Enzyme or whole cell immobilization for efficient biocatalysis: focusing on novel supporting platforms and immobilization techniques

Biocatalysts represented by enzymes and enzyme-containing whole cells are generally fragile and easily inactivated in practical application conditions. The immobilization concept and techniques have been recognized as classic and powerful strategy for tackling such challenges (Hanefeld et al., 2009). Based on this background, a special Research Topic entitled Enzyme or Whole Cell Immobilization for Efficient Biocatalysis: Focusing on Novel Supporting Platforms and Immobilization Techniques had been organized and presented in the platform of Frontiers in Bioengineering and Biotechnology, which aimed to collect different insights and latest findings regarding but not limited to new theories, techniques and methodologies in this area. Over the past year since Sept. 2019, this Research Topic has attracted 242 authors from more than 10 countries to participate and contribute their manuscripts. Consequently, this special issue has selected and presented 40 peer-reviewed articles to meet the readers, including 31 Original Researches, four Brief Research Reports, four Reviews, and one General Commentary, which involved various aspects and every corner of this area

Risk attitudes and informal employment in a developing economy

© 2012 Bennett et al.; licensee Springer. This is an Open Access article distributed under the terms of the Creative Commons Attribution License(http://creativecommons.org/licenses/by/2.0),which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.We model an urban labour market in a developing economy, incorporating workers’ risk attitudes. Trade-offs between risk aversion and ability determine worker allocation across formal and informal wage employment, and voluntary and involuntary self employment. Greater risk of informal wage non-payment can raise or lower informal wage employment, depending on the source of risk. Informal wage employment can be reduced by increasing detection efforts or by strengthening contract enforcement for informal wage payment. As the average ability of workers rises, informal wage employment first rises, then falls. Greater demand for formal production may lead to more involuntary self employment

Two-phase equilibrium and molecular hydrogen formation in damped Lyman-alpha systems

Molecular hydrogen is quite underabundant in damped Lyman-alpha systems at high redshift, when compared to the interstellar medium near the Sun. This has been interpreted as implying that the gas in damped Lyman-alpha systems is warm. like the nearby neutral intercloud medium, rather than cool, as in the clouds which give rise to most H I absorption in the Milky Way. Other lines of evidence suggest that the gas in damped Lyman-alpha systems -- in whole or part -- is actually cool; spectroscopy of neutral and ionized carbon, discussed here, shows that the damped Lyman-alpha systems observed at lower redshift z $$ 2.8 are warm (though not devoid of H2). To interpret the observations of carbon and hydrogen we constructed detailed numerical models of H2 formation under the conditions of two-phase thermal equilibrium, like those which account for conditions near the Sun, but with varying metallicity, dust-gas ratio, $etc$. We find that the low metallicity of damped Lyman-alpha systems is enough to suppress H2 formation by many orders of magnitude even in cool diffuse clouds, as long as the ambient optical/uv radiation field is not too small. For very low metallicity and under the most diffuse conditions, H2 formation will be dominated by slow gas-phase processes not involving grains, and a minimum molecular fraction in the range $10^{-8}-10^{-7}$ is expected.Comment: 13 pages, 7 figures; accepted 2002-04-30 by Astronomy and Astrophysic

A reassuring presence: An evaluation of Bradford District Hospice at Home service

Within the United Kingdom, a developing role for primary care services in cancer and palliative care has resulted in an increase in palliative home care teams. The provision of professional care in the home setting seeks to provide necessary services and enhanced choice for patients whose preference is to die at home. A mismatch between patient preference for home death and the actual number of people who died at home was identified within Bradford, the locality of this study. In response to this mismatch, and reflecting the policy environment of wishing to enhance community service provision, the four Primary Care Trusts (PCTs) in the city sought to offer support to patients who wished to remain in their own homes through the final stages of a terminal illness. To offer this support they set up a dedicated hospice at home team. This would provide services and support for patients in achieving a dignified, symptom free and peaceful death, allowing families to maximise time spent together. The aim of the study was to evaluate the Bradford hospice at home service from the perspective of carers, nurses and General Practitioners. Postal questionnaires were sent to carers (n = 289), district nurses (n = 508) and GP's (n = 444) using Bradford's hospice at home service. Resulting quantitative data was analysed using the Statical Package for Social Sciences (SPSS) and qualitative data was analysed using grounded theory techniques. The data from carers, district nurses and GPs provide general support for the Bradford hospice at home service. Carers valued highly the opportunity to 'fulfil a promise' to the individual who wished to be cared for at home. District nurses and GPs cited the positive impact of access to specialist expertise. This was a 'reassuring presence' for primary healthcare teams and offered 'relief of carer anxiety' by providing prompt, accessible and sensitive care. Carers and health professionals welcomed the increased possibility of patients being cared for at home. The study identified the need to focus on improving skill levels of staff and on ensuring continuity of care

Electronic response of aligned multishell carbon nanotubes

We report calculations of the effective electronic response of aligned multishell carbon nanotubes. A local graphite-like dielectric tensor is assigned to every point of the multishell tubules, and the effective transverse dielectric function of the composite is computed by solving Maxwell's equations. Calculations of both real and imaginary parts of the effective dielectric function are presented, for various values of the filling fraction and the ratio of the internal and external radii of hollow tubules. Our full calculations indicate that the experimentally measured macroscopic dielectric function of carbon nanotube materials is the result of a strong electromagnetic coupling between the tubes, which cannot be accounted for with the use of simplified effective medium theories. The presence of surface plasmons is investigated, and both optical absorption cross sections and energy-loss spectra of aligned tubules are calculated.Comment: 4 pages, 4 figures, to appear in Phys. Rev.

Time-separated entangled light pulses from a single-atom emitter

The controlled interaction between a single, trapped, laser-driven atom and the mode of a high-finesse optical cavity allows for the generation of temporally separated, entangled light pulses. Entanglement between the photon-number fluctuations of the pulses is created and mediated via the atomic center-of-mass motion, which is interfaced with light through the mechanical effect of atom-photon interaction. By means of a quantum noise analysis we determine the correlation matrix which characterizes the entanglement, as a function of the system parameters. The scheme is feasible in experimentally accessible parameter regimes. It may be easily extended to the generation of entangled pulses at different frequencies, even at vastly different wavelengths.Comment: 17 pages, 5 figures. Modified version, to appear in the New Journal of Physic

Electronic properties of FC(O)SCH2CH3: a combined Helium(I) photoelectron spectroscopy and synchrotron radiation study

The valence electronic properties of S-ethyl flouromethanethioate (S-ethyl fluoromethsanethioate), FC(O)SCH2CH3, were investigated by means of He(I) photoelectron spectroscopy in conjunction with the analysis of the photofragmentation products determined by PEPICO (phtoelectron-photoion- coincidence) by using synchrotron radiation in the 11.1-21.6 eV photon energy range. The first band observed at 10.28 eV in the HeI photoelectron spectrum can be assigned with confidence to the ionization process from the HOMO [n π(S) orbital], which is described as a lone pair formally localized on the sulfur atom, in agreement with quantum chemical calculations using the outer valence Green function method [OVGF/6-311++G (d,p)]. One of the most important fragmentation channels also observed in the valence region corresponds to the decarbonylation process yielding the [M-CO] ·+ ion, which is clearly observed at m/z = 80. Moreover, S 2p and S 2s absorption edges have been examined by measuring the total ion yield spectra in the 160-240 eV region using variable synchrotron radiation. The dynamic of ionic fragmentation following the Auger electronic decay has been evaluated with the help of the PEPIPICO (photoion-photoion-photoelectron- coincidence spectra) technique.Centro de Química Inorgánic

Electronic properties of FC(O)SCH2CH3: A combined helium(I) photoelectron spectroscopy and synchrotron radiation study

The valence electronic properties of S-ethyl flouromethanethioate (S-ethyl fluoromethsanethioate), FC(O)SCH2CH3, were investigated by means of He(I) photoelectron spectroscopy in conjunction with the analysis of the photofragmentation products determined by PEPICO (phtoelectron-photoion- coincidence) by using synchrotron radiation in the 11.1-21.6 eV photon energy range. The first band observed at 10.28 eV in the HeI photoelectron spectrum can be assigned with confidence to the ionization process from the HOMO [n π(S) orbital], which is described as a lone pair formally localized on the sulfur atom, in agreement with quantum chemical calculations using the outer valence Green function method [OVGF/6-311++G (d,p)]. One of the most important fragmentation channels also observed in the valence region corresponds to the decarbonylation process yielding the [M-CO] ·+ ion, which is clearly observed at m/z = 80. Moreover, S 2p and S 2s absorption edges have been examined by measuring the total ion yield spectra in the 160-240 eV region using variable synchrotron radiation. The dynamic of ionic fragmentation following the Auger electronic decay has been evaluated with the help of the PEPIPICO (photoion-photoion-photoelectron- coincidence spectra) technique.Fil: Rodriguez Pirani, Lucas Sebastian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; ArgentinaFil: Erben, Mauricio Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; ArgentinaFil: Gerones, Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; ArgentinaFil: Romano, Rosana Mariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; ArgentinaFil: Cavasso Filho, Reinaldo L.. Universidade Federal Do Abc;Fil: Ma, Chunping. Institute Of Chemistry Chinese Academy Of Sciences; ChinaFil: Ge, Maofa. Institute Of Chemistry Chinese Academy Of Sciences; ChinaFil: Della Védova, Carlos Omar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; Argentin

Electronic Properties and Dissociative Photoionization of Thiocyanates : Part II. Valence and Shallow-Core (Sulfur and Chlorine 2p) Regions of Chloromethyl Thiocyanate, CH₂ClSCN

A combination of photoelectron spectroscopy and synchrotron based photoelectron photoion coincidence (PEPICO) spectra has been applied to investigate the electronic structure and the dissociative ionization of the CH2ClSCN molecule in the valence region. The PES is assigned with the electronic structure calculations at the outer-valence Green’s function and symmetry adapted cluster/configuration interaction (SAC-CI) levels offer an explanation of our experimental results. Upon vacuum ultraviolet irradiation the lowlying radical cation, located at 10.39 eV is formed. The molecular ion is observed in the time-of-flight mass spectra, together with the CH2SCN⁺ and CH2Cl⁺ daughter ions. The total ion yield spectra have been measured in the S 2p and Cl 2p regions and several channels have been determined in dissociative photoionization events for the coreexcited species. Thus, by using time-of-flight mass spectrometry and synchrotron radiation the relative abundances of the ionic fragments and their kinetic energy release values were obtained from both PEPICO and photoelectron photoion photoion coincidence spectra. Possible fragmentation processes are discussed and compared with that found for the related CH3SCN species.Facultad de Ciencias ExactasCentro de Química InorgánicaInstituto de Física La PlataLaboratorio de Servicios a la Industria y al Sistema Científic

Low specificity of determine HIV1/2 RDT using whole blood in south west Tanzania

Objective: To evaluate the diagnostic performance of two rapid detection tests (RDTs) for HIV 1/2 in plasma and in whole blood samples. Methods: More than 15,000 study subjects above the age of two years participated in two rounds of a cohort study to determine the prevalence of HIV. HIV testing was performed using the Determine HIV 1/2 test (Abbott) in the first (2006/2007) and the HIV 1/2 STAT-PAK Dipstick Assay (Chembio) in the second round (2007/2008) of the survey. Positive results were classified into faint and strong bands depending on the visual appearance of the test strip and confirmed by ELISA and Western blot. Results: The sensitivity and specificity of the Determine RDT were 100% (95% confidence interval = 86.8 to 100%) and 96.8% (95.9 to 97.6%) in whole blood and 100% (99.7 to 100%) and 97.9% (97.6 to 98.1%) in plasma respectively. Specificity was highly dependent on the tested sample type: when using whole blood, 67.1% of positive results were false positive, as opposed to 17.4% in plasma. Test strips with only faint positive bands were more often false positive than strips showing strong bands and were more common in whole blood than in plasma. Evaluation of the STAT-PAK RDT in plasma during the second year resulted in a sensitivity of 99.7% (99.1 to 99.9%) and a specificity of 99.3% (99.1 to 99.4%) with 6.9% of the positive results being false. Conclusions: Our study shows that the Determine HIV 1/2 strip test with its high sensitivity is an excellent tool to screen for HIV infection, but that – at least in our setting – it can not be recommended as a confirmatory test in VCT campaigns where whole blood is used