Security and eavesdropping in terahertz wireless links.

Resiliency against eavesdropping and other security threats has become one of the key design considerations for communication systems. As wireless systems become ubiquitous, there is an increasing need for security protocols at all levels, including software (such as encryption), hardware (such as trusted platform modules) and the physical layer (such as wave-front engineering)1-5. With the inevitable shift to higher carrier frequencies, especially in the terahertz range (above 100 gigahertz), an important consideration is the decreased angular divergence (that is, the increased directionality) of transmitted signals, owing to the reduced effects of diffraction on waves with shorter wavelengths. In recent years, research on wireless devices6-8 and systems9-11 that operate at terahertz frequencies has ramped up markedly. These high-frequency, narrow-angle broadcasts present a more challenging environment for eavesdroppers compared to the wide-area broadcasts used at lower frequencies12,13. However, despite the widespread assumption of improved security for high-frequency wireless data links14-16, the possibility of terahertz eavesdropping has not yet been characterized. A few recent studies have considered the issue at lower frequencies5,12,13,17,18, but generally with the idea that the eavesdropper's antenna must be located within the broadcast sector of the transmitting antenna, leading to the conclusion that eavesdropping becomes essentially impossible when the transmitted signal has sufficiently high directionality15. Here we demonstrate that, contrary to this expectation, an eavesdropper can intercept signals in line-of-sight transmissions, even when they are transmitted at high frequencies with narrow beams. The eavesdropper's techniques are different from those for lower-frequency transmissions, as they involve placing an object in the path of the transmission to scatter radiation towards the eavesdropper. We also discuss one counter-measure for this eavesdropping technique, which involves characterizing the backscatter of the channel. We show that this counter-measure can be used to detect some, although not all, eavesdroppers. Our work highlights the importance of physical-layer security in terahertz wireless networks and the need for transceiver designs that incorporate new counter-measures.

Nanoparticles: Synthesis, Morphophysiological Effects, and Proteomic Responses of Crop Plants.

Plant cells are frequently challenged with a wide range of adverse environmental conditions that restrict plant growth and limit the productivity of agricultural crops. Rapid development of nanotechnology and unsystematic discharge of metal containing nanoparticles (NPs) into the environment pose a serious threat to the ecological receptors including plants. Engineered nanoparticles are synthesized by physical, chemical, biological, or hybrid methods. In addition, volcanic eruption, mechanical grinding of earthquake-generating faults in Earth's crust, ocean spray, and ultrafine cosmic dust are the natural source of NPs in the atmosphere. Untying the nature of plant interactions with NPs is fundamental for assessing their uptake and distribution, as well as evaluating phytotoxicity. Modern mass spectrometry-based proteomic techniques allow precise identification of low abundant proteins, protein-protein interactions, and in-depth analyses of cellular signaling networks. The present review highlights current understanding of plant responses to NPs exploiting high-throughput proteomics techniques. Synthesis of NPs, their morphophysiological effects on crops, and applications of proteomic techniques, are discussed in details to comprehend the underlying mechanism of NPs stress acclimation.

Preface-Plant Proteomic Research.

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Ultraweak photon emission and proteomics analyses in soybean under abiotic stress.

Biophotons are ultraweak photon emissions that are closely related to various biological activities and processes. In mammals, biophoton emissions originate from oxidative bursts in immunocytes during immunological responses. Biophotons emitted from plant organs provide novel information about the physiological state of plant under in vivo condition. In this review, the principles and recent advances in the measurement of biophoton emissions in plants are described. Furthermore, examples of biophoton emission and proteomics in soybean under abiotic stress are reviewed and discussed. Finally, this review suggests that the application of proteomics should provide a better interpretation of plant response to biophoton emission and allow the identification of genes that will allow the screening of crops able to produce maximal yields, even in stressful environments.

Plant Responses to Nanoparticle Stress.

With the rapid advancement in nanotechnology, release of nanoscale materials into the environment is inevitable. Such contamination may negatively influence the functioning of the ecosystems. Many manufactured nanoparticles (NPs) contain heavy metals, which can cause soil and water contamination. Proteomic techniques have contributed substantially in understanding the molecular mechanisms of plant responses against various stresses by providing a link between gene expression and cell metabolism. As the coding regions of genome are responsible for plant adaptation to adverse conditions, protein signatures provide insights into the phytotoxicity of NPs at proteome level. This review summarizes the recent contributions of plant proteomic research to elaborate the complex molecular pathways of plant response to NPs stress.

Untying arsenite tolerance mechanisms in contrasting maize genotypes attributed to NIPs-mediated controlled influx and root-to-shoot translocation, redox homeostasis and phytochelatin-mediated detoxification pathway.

Contamination of ground water and soil with toxic metalloids like arsenic (As) poses a serious hazard to the global agricultural food production. One of the best ways to restrict entry of As into the food chain is selection of germplasms which accrue extremely low level of As in grains. Here, we screened diverse maize genotypes under high arsenite (100 µM AsIII) stress and identified PMI-PV-9 and PMI-PV-3 as AsIII-tolerant and -sensitive maize genotype respectively. Expression of genes associated with As uptake, vacuolar sequestration, biosynthesis of phytochelatins, root-to-shoot translocation, in vivo ROS generation, fine tuning of antioxidant defense system, DNA and membrane damage, H2O2 and superoxide anion (O2•-) levels were compared among the selected genotypes. PMI-PV-9 plants performed much better than PMI-PV-3 in terms of plant growth with no visible symptom of As toxicity. Susceptibility of PMI-PV-3 to AsIII stress may be attributed to comparatively low expression of genes involved in phytochelatins (PCs) biosynthesis. Concomitant decrease in ABCC1 expression might be another key factor for futile sequestration of AsIII into root vacuoles. Moreover, up-regulation of ZmNIP3;1 might contribute in high root-to-leaf As translocation. Substantial spike in H2O2, O2•- and MDA levels indicates that PMI-PV-3 plants have experienced more oxidative stress than PMI-PV-9 plants. Appearance of prominent deep brown and dark blue spots/stripes on leaves as revealed after DAB and NBT staining respectively suggest severe oxidative burst in PMI-PV-3 plants. Marked reduction in DHAR and MDAR activity rendered PMI-PV-3 cells to recycle ascorbate pool ineffectively, which might have exacerbated their susceptibility to AsIII stress. In a nutshell, incompetent PCs mediated detoxification system and disruption of cellular redox homeostasis owing to feeble antioxidant defence system resulting oxidative burst might be the prime reasons behind reduced performance of PMI-PV-3 plants under AsIII stress.

Soybean proteomics for unraveling abiotic stress response mechanism.

Plant response to abiotic stresses depends upon the fast activation of molecular cascades involving stress perception, signal transduction, changes in gene and protein expression and post-translational modification of stress-induced proteins. Legumes are extremely sensitive to flooding, drought, salinity and heavy metal stresses, and soybean is not an exception of that. Invention of immobilized pH gradient strips followed by advancement in mass spectrometry has made proteomics a fast, sensitive and reliable technique for separation, identification and characterization of stress-induced proteins. As the functional translated portion of the genome plays an essential role in plant stress response, proteomic studies provide us a finer picture of protein networks and metabolic pathways primarily involved in stress tolerance mechanism. Identifying master regulator proteins that play key roles in the abiotic stress response pathway is fundamental in providing opportunities for developing genetically engineered stress-tolerant crop plants. This review highlights recent contributions in the field of soybean biology to comprehend the complex mechanism of abiotic stress acclimation. Furthermore, strengths and weaknesses of different proteomic methodologies of extracting complete proteome and challenges and future prospects of soybean proteome study both at organ and whole plant levels are discussed in detail to get new insights into the plant abiotic stress response mechanism.

microRNAomic profiling of maize root reveals multifaceted mechanisms to cope with Cr (VI) stress.

Chromium (Cr) contamination of soil and water poses serious threats to agricultural crop production. MicroRNAs (miRNAs) are conserved, non-coding small RNAs that play pivotal roles in plant growth, development and stress responses through fine-tuning of post-transcriptional gene expression. To better understand the molecular circuit of Cr-responsive miRNAs, two sRNA libraries were prepared from control and Cr (VI) [100 ppm] exposed maize roots. Using deep sequencing, we identified 80 known (1 up and 79 down) and 18 downregulated novel miRNAs from Cr (VI) challenged roots. Gene ontology (GO) analysis reveals that predicted target genes of Cr (VI) responsive miRNAs are potentially involved in diverse cellular and biological processes including plant growth and development (miR159c, miR164d, miR319b-3p and zma_25.145), redox homeostasis (miR528-5p, miR396a-5p and zma_9.132), heavy metal uptake and detoxification (miR159f-5p, 164e-5p, miR408a, miR444f and zma_2.127), signal transduction (miR159f, miR160a-5p, miR393a-5p, miR408-5p and zma_43.158), cell signalling (miR156j, 159c-5p, miR166c-5p and miR398b). Higher accumulation of Cr in maize roots might be due to upregulation of ABC transporter G family member 29 targeted by miR444f. Instead of isolated increase in SOD expression, significant decline in GSH:GSSH ratio and histochemical staining strongly suggest Cr (VI) stress mediated disruption of ROS scavenging machinery thus unbalancing normal cellular homeostasis. Moreover, miR159c-mediated enhanced expression of GAMYB might be a reason for impaired root growth under Cr (VI) stress. In a nutshell, the present microRNAomic study sheds light on the miRNA-target gene regulatory network involved in adaptive responses of maize seedlings to Cr (VI) stress.

Plant cell organelle proteomics in response to abiotic stress.

Proteomics is one of the finest molecular techniques extensively being used for the study of protein profiling of a given plant species experiencing stressed conditions. Plants respond to a stress by alteration in the pattern of protein expression, either by up-regulating of the existing protein pool or by the synthesizing novel proteins primarily associated with plants antioxidative defense mechanism. Improved protein extraction protocols and advance techniques for identification of novel proteins have been standardized in different plant species at both cellular and whole plant level for better understanding of abiotic stress sensing and intracellular stress signal transduction mechanisms. In contrast, an in-depth proteome study of subcellular organelles could generate much detail information about the intrinsic mechanism of stress response as it correlates the possible relationship between the protein abundance and plant stress tolerance. Although a wealth of reviews devoted to plant proteomics are available, review articles dedicated to plant cell organelle proteins response under abiotic stress are very scanty. In the present review, an attempt has been made to summarize all significant contributions related to abiotic stresses and their impacts on organelle proteomes for better understanding of plants abiotic stress tolerance mechanism at protein level. This review will not only provide new insights into the plants stress response mechanisms, which are necessary for future development of genetically engineered stress tolerant crop plants for the benefit of humankind, but will also highlight the importance of studying changes in protein abundance within the cell organelles in response to abiotic stress.

Comparative proteome analysis of high and low cadmium accumulating soybeans under cadmium stress.

A comparative proteomic study was performed to unravel the protein networks involved in cadmium stress response in soybean. Ten-day-old seedlings of contrasting cadmium accumulating soybean cultivars-Harosoy (high cadmium accumulator), Fukuyutaka (low cadmium accumulator), and their recombinant inbred line CDH-80 (high cadmium accumulator) were exposed to 100 µM CdCl(2) treatment for 3 days. Root growth was found to be affected under cadmium stress in all. Varietal differences at root protein level were evaluated. NADP-dependent alkenal double bond reductase P1 was found to be more abundant in low cadmium accumulating Fukuyutaka. Leaf proteome analysis revealed that differentially expressed proteins were primarily involved in metabolism and energy production. The results indicate that both high and low cadmium accumulating cultivars and CDH-80 share some common defense strategies to cope with the cadmium stress. High abundance of enzymes involved in glycolysis and TCA cycle might help cadmium challenged cells to produce more energy necessary to meet the high energy demand. Moreover, enhanced expressions of photosynthesis related proteins indicate quick utilization of photoassimilates in energy generation. Increased abundance of glutamine synthetase in all might be involved in phytochelatin mediated detoxification of cadmium ions. In addition, increased abundance of antioxidant enzymes, namely superoxide dismutase, ascorbate peroxidase, catalase, ensures cellular protection from reactive oxygen species mediated damages under cadmium stress. Enhanced expression of molecular chaperones in high cadmium accumulating cultivar might be another additional defense mechanism for refolding of misfolded proteins and to stabilize protein structure and function, thus maintain cellular homeostasis.

Characterization of ascorbate peroxidase in soybean under flooding and drought stresses.

Flooding and drought are the two different forms of water stress that adversely affect the growth and development of soybean plant in particular at early stage. Ascorbate peroxidase (APX) is a known antioxidant enzyme that plays key role in abiotic stresses. To investigate the changes in APX in soybean under drought and flooding stresses, western blotting, enzyme activity assay and biophoton emission techniques were used. Flooding stress was imposed by adding excess amount of water in the sand and drought by withholding water supply. Under flooding stress, a decrease in APX was detected with time. Completely opposite trend was evident in hypocotyl and root of plants exposed to drought. Western blotting and APX activity results are complementary to each other. Biophoton emissions further confirmed the increasing and decreasing trend of APX under drought and flooding stress, respectively.

Impact of CuO nanoparticles on maize: Comparison with CuO bulk particles with special reference to oxidative stress damages and antioxidant defense status.

The present study aimed to systematically investigate the particle size effects of copper (II) oxide [CuO nanoparticles (<50 nm) and CuO bulk particles (<10 µm)] on maize (Zea mays L.). Bioaccumulation of Cu, in vivo ROS generation, membrane damage, transcriptional modulation of antioxidant genes, cellular redox status of glutathione and ascorbate pool, expression patterns of COPPER TRANSPORTER 4 and stress responsive miRNAs (miR398a, miR171b, miR159f-3p) with their targets were investigated for better understanding of the underlying mechanisms and the extent of CuO nanoparticles and CuO bulk particles induced oxidative stress damages. More restricted seedling growth, comparatively higher membrane injury, marked decline in the levels of chlorophylls and carotenoids and severe oxidative burst were evident in CuO bulk particles challenged leaves. Dihydroethidium and CM-H2DCFDA staining further supported elevated reactive oxygen species generation in CuO bulk particles stressed roots. CuO bulk particles exposed seedlings accumulated much higher amount of Cu in roots as compared to CuO nanoparticles stressed plants with low root-to-shoot Cu translocation. Moderately high GR expression with maintenance of a steady GSH-GSSG ratio in CuO nanoparticles challenged leaves might be accountable for their rather improved performance under stressed condition. miR171b-mediated enhanced expression of SCARECROW 6 might participate in the marked decline of chlorophyll content in CuO bulk particles exposed leaves. Ineffective recycling of AsA pool is another decisive feature of inadequate performance of CuO bulk particles stressed seedlings in combating oxidative stress damages. Taken together, our findings revealed that toxicity of CuO bulk particles was higher than CuO nanoparticles and the adverse effects of CuO bulk particles on maize seedlings might be due to higher Cu ions dissolution.

Assessment of ZnO-NPs toxicity in maize: An integrative microRNAomic approach.

Rapid expansion of nanotechnology and indiscriminate discharge of metal oxide nanoparticles (NPs) into the environment pose a serious hazard to the ecological receptors including plants. To better understand the role of miRNAs in ZnO-NPs stress adaptation, two small RNA libraries were prepared from control and ZnO-NPs (800 ppm, <50 nm particle size) stressed maize leaves. Meager performance of ZnO-NPs treated seedlings was associated with elevated tissue zinc accumulation, enhanced ROS generation, loss of root cell viability, increased foliar MDA content, decrease in chlorophyll and carotenoids contents. Deep sequencing identified 3 (2 known and 1 novel) up- and 77 (73 known and 4 novel) down-regulated miRNAs from ZnO-NPs challenged leaves. GO analysis reveals that potential targets of ZnO-NPs responsive miRNAs regulate diverse biological processes viz. plant growth and development (miR159f-3p, zma_18), ROS homeostasis (miR156b, miR166l), heavy metal transport and detoxification (miR444a, miR167c-3p), photosynthesis (miR171b) etc. Up-regulation of SCARECROW 6 in ZnO-NPs treated leaves might be responsible for suppression of chlorophyll biosynthesis leading to yellowing of leaves. miR156b.1 mediated up-regulation of CALLOSE SYNTHASE also does not give much protection against ZnO-NPs treatment. Taken together, the findings shed light on the miRNA-guided stress regulatory networks involved in plant adaptive responses to ZnO-NPs stress.

Antioxidant enzymatic activity is linked to waterlogging stress tolerance in citrus.

Soil flooding constitutes a seasonal factor that negatively affects plant performance and crop yields. In this work, the relationship between oxidative damage and flooding sensitivity was addressed in three citrus genotypes with different abilities to tolerate waterlogging. We examined leaf visible damage, oxidative damage in terms of malondialdehyde (MDA) concentration, leaf proline concentration, leaf and root ascorbate and glutathione contents and the antioxidant enzyme activities superoxide dismutase (EC 1.15.1.1), ascorbate peroxidase (EC 1.11.1.11), catalase (EC 1.11.1.6) and glutathione reductase (EC 1.8.1.7). No differences in the extent of oxidative damage relative to controls were found among genotypes. However, a different ability to delay the apparition of oxidative damage was associated to a higher tolerance to waterlogging. This ability was linked to an enhanced activated oxygen species' scavenging capacity in terms of an increased antioxidant enzyme activity and higher content in polar antioxidant compounds. Therefore, the existence of a direct relationship between stress sensitivity and the early accumulation of MDA is proposed. In addition, data indicate that the protective role of proline has to be considered minimal as its accumulation was inversely correlated with tolerance to the stress. The positive antioxidant response in Carrizo citrange (Poncirus trifoliata L. Raf. x Citrus sinensis L. Osb.) and Citrumelo CPB 4475 (Poncirus trifoliata L. Raf. x Citrus paradisi L. Macf.) might be responsible for a higher tolerance to flooding stress, whereas in Cleopatra mandarin (Citrus reshni Hort. Ex Tan.), the early accumulation of MDA seems to be associated to an impaired ability for H2O2 scavenging.

Development of NaCl-tolerant line in Chrysanthemum morifolium Ramat. through shoot organogenesis of selected callus line.

Plants were regenerated successfully through shoot organogenesis of a NaCl-selected callus line of Chrysanthemum morifolium Ramat. cv. Maghi Yellow (a salt sensitive cultivar), developed through stepwise increase in NaCl concentration (0-100mM) in the MS medium. The stepwise increase in NaCl concentration from a relatively low level to cytotoxic level was found to be a better way to isolate NaCl-tolerant callus line, since direct transfer of callus to high saline medium was detrimental to callus survival and growth. The selected callus line exhibited significant increase in superoxide dismutase (EC 1.15.1.1), ascorbate peroxidase (EC 1.11.1.11) and glutathione reductase (EC 1.6.4.2) activities compared to control callus (grown in medium devoid of NaCl). Stability of salt tolerance character of the selected callus line was checked by growing the calli in NaCl-free medium for 3 consecutive months followed by re-exposure to higher salinity stress (120mM NaCl). Among different growth regulator treatments, a combination of 5mgl(-1) TDZ (Thidiazuron) along with 0.25mgl(-1) NAA and 0.5mgl(-1) GA(3) was found to be the most effective for shoot organogenesis in selected callus line. The regeneration potential of the NaCl-tolerant callus ranged from 20.8% to 0% against 62.4% to 0% in control callus line. Under elevated stress condition (medium supplemented with 250mM NaCl), selected calli derived regenerants (S1 plants) exhibited significantly higher SOD and APX activities over both PC (positive control: control callus derived plants grown on MS medium devoid of NaCl) and NC (negative control: control callus derived plants subjected to 250mM NaCl stress) plants. In addition, the NC plants showed stunted growth, delayed root initiation, and had lesser number of roots as compared to S1 plants. Based on growth performance and antioxidant capacity, the S1 plants could be considered as NaCl-tolerant line showing all positive adaptive features towards the salinity stress. Further study on agronomic performance of these S1 plants under saline soil condition need to be undertaken to check the genetic stability of the induced salt-tolerance.

Decline in ascorbate peroxidase activity--a prerequisite factor for tepal senescence in gladiolus.

Flower senescence was studied in Gladiolus cv. "Snow Princess" over five arbitrarily divided developmental stages (stage 1, half bloom; stage 2, full bloom; stage 3, beginning of wilting; stage 4, 50% wilting; stage 5, complete wilting) in terms of changes in fresh weight, antioxidant enzymes (superoxide dismutase, SOD; ascorbate peroxidase, APX; glutathione reductase, GR) activities and membrane integrity. A significant decrease in tepal fresh weight was observed over the senescence period (after stage 2). Membrane integrity was studied by measuring lipid peroxidation [in terms of thiobarbituric acid reactive substances (TBARS) content] and membrane stability index (MSI) percentage. Maximum TBARS content was recorded in stage 4 (50% wilting). This increase in lipid peroxidation over the senescence period was in close association with high degree of membrane deterioration expressed as decrease in membrane stability index percentage. A significant decrease (two and half-fold) in MSI% in stage 5 (as compared to stage 1) indicates complete membrane deterioration. Progressive increase in endogenous H2O2 level was recorded over senescence period. Maximum H2O2 content (19.7+/-1.4 micromol g(-1) DW) was recorded at stage 5 (complete wilting). Three different patterns were observed in antioxidant enzymes behavior over the senescence period. APX activity was declined significantly as, the flower entered stage 3 (beginning of wilting) from full bloom condition (stage 2). Progressive and significant increase in SOD activity was measured as a function of time. Maximum SOD activity (24.2+/-0.8 U mg(-1) DW) was recorded in stage 5 (three-fold increase over stage 1). GR activity initially increased up to stage 4 (50% wilting) and declined significantly thereafter (approximately seven-fold). An increase in endogenous H2O2 level during senescence may be the result of a programmed down-regulation of APX enzyme activity, which seems to be the prerequisite factor for initiating senescence process in gladiolus tepal.

Insights into the proteomic response of soybean towards Al2O3, ZnO, and Ag nanoparticles stress.

Understanding the complex mechanisms involved in plant response to nanoparticles is indispensable in assessing the impact of nano-pollutants on environment. The present study compares the phytotoxicity of three different metal-based nanoparticles (Al2O3, ZnO, and Ag) in soybean seedling at proteome level. Plant growth, rigidity of roots, and root cell viability were markedly affected by ZnO- and Ag-NPs stress; while, Al2O3-NPs challenged soybean maintained normal seedling growth like control. Moreover, severe oxidative burst was evident in ZnO-NPs and Ag-NPs treatments. Gel-free proteomic analysis of NPs stressed soybean roots revealed 104 commonly changed proteins primarily associated with secondary metabolism, cell organization, and hormone metabolism. Oxidation-reduction cascade related genes, such as GDSL motif lipase 5, SKU5 similar 4, galactose oxidase, and quinone reductase were up-regulated in Al2O3-NPs challenged roots and down-regulated in ZnO- and Ag-NPs treatments. In comparison to root, 16 common proteins were found to be significantly changed in leaves of NPs exposed soybean that were predominantly associated to photosystem and protein degradation. The proteomic findings suggest that high abundance of proteins involved in oxidation-reduction, stress signaling, hormonal pathways related to growth and development might be the principal key for optimum growth of soybean under Al2O3-NPs stress.

Nonmissile Penetrating Injury to the Head: Experience with 17 Cases.

BACKGROUND: Penetrating nonmissile injuries to the head are far less common than missile penetrating injuries. Here we describe our experience in managing 17 cases of nonmissile injury to the head, likely the largest such series reported to date. We also highlight the surgical steps and techniques used to remove in situ objects (including weapons) in the penetrating wounds that have not been described previously. METHODS: We conducted a retrospective study of cases of nonmissile, low-velocity penetrating injuries of the head managed in our department. The recorded data of patients with penetrating head injuries were studied for the cause of the injury, type of object, type and extent of penetration, Glasgow Coma Scale score on admission, other clinical issues, evaluation and assessment, interval from penetration to operation, surgical steps and notes, difficulty during the operation, major and minor complications, follow-up, and ultimate outcome. RESULTS: Our 17 cases included 6 cases of accidental penetration and 11 cases of penetration as the result of violence. Weapons and other foreign objects causing injury included a teta (a pointed metal weapon with a wooden handle and a barb near the tip, used for hunting and fishing) in 4 cases, a dao (a sharp metal cutting instrument with a wooden handle used for cutting vegetables, fish, meat, bamboo, wood, etc.) in 3 cases, a bamboo stick in 3 cases, a metal rod in 2 cases, a knife in 2 cases, a sharp stone in 1 case, a metal steam chamber cover in 1 case, and a long peg in 1 case. GCS on admission was between 13 and 15 in 15 cases. Only 1 patient exhibited limb weakness. Four patients with an orbitocranial penetrating injury had 1-sided vision loss; 2 of these patients had orbital evisceration, and 1 of these patients died. In 14 patients, the foreign object was in situ at presentation and was removed surgically. Computed tomography scan and plain X-ray of the head were obtained in all patients. Postoperatively, 2 patients (11.7%) needed support in the intensive care unit but died early after surgery. One patient developed late osteomyelitis. The remaining patients were doing well at the most recent follow-up. CONCLUSIONS: The presenting picture of nonmissile penetrating injury to head may be daunting, but these cases can be managed with very good results with proper (clinical and radiologic) evaluation and simple neurosurgical techniques.

ß-aminobutyric acid mediated drought stress alleviation in maize (Zea mays L.).

The present study highlights the role of ß-aminobutyric acid (BABA) in alleviating drought stress effects in maize (Zea mays L.). Chemical priming was imposed by pretreating 1-week-old plants with 600 µM BABA prior to applying drought stress. Specific activities of key antioxidant enzymes and metabolites (ascorbate and glutathione) levels of ascorbate-glutathione cycle were studied to unravel the priming-induced modulation of plant defense system. Furthermore, changes in endogenous ABA and JA concentrations as well as mRNA expressions of key genes involved in their respective biosynthesis pathways were monitored in BABA-primed (BABA+) and non-primed (BABA-) leaves of drought-challenged plants to better understand the mechanistic insights into the BABA-induced hormonal regulation of plant response to water-deficit stress. Accelerated stomatal closure, high relative water content, and less membrane damage were observed in BABA-primed leaves under water-deficit condition. Elevated APX and SOD activity in non-primed leaves found to be insufficient to scavenge all H2O2 and O2 (·-) resulting in oxidative burst as evident after histochemical staining with NBT and DAB. A higher proline accumulation in non-primed leaves also does not give much protection against drought stress. Increased GR activity supported with the enhanced mRNA and protein expressions might help the BABA-primed plants to maintain a high GSH pool essential for sustaining balanced redox status to counter drought-induced oxidative stress damages. Hormonal analysis suggests that in maize, BABA-potentiated drought tolerance is primarily mediated through JA-dependent pathway by the activation of antioxidant defense systems while ABA biosynthesis pathway also plays an important role in fine-tuning of drought stress response.

Proteomic study on the effects of silver nanoparticles on soybean under flooding stress.

Flooding negatively affects the soybean growth; however, silver nanoparticles (AgNPs) enhanced the growth under stress. To study the effects of AgNPs on soybean under flooding, a gel-free proteomic technique was used. The morphological analysis of early-stage soybean exposed to flooding with AgNPs of various sizes and concentrations revealed enhanced seedling growth by treatment with 15n m AgNPs at 2 ppm. Differentially changed 107 root proteins were predominantly associated with stress, signaling, and cell metabolism. Hierarchical clustering divided these proteins into 3 clusters. Based on cluster analysis, the abundances of glyoxalase II 3 and fermentation related proteins were time-dependently increased under flooding stress, but decreased in response to AgNPs. Six enzymes involved in metabolic pathways were analyzed at the transcriptional level. The alcohol dehydrogenase 1 and pyruvate decarboxylase 2 genes were up-regulated under flooding stress while down-regulated in response to AgNPs. Moreover, comparatively low transcript level of glyoxalase II 3 under AgNPs treatment implies that less cytotoxic by-products of glycolysis are produced in AgNPs exposed soybeans as compared to flooded soybean. These results suggest that the AgNPs treated soybeans might have experienced less oxygen-deprivation stress, which might be the key factor for better growth performance of AgNPs treated soybeans under flooding stress. BIOLOGICAL SIGNIFICANCE: This study highlighted the effect of silver nanoparticles (AgNPs) on the soybean under flooding stress. Silver nanoparticles (2 ppm AgNPs, 15 nm in size) treatment facilitate the soybean under flooding stress enhancing seedling growth. A time-course comparative gel-free proteomic study was performed to analyze the changes inproteome profiles in response to AgNPs treatment under flooding. The 107 differentially changed root proteins were predominantly associated with stress, signaling, cell metabolism. The abundances of the glyoxalase II 3 and fermentation related proteins were significantly increased on exposure to flooding; however, decreased by AgNPs treatment. Comparatively low transcript level of glyoxalase II 3 under AgNPs treatment implies that less cytotoxic by-products of glycolysis are produced in AgNPs exposed soybeans as compared to flooded soybean. Moreover, the observed up-regulation of the alcohol dehydrogenase 1 and pyruvate decarboxylase 2 genes under flooding stress condition and its down-regulation in response to AgNPs treatment might be related to a metabolic shift towards normal cellular processes.