea, vomiting and delayed vomiting in the treatment group were better than those in the control group (P < 0.05). CONCLUSION: Electroacupuncture at Yongquan (KI 1) can better prevent and improve the symptoms of nausea and vomiting in the patient with chemotherapy of Cisplatin.

Adolescent↗

PubMed2006

[Three-dimensional conformal radiotherapy combined with transcatheter arterial chemoembolization for hepatocellular carcinoma].

OBJECTIVE: To evaluate the response and tolerance in hepatocellular carcinoma (HCC) patients treated by three-dimensional conformal radiotherapy (3DCRT) combined with. transcatheter arterial chemoembolization (TACE). METHODS: Fourty-six HCC patients confirmed by cytology or histology were studied. All patients underwent TACE 1 to 3 courses. Then they received 3DCRT after an interval of about one month. 3DCRT was given with the field covering the tumor with a generous margin. 6 MV X-ray was used. The total dose was 30 - 54 Gy, in daily 2 Gy fractions. Immediate response was recorded according to the WHO criteria carried out by serial CT scan one month after 3DCRT. Irradiation toxicities were scored by the RTOG criteria. Acute liver toxicity was graded according to the common toxicity criteria (CTC) of National Cancer Institute. Late toxicity was focused on radiation-induced liver disease (RILD). RESULTS: Partial response was observed in 8 (17.4%) patients. Stable disease and progressive disease was observed in 35 (76.1%) patients and 3 (6.5%) patients, respectively. No complete response was observed at the time of the response evaluation. The overall survival rate at 1-, 2- and 3-year was 60.9%, 39.1% and 28.3%, respectively, with a median survival period of 16 months. The 1-, 2- and 3-year local progression-free rate was 73.9%, 56.5% and 39.1%, respectively. The 1-, 2- and 3-year distant metastasis rate was 15.2%, 21.7% and 34.8%. Univariate analysis showed that favorable prognostic predictors for survival were: T3 stage, CACA 2001 stage I, absence of portal thrombosis, Child-Pugh grade A and irradiation dose of >45 Gy. Irradiation dose and liver cirrhosis were identified by Cox-regression analysis as independent predictors for survival. Two patients experienced CTC grade 1 acute hepatic toxicity and three patients experienced grade 3 acute hepatic toxicity. Two patients developed RILD. Three patients experienced RTOG grade 1 acute gastrointestinal complication and one patient experienced acute gastrointestinal bleeding. Five patients experienced RTOG grade 1 leucopenia, and five patients experienced grade 2 leucopenia. CONCLUSION: 3DCRT combined with TACE is safe and effective for HCC. It is worthy of a further dose escalation study.

Adult↗

PubMed2005

Acute toxicological effects of copper nanoparticles in vivo.

To assess the toxicity of copper nanoparticles (23.5 nm) in vivo, LD(50), morphological changes, pathological examinations and blood biochemical indexes of experimental mice are studied comparatively with micro-copper particles (17 microm) and cupric ions (CuCl(2).2H(2)O). The LD(50) for the nano-, micro-copper particles and cupric ions exposed to mice via oral gavage are 413, >5000 and 110 mg/kg body weight, respectively. The toxicity classes of nano and ionic copper particles both are class 3 (moderately toxic), and micro-copper is class 5 (practically non-toxic) of Hodge and Sterner Scale. Kidney, liver and spleen are found to be target organs of nano-copper particles. Nanoparticles induce gravely toxicological effects and heavy injuries on kidney, liver and spleen of experimental mice, but micro-copper particles do not, on mass basis. Results indicate a gender dependent feature of nanotoxicity. Several factors such as huge specific surface area, ultrahigh reactivity, exceeding consumption of H(+), etc. that likely cause the grave nanotoxicity observed in vivo are discussed.

Administration, Oral↗

PubMed2005

Synthesis of ferrocene-grafted poly(p-phenylene-ethynylenes) and control of electrochemical behaviors of their thin films.

New ferrocene-coated poly(p-phenylene-ethynylenes) (PPEs) with end capping groups of protected thiol were prepared by a palladium-catalyzed Sonogashira coupling reaction. Ferrocene groups were covalently attached to polymers A and B through ethylene oxide tethers and to polymer C through methylene tethers. Polymers A and B are soluble in common solvents such as tetrahydrofuran (THF), chloroform, methylene chloride, acetone, dimethylformamide (DMF), and dimethyl sulfoxide (DMSO), and polymer C is soluble in toluene, THF, chloroform, and methylene chloride. Polymers A-C display low quantum yield, caused by electron-transfer quenching of ferrocene groups as electron donors. The polymer thin films were prepared through incubation of gold electrodes in THF solutions containing the polymers for 2 days. Ferrocene in thin films of polymers A and B display significantly faster electron-transfer rate than that of polymer C. Hydrophilic ethylene oxide side chains of polymers A and B decrease formal potential of tethered ferrocene groups because of electron-donating effect from ethylene oxide side chains, which stabilizes the ferrocenium ion and leads to a cathodic shift of the redox wave.

Alkynes↗