•Plastic recycling models are quantitatively inadequate for sustainability.•Developments in the field of biopolymer degradation to reduce carbon foot-print.•Modification of biopolymers to enhance ...mechanical and physical properties.•Popularization of bioplastics for various industrial and packaging applications.
The progression of plastic pollution is a global concern. “Reuse, reduce and recycle” offers a solution to the burdening issue, although not enough to curb the rampant use of plastics. Biodegradable plastics are gaining acceptability in agriculture and food packaging industries; nevertheless, they occupy a rather small section of the plastic market. This review summarizes recent advances in the development of biodegradable plastics and their safe degradation potentials. Here, biodegradable plastics have been categorized and technology and developments in the field of biopolymers, their applicability, degradation and role in sustainable development has been reviewed. Also, the use of natural polymers with improved mechanical and physical properties that brings them at par with their counterparts has been discussed. Biodegradable polymers add value to the industries that would help in achieving sustainable development and consequently reinforce green economy, reducing the burden of greenhouse gases in the environment and valorisation of waste biomass.
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•Furfural and HMF are genotoxic and carcinogenic by-products of thermal degradation.•Developed a method to detect furfural and HMF in beverages and fruit juices.•Translated the method ...into chromogenic test-strips for point-of-use applications.•The method sensitivity is 0.006 and 0.005% (v/v) for furfural and HMF, respectively.
Improper storage and transportation of non-alcoholic beverages can, over longer periods, induce Maillard reaction, degrading nutritional components and generating genotoxic and carcinogenic by-products such as furfural and 5-hydroxymethylfurfural (HMF), rendering products unsafe for human consumption. Here, we describe a rapid quantitative solution-based method and test-strips for detection of furfural and HMF. The standard spectroscopic method indicated an LOD of 0.006 ± 0.003% (v/v) and 0.005 ± 0.002% (v/v) for furfural and HMF, respectively in fruit juice samples. The novel chromogenic test-strip has sensitivity of 0.008% (v/v) and 0.004% (v/v) for furfural and HMF, respectively in the same samples of fruit juice. Thus, the developed method and test-strips were specific for furfural and HMF and can be used to help ensure food safety and quality in various industrial applications
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•MoS2 and MoS2-MWCNTs composite were obtained via facile hydrothermal route.•Structural analysis confirmed the presence of various defects in obtained materials.•Electrical ...measurements on 2-Terminal devices revealed their semiconducting nature.•Composite based sensor displayed superior response and selectivity towards ammonia.•Theoretical limit of detection for MoS2 based sensor is found to be 1.2 ppm.
MoS2 and its composite with multi-walled carbon nanotube (MWCNTs) were synthesized using facile hydrothermal approach. Structural and vibrational analysis revealed the presence of various defects in MoS2 and its composite with MWCNT. Two-terminal devices were made on a quartz substrate with pre-deposited silver contacts. The resulting Ag/MoS2/Ag and Ag/MoS2-MWCNT/Ag devices exhibit n-type semiconducting behavior and have shown room-temperature ammonia detection down to 12 ppm level. In case of former, the corresponding response time (tresponse = 400 s) and recovery time (trecovery = 280 s) are very large with limit of detection down to 1.2 ppm. The latter, i.e., Ag/MoS2-MWCNT/Ag device on the other hand exhibits faster response-recovery (65 and 70 s, respectively) features along with enhanced relative response for various ammonia concentrations ranging from 12 to 325 ppm. Further, the composite device also displays superior selectivity to its counterpart. It is argued that these differences might arise from different adsorption energy for different gas molecules on the surface of MoS2 or MoS2-MWCNT semiconducting channel. Present results suggest that composite materials such as MoS2-MWCNT may serve as a novel gas sensing platform with superior sensing characteristics and selectivity features.
While the toxicity of metals and metalloids, like arsenic, cadmium, mercury, lead and chromium, is undisputed, the underlying molecular mechanisms are not entirely clear. General consensus holds that ...proteins are the prime targets; heavy metals interfere with the physiological activity of specific, particularly susceptible proteins, either by forming a complex with functional side chain groups or by displacing essential metal ions in metalloproteins. Recent studies have revealed an additional mode of metal action targeted at proteins in a non-native state; certain heavy metals and metalloids have been found to inhibit the in vitro refolding of chemically denatured proteins, to interfere with protein folding in vivo and to cause aggregation of nascent proteins in living cells. Apparently, unfolded proteins with motile backbone and side chains are considerably more prone to engage in stable, pluridentate metal complexes than native proteins with their well-defined 3D structure. By interfering with the folding process, heavy metal ions and metalloids profoundly affect protein homeostasis and cell viability. This review describes how heavy metals impede protein folding and promote protein aggregation, how cells regulate quality control systems to protect themselves from metal toxicity and how metals might contribute to protein misfolding disorders.
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•Extraction, processing and storageconditions affect the quality of fruit juices.•Degradation by-products and spoilage indicators in packaged fruit juices.•Standard analytical ...techniques for assessment of fruit juices quality.•Intervening role of biosensors for ensuring fruit juice quality.
The quality of packaged fruit juices is affected during their processing, packaging and storage that might cause deteriorative biological, chemical and physical alterations. Consumption of spoiled juices, either from biological or non-biological sources can pose a potential health hazard for the consumers. Sensitive and reliable methods are required to ensure the quality of fruit juices. Standard analytical methods such as chromatography, spectrophotometry, electrophoresis and titration, that require sophisticated equipment and expertise, are traditionally used to assess the quality of fruit juices. Using biosensors, that are simple, portable and rapid presents a promising alternative to the tedious analytical methods for the detection of various degradation and spoilage indicators formed in the packaged fruit juices. Here, we review the challenges in maintaining the quality of fruit juices and the recent developments in techniques and biosensors for quick analysis of fruit juice components.
Use of Plant growth promoting rhizobacteria (PGPR) is a promising strategy to improve the crop production under optimal or sub-optimal conditions. In the present study, five diazotrophic salt ...tolerant bacteria were isolated from the roots of a halophyte,
. The isolates were partially characterized
for plant growth promoting traits and evaluated for their potential to promote growth and enhanced salt tolerance in peanut. The 16S rRNA gene sequence homology indicated that these bacterial isolates belong to the genera,
, and
. All isolates were
positive and able to produce indole -3-acetic acid (ranging from 11.5 to 19.1 μg ml
). The isolates showed phosphate solubilisation activity (ranging from 1.4 to 55.6 μg phosphate /mg dry weight), 1-aminocyclopropane-1-carboxylate deaminase activity (0.1 to 0.31 μmol α-kB/μg protein/h) and were capable of reducing acetylene in acetylene reduction assay (ranging from 0.95 to 1.8 μmol C
H
mg protein/h). These isolates successfully colonized the peanut roots and were capable of promoting the growth under non-stress condition. A significant increase in total nitrogen (N) content (up to 76%) was observed over the non-inoculated control. All isolates showed tolerance to NaCl ranging from 4 to 8% in nutrient broth medium. Under salt stress, inoculated peanut seedlings maintained ion homeostasis, accumulated less reactive oxygen species (ROS) and showed enhanced growth compared to non-inoculated seedlings. Overall, the present study has characterized several potential bacterial strains that showed an enhanced growth promotion effect on peanut under control as well as saline conditions. The results show the possibility to reduce chemical fertilizer inputs and may promote the use of bio-inoculants.
Cloud computing facilitates the storage and management of huge volumes of data. It offers flexibility for retrieving the data anytime and anywhere. In recent years, storing data onto the cloud ...achieved fame among corporations as well as private users. Although, the cloud is drawing a lot of attention still there are data security, privacy, reliability and interoperability concerns that need to be taken care. To deal with these issues, cloud data encryption comes to the rescue. Encrypting the data before uploading it onto the cloud prevents unauthorized users from accessing the data. A lot of encryption algorithms have been developed to secure data stored on the cloud. In this paper, a novel cryptographic technique has been presented that uses client-side data encryption for encrypting the data before uploading it onto the cloud. It is a multifold symmetric-key cryptography technique which is based upon DNA cryptography. Besides presenting the detailed design of our approach, we have compared it with the existing symmetric-key algorithms (DNA, AES, DES and Blowfish). The experimental results illustrate that our proposed algorithm outperforms these traditional algorithms in terms of ciphertext size, encryption time and throughput. Hence, the newly proposed technique is more efficient and offers better performance.
Iron-sulfur clusters are a universal biological motif. They carry out electron transfer, redox chemistry and even oxygen sensing, in diverse processes including nitrogen fixation, respiration and ...photosynthesis. Their low-lying electronic states are key to their remarkable reactivity, but they cannot be directly observed. Here, we present the first ever quantum calculation of the electronic levels of 2Fe-2S and 4Fe-4S clusters free from any model assumptions. Our results highlight the limitations of long-standing models of their electronic structure. In particular, we demonstrate that the widely used Heisenberg double exchange model underestimates the number of states by one to two orders of magnitude, which can conclusively be traced to the absence of Fe dd excitations, thought to be important in these clusters. Furthermore, the electronic energy levels of even the same spin are dense on the scale of vibrational fluctuations and this provides a natural explanation for the ubiquity of these clusters in catalysis in nature.
We present two efficient and intruder-free methods for treating dynamic correlation on top of general multiconfiguration reference wave functions including such as obtained by the density matrix ...renormalization group (DMRG) with large active spaces. The new methods are the second order variant of the recently proposed multireference linearized coupled cluster method (MRLCC) Sharma, S.; Alavi, A. J. Chem. Phys. 2015, 143, 102815 and of N-electron valence perturbation theory (NEVPT2), with expected accuracies similar to MRCI+Q and (at least) CASPT2, respectively. Great efficiency gains are realized by representing the first order wave function with a combination of internal contraction (IC) and matrix product state perturbation theory (MPSPT). With this combination, only third order reduced density matrices (RDMs) are required. Thus, we obviate the need for calculating (or estimating) RDMs of fourth or higher order; these had so far posed a severe bottleneck for dynamic correlation treatments involving the large active spaces accessible to DMRG. Using several benchmark systems, including first and second row containing small molecules, Cr2, pentacene, and oxo-Mn(Salen), we show that active spaces containing at least 30 orbitals can be treated using this method. On a single node, MRLCC2 and NEVPT2 calculations can be performed with over 550 and 1100 virtual orbitals, respectively. We also critically examine the errors incurred due to the three sources of errors introduced in the present implementation – calculating second order instead of third order energy corrections, use of internal contraction, and approximations made in the reference wave function due to DMRG.
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