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The combination of low-temperature scanning tunnelling microscopy with a mass-selective electro-spray ion-beam deposition established the investigation of large biomolecules at nanometer and sub-nanometer scale. Due to complex architecture and conformational freedom, however, the chemical identification of building blocks of these biopolymers often relies on the presence of markers, extensive simulations, or is not possible at all. Here, we present a molecular probe-sensitisation approach addressing the identification of a specific amino acid within different peptides. A selective intermolecular interaction between the sensitiser attached at the tip-apex and the target amino acid on the surface induces an enhanced tunnelling conductance of one specific spectral feature, which can be mapped in spectroscopic imaging. Density functional theory calculations suggest a mechanism that relies on conformational changes of the sensitiser that are accompanied by local charge redistributions in the tunnelling junction, which, in turn, lower the tunnelling barrier at that specific part of the peptide. Chemical identification of the building blocks of biopolymers often considerably relies on the presence of markers, extensive simulations, or is not possible at all. Here, the authors report a molecular probe-sensitisation approach addressing the identification of a specific amino acid within different peptides. [ABSTRACT FROM AUTHOR]

Direct-seeded rice (DSR) is an emerging resource-saving rice production practice. It can be alternative to input-intensive conventional transplanted puddled rice, which has encountered problems, relating to water, nutrients, energy, and environment. DSR can save water, labour, and energy, reduce greenhouse gases emission and improve soil properties. But, weeds are major constraint, which can cause complete failure of rice. Effective weed management is essential to achieve higher yield and resource-use efficiencies. Herbicide is a more effective and economical option than other weed control methods. But, its efficacy is influenced by herbicides and their use rates, and the weed species that vary across locations, depending on climate and soil. Therefore, this field experiment was carried out to evaluate the combinations of pre-emergence (~ PE) and post-emergence (~ PoE) herbicides as sequential applications, and their impacts on weeds, crops, economics, water productivity, and major nutrients-use efficiencies. It was observed that weed control treatments reduced weed density by 68–84.5% and weed dry weight by 71.6–86.7% at 60 days after sowing (DAS) compared to unweeded control (UWC). Among them, the pendimethalin 1000 g ha–1 PE at 1 DAS followed by (~ fb) penoxsulam + cyhalofop-butyl 130 g ha–1 (pre-mix) PoE at 25 DAS resulted in significant reduction in weed density (~ 84.5%) and weed dry weight (~ 86.7%) at 60 DAS. These sequential herbicides application increased effective tillers (233.3 m–2), grains weight per panicle (2.54 g), and grain yield (3.92 t ha–1) of rice, and irrigation (0.87 kg m–3) and total water productivity (0.31 kg m–3) by 288.2%, 75.2%, 378.9%, 378%, and 380%, respectively, than those in UWC. This resulted in 17.9% and 73.3% higher net returns and net benefit: cost, respectively, than even weed-free control (WFC) and was superior to all. Contrast analysis revealed that the brown manuring (BM) fb almix 20 g ha–1 (pre-mix) applied at 40 DAS was similar to it, reducing weed density by 82.7% and dry weight by 83.3%. This study suggests that the sequential applications of herbicides or integration of herbicides with BM would provide broad-spectrum weed control and higher productivity and profitability in DSR. Controlling weeds may also reduce/economize water use and increase use efficiencies of N, P, and K in DSR. [ABSTRACT FROM AUTHOR]

This mini-review summarizes the latest accomplishments with group 6 metal alkylidene- N-heterocyclic carbene complexes (metal = Mo, W) for use in olefin metathesis. Both the fundamentals and the unique features of this novel class of olefin metathesis catalysts are presented. Also, their use and performance in ring-closing metathesis, cross metathesis, homometathesis, and self-metathesis reactions as well as in ring-opening metathesis polymerization and cyclopolymerization is outlined. Graphical abstract: [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

The impact of field-grown transgenic trees on wood characteristics and enzymatic saccharification was evaluated. Genes 4CL and CAld5H were down regulated or overexpressed to modify the lignin content or structure (S/V ratio) on black cottonwood ( Populus trichocarpa Nisqually-1). These transgenic trees were grown in the real environment and evaluated after 2 and 3 years. The results exhibited that the lignin content for most of the transgenic black cottonwoods increased compared to their initial lignin content when grown inside the greenhouse. The lignin contents approached those of the wild types. Acid and green-liquor pretreatments were applied to the transgenic wood saw dust samples. Cellulase mediated saccharifications were then conducted for the pretreated and untreated samples. Sugar yield and carbohydrate saccharification efficiency of the enzymatic saccharification for most of the transgenic trees were observed to be higher than those of the wild types even though their lignin contents became similar. [ABSTRACT FROM AUTHOR]

The human proteome has millions of protein variants due to alternative RNA splicing and post-translational modifications, and variants that are related to diseases are frequently present in minute concentrations. For DNA and RNA, low concentrations can be amplified using the polymerase chain reaction, but there is no such reaction for proteins. Therefore, the development of single-molecule protein sequencing is a critical step in the search for protein biomarkers. Here, we show that single amino acids can be identified by trapping the molecules between two electrodes that are coated with a layer of recognition molecules, then measuring the electron tunnelling current across the junction. A given molecule can bind in more than one way in the junction, and we therefore use a machine-learning algorithm to distinguish between the sets of electronic 'fingerprints' associated with each binding motif. With this recognition tunnelling technique, we are able to identify D and L enantiomers, a methylated amino acid, isobaric isomers and short peptides. The results suggest that direct electronic sequencing of single proteins could be possible by sequentially measuring the products of processive exopeptidase digestion, or by using a molecular motor to pull proteins through a tunnel junction integrated with a nanopore. [ABSTRACT FROM AUTHOR]

The concept of business responsibility, usually termed as corporate social responsibility (CSR), originated in the early 1930s after the Wall Street crash of 1929 exposed corporate irresponsibility in large organisations. The understanding of CSR has evolved since then and its scope has now broadened from mere compliance to corporate laws to active alignment of internal business goals with externally set societal aspirations. Unfortunately, the significance of this multidimensional concept within the small and medium enterprise (SME) sector has continued to be overshadowed by its application in large and multinational organisations. More importantly, this has led to the practice of judging SMEs, which are experiencing increasing pressure to engage in social activities, as if they are no different from their larger counterparts. This study therefore investigates CSR from the perspective of SMEs in Australia without any theoretical presumptions and then comments on the relevance and applicability of the two theories that have been commonly used to investigate business responsibility, namely, stakeholder theory (ST) and social capital theory (SCT). The research findings indicate that CSR within the SME sector is more aligned to the fundamentals of SCT, mainly owing to the unique resource and survival challenges that they face, and which are, arguably, not so pronounced in large organisations. [ABSTRACT FROM AUTHOR]

Reductive functionalization of the C=O unit in carboxylic acids, carbonic acid derivatives, and ultimately in carbon dioxide itself is a challenging task of key importance for the synthesis of value-added chemicals. In particular, it can open novel pathways for the valorization of non-fossil feedstocks. Catalysts based on earth-abundant, cheap, and benign metals would greatly contribute to the development of sustainable synthetic processes derived from this concept. Herein, a manganese pincer complex [Mn(Ph2PCH2SiMe2)2NH(CO)2Br] (1) is reported to enable the reduction of a broad range of carboxylic acids, carbonates, and even CO2 using pinacolborane as reducing agent. The complex is shown to operate under mild reaction conditions (80-120 °C), low catalyst loadings (0.1-0.2 mol%) and runs under solvent-less conditions. Mechanistic studies including crystallographic characterisation of a borane adduct of the pincer complex (1) imply that metal-ligand cooperation facilitates substrate activation. Catalytic reduction of CO2 and biomass derivatives is of great current interest from a sustainable chemistry perspective. Here, the authors report a manganese pincer complex able to reduce under mild conditions carboxylic acids, carbonates and even carbon dioxide using pinacolborane as reducing agent. [ABSTRACT FROM AUTHOR]