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Solar energy is a most promising resource of non-conventional energy to utilize for heating. Based on the application there are two kinds of utilization one is water heating and the second one is air heating. This is generally done by flat plate solar collector but due to its limitations to use in higher temperature ranges (i.e., 70–95 °C) and poor performance led to introduce the application of evacuated tube and parabolic trough collector. To fabricate the solar air heater, one ended evacuated tube is used as a receiver of the parabolic trough and U-tube copper pipe is inserted within the evacuated tube. The air heating process is done at various mass flow rates and it was found that the average outlet temperature was more at the minimum mass flow rate, but the average efficiency was less. At maximum mass flow rate, the average outlet temperature was minimum, and the average thermal efficiency was maximum. The maximum thermal efficiency obtained was 24.1% at the 0.0082 kg/s mass flow rate and the maximum temperature that was obtained was 151 °C at 0.0062 kg/s mass flow rate. Hot air being used for different application in space heating, food processing, fruits and vegetable drying and in regeneration of desiccant.

Nitric oxide (NO) is a free-radical gasotransmitter signaling molecule associated with a varied spectrum of signal transduction pathways linked to inducing cross-adaptation against abiotic stresses. It has crucial roles from seed germination to plant maturity, depending upon its cellular concentration. The functional cross-talk of NO among different stress signaling cascades leads to alteration in the expression of developmental genes that regulate biosynthesis and function of plant growth regulators (PGRs). NO-PGRs and secondary signaling compounds cross-talk trigger reprogramming of stress-responsive gene expressions, transcriptional gene modulations, redox regulating machinery, oxidative metabolisms, and multiple regulatory pathways under plant abiotic stress. Recent findings suggest NO as critical components of numerous plant signaling network that interplays with auxin, gibberellins (GA), abscisic acid (ABA), ethylene (ET), jasmonic acid (JA), brassinosteroids (BRs), H2O2, melatonin, hydrogen sulfide (H2S), salicylic acid (SA), and other PGRs to modulate growth and development under multiple stresses. Considering the importance of NO signaling crosstalk under stress adaptation, in this review, we point out the biosynthesis and metabolism of NO and its crosstalk with numerous other signaling compounds. Further, recent cellular and molecular advances in NO signaling cross-talk under abiotic stress adaptations also have been discussed.

Elicitor-induced defense response against potential plant pathogens has been widely reported in several crop plants; however, transcriptome dynamics underlying such defense response remains elusive. Our previous study identified and characterized a novel elicitor, κ-carrageenan, from Kappaphycus alvarezii, a marine red seaweed. Our preliminary studies have shown that the elicitor-treatment enhances the tolerance of a susceptible tomato cultivar to Septoria lycopersici (causative agent of leaf spot disease). To gain further insights into the genes regulated during elicitor treatment followed by pathogen infection, we have performed RNA-Seq experiments under different treatments, namely, control (untreated and uninfected), elicitor treatment, pathogen infection alone, and elicitor treatment followed by pathogen infection. To validate the results, forty-three genes belonging to five different classes, namely, ROS activating and detoxifying enzyme encoding genes, DEAD-box RNA helicase genes, autophagy-related genes, cysteine proteases, and pathogenesis-related genes, were chosen. Expression profiling of each gene was performed using qRT-PCR, and the data was correlated with the RNA-seq data. Altogether, the study has pinpointed a repertoire of genes that could be potential candidates for further functional characterization to provide insights into novel elicitor-induced fungal defense and develop transgenic lines resistant to foliar diseases.

Background Although quantitative single-cell analysis is frequently applied in animal systems, e.g. to identify novel drugs, similar applications on plant single cells are largely missing. We have exploited the applicability of high-throughput microscopic image analysis on plant single cells using tobacco leaf protoplasts, cell-wall free single cells isolated by lytic digestion. Protoplasts regenerate their cell wall within several days after isolation and have the potential to expand and proliferate, generating microcalli and finally whole plants after the application of suitable regeneration conditions. Results High-throughput automated microscopy coupled with the development of image processing pipelines allowed to quantify various developmental properties of thousands of protoplasts during the initial days following cultivation by immobilization in multi-well-plates. The focus on early protoplast responses allowed to study cell expansion prior to the initiation of proliferation and without the effects of shape-compromising cell walls. We compared growth parameters of wild-type tobacco cells with cells expressing the antiapoptotic protein Bcl2-associated athanogene 4 from Arabidopsis (AtBAG4). Conclusions AtBAG4-expressing protoplasts showed a higher proportion of cells responding with positive area increases than the wild type and showed increased growth rates as well as increased proliferation rates upon continued cultivation. These features are associated with reported observations on a BAG4-mediated increased resilience to various stress responses and improved cellular survival rates following transformation approaches. Moreover, our single-cell expansion results suggest a BAG4-mediated, cell-independent increase of potassium channel abundance which was hitherto reported for guard cells only. The possibility to explain plant phenotypes with single-cell properties, extracted with the single-cell processing and analysis pipeline developed, allows to envision novel biotechnological screening strategies able to determine improved plant properties via single-cell analysis.

Patients with severe trauma exhibit augmented renal clearance, which can alter the dosing requirement of renally eliminated drugs. This study aimed to develop a population pharmacokinetic model for levetiracetam in patients with severe traumatic brain injury and aneurysmal subarachnoid hemorrhage, and use it to describe optimal dosing regimens. This was a prospective open-label observational study. Critically ill adult patients with severe traumatic brain injury or aneurysmal subarachnoid hemorrhage without renal dysfunction and receiving levetiracetam were eligible. Serial levetiracetam plasma concentrations were analyzed to develop a population pharmacokinetic model and perform dosing simulations. A two-compartment model best described the concentration–time data from 30 patients. The mean ± standard deviation parameter estimates were bioavailability (F) of 0.8 ± 0.2, absorption rate constant of 2.4 ± 2 h−1, clearance 2.5 ± 1.1 L/h, central volume of distribution 8.9 ± 3.0 L/h, and transfer rate constraints of 1.8 ± 1.1 h−1 from central to peripheral compartments and 0.7 ± 0.3 h−1 from peripheral to central compartments. For the simulated intermittent dosing regimens, on average, the median trough concentration reduced by 50% for every 40-mL/min/1.73 m2 increase in urinary creatinine clearance. Simulated doses of at least 6 g/day were required for some levels of augmented renal clearance. Patients with severe traumatic brain injury and aneurysmal subarachnoid hemorrhage with augmented renal clearance are at risk of not achieving target levetiracetam plasma concentrations. We suggest dose titration guided by measured creatinine clearance, and/or, therapeutic drug monitoring if available, to minimize the risk of seizures.

A simple method for the simultaneous quantification of meropenem and the recently approved β-lactamase inhibitor, vaborbactam, in human plasma and renal replacement therapy effluent (RRTE) was developed and validated. This antibiotic combination protects a primary β-lactam, meropenem, with a new β-lactamase inhibitor, and expands the limited options for treatment of multidrug-resistant Gram-negative infections. Meropenem, vaborbactam, and the internal standards [2H6]-meropenem and sulbactam in plasma and RRTE were processed using acetonitrile followed by a chromatographic separation on a Poroshell HPH-C18 column with a gradient elution of the mobile phases and monitored using mass spectrometry detection. The calibration range was 0.05 to 100 μg mL−1 for both meropenem and vaborbactam. The intra-day and inter-day precision and accuracy were less than 15% for both meropenem and vaborbactam and the recovery from plasma was 96% for both meropenem and vaborbactam and the recovery from RRTE was 93% and 103% for meropenem and vaborbactam, respectively. This methodology was successfully applied to an ex vivo characterisation study of the effects of renal replacement therapy modalities on the pharmacokinetics of meropenem and vaborbactam (Antimicrob Agents Chemother 62(10), 2018).

We present a novel optical beam steering technique for fiber to free-space to fiber-coupling schemes on optical breadboards, which is based on a glass plate and a pair of glass wedges. Our approach permits much finer adjustments of the beam direction and position when compared to conventional beam steering techniques that use adjusting elements of the same mechanical precision. This results in a much increased precision, accuracy, and stability. Furthermore, the presence of a beam steering element in proximity to the fiber coupler allows a great simplification of the design of this element which is typically considered as the most complex and sensitive element on an optical fiber breadboard. Overall, a beam steering precision of better than $$5\,\upmu $$rad and $$5\,\upmu $$m is demonstrated, resulting in a resolution in coupling efficiency of 0.1%. Likewise, we demonstrate a fiber-to-fiber-coupling efficiency of more than 89.8%, with a stability of 0.2% in a stable temperature environment and 2% fluctuations over a temperature range from 10 to 40 °C over a measurement time of 14 h. Finally, we observe no non-reversible change in the coupling efficiency after performing a series of tests over large temperature variations ($$\varDelta T > 30$$ K). This technique can find direct application in proposed missions for quantum experiments in space (Bongs et al. in STE-QUEST space–time explorer and quantum equivalence principle space test, Technical report STE-QUEST, European Space Agency, 2013; Kaltenbaek et al. in EPJ Quantum Technol 3(1):5, 2016; Carraz et al. in Microgravity Sci Technol 26:139, 2014), e.g., in space-based quantum sensing, where precisely controlled laser light is used to cool and manipulate atoms, or in inter-satellite quantum key distribution.

Background The population pharmacokinetics of total and unbound posaconazole following intravenous administration has not yet been described for the critically ill patient population. The aim of this work was, therefore, to describe the total and unbound population pharmacokinetics of intravenous posaconazole in critically ill patients and identify optimal dosing regimens. Methods This was a prospective observational population pharmacokinetic study in critically ill adult patients with presumed/confirmed invasive fungal infection. A single dose of 300 mg posaconazole was administered intravenously as an add-on to standard antifungal therapy, and serial plasma samples were collected over 48 h. Total and unbound posaconazole concentrations, measured by chromatographic method, were used to develop a population pharmacokinetic model and perform dosing simulations in R using Pmetrics. Results From eight patients, 93 pairs of total and unbound concentrations were measured. A two-compartment linear model with capacity-limited plasma protein binding best described the concentration-time data. Albumin and body mass index (BMI) were included as covariates in the final model. Mean (SD) parameter estimates for the volume of the central compartment (V) and the elimination rate constant were 72 (43) L and 42.1 (23.7) h−1, respectively. Dosing simulations showed that high BMI was associated with a reduced probability of achieving target total and unbound posaconazole concentrations. Low serum albumin concentration was associated with a reduced probability of attaining target total but not unbound posaconazole concentrations. Conclusions An important clinical message of this study is that critically ill patients with increased BMI may require larger than approved loading doses of intravenous posaconazole when considering currently recommended dosing targets. Variability in plasma albumin concentration appears unlikely to affect dosing requirements when the assessment is based on unbound concentrations. Where available, therapeutic drug monitoring of unbound concentrations may be useful.

Tuberculosis (TB), a disease caused by Mycobacterium tuberculosis (M.tb), takes one human life every 15 s globally. Disease relapse occurs due to incomplete clearance of the pathogen and reactivation of the antibiotic tolerant bacilli. M.tb, like other bacterial pathogens, creates an ecosystem of biofilm formed by several proteins including the cyclophilins. We show that the M.tb cyclophilin peptidyl-prolyl isomerase (PpiB), an essential gene, is involved in biofilm formation and tolerance to anti-mycobacterial drugs. We predicted interaction between PpiB and US FDA approved drugs (cyclosporine-A and acarbose) by in-silico docking studies and this was confirmed by surface plasmon resonance (SPR) spectroscopy. While all these drugs inhibited growth of Mycobacterium smegmatis (M.smegmatis) when cultured in vitro, acarbose and cyclosporine-A showed bacteriostatic effect while gallium nanoparticle (GaNP) exhibited bactericidal effect. Cyclosporine-A and GaNP additionally disrupted M.tb H37Rv biofilm formation. Co-culturing M.tb in their presence resulted in significant (2–4 fold) decrease in dosage of anti-tubercular drugs- isoniazid and ethambutol. Comparison of the cyclosporine-A and acarbose binding sites in PpiB homologues of other biofilm forming infectious pathogens revealed that these have largely remained unaltered across bacterial species. Targeting bacterial biofilms could be a generic strategy for intervention against bacterial pathogens. Tuberculosis, caused by Mycobacterium tuberculosis, is the leading cause of death due to a single infectious agent. New therapeutic options are needed, and repurposing clinically approved drugs to destroy biofilms is an attractive approach, as these microbial communities are often less susceptible to antibiotics. A team lead by Seyed Hasnain at the Indian Institute of Technology Delhi identified an enzyme, PpiB, from M. tuberculosis that promoted biofilm formation and showed that PpiB interacts with several drugs that are currently used to treat diabetes, immunological diseases and cancer. These drugs destabilise M. tuberculosis biofilms in culture and enhanced the potency of two current anti-tuberculosis antibiotics. Future work is needed to test these medications against tuberculosis in humans, but given PpiB is found in different bacteria, there may be broader promise of using these repurposed drugs to combat other infections.

Excessive generation of reactive oxygen species (ROS) due to environmental stresses critically effects plant development and productivity. Plants efficiently detoxify ROS by both non-enzymatic and enzymatic mechanisms. Plant glutathione peroxidases (GPXs) are non-haeme thiol peroxidases that catalyze the reduction of H2O2 (or organic hydroperoxides) to water or the respective alcohols using reduced glutathione or thioredoxin. Genome-wide analysis of the known GPXs from rice and Arabidopsis genomes revealed their gene structure, conserved motifs, localization and tissue-specific and/or organ-specific expression profiles in response to various abiotic stresses. Among the eight genes that encoded GPX proteins from Arabidopsis, AtGPX3 showed two alternate spliced forms that spread over four chromosomes. Five genes encoded for rice GPX proteins, while OsGPX1 showed three spliced variants that were distributed on five chromosomes. Utilizing the publicly available microarray and massively parallel signature sequencing (MPSS) data, the GPXs revealed stress-responsive, tissue-specific and/or organ-specific expression profiles. Presence of important cis-regulatory elements analyzed in the GPX promoter sequences revealed their overlapping or specific responsiveness to different abiotic stresses. Co-expression data of Arabidopsis GPX genes suggested that various protein kinase family members and stress-responsive proteins co-expressed with the GPX proteins. Transcript profile of rice GPX genes by qRT-PCR validated their functional roles in signal transduction and stress pathways. Results revealed that plant GPXs play a crucial role in response to stress and significantly contribute towards their growth and development.

In higher plants, two pathways are implicated in the synthesis of isoprenoids: the mevalonate pathway and methyl-d-erythritol 4-phosphate (MEP) pathway. In MEP pathway, 1-deoxy-d-xylulose-5-phosphate synthase (DXS) enzyme catalyzes the first committed step and it is recognized as a rate-limiting enzyme. In this study, a partial cDNA encoding DXS1 domain isolated from Aconitum balfourii Stapf. was cloned and characterized (AbDXS1). Analysis of DXS domain was performed and we found that AbDXS1 had extensive similarities to other DXS1 proteins. It comprised highly conserved DRAG and PSD domains. A comparative analysis of expression patterns for AbDXS1 using the already existing transcriptome profiles of model plants suggests its role in primary metabolism which needs to be validated further through functional genomics. These data would be helpful for exploring the functions of DXS and its isoforms in MEP pathway of Aconitum balfourii Stapf.

The terpolymer, poly (styrene-acrylonitrile-linalool) has been synthesized by free radical solution polymerization of the electron-donating monomers, linalool (optically active) (LIN) and styrene (STY) with the electron-accepting monomer, acrylonitrile (AN) using benzoyl peroxide (BPO) as an initiator and xylene as diluent at 75 °C for 40 minutes. The system follows ideal kinetics. Rp α [BPO]0.5 [LIN]1.0 [STY]1.0 [AN]1.0.

Arginine repressor of E. coli is a multifunctional hexameric protein that provides feedback regulation of arginine metabolism upon activation by the negatively cooperative binding of L-arginine. Interpretation of this complex system requires an understanding of the protein's conformational landscape. The ~50 kDa hexameric C-terminal domain was studied by 100 ns molecular dynamics simulations in the presence and absence of the six L-arg ligands that bind at the trimer-trimer interface. A rotational shift between trimers followed by rotational oscillation occurs in the production phase of the simulations only when L-arg is absent. Analysis of the system reveals that the degree of rotation is correlated with the number of hydrogen bonds across the trimer interface. The trajectory presents frames with one or more apparently open binding sites into which one L-arg could be docked successfully in three different instances, indicating that a binding-competent state of the system is occasionally sampled. Simulations of the resulting singly-liganded systems reveal for the first time that the binding of one L-arg results in a holoprotein-like conformational distribution.

Reaching a desired position with a specific orientationin space by a robot, mounted on a freely floating base, is an importantpath planning and control problem. Research in this area has mainlyconcentrated on the use of revolute-jointed serial manipulators. It iswell known that the dynamic equations of such manipulators are quitecomplex. In this paper, we propose the use of a 6-link fully prismatic-jointedrobot to achieve a desired position and orientation in space instead of arevolute-jointed robot. The use of pure prismatic-jointed robots forsuch a purpose is counter intuitive. On earth, such a structure is unableto provide a desired orientation to the end-effector. However, it can beshown that in space, arbitrary end-effector orientations are possible.Due to the relative simplicity of kinematics, dynamics and workspace ofprismatic-jointed robots compared to revolute-jointed robots, their useresults in significant computational advantages in path planning andcontrol. Also, in this paper, we adopt an unconventional motion planning methodthat avoids inversion of the Jacobian matrix and results in singularityfree paths for the end-effector. In this method, the joint trajectoriesare considered to be modal sums of basis functions of time. Within this framework, constraints on jointangles and joint rates can be imposed. The results are demonstratedwith an example of a 6-link fully prismatic-jointed robot.