bluuebunny/crossref_metadata_2025_split huggingface dataset:
Polyesters of phosphoric acid: Synthesis and kinetics of hydrolysis
Authors: Penczek S. , Pretula J. , Kaluzynski K. 
Published: March 2011

AbstractThree major methods have been elaborated in our laboratory for preparation of polymers with poly(alkylene phosphates) backbones: ring‐opening polymerization, poly‐condensation and transesterification, and polyaddition. The second method is based on the reaction of the commercially available compounds, namely dialkyl (or diaryl)‐H‐phosphonates and glycols. Reaction of the aliphatic H‐phosphonates with aliphatic glycols is a reversible process, whereas polycondensation of diphenyl H‐phosphonates with aliphatic and cycloaliphatic diols is practically irreversible. This latter method has recently been developed and is described in this paper.Poly H‐phosphonates with M̄n up to 40–103 were prepared. Polymers are easily oxidized and quantitatively converted into the relatively stable poly(alkylene phosphates). Some physical properties of these polymers and kinetics of their hydrolysis is discussed.
Aromatic components in copolyesters: Model structures help to understand biodegradability
Authors: Rantze Elke , Kleeberg Ilona , Witt Uwe , Müller Rolf‐Joachim , Deckwer Wolf‐Dieter 
Published: March 2011

AbstractCopolyesters build of aliphatic and aromatic components have been shown to be degraded by microorganisms in a certain range of composition. While aliphatic polyesters of diol and dicarbonic acid often are hydrolyzed e.g. by lipases, pure aromatic polyesters like polyethylene terephthalate are not biodegradable. To understand the degradation mechanism of complex aliphatic/aromatic copolymers, we performed degradation experiments with different enzymatic systems and also especially screened highly active microorganisms. Several polymers and monomeric esters representing distinct structure elements within the polymer‐chain have been synthesized. These model structures were investigated in terms to understand the correlation of the stereo selectivity of the tested enzymes and the biodegradability of the polymer structure.
Molecular design strategies for biomaterials that heal
Authors: Ratner Buddy D. 
Published: March 2011

AbstractBiomaterials are widely used in medical devices with good success. However, the surface chemistries of our present generation of biomaterials are not specifically recognized by living organisms. Thus, biological reactions to biomaterials in use today are primarily influenced by non‐specific interactions occurring at their surfaces. This paper develops a hypothesis for the development of a future generation of biomaterials. A discussion of the meaning of biocompatibility is followed by a strategy for developing biomaterials that actively induce healing and reconstruction by turning on specific biologic pathways. Materials strategies for encouraging specific reactions and inhibiting non‐specific bioreaction are presented.
Water‐soluble biodegradable polymers: Synthetic or natural‐based raw materials?
Authors: Swift Graham 
Published: March 2011

AbstractIn this paper, we review some of the significant synthesis approaches that we and others have evaluated for producing commercially viable water‐soluble biodegradable polymers. The goals set for these polymers, cost/performance equivalent with current non‐biodegradable polymers and complete biodegradation or a high degree of certainty that they are free from potential adverse environmental impact, are realistic but very difficult to achieve. Hence, we believe that few new polymers are emerging or are likely to emerge in the near future because of the radical directional changes needed in the synthesis and environmental testing procedures for water‐soluble biodegradable polymers. We consider polymers with structures and compositions that mimic nature most likely to eventually be successful in the market place regardless of raw material origin, provided that cost/performance comparable with current commercial polymers can be achieved. Poly(aspartic acid), recently developed, may be considered as a prototype of things to come.
Ring‐opening polymerization of L‐lactide by means of different iron compounds
Authors: Södergård Anders , Stolt Mikael 
Published: March 2011

AbstractL‐lactide was bulk‐polymerized in the presence of various commercially available iron compounds. The polymerization temperature was in the range of 140 and 230 °C, the monomer to initiator/catalyst ratio varied between 100 and 10 000, and the polymerization time between 30 minutes and 24 hours.Iron oxides, iron chlorides and sulfuric iron compounds were low efficient and are not suitable for melt polymerization of lactide. The oxidation state was noticed not to affect the efficiency. Ferrocene required long polymerization times and a high concentration of the compound before a high molar mass polymer was received. Organic iron salts were also found to be efficient initiators/catalysts, except for the hydrated iron(III)citrate. Especially iron(II)acetate caused a rapid polymerization with a high conversion and molar mass.
The novel benzimidazole derivative, MPTB, induces cell apoptosis in human chondrosarcoma cells
Authors: Li Te‐Mao , Lin Tsang‐Yu , Hsu Sheng‐Feng , Wu Chi‐Ming , Su Yi‐Chang , Kao Shung‐Te , Chang Chih‐Shiang , Fong Yi‐Chin , Tang Chih‐Hsin 
Published: March 2011

AbstractChondrosarcoma is a malignant primary bone tumor that responds poorly to both chemotherapy and radiation therapy. This study is the first to investigate the anti‐cancer effects of the new benzimidazole derivative (5‐methyl‐2(pyridine‐3‐yl)‐1‐(3,4,5‐trimethoxybenzyl)benzimidazole; MPTB) in human chondrosarcoma cells. MPTB‐induced cell apoptosis in two human chondrosarcoma cell lines, JJ012 and SW1353 but not in primary chondrocytes. MPTB‐induced upregulation of Bax and Bak and dysfunction of mitochondria in chondrosarcoma. MPTB triggered endoplasmic reticulum (ER) stress, as indicated by changes in cytosol calcium levels, and increased glucose‐regulated protein (GRP) expression. MPTB also increased calpain expression. Transfection of cells with GRP78 or calpain siRNA reduced MPTB‐mediated cell apoptosis in JJ012 cells. Importantly, animal studies have revealed a dramatic 44% reduction in tumor volume after 21 d of treatment. This study demonstrates novel anti‐cancer activity of MPTB against human chondrosarcoma cells and in murine tumor models. Mol. Carcinog. ©2011 Wiley‐Liss, Inc.
Chemoprevention of lung carcinogenesis by the combination of aerosolized budesonide and oral pioglitazone in A/J mice
Authors: Fu Huijing , Zhang Jingjie , Pan Jing , Zhang Qi , Lu Yan , Wen Weidong , Lubet Ronald A. , Szabo Eva , Chen Ruth , Wang Yian , Chen Da‐Ren , You Ming 
Published: March 2011

AbstractBudesonide, a synthetic glucocorticoid used for treating asthma, and pioglitazone, a synthetic peroxisome proliferator‐activated receptors γ ligand used for the treatment of diabetes, were evaluated for their combinational chemopreventive efficacy on mouse lung cancer using female A/J mice with benzo(a)pyrene used as the carcinogen. All chemopreventive treatments began 2‐wk post‐carcinogen treatment and continued daily for 20 wk. Budesonide was administered by the aerosol route using an improved aerosol delivery system. Pioglitazone was introduced by oral gavage. The characterization of drug distribution showed that budesonide introduced by aerosol delivery accumulated only in the lung. Budesonide alone reduced tumor load by 78% and pioglitazone alone reduced tumor load by 63%. By combining aerosolized budesonide with pioglitazone, the inhibition on tumor load was 90%. In vitro experiments using human cancer cells showed that budesonide and pioglitazone exhibited independent, additive inhibitory effects on cell growth. Our results provide evidence that aerosolized budesonide and oral pioglitazone could be a promising drug combination for lung cancer chemoprevention. © 2011 Wiley Periodicals, Inc.
Macrophages induce neuroendocrine differentiation of prostate cancer cells via BMP6‐IL6 Loop
Authors: Lee Geun Taek , Kwon Seok Joo , Lee Jae‐Ho , Jeon Seong Soo , Jang Kee Taek , Choi Han Yong , Lee Hyun Moo , Kim Wun‐Jae , Lee Dong Hyeon , Kim Isaac Yi 
Published: March 2011

AbstractBACKGROUNDFrequently associated with hormone refractory prostate cancer are neuroendocrine cells. Because these cells do not express androgen receptors and are castration‐resistant, further understanding the mechanism of neuroendocrine differentiation (NED) of prostate cancer cells may yield novel intervention methods in hormone refractory prostate cancer. In this regard, the present study investigated the effect of macrophages on prostate cancer NED.METHODSTHP‐1 and LNCaP or RAW264.7 and TRAMP‐C2 cell line co‐cultures were used to investigate NED–macrophage interactions. Also interleukin‐6 (IL‐6) knockout mice and macrophage‐depleted mice were used to test NED in vivo.RESULTSWe found that co‐culturing with THP‐1 human monocytic cell line and RAW 264.7 murine macrophage cell line led to the NED of LNCaP and TRAMP‐C2 prostate cancer cells, respectively. Specifically, the conditioned media of activated macrophages stimulated the expression of parathyroid hormone‐related peptide (PTHrP), a marker of NED, in both LNCaP and TRAMP‐C2 cells. Mechanistically, bone morphogenetic protein‐6 (BMP‐6) derived from prostate cancer cells increased the expression of IL‐6 in macrophages. Subsequently, IL‐6 induced the NED of prostate cancer cells. When this feedback loop was disrupted with neutralizing antibodies to either BMP‐6 or IL‐6, NED was no longer observed. In human prostate cancer tissues, neuroendocrine cells frequently co‐localized with macrophages and BMP‐6. In mice, the removal of IL‐6 or macrophages blocked the BMP‐6‐induced NED of prostate cancer cells.CONCLUSIONSTherefore, we propose that BMP‐6 secreted by prostate cancer cells induces IL‐6 expression in macrophages; IL‐6, in turn, stimulates the NED of prostate cancer cells. Prostate 71:1525–1537, 2011. © 2011 Wiley‐Liss, Inc.
Nanodevices: Location of Biomarkers and Reagents within Agarose Beads of a Programmable Nano‐bio‐chip (Small 5/2011)
Authors: Jokerst Jesse V. , Chou Jie , Camp James P. , Wong Jorge , Lennart Alexis , Pollard Amanda A. , Floriano Pierre N. , Christodoulides Nicolaos , Simmons Glennon W. , Zhou Yanjie , Ali Mehnaaz F. , McDevitt John T. 
Published: March 2011

AbstractThe slow development of cost‐effective medical microdevices with strong analytical performance characteristics is due to a lack of selective and efficient analyte capture and signaling. The recently developed programmable nano‐bio‐chip (PNBC) is a flexible detection device with analytical behavior rivaling established macroscopic methods. The PNBC system employs ≈300 μm‐diameter bead sensors composed of agarose “nanonets” that populate a microelectromechanical support structure with integrated microfluidic elements. The beads are an efficient and selective protein‐capture medium suitable for the analysis of complex fluid samples. Microscopy and computational studies probe the 3D interior of the beads. The relative contributions that the capture and detection of moieties, analyte size, and bead porosity make to signal distribution and intensity are reported. Agarose pore sizes ranging from 45 to 620 nm are examined and those near 140 nm provide optimal transport characteristics for rapid (<15 min) tests. The system exhibits efficient (99.5%) detection of bead‐bound analyte along with low (≈2%) nonspecific immobilization of the detection probe for carcinoembryonic antigen assay. Furthermore, the role analyte dimensions play in signal distribution is explored, and enhanced methods for assay building that consider the unique features of biomarker size are offered.
Mercury transfer in a subtropical coastal lagoon food web (SE Gulf of California) under two contrasting climatic conditions
Authors: Jara‐Marini Martin E. , Soto‐Jiménez Martín F. , Páez‐Osuna Federico 
Published: March 2011

AbstractMercury (Hg) transference through an established and defined food web from an urbanized subtropical coastal lagoon (SE Gulf of California) was examined by using carbon and nitrogen stable isotope and Hg analyses. Concentrations of Hg in seawater (0.045–0.078 μg L−1), predominantly incorporated to the particulate fraction (60% of total), were lower than those found in highly contaminated coastal areas around the world (0.18–16 μg L−1). Although levels of Hg available for the biota (e.g., associated to the reactive and pyrite fractions; 0.11–0.15 μg g−1) were within of effects range‐low (ER‐L, 0.15–0.71 μg g−1) these concentrations represented from 46.6 to 67.0% of the total Hg pool that may be transferred through food web. The sequence of bio‐accumulation of Hg in studied species was according with their functional guild: tertiary consumer (0.85–1.15 μg g−1) > secondary consumers (0.084–0.168 μg g−1) > primary consumers (0.014–0.160 μg g−1) > primary producers (0.016–0.056 μg g−1). Hg concentrations increased for each successive trophic position estimate through δ15N isotopic values, although these relationships showed differences between dry and rainy seasons (R2 = 0.37 and R2 = 0.39 between δ15N vs. Hg in organisms, respectively). We concluded that Hg is being positively transferred (biomagnification factor >1) through the studied food web probably enhanced by the favorable environmental conditions for Hg‐methylation (e.g., fine sediments rich in organic matter, and environmental conditions changes of the redox, pH, and temperature) found in this urbanized coastal water, however, the study of processes methlylation and biomagnifcation of Hg need further investigations. © 2011Wiley Periodicals, Inc. Environ Toxicol, 2012.
Physiological, anatomical, biochemical, and cytogenetic effects of thiamethoxam treatment on Allium cepa (amaryllidaceae) L.
Authors: Çavuşoğlu Kültiğin , Yalçin Emine , Türkmen Zafer , Yapar Kürşad , Sağir Saffet 
Published: March 2011

Abstractn the present study, toxic effects of active substance thiamethoxam of the insecticide Eforia were investigated on Allium cepa L. For this aim, we used the germination percentage, root length, weight gain, malondialdehyde (MDA) level, frequency of micronucleus (MN), chromosomal aberrations (CAs), and mitotic index (MI) as indicators of toxicity. Also, the changes in the root anatomy of A. cepa seeds treated with thiamethoxam were examined. The seeds in all the treatment groups were treated with three different doses (100, 250, and 500 mg/kg) of thiamethoxam for 72 h. The results showed that there were significant alterations in the germination percentage, root length, weight gain, MDA level, MN, CAs, and MI frequency depending on application dose in the seeds exposed to thiamethoxam compared to control group. Thiamethoxam treatments significantly reduced the germination percentage, root length, and weight gain in all the treatment groups (P < 0.05). But, it caused an increase in MN and CAs formation (P < 0.05). It was also found that thiamethoxam has a mito‐depressive action on mitosis, and the MI was decreased depending on the dose of applied‐thiamethoxam (P < 0.05). About 100, 250, and 500 mg/kg doses of thiamethoxam significantly enhanced the lipid peroxidation and caused an increase in MDA levels at each dose treatment (P < 0.05). Some anatomical damages such as necrotic cell death, unclear vascular tissue, unclear epidermis layer, cell deformation, and unusual form of cell nucleus were observed by using light micrographs. Each dose of thiamethoxam caused severe toxic effects on A. cepa cells, and the maximum toxic effect was observed at the dose level of 500 mg/kg. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2011.
Necrosis and apoptosis of renal tubular epithelial cells in rats exposed to 3‐methyl‐4‐nitrophenol
Authors: Yue Zhuo , She Rui‐Ping , Bao Hui‐Hui , Tian Jijing , Yu Pin , Zhu Jinfeng , Chang Lingling , Ding Ye , Sun Quan 
Published: March 2011

AbstractThe 3‐methyl‐4‐nitrophenol (4‐nitro‐m‐cresol; PNMC) exists in diesel exhaust particles (DEP), and is also one of the degradation products of insecticide fenitrothion. To assess potential nephrotoxicity of PNMC, male Sprague‐Dawley (SD) rats were subcutaneously dosed with PNMC at 1, 10, and 100 mg/kg/day for five consecutive days. No significant changes were detected in body weights and relative weights of kidneys by the treatment of PNMC. However, the extent of cellular necrosis was found to be severe in renal tubular epithelial cells of PNMC‐treated rats. In addition, PNMC exposure significantly increased the number of terminal deoxynucleotidyle transferase‐mediated dUTP nick end‐labeling (TUNEL)‐positive cells compared to the control in renal tubule of PNMC‐treated rats. Moreover, immunohistochemical results indicated that significant decrease in the B‐cell lymphoma 2 (Bcl‐2) expressions andincrease in the Bcl‐2 associated × protein (Bax) expression were detected in PNMC‐treated rats. The ratio of Bcl‐2/Bax was also reduced significantly at PNMC‐treated rats dosed at 10 or 100 mg kg−1. Furthermore, the significant increase of FAS (CD95/APO‐1) expression was found in the groups dosed at 10 or 100 mg kg−1 of PNMC. The expression of Caspase‐3 was higher in PNMC‐treated rats, compared to the control group. Our results indicated that activation of mitochondria and Caspase‐3 protease may contribute to the PNMC‐induced apoptosis, suggesting that PNMC could cause both necrosis and apoptosis resulting in cell death of renal epithelium cells and could induce renal toxicity. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2011.
Drug delivery from structured porous inorganic materials
Authors: Arruebo Manuel 
Published: March 2011

AbstractStructured porous inorganic materials show high chemical and mechanical stability under an array of physiological conditions. Their hydrophilic character and porous structure can in principle be tailored to control the diffusion rate of an adsorbed or encapsulated drug, gene, or protein. This organized porosity has been used to achieve a sustained, controlled, or pulsed release in drug delivery applications. Their large surface areas together with their large pore volumes have been used to improve the solubility of poorly soluble drugs. Their low density allows them to float in the gastrointestinal tract and prolong the gastric retention of oral drugs. In addition, their easy surface functionalization allows their grafting with bioadhesive and targeting moieties, and their interior pore volume protects biological payloads from physiological degradation. Some of those porous inorganic materials can be synthesized or microfabricated to form deposits thus acting as drug reservoirs. Finally, diffusion‐controlling porous membranes or coatings of those materials can be tailored with specific pore sizes to control drug release in eluting devices. Current research is focused on designingondemandtargeted drug delivery systems using those inorganic porous materials as reservoirs together with triggering systems on their pore entrances to be externally activated to release the encapsulated therapeutic moiety. All of the previous scenarios will be overviewed to demonstrate the numerous possibilities of structured porous inorganic materials in drug delivery applications.WIREs Nanomed Nanobiotechnol2012, 4:16–30. doi: 10.1002/wnan.132This article is categorized under:Implantable Materials and Surgical Technologies > Nanomaterials and Implants
Short Term Earthquake Forecasts at Koyna, India
Authors: Gupta Harsh , Shashidhar D. , Mallika K. , Purnachandra Rao N. , Srinagesh D. , Satyanarayana H.V.S. , Saha Satish , Naik R.T.B. 
Published: March 2011

Abstract
Earthquake activity is monitored in real time at the Koyna reservoir in western India, beginning from August 2005 and successful short term forecasts have been made of M ~ 4 earthquakes. The basis of these forecasts is the observation of nucleation that precedes such earthquakes. Here we report that a total of 29 earthquakes in the magnitude range of 3.5 to 5.1 occurred in the region during the period of August 2005 through May 2010. These earthquakes could broadly be put in three zones. Zone-A has been most active accounting for 18 earthquakes, while 5 earthquakes in Zone-B and 6 in Zone-C have occurred. Earthquakes in Zone-A are preceded by well defined nucleation, while it is not the case with zones B and C. This indicates the complexity of the earthquakes processes and the fact that even in a small seismically active area of only 20 km x 30 km earthquake forecast is difficult.
Playa Sediments of the Didwana Lake, Rajasthan: A New Environment for Surficial-type Uranium Mineralisation in India
Authors: Kumar K. Ramesh , Pande Dheeraj , Misra Arpan , Nanda L. K. 
Published: March 2011

Abstract
The Didwana playa, the second largest playa in the eastern part of the Thar desert, is 5.6 km long and 2.4 km wide and supports commercial salt production. The thickness of lake sediment package is reported to be 20 m and comprises fine grained clays and silts, with abundant calcite, gypsum, and halite,associated with hypersaline water. Isolated hills of graphitic phyllite and quartzite are seen on the western side of the lake. During the course of investigations for uranium in surficial environment of semi-arid terrain of Rajasthan, ground water sampling defined a NE-SW trending uranium halo encompassing the Didwana playa. Subsequent sampling of unlined dug wells, up to water table in central part of the playa, indicated uranium values up to 190 ppm and 2072 ppb in lake sediments and brine respectively. These values are of the order of 21 ppm and 192 ppb towards the southwestern periphery of the lake. The average uranium content, as inferred from 12 samples in the central part of the lake, is around 60 ppm over a thickness of 5 m. It appears that the uranium is loosely bonded to the sediments in amorphous form and is, hence, easily leachable. Samples of brine (n=10), from both the central and southwestern portions of the lake, analysed high (1,67,500-3,00,000 mg/l) TDS, HCO3 – (1128-8395 mg/l), and SO4 (30,536-88,000 mg/l). These are of alkaline (pH: 7.2-9.3) and reducing (Eh: -200 to -340 mV) nature. Under these Eh-pH conditions below the groundwater table, and for such uranium bearing groundwater, precipitation of primary uranium is expected. It is, therefore, modelled that uranium in lake sediment package above water table is concentrated by evaporation process and by chemical reduction below the water table.
As the sampling is so far confined to zones above water table, the above possibility is still to be examined. Features like high intrinsic uranium in lake (playa) sediments as well as groundwater, the alkaline and reducing nature of groundwater, which may facilitate precipitation of primary uranium below water table, and the large extent of the lake sediments (10 sq km x 20 m thickness) make the Didwana Lake, a potential candidate for hosting a surficial-type uranium occurrence of significance, for which samples below water table need to be generated. These studies are expected to establish the lake sediment environment in semi-arid tracts of Rajasthan as a new target horizon for locating surficial-type uranium mineralisation in India.