Demonstration of the first monolithically integrated self-rolled-up tube based vertical photonic coupler

We demonstrated the first monolithically integrated self-rolled-up SiN_x tube based vertical photonic coupler on top of a planar ridge waveguide. The coupling efficiency between the elements is >10 times higher than similar non-integrated device

A novel pyruvate kinase and its application in lactic acid production under oxygen deprivation in Corynebacterium glutamicum

BACKGROUND: Pyruvate kinase (Pyk) catalyzes the generation of pyruvate and ATP in glycolysis and functions as a key switch in the regulation of carbon flux distribution. Both the substrates and products of Pyk are involved in the tricarboxylic acid cycle, anaplerosis and energy anabolism, which places Pyk at a primary metabolic intersection. Pyks are highly conserved in most bacteria and lower eukaryotes. Corynebacterium glutamicum is an industrial workhorse for the production of various amino acids and organic acids. Although C. glutamicum was assumed to possess only one Pyk (pyk1, NCgl2008), NCgl2809 was annotated as a pyruvate kinase with an unknown role. RESULTS: Here, we identified that NCgl2809 was a novel pyruvate kinase (pyk2) in C. glutamicum. Complementation of the WTΔpyk1Δpyk2 strain with the pyk2 gene restored its growth on d-ribose, which demonstrated that Pyk2 could substitute for Pyk1 in vivo. Pyk2 was co-dependent on Mn(2+) and K(+) and had a higher affinity for ADP than phosphoenolpyruvate (PEP). The catalytic activity of Pyk2 was allosterically regulated by fructose 1,6-bisphosphate (FBP) activation and ATP inhibition. Furthermore, pyk2 and ldhA, which encodes l-lactate dehydrogenase, were co-transcribed as a bicistronic mRNA under aerobic conditions and pyk2 deficiency had a slight effect on the intracellular activity of Pyk. However, the mRNA level of pyk2 in the wild-type strain under oxygen deprivation was 14.24-fold higher than that under aerobic conditions. Under oxygen deprivation, pyk1 or pyk2 deficiency decreased the generation of lactic acid, and the overexpression of either pyk1 or pyk2 increased the production of lactic acid as the activity of Pyk increased. Fed-batch fermentation of the pyk2-overexpressing WTΔpyk1 strain produced 60.27 ± 1.40 g/L of lactic acid, which was a 47% increase compared to the parent strain under oxygen deprivation. CONCLUSIONS: Pyk2 functioned as a pyruvate kinase and contributed to the increased level of Pyk activity under oxygen deprivation. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12896-016-0313-6) contains supplementary material, which is available to authorized users

Gegenseitige Beeinflussung von Mizellaren Strukturen und Photodimerisierung von Cumarinderivaten

In dieser Arbeit wurde die gegenseitige Beeinflussung von mizellaren Strukturen und Photodimerisierung von Cumarinderivaten untersucht. Als Mizellbildner wurden das kationische Cetyltrimethylammoniumbromid (CTAB) und das nicht-ionische Triton X-100, als Solubilisate Cumarinderivaten verwendet. Es wurden rheologische, thermodynamische und photochemische Untersuchungen durchgeführt. Die Viskosität der beiden Tensidsysteme steigt mit zunehmender Solubilisatkonzentration je nach Cumarinderivat unterschiedlich stark an. Dabei zeigten 6-Alkylcumarine als Solubilisate die größten "rheologischen Effekte". Die Photodimerisierung der solubilisierten Cumarine führte zu einem weiteren Anstieg oder zu einer Abnahme der Viskosität der CTAB- und Triton X-100-Lösungen - "photorheologischer Effekt". In Abhängigkeit von der Konzentration werden Strukturänderungen der mizellaren Aggregate induziert, die teilweise zu drastischen Änderungen der makroskopischen Eigenschaften der Tensidlösungen-Lösung führen. Die Photodimerisierung fungiert dabei als "large-response-trigger". Die Kettenlänge der solubilisierten 6-Alkylcumarine beeinflusst das Fießverhalten der CTAB-Lösungen und Triton X-100-Lösungen. Mit zunehmender Kettenlänge steigt die Viskosität der beiden Tensidlösungen zunächst an, um dann bei noch längeren Ketten wieder abzunehmen. In beiden Tensidsystemen liegt der Maximalwert bei 6-Oktylcumarin. Der Photodimerisierung beeinflusst die Viskosität der beiden Tensid-Systeme unterschiedlich. In CTAB-Lösungen in Anwesenheit von kürzeren Alkylcumarinen steigt die Viskosität mit der Photodimerisierung weiter. Ab Pentylcumarin nimmt die Viskosität nach der Photodimerisierung jedoch ab. Im Triton X-100 System ist der photorheologische Effekt dagegen stets positiv. Thermodynamische Untersuchungen zeigen eine Korrelation mit dem rheologischen Effekt: Je größer die Viskosität, desto negativer sind Enthalpie- und Entropiedifferenzen bei der Bildung der mizellaren Aggregate. Die Ergebnisse legen als Ursache für die Viskositätseffekte Unterschiede in der Ausdehnung der Hydratwasserschicht der Mizellen nahe. Bei der photochemischen Untersuchungen wurden mit Hilfe von NMR-Spektroskopie und Kristallstrukturanalyse die isomeren Produkte der Photodimeriserung von Cumarinderivaten charakterisiert und die Produktverteilung unter verschiedenen Bedingungen ermittelt. In CTAB-Lösung konnte eine Möglichkeit Steuerung der Selektivität der Produktbildung gefunden werden: Lange 6-Alkylsubstituenten (ab 6-Propylcumarin) steuern zu Anti- und zu KK-Dimeren, während bei kurzen Ketten bzw. beim unsubstituierten Cumarin mehr Syn- und KS-Dimere gebildet werden. Bei dem im Detail untersuchten 6-Methylcumarin steigt die relative Quantenausbeute mit fallender Temperatur, abnehmender Konzentration und mit Zugabe des Triplettsensibilisators Benzophenon. In Gegenwart des Sensibilisators entsteht vermehrt das Anti-KK-Dimer, was darauf schließen lässt, dass dieses aus dem Triplett-Zustand gebildet wird. In ionischer mizellarer Lösung CTAB bilden sich bevorzugt Syn-Dimere. In unpolaren Lösungsmitteln entsteht nur Anti-KK, während in polaren Lösungsmitteln auch kleine Mengen Syn-Dimere gebildet werden. Die Lewis-Säure BF3 beschleunigt die Photodimerisierung deutlich und steuert zu Syn-KS

Construction of Bio-Engineering Comprehensive Experimental Teaching Innovation System

Analysis of the current situation and development prospects of need of bio-engineering professionals to build the education idea of social demand-oriented, “all for students, the whole process for educating people, all-round education,” take CDIO engineering education philosophy as the guiding ideology, practice curriculum system for the carrier, developing ability as the main line, to build an “innovative educational concept - Research theory Teaching - entrepreneurial practice Teaching - specialized personnel training,” experimental zone training model, developed with the appropriate professional teaching programs, course syllabus, experiments and practical syllabus. Talents experimental area constructed has achieved good teaching results

Does green finance promote the social responsibility fulfilment of highly polluting enterprises? – empirical evidence from China

This study explores whether and how the development of green finance can facilitate the social responsibility of highly polluting enterprises. We conducted a quasi-natural experiment in 2017 in five Chinese provinces (districts), based on the establishment of green finance reform and innovation pilot zones. The research samples were China’s A-share heavy pollution-industry-listed companies from 2013 to 2020, and the difference in differences model was used to examine the relationship between green finance and social responsibility fulfilment of highly polluting firms. The mediating and moderating effects of financial constraints and media monitoring were also discussed. The findings indicate that the advancement of green finance significantly improves the level of social responsibility fulfilment of highly polluting firms, particularly in the area of environmental responsibility. Furthermore, strengthened financing constraints partially mediate the aforementioned relationship, and media monitoring positively moderates the facilitation effect of green finance development on highly polluting firms’ social responsibility fulfilment. Our study demonstrates that a higher degree of financing constraints is an important channel for establishing a green finance reform and innovation pilot zone to force enterprises to fulfilment their social responsibility, and provides theoretical support for governments and enterprises to better understand the policy effects

On the Electrochemical Reduction of 4-(Thiazol-2-ylazo)-Substituted 1-Chloronaphthalenes: Formation and Characterization of Stable Radical Anions

The electrochemical reduction of two chloro-substituted 4-(thiazol-2-ylazo)has been studied by means of spectroelectrochemistry and simulated with the DFT method. Whereas the 1-chloro-4-(4-chlorothiazol-2-ylazo)forms both a stable radical anion and a dianion, the dianion of 1-chloro-4-(thiazol-2-ylazo)is instable. In the radical anion of both compounds, the spin densities are high not only at the azo moiety but also at C3 in the naphthalene and at C5 in the thiazole moiety. This is in agreement with former experimental results demonstrating the remarkable reactivity of these positions towards thiols which can act as nucleophiles as well as electron donors. © 2020 Wiley-VCH Verlag GmbH & Co. KGaA, Weinhei

Modification of microcrystalline cellulose with acrylamide under microwave irradiation and its application as flocculant.

Grafting polyacrylamide (PAM) chains onto microparticles may combine the advantages of the flocculation property of the former and the fast sedimentation of the later to realize better flocculation performance. In this work, inexpensive microcrystalline cellulose (MCC) microparticles, and monomer of acrylamide (AM) were mixed, and then irradiated under microwave. The obtained material was characterized by Fourier transform infrared spectroscopy and X-ray diffraction, and the results demonstrated successful modification of MCC with AM on the particle surface. The modification procedure has been carefully investigated to obtain an optimum preparation condition. Kaolin suspension was selected as a model to evaluate the flocculation properties of the obtained AM-MCC. Our results indicate that the AM-MCC with the highest grafting ratio of 95.5% exhibits the best flocculation performance, which is even better than that of PAM, and the turbidity can be decreased to 1.4% of the naked kaolin suspension within 2.5 min. Therefore, this work provides a low cost strategy to prepare biodegradable AM-MCC, which may have promising potential application in the water treatment and other fields

Characterization of Small Interfering RNAs Derived from the Geminivirus/Betasatellite Complex Using Deep Sequencing

BACKGROUND: Small RNA (sRNA)-guided RNA silencing is a critical antiviral defense mechanism employed by a variety of eukaryotic organisms. Although the induction of RNA silencing by bipartite and monopartite begomoviruses has been described in plants, the nature of begomovirus/betasatellite complexes remains undefined. METHODOLOGY/PRINCIPAL FINDINGS: Solanum lycopersicum plant leaves systemically infected with Tomato yellow leaf curl China virus (TYLCCNV) alone or together with its associated betasatellite (TYLCCNB), and Nicotiana benthamiana plant leaves systemically infected with TYLCCNV alone, or together with TYLCCNB or with mutant TYLCCNB were harvested for RNA extraction; sRNA cDNA libraries were then constructed and submitted to Solexa-based deep sequencing. Both sense and anti-sense TYLCCNV and TYLCCNB-derived sRNAs (V-sRNAs and S-sRNAs) accumulated preferentially as 22 nucleotide species in infected S. lycopersicum and N. benthamiana plants. High resolution mapping of V-sRNAs and S-sRNAs revealed heterogeneous distribution of V-sRNA and S-sRNA sequences across the TYLCCNV and TYLCCNB genomes. In TYLCCNV-infected S. lycopersicum or N. benthamiana and TYLCCNV and βC1-mutant TYLCCNB co-infected N. benthamiana plants, the primary TYLCCNV targets were AV2 and the 5' terminus of AV1. In TYLCCNV and betasatellite-infected plants, the number of V-sRNAs targeting this region decreased and the production of V-sRNAs increased corresponding to the overlapping regions of AC2 and AC3, as well as the 3' terminal of AC1. βC1 is the primary determinant mediating symptom induction and also the primary silencing target of the TYLCCNB genome even in its mutated form. CONCLUSIONS/SIGNIFICANCE: We report the first high-resolution sRNA map for a monopartite begomovirus and its associated betasatellite using Solexa-based deep sequencing. Our results suggest that viral transcript might act as RDR substrates resulting in dsRNA and secondary siRNA production. In addition, the betasatellite affected the amount of V-sRNAs detected in S. lycopersicum and N. benthamiana plants