Immobilization of cellulase enzyme onto iron oxide nanoparticles to improve thermal and pH stability

Lignocellulosic enzymes have been used in the pretreatment and hydrolysis of the biomass, are getting special attention to produce the sustainable green biofuel. However, free enzymes not only difficult to separate from reaction media but also highly temperature and pH sensitive, so a controlled environment is required to maintain. A proper immobilization support material needs to adopt to improve their stability and reusability. In this research, cellulase immobilized magnetic nanoparticles were prepared to improve thermal and pH stability and reusability of enzyme

Enzymatic pretreatment of lignocellulosic biomass: An overview

Lignocellulosic biomass is nature's most abundant alternative source of biofuels replacing traditional fossil fuels. Globally, more than 70% of renewable energy depends on biomass and contributes 14% of the total energy supply. The pretreatment of lignocellulosic biomass is to remove lignin, modify the lignin structure, reduce the cellulose crystallinity and increase the porosity and surface area of lignocellulosic material. The pretreatment of lignocellulosic biomass is one of the most expensive steps for biomass conversion and consumes about 40% of total costs. Traditionally physical and chemical methods have been used for the pretreatment of lignocellulosic biomass. However, these methods are unsustainable and have a huge negative impact on the environment. Pretreatment by the lignocellulosic laccase enzyme can overcome these problems. So the pretreatment of lignocellulosic biomass has been studied, presenting special attention to the enzymatic pretreatment of lignocellulosic biomass

Prostate cancer cells modulate osteoblast mineralisation and osteoclast differentiation through Id-1

Background: Id-1 is overexpressed in and correlated with metastatic potential of prostate cancer. The role of Id-1 in this metastatic process was further analysed. Methods: Conditioned media from prostate cancer cells, expressing various levels of Id-1, were used to stimulate pre-osteoclast differentiation and osteoblast mineralisation. Downstream effectors of Id-1 were identified. Expressions of Id-1 and its downstream effectors in prostate cancers were studied using immunohistochemistry in a prostate cancer patient cohort (N110). Results: We found that conditioned media from LNCaP prostate cancer cells overexpressing Id-1 had a higher ability to drive osteoclast differentiation and a lower ability to stimulate osteoblast mineralisation than control, whereas conditioned media from PC3 prostate cancer cells with Id-1 knockdown were less able to stimulate osteoclast differentiation. Id-1 was found to negatively regulate TNF-Β and this correlation was confirmed in human prostate cancer specimens (P0.03). Furthermore, addition of recombinant TNF-Β to LNCaP Id-1 cell-derived media blocked the effect of Id-1 overexpression on osteoblast mineralisation. Conclusion: In prostate cancer cells, the ability of Id-1 to modulate bone cell differentiation favouring metastatic bone disease is partially mediated by TNF-Β, and Id-1 could be a potential therapeutic target for prostate cancer to bone metastasis. © 2010 Cancer Research UK. All rights reserved.link_to_OA_fulltex

An essential role for the Id1/PI3K/Akt/NFkB/survivin signalling pathway in promoting the proliferation of endothelial progenitor cells in vitro

The enhancement of re-endothelialisation is a critical therapeutic option for repairing injured blood vessels. Endothelial progenitor cells (EPCs) are the major source of cells that participate in endothelium repair and contribute to re-endothelialisation by reducing neointima formation after vascular injury. The over-expression of the inhibitor of differentiation or DNA binding 1 (Id1) significantly improved EPC proliferation. This study aimed to investigate the effects of Id1 on the phosphatidylinositol-3-kinase (PI3K)/Akt/nuclear factor kappa B (NFκB)/survivin signalling pathway and its significance in promoting EPC proliferation in vitro. Spleen-derived EPCs were cultured as previously described. Id1 was presented at low levels in EPCs, and was rapidly up-regulated by stimulation with vascular endothelial growth factor. We demonstrated that transient transfection of Id1 into EPCs activated the PI3K/Akt/NFκB/survivin signalling pathway and promoted EPC proliferation. The proliferation of EPCs was extensively inhibited by silencing of endogenous Id1, and knockdown of Id1 expression led to suppression of PI3K/Akt/NFκB/survivin signalling pathway in EPCs. In addition, blockade by the PI3K-specific inhibitor LY294002, Akt inhibitor, the NFκB inhibitor BAY 11-7082, the survivin inhibitor Curcumin, or the survivin inhibitor YM155 reduced the effects of Id1 transfection. These results suggest that the Id1/PI3K/Akt/NFκB/survivin signalling pathway plays a critical role in EPC proliferation. The Id1/PI3K/Akt/NFκB/survivin signalling pathway may represent a novel therapeutic target in the prevention of restenosis after vascular injury

Accounts of severe acute obstetric complications in Rural Bangladesh

<p>Abstract</p> <p>Background</p> <p>As maternal deaths have decreased worldwide, increasing attention has been placed on the study of severe obstetric complications, such as hemorrhage, eclampsia, and obstructed labor, to identify where improvements can be made in maternal health. Though access to medical care is considered to be life-saving during obstetric emergencies, data on the factors associated with health care decision-making during obstetric emergencies are lacking. We aim to describe the health care decision-making process during severe acute obstetric complications among women and their families in rural Bangladesh.</p> <p>Methods</p> <p>Using the pregnancy surveillance infrastructure from a large community trial in northwest rural Bangladesh, we nested a qualitative study to document barriers to timely receipt of medical care for severe obstetric complications. We conducted 40 semi-structured, in-depth interviews with women reporting severe acute obstetric complications and purposively selected for conditions representing the top five most common obstetric complications. The interviews were transcribed and coded to highlight common themes and to develop an overall conceptual model.</p> <p>Results</p> <p>Women attributed their life-threatening experiences to societal and socioeconomic factors that led to delays in seeking timely medical care by decision makers, usually husbands or other male relatives. Despite the dominance of male relatives and husbands in the decision-making process, women who underwent induced abortions made their own decisions about their health care and relied on female relatives for advice. The study shows that non-certified providers such as village doctors and untrained birth attendants were the first-line providers for women in all categories of severe complications. Coordination of transportation and finances was often arranged through mobile phones, and referrals were likely to be provided by village doctors.</p> <p>Conclusions</p> <p>Strategies to increase timely and appropriate care seeking for severe obstetric complications may consider targeting of non-certified providers for strengthening of referral linkages between patients and certified facility-based providers. Future research may characterize the treatments and appropriateness of emergency care provided by ubiquitous village doctors and other non-certified treatment providers in rural South Asian settings. In addition, future studies may explore the use of mobile phones in decreasing delays to certified medical care during obstetric emergencies.</p

HERA Phase i Limits on the Cosmic 21 cm Signal: Constraints on Astrophysics and Cosmology during the Epoch of Reionization

Recently, the Hydrogen Epoch of Reionization Array (HERA) has produced the experiment's first upper limits on the power spectrum of 21 cm fluctuations at z ∼ 8 and 10. Here, we use several independent theoretical models to infer constraints on the intergalactic medium (IGM) and galaxies during the epoch of reionization from these limits. We find that the IGM must have been heated above the adiabatic-cooling threshold by z ∼ 8, independent of uncertainties about IGM ionization and the radio background. Combining HERA limits with complementary observations constrains the spin temperature of the z ∼ 8 neutral IGM to 27 K 630 K (2.3 K 640 K) at 68% (95%) confidence. They therefore also place a lower bound on X-ray heating, a previously unconstrained aspects of early galaxies. For example, if the cosmic microwave background dominates the z ∼ 8 radio background, the new HERA limits imply that the first galaxies produced X-rays more efficiently than local ones. The z ∼ 10 limits require even earlier heating if dark-matter interactions cool the hydrogen gas. If an extra radio background is produced by galaxies, we rule out (at 95% confidence) the combination of high radio and low X-ray luminosities of L r,ν /SFR &gt; 4 × 1024 W Hz-1 yr and L X /SFR &lt; 7.6 × 1039 erg s-1 yr. The new HERA upper limits neither support nor disfavor a cosmological interpretation of the recent Experiment to Detect the Global EOR Signature (EDGES) measurement. The framework described here provides a foundation for the interpretation of future HERA results

Chronic p53-independent p21 expression causes genomic instability by deregulating replication licensing

The cyclin-dependent kinase inhibitor p21WAF1/CIP1 (p21) is a cell-cycle checkpoint effector and inducer of senescence, regulated by p53. Yet, evidence suggests that p21 could also be oncogenic, through a mechanism that has so far remained obscure. We report that a subset of atypical cancerous cells strongly expressing p21 showed proliferation features. This occurred predominantly in p53-mutant human cancers, suggesting p53-independent upregulation of p21 selectively in more aggressive tumour cells. Multifaceted phenotypic and genomic analyses of p21-inducible, p53-null, cancerous and near-normal cellular models showed that after an initial senescence-like phase, a subpopulation of p21-expressing proliferating cells emerged, featuring increased genomic instability, aggressiveness and chemoresistance. Mechanistically, sustained p21 accumulation inhibited mainly the CRL4–CDT2 ubiquitin ligase, leading to deregulated origin licensing and replication stress. Collectively, our data reveal the tumour-promoting ability of p21 through deregulation of DNA replication licensing machinery—an unorthodox role to be considered in cancer treatment, since p21 responds to various stimuli including some chemotherapy drugs

Initial Decomposition Reactions of Bicyclo-HMX [BCHMX or cis

We investigated the initial chemical reactions of BCHMX [cis-1,3,4,6-tetranitrooctahydroimidazo-[4,5-d]imidazole] with the following procedure. First we used density functional theory molecular dynamics simulations (DFT-MD) on the periodic crystal to discover the initial reaction steps. This allowed us to determine the most important reactions through DFT-MD simulations at high temperatures. Then we started with the midpoint of the reaction (unimolecular or bimolecular) from the DFT-MD and carried out higher quality finite cluster DFT calculations to locate the true transition state of the reaction, followed by calculations along the reaction path to determine the initial and final states. We find that for the noncompressed BCHMX the nitro-aci isomerization reaction occurs earlier than the NO2-releasing reaction, while for compressed BCHMX intermolecular hydrogen-transfer and bimolecular NO2-releasing reactions occur earlier than the nitrous acid (HONO)-releasing reaction. At high pressures, the initial reaction involves intermolecular hydrogen transfer rather than intramolecular hydrogen transfer, and the intermolecular hydrogen transfer decreases the reaction barrier for release of NO2 by ∼7 kcal/mol. Thus, the HONO-releasing reaction takes place more easily in compressed BCHMX. We find that this reaction barrier is 10 kcal/mol lower than the unimolecular NO2 release and ∼3 kcal/mol lower than the bimolecular NO2 release. This rationalizes the origin of the higher sensitivity of BCHMX compared to RDX (1,3,5-trinitrohexahydro-1,3,5-triazine) and HMX (octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine). We suggest changes in BCHMX that might help decrease the sensitivity by avoiding the intermolecular hydrogen-transfer and HONO-releasing reaction