Abstract:
:In the manufacture of chemical feedstocks and subsequent processing into derivatives and materials, the U.S. chemical industry sets the current standard of excellence for technological competitiveness. This world-class leadership is attributed to the innovation and advancement of chemical engineering process technology. Whether this status is sustained over the next decade depends strongly on meeting increasingly demanding challenges stimulated by growing concerns about the safe production and use of chemicals without harmful impacts on the environment. To comply with stringent environmental regulations while remaining economically competitive, industry must exploit alternative benign starting materials and develop environmentally neutral industrial processes. Opportunities are described for development of environmentally compatible alternatives and substitutes for some of the most abundantly produced, potentially hazardous industrial chemicals now labeled as "high-priority toxic chemicals." For several other uniquely important commodity chemicals where no economically competitive, environmentally satisfactory, nontoxic alternative starting material exists, we advocate the development of new dynamic processes for the on-demand generation of toxic chemicals. In this general concept, which obviates mass storage and transportation of chemicals, toxic raw materials are produced in real time, where possible, from less-hazardous starting materials and then chemically transformed immediately into the final product. As a selected example for semiconductor technology, recent progress is reviewed for the on-demand production of arsine in turnkey electrochemical generators. Innovation of on-demand chemical generators and alternative processes provide rich areas for environmentally responsive chemical engineering processing research and development for next-generation technology.
journal_name
Proc Natl Acad Sci U S Aauthors
Mitchell JWdoi
10.1073/pnas.89.3.821keywords:
subject
Has Abstractpub_date
1992-02-01 00:00:00pages
821-6issue
3eissn
0027-8424issn
1091-6490journal_volume
89pub_type
杂志文章abstract::The existence of immunoregulatory genes conferring dominant resistance to autoimmunity is well documented. In an effort to better understand the nature and mechanisms of action of these genes, we utilized the murine model of autoimmune orchitis as a prototype. When the orchitis-resistant strain DBA/2J is crossed with ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.92.12.5684
更新日期:1995-06-06 00:00:00
abstract::Misfolded proteins are eliminated from the endoplasmic reticulum (ER) by retrotranslocation into the cytosol, a pathway hijacked by certain viruses to destroy MHC class I heavy chains. The translocation of polypeptides across the ER membrane requires their polyubiquitination and subsequent extraction from the membrane...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0505006102
更新日期:2005-10-04 00:00:00
abstract::Endosymbiotic acquisition of bacteria by a protist, with subsequent evolution of the bacteria into mitochondria and plastids, had a transformative impact on eukaryotic biology. Reconstructing events that created a stable association between endosymbiont and host during the process of organellogenesis--including establ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1118800109
更新日期:2012-04-03 00:00:00
abstract::Progress in ecosystem service science has been rapid, and there is now a healthy appetite among key public and private sector decision makers for this science. However, changing policy and management is a long-term project, one that raises a number of specific practical challenges. One impediment to broad adoption of ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1406490112
更新日期:2015-06-16 00:00:00
abstract::A four-factor cross between two strains of Phycomyces involving two auxotrophic, one color, and the mating type marker is described. Samples of 40 germspores from 84 individual fertile germsporangia were characterized. The results show: (i) The germspores of a germsporangium are derived from one meiosis in approximate...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.72.10.4076
更新日期:1975-10-01 00:00:00
abstract::Muscle contraction and relaxation is regulated by transient elevations of myoplasmic Ca(2+). Ca(2+) is released from stores in the lumen of the sarco(endo)plasmic reticulum (SER) to initiate formation of the Ca(2+) transient by activation of a class of Ca(2+) release channels referred to as ryanodine receptors (RyRs) ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0905186106
更新日期:2009-07-07 00:00:00
abstract::Our purpose is to investigate the feasibility of imaging tumor metabolism in breast cancer patients using 13C magnetic resonance spectroscopic imaging (MRSI) of hyperpolarized 13C label exchange between injected [1-13C]pyruvate and the endogenous tumor lactate pool. Treatment-naïve breast cancer patients were recruite...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1913841117
更新日期:2020-01-28 00:00:00
abstract::Social ties are crucial for physical and mental health. However, psychiatric patients frequently encounter social rejection. Moreover, an increased reactivity to social exclusion influences the development, progression, and treatment of various psychiatric disorders. Nevertheless, the neuromodulatory substrates of rej...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章,随机对照试验
doi:10.1073/pnas.1524187113
更新日期:2016-05-03 00:00:00
abstract::HIV infection leads to a state of chronic immune activation and progressive deterioration in immune function, manifested most recognizably by the progressive depletion of CD4+ T cells. A substantial percentage of natural killer (NK) cells from patients with HIV infection are activated and express the natural cytotoxic...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0504315102
更新日期:2005-08-02 00:00:00
abstract::Excessive poly(ADP-ribose) (PAR) polymerase-1 (PARP-1) activation kills cells via a cell-death process designated "parthanatos" in which PAR induces the mitochondrial release and nuclear translocation of apoptosis-inducing factor to initiate chromatinolysis and cell death. Accompanying the formation of PAR are the red...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1405158111
更新日期:2014-07-15 00:00:00
abstract::Activation of the mitogen-activated protein kinase (MAP kinase) isoforms ERK1 and ERK2 was investigated in rat adipocytes. Kinase activities were measured by using myelin basic protein as substrate after the isoforms were resolved by Mono Q chromatography or by immunoprecipitation with specific antibodies. Insulin inc...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.90.21.10305
更新日期:1993-11-01 00:00:00
abstract::A tremendous amount of radioactivity was discharged because of the damage to cooling systems of nuclear reactors in the Fukushima No. 1 nuclear power plant in March 2011. Fukushima and its adjacent prefectures were contaminated with fission products from the accident. Here, we show a geographical distribution of radio...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1111724108
更新日期:2011-12-06 00:00:00
abstract::Increased clouds and precipitation normally decrease the diurnal temperature range (DTR) and thus have commonly been offered as explanation for the trend of reduced DTR observed for many land areas over the last several decades. Observations show, however, that the DTR was reduced most in dry regions and especially in...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0700290104
更新日期:2007-11-13 00:00:00
abstract::Hypoxia-inducible factor-1 (HIF-1) plays an essential role in tumor development and progression by regulating genes that are vital for proliferation, glycolysis, angiogenesis, and metastasis. To identify strategies of targeting the HIF-1 pathway, we screened a siRNA library against the entire druggable genome and a sm...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0706585104
更新日期:2008-01-08 00:00:00
abstract::The internal promoter of the Xenopus laevis oocyte-type 5S RNA gene is preferentially cleaved by S1 and Bal-31 nucleases in plasmid DNA. S1 nuclease sensitivity is largely dependent on supercoiling; however, Bal-31 cleaves within the 5S RNA gene in linear as well as in supercoiled DNA. The S1 nuclease-hypersensitive s...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.82.12.4018
更新日期:1985-06-01 00:00:00
abstract::A 43-kDa peripheral membrane protein is known to copurify with acetylcholine receptor (AcChoR)-rich membranes isolated from the electric organ of Torpedo californica. Immunoelectron microscopy and crosslinking studies have demonstrated that this 43-kDa protein is closely associated with the cytoplasmic domain(s) of th...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.82.23.8270
更新日期:1985-12-01 00:00:00
abstract::Fast axoplasmic transport was studied in dorsal root ganglion cells of the cat. Proteins carried in the fast axoplasmic flow were labeled after an intraganglionic injection of (L)-[4,5-(3)H]leucine. The rate of transport was 380 +/- 26 mm/day in both the central and peripheral branches of the bifurcating axons that ar...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.70.5.1521
更新日期:1973-05-01 00:00:00
abstract::For brain functions such as working memory and motor planning, neuronal circuits are able to sustain persistent activity after transient inputs. Theoretical studies have suggested that persistent activity can exist in recurrently connected networks as active reverberation. However, the actual cellular processes underl...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0500717102
更新日期:2005-07-19 00:00:00
abstract::Dense granular materials display a complicated set of flow properties, which differentiate them from ordinary fluids. Despite their ubiquity, no model has been developed that captures or predicts the complexities of granular flow, posing an obstacle in industrial and geophysical applications. Here we propose a 3D cons...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1219153110
更新日期:2013-04-23 00:00:00
abstract::Circulating peripheral blood cells and disaggregated yolk sac cells were obtained from normal mouse embryos as early as day 9 of gestation, prior to the formation of the fetal liver. These were cultured in vitro in plasma clots or methylcellulose, in the presence of either embryonic fluid or adult spleen cell-conditio...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.79.9.2952
更新日期:1982-05-01 00:00:00
abstract::Changes in nuclear K+ electrochemical activity and total nuclear K+ content in salivary glands of Chironomus tentans were measured with ion-selective microelectrodes based on valinomycin and with flameless atomic absorption spectrometry, respectively. The K+ activity increased by a factor of 2.6 and the total K+, by a...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.76.2.806
更新日期:1979-02-01 00:00:00
abstract::Although most nuclear hormone receptors are ligand-dependent transcriptional activators, certain members of this superfamily, such as thyroid hormone receptor (TR) and retinoic acid receptor (RAR), are involved in transcriptional repression. The silencing function of these receptors has been localized to the ligand bi...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.92.25.11691
更新日期:1995-12-05 00:00:00
abstract::The notion that tRNA and 5S rRNA interact through evolutionarily conserved complementary sequences has been tested by nucleolytic modification of the 5S rRNA, using the modified rRNA to reconstitute the large ribosomal subunit, and assaying for poly(uridylic acid)-directed polyphenylalanine synthesis. The 5S rRNA sequ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.79.1.36
更新日期:1982-01-01 00:00:00
abstract::A murine hybridoma-derived antibody (IPH.134) has been produced which has apparent high binding specificity for an extract of Schistosoma japonicum adult worms. No binding was detected to extracts of S. japonicum eggs or to extracts from other adult trematodes (Fasciola hepatica, Paragonimus westermanii, Clonorchis si...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.78.5.3165
更新日期:1981-05-01 00:00:00
abstract::pRK212.2, a derivative of the broad host range plasmid RK2, contains two EcoRI cleavage fragments, A and B, neither of which can replicate by itself in Escherichia coli. Fragment A (41.7 kilobases), but not fragment B (14.4 kilobases), can be cloned by insertion into the unrelated plasmids mini-F and ColE1. Fragment B...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.76.4.1648
更新日期:1979-04-01 00:00:00
abstract::Dominantly inherited mutations in the genes encoding presenilins (PS) and the amyloid precursor protein (APP) are the major causes of familial Alzheimer's disease (AD). The prevailing view of AD pathogenesis posits that accumulation of beta-amyloid (Abeta) peptides, particularly Abeta42, is the central event triggerin...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章,评审
doi:10.1073/pnas.0608332104
更新日期:2007-01-09 00:00:00
abstract::Recent advances in fluorescence microscopy provided tools for the investigation and the analysis of the viral replication steps in the cellular context. In the HIV field, the current visualization systems successfully achieve the fluorescent labeling of the viral envelope and proteins, but not the genome. Here, we dev...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1216254110
更新日期:2013-04-02 00:00:00
abstract::Low density lipoprotein (LDL) isolated from human plasma anticoagulated with EDTA (EDTA/LDL) was 4-fold more resistant to oxidation by reagent H2O2, as assayed by the thiobarbituric acid (TBA) assay, than LDL prepared from plasma anticoagulated with citrate (CDP/LDL). The LDLs required 1-3 mM H2O2 for maximal oxidatio...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.83.17.6631
更新日期:1986-09-01 00:00:00
abstract::The bifunctional Neurospora crassa mitochondrial tyrosyl-tRNA synthetase (CYT-18 protein) both aminoacylates mitochondrial tRNA(Tyr) and acts as a structure-stabilizing splicing cofactor for group I introns. Previous studies showed that CYT-18 has distinct tRNA(Tyr) and group I intron-binding sites, with the latter fo...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0801722105
更新日期:2008-04-22 00:00:00
abstract::The human beta-globin locus is activated transcriptionally by a complex series of events that culminate in appropriate temporal and tissue-specific control over five separate genes during embryonic and early postnatal development. One cis-regulatory element in the locus, originally identified as an enhancer 3' to the ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.95.17.9944
更新日期:1998-08-18 00:00:00