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1.
Abstract

The demand to repair areas contaminated with hydrocarbon products has led to the development of new technologies for the treatment of contaminants in an unconventional method, that is, no physical or chemical methods are used. Biosurfactants are amphiphilic biomolecules produced by microorganisms that can be used in environments contaminated by petroleum products due to their unexceptionable tensile properties. Petroleum degrading strain Rhodococcus erythropolis HX-2 was found to be an effective producer of biosurfactants. The resulting biosurfactant (named NK) exhibits high physicochemical properties in terms of surface activity. It is capable of reducing surface tension from 54.99 to 28.89?mN/m and critical micelle concentration (CMC) is 100?mg/L. NK was found to be a substitute for chemically synthesized surfactants because of its higher solubilization efficiency for petroleum and polycyclic aromatic hydrocarbons, superior to SDS, Tween 80, Triton X-100 and Rhamnolipid (a wide used biosurfactant). In addition, it exhibits favorable emulsion stability over a wide range of pH (3–10), temperature (20–100?°C) and salinity ranges (5–20?g/L). It was found that the addition of biosurfactant can improve the efficiency of petroleum degradation, therefore it has potential applications in bioremediation.
  • Highlights
  • Rhodococcus erythropolis HX-2 is an effective petroleum degrading strain.

  • HX-2 is a potential source of biosurfactant production.

  • The biosurfactant NK reduces surface tension and exhibits high emulsification activity.

  • The biosurfactant NK is effective over a wide range of temperatures, pH and salinity.

  • The biosurfactant NK shows high solubilization efficiency for petroleum as well as polycyclic aromatic hydrocarbons.

  相似文献   

2.
Abstract

A novel tryptophan-derived Schiff base ligand (potassium (E)-2-((4-chloro-3-nitrobenzylidene)amino)-3-(1H-indol-3-yl)propanoate) and a series of its transition metal complexes of the types [ML2] and [ML(1,10-phen)2]Cl where M?=?Cu(II), Co(II), Ni(II) and Zn(II) were prepared. They were analyzed by various spectral and physicochemical studies. The XRD data were also used to determine the average lattice parameters and crystalline size of the compounds. All the synthesized compounds were tested against a series of five bacterial and fungal strains. The obtained results showed that the biological activity of free ligand was increased on complexation. PASS online software predicts the various biological activities of ligand such as enzyme inhibitor, antiviral, analgesic and antituberculosis. The in silico theoretical prediction of synthesized compounds is also deliberated by Swiss ADME predictor which gives the properties of molecular hydrophobicity (log P), topological polar surface area (TPSA) and oral bioavailability score. The binding energy of the docked molecule with macromolecules 1BNA and 3EQM is also determined by using Hex 8.0 software. The ligand has the least binding energy score which signifies that the potential of binding is greater in the receptor. Moreover, the interactions of complexes with DNA have been explored by electronic absorption titration, fluorescence emission titration, viscosity measurements and gel electrophoresis.
  • Highlights
  • Synthesis and characterization of novel indole-derived compounds.

  • X-ray diffraction studies demonstrate average crystalline size of the compounds.

  • Metal complexes act as good metallointercalators.

  • Metal complexes show higher antimicrobial activity compared to ligand.

  • Prediction of biological activities of the ligand by PASS online software.

  • Drug-like nature and bioavailability of synthesized compounds predicted by Swiss ADME predictor

  • Docking of the synthesized compounds with 1BNA and 3EQM using HEX 8.0 software.

Communicated by Ramaswamy H. Sarma  相似文献   

3.
4.
Abstract

Hydrogen sulfide (nH2S) and sulfur oxide (SO n ; n?=?1, 2, 3) gases in early Earth’s globally anoxic atmosphere were subjected to gas-phase chemical transformations by UV light. A principal photolysis pathway at that time produced elemental sulfur aerosols with mass-independently fractionated (MIF) isotopic values carrying variable minor isotope (33S, 36S) compositions. These rained into the sulfate-deficient Archean (ca. 3.85–2.5 Ga) oceans to react with [Fe2+]aq and form sedimentary sulfides. The MIF-bearing sulfides were incorporated into Archean sediments, including banded iron formations (BIF). Such aerosols may also have fueled microbial sulfur metabolisms, and thus are traceable by the MIF sulfur isotopes. Yet, data show that before ~3.5 Ga mass-dependent34S/32S values in Early Archean sediments tend to fall within a narrow (±0.1%) range even as they carry mass-independent values. By about 3.5 Ga, 34S/32S values show much greater changes (>1%) in range congruent with microbial metabolic processing. Here, we trace probable pathways of elemental sulfur aerosols into Archean sediments, and couple our study with analysis of the evolutionary relationships of enzymes involved in sulfur metabolism to explain the observed trends. Our model explains why elemental sulfur aerosols were apparently not utilized by the Eoarchean (pre-3.65 Ga) biosphere even though an immediate precursor to the required enzyme may have already been present.
  • Highlights
  • Evolution of microbial sulfur metabolisms is tracked by multiple sulfur isotopes

  • Alkaline hydrothermal vents were an abode for early microbial life

  • Sulfite detoxification prompted anaerobic respiration

  • Reversal of respiratory electron transport chain (ETC) stimulated photothiotrophy

  • Surplus e- acceptors permitted the emergence of elemental sulfur reduction

  相似文献   

5.
Abstract

Background: Heart failure with preserved ejection fraction (HFpEF) is a heterogeneous syndrome for which clear evidence of effective therapies is lacking. Understanding which factors determine this heterogeneity may be helped by better phenotyping. An unsupervised statistical approach applied to a large set of biomarkers may identify distinct HFpEF phenotypes.

Methods: Relevant proteomic biomarkers were analyzed in 392 HFpEF patients included in Metabolic Road to Diastolic HF (MEDIA-DHF). We performed an unsupervised cluster analysis to define distinct phenotypes. Cluster characteristics were explored with logistic regression. The association between clusters and 1-year cardiovascular (CV) death and/or CV hospitalization was studied using Cox regression.

Results: Based on 415 biomarkers, we identified 2 distinct clusters. Clinical variables associated with cluster 2 were diabetes, impaired renal function, loop diuretics and/or betablockers. In addition, 17 biomarkers were higher expressed in cluster 2 vs. 1. Patients in cluster 2 vs. those in 1 experienced higher rates of CV death/CV hospitalization (adj. HR 1.93, 95% CI 1.12–3.32, p?=?0.017). Complex-network analyses linked these biomarkers to immune system activation, signal transduction cascades, cell interactions and metabolism.

Conclusion: Unsupervised machine-learning algorithms applied to a wide range of biomarkers identified 2 HFpEF clusters with different CV phenotypes and outcomes. The identified pathways may provide a basis for future research.
  • Clinical significance
  • More insight is obtained in the mechanisms related to poor outcome in HFpEF patients since it was demonstrated that biomarkers associated with the high-risk cluster were related to the immune system, signal transduction cascades, cell interactions and metabolism

  • Biomarkers (and pathways) identified in this study may help select high-risk HFpEF patients which could be helpful for the inclusion/exclusion of patients in future trials.

  • Our findings may be the basis of investigating therapies specifically targeting these pathways and the potential use of corresponding markers potentially identifying patients with distinct mechanistic bioprofiles most likely to respond to the selected mechanistically targeted therapies.

  相似文献   

6.
Abstract

Nanoemulsions (NE) are employed as carrier systems of lipophilic active compounds that have low bioavailability and need to be protected from the environment; such as curcumin. In this study, enzymatically prepared monoacylglycerides (MAG) and diacylglycerides (DAG) structured with three bioactive lipids: conjugated linoleic acid (CLA), medium chain fatty acids (MCFA), and ω-3 fatty acids (ω-3?FA). The highest amounts of MAG and DAG containing ω-3 (68.8%) were obtained at 75?°C, 3:1 substrate molar ratios (SMR), 15% of Novozyme 435 and 400?rpm for 90?min. MAG and DAG containing CLA (96.84%) were successfully produced at 40?°C, 1:1 w/w, 15% of lipase RMLM and 400?rpm, for 60?min. Finally, MCFA (95.16%) were prepared at 50?°C with a substrates ratio of 1:1 w/w, 5% of Novozyme 435, and 300?rpm for 30?min. Seven nanoemulsions were formulated using: MAG-ω-3, DAG-ω-3, MAG-CLA, and DAG-CLA individually, as well as reaction mixtures containing MAG and DAG, and MCFA. All exhibited desirable characteristics of average particle size (d?<?200?nm), polydispersity index (PDI; <0.2) and zeta potential (≈?30?mV) and in most cases, the NE maintained their physical properties for up to 5 weeks. It was also determined that when using the reaction mixture containing a high percentage of MAG and DAG of each lipid, the resulting NE exhibited better performance.
  • Practical applications
  • Nanoemulsions are a new and novel carrier for the transportation of bioactive compounds that can be affected during digestion. Then, the use of the enzyme-catalysed synthesis of structured lipids as emulsifiers is an alternative for increasing the bioavailability of compounds such as curcumin.

  相似文献   

7.
Abstract

We have developed an improved and effective method to immobilize lipase on hydrophobic polyurethane foam (PUF) with different modifications. PUF was treated with hydrochloric acid to increase the active sites and then the active carboxyl groups and amino groups were exposed. Enzyme activity of lipase immobilized on PUF-HCL (8000?U/g) was 50% higher than that of lipase immobilized on PUF (5300?U/g). There is an increase in the activity of the immobilized lipase on AA/PEI-modified support (115,000?U/g), a 2.17-fold increase compared to lipase immobilized on the native support was observed. The activity of immobilized lipases was dependent on the PEI molecular weight, with best results from enzyme immobilized on PUF-HCL-AA/PEI (MW 70,000?Da, 12,800?U/g)), which was 2.41 times higher compared to that of the same enzyme immobilized on PUF. These results suggest that the activity of immobilized lipase is influenced by the support surface properties, and a moderate support surface micro-environment is crucial for improving enzyme activity. Finally, the immobilized lipase was used for the production of vitamin A palmitate. The immobilized lipase can be reused for up to 18 times with a conversion rate above 90% for 12?h in a 3?L bioreactor.
  • Research highlights
  • An efficient immobilization protocol on polyurethane foam was developed

  • Polyethyleneimine and acetic acid were used to regulate the micro-environment concurrently

  • The activity of lipase immobilized on PUF-HCL-AA/PEI was improved by 2.41 times

  • Immobilized lipase exhibited excellent operational stability for vitamin A palmitate synthesis

  相似文献   

8.
Purpose

Many consumers are transitioning away from single-use plastic products and turning to reusable alternatives. Oftentimes, this change is being made with the assumption that these alternatives have fewer environmental impacts; however, reusable products are frequently made from more environmentally intensive materials and have use phase impacts. This study used LCA to examine the GWP, water consumption, and primary nonrenewable energy use associated with reusable alternatives for single-use plastic kitchenware products and determined environmental payback periods.

Methods

The environmental impacts for each reusable alternative are calculated on the functional units of 1 use, 1 year (5 uses/week), and 5 years (5 uses/week). Payback periods are calculated for each reusable alternative and defined as the number of times a consumer must reuse an alternative in order for the environmental impact per use to be equivalent to the environmental impact for the single-use product. The research explored the sensitivity of the results to different consumer washing and reuse behaviors, as well as local conditions such as overall transportation distances and the carbon intensity of different electricity grids. Product types studied included straws (4 reusable, 2 single-use), sandwich storage (2 reusable, 3 single-use), coffee cups (3 reusable, 2 single-use), and forks (1 single-use, 3 reusable).

Results and discussion

Environmental impacts associated with the reusable alternatives were highly dependent on the use phase due to dishwashing, making payback period sensitive to washing frequency and method, and for GWP, carbon intensity of the energy grid (used for water heating). For single-use products, the material/manufacturing phase was the largest contributor to overall impacts. It was found that nine of the twelve reusable alternatives were able to breakeven in all three environmental indicators. The coffee cup product type was the only product type to have one reusable alternative, the ceramic mug, and have the shortest payback period for all three impact categories. Both the bamboo straw and beeswax wrap were unable to breakeven in any scenario due to high use phase impacts from manual washing.

Conclusions

The research found that reusable alternatives can payback the environmental impacts of GWP, water consumption, and energy use associated with their more resource intensive materials, but it is dependent on number of uses, consumer behavior, and for GWP, carbon intensity of the energy grid. A key takeaway is that consumer behavior and use patterns influence the ultimate environmental impact of reusable kitchenware products.

Recommendations

Some recommendations for consumers looking to reduce the overall impact of kitchenware products include the following:

  1. 1)

    Not always assuming reusable is the best option.

  2. 2)

    Extending product lifetime.

  3. 3)

    Researching which reusable option has the lowest impact.

  4. 4)

    Following best practice washing behaviors.

  5. 5)

    Not washing products after every use.

  6. 6)

    Advocating for integration of renewables into the local energy grid.

  7. 7)

    Reducing consumption of these product types (reusable or single-use).

  相似文献   

9.
Abstract

Nucleic Acids in Ripening of Castor Bean Endosperm. - I. Quantitative and Qualitative Changes of total RNA. — The ripe Castor Bean seed endosperm (Ricinus Communis var. Sanguinea) has a very low level of nucleic acids and particularly of ribosomal RNA. However, they rapidly increase during the germination of the seed (S. Cocucci et al., Acc. Naz. Lincei, 38, 545, 1965).

The behaviour of the nucleic acids, obtained by phenol extraction from Castor Bean seed endosperm at different ripening stages, is the following:

  1. From the moment when the developing seed has reached the maximal fresh weight to the moment of its complete ripening, the RNA content decreases from about 700 μg per seed to about 200 μg.

  2. During the same period the DNA level (about 13–15 μg per seed) remains nearly costant.

  3. Fractionation by sucrose density gradient of the phenol extracted RNA (H. L. Sanger and C. A. Knight, Biochem. Biophys. Reserch Commun., 13, 445, 1963) shows that during the ripening of the seed the high molecular weight RNA decreases much more than the low molecular weight RNA.

  4. Radioactive phosphate injected in the seeds is incorporated in the RNA at all the stages. Fractionation by sucrose density giadient shows that the phosphate is essentially incorporated in low molecular weight RNA and there is pratically no labelling of the heavier RNA after quite a long period (2 hr.).

These data suggest that the decrease of the RNA during the ripening of the seed can be due to a fall in the ability to synthesize high molecular RNA.  相似文献   

10.
Abstract

Select LAB, including Lactobacillus fermentum TISTR 950, Lactobacillus plantarum TISTR 2265 and Lactobacillus casei TISTR 1500 were investigated for their ability to enhance GABA, TPC and the antioxidant activity of perilla seed juice. L. casei TISTR 1500 produced higher GABA and TPC contents and presented higher antioxidant activity than other strains. Furthermore, the optimal fermentation condition to perilla seeds inoculated with L. casei TISTR 1500 to improve the GABA, TPC and antioxidant activity was performed using 33 full factorial design. The final optimal values for perilla fermentation was found at fermentation time of 4.82 days (4 days 19?h 40?min), initial substrate of 5% (w/v) and fermentation temperature of 30.07?°C. Under the optimal fermentation condition, an observed values of GABA, TPC, ABTS, DPPH and FRAP were 71.46 µg/g, 3175.00 µg GAE/g, 1991.40 µg TEAC/g, 9178.29 µg TEAC/g and 7753.34 µg TEAC/g, respectively, which was 3.3, 0.9, 2.9, 10.8 and 10.2 times higher than that of unfermented perilla seeds, and 2.1, 0.8, 0.9, 10 and 9.2 times of fermented perilla seeds before the optimization. These results may provide the foundation to further target in industrial application for the production of plant-based and develop functional perilla seed products containing GABA.
  • Highlights
  • Improved GABA, TPC and antioxidant contents were found using Lactobacillus casei TISTR 1500

  • Full factorial design applied to optimize fermented perilla seeds by lactic acid fermentation

  • The optimized conditions dramatically increased GABA and TPC contents

  相似文献   

11.
AimsOVE26 mice (FVB background), genetically overexpressing calmodulin in pancreatic beta cells, develop early onset type 1 diabetes, leading to progressive diabetic nephropathy (DN), with features of established human DN. The role of gender in characteristics of renal lesions has remained unexplored.MethodsMale and female OVE26 mice were compared to age and sex matched wild-type, nondiabetic FVB mice at ages of 4, 12, 24 and 36 weeks. Nephropathy was examined by measuring urine albumin-to-creatinine ratio, histopathology, expression of pathological markers and immunochemistry in the same cohort of mice.ResultsProgression of diabetic kidney disease was evident first in the OVE26 glomerulus, initially as mesangial matrix expansion at 4 weeks followed by loss of podocytes, glomerular volume expansion and severe albuminuria at 12 weeks. Tubule dilation and initiation of interstitial fibrosis did not become significant until 24 weeks. T-lymphocyte infiltration into the renal parenchyma appeared at 36 weeks. OVE26 female mice developed more advanced DN than male OVE26 mice, such as more severe albuminuria, greater podocyte loss, additional fibrosis and significantly more inflammatory cell infiltration. The female OVE26 mice had lowest level of plasma estradiol in all 36 weeks old mice, as well as renal estrogen receptors.ConclusionsThis demonstration of the role of gender, combined with the detailed characterization of DN progression illustrates the value of OVE26 mice for understanding gender effects on DN and provides the basis for researchers to better select the age and sex of OVE26 mice in future studies of type 1 DN.Research in contextWhat is already known about this subject?
  • •OVE26 mice, genetically overexpressing calmodulin in pancreatic beta cells, develop early onset type 1 diabetes.
  • •OVE26 mice are a widely used and valuable rodent model which develop severe, progressive diabetic nephropathy, with features of established human diabetic nephropathy.
What is the key question?
  • •Does gender play a role in determining characteristics of renal lesions and severity of nephropathy?
What are the new findings?
  • •Female OVE26 mice had more severe albuminuria, greater podocyte loss.
  • •Female OVE26 mice had additional fibrosis and significantly more inflammatory cell infiltration.
  • •Diabetes induced reductions in estradiol levels and renal estrogen receptors may be responsible for the female sensitization to DN in OVE26 mice.
How might this impact on clinical practice in the foreseeable future?
  • •Our findings provide the basis for researchers to better select the age and sex of OVE26 mice in future studies of type 1 DN.
  相似文献   

12.
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Highlights
  • •A detailed investigation of the protein extraction step from FFPE tissue is shown.
  • •Acidification during peptide wash increased peptide recovery of the SP3 method.
  • •LCM of substantia nigra enriched neuron-specific proteins including TH.
  • •>5,600 proteins were quantified using 3000 cells per sample from substantia nigra.
  相似文献   

13.
Purpose

The European Commission is thinking about policy options for the European Environmental Footprint (EF) method and aims for a broad support. The SwitchMed initiative is a programme with the overall objective to facilitate the shift towards sustainable consumption and production in the Southern Mediterranean region. One of the objectives of this initiative, carried out in Egypt, Lebanon, Morocco, and Tunisia, is to facilitate access of companies from this region to the outcomes of the EF Rules pilot phase.

Methods

The project was composed of three consecutive phases: (I) awareness raising; (II) local pilots; and (III) dissemination events. The awareness raising and technical workshop activities were meant to expose national stakeholders to the potential impact of the EF system for the national economies. Next, nine environmental footprint studies for selected product categories (so-called PEF pilot studies) were performed to create local capacity and expertise. These were leather and intermediate paper product for Egypt; two studies on wine and one on intermediate paper product in Lebanon; olive oil for Morocco; and pasta, olive oil, and dairy for Tunisia. The learnings from the pilot studies were shared in national dissemination events and used to formulate recommendations for enabling EF-compliant studies in regions outside of Europe.

Results and discussion

There was high attendance to the awareness events in each country. The pilot studies showed many similarities with the European screening studies, but also important differences in the identification of most relevant impact categories, life cycle stages, and processes (‘hotspots analyses’), e.g. related to the local scarcity of water. Based on their pilot study, the local experts made concrete suggestions for shifting towards more sustainable consumption and production. One of the biggest successes of this project is that a couple of these recommendations have already been taken into account by the companies.

Conclusions and recommendations

In Egypt, Lebanon, and Tunisia, a few local experts with a significant level of LCA expertise could be identified and through this project we managed to create local PEF capacity too. In Morocco, more assistance was needed to finish the pilot study. This project made clear that the current ‘PEF and OEF methods’ have serious drawbacks for regions other than Europe. The rules of the EF method need to be reconsidered in order to enable EF-compliant studies in regions outside of Europe. In short, we recommend:

  1. 1.

    Developing databases with local inventory data for regions outside of Europe;

  2. 2.

    Enlarging access to EF-compliant data by extension of the free access and by facilitation of the availability of conversion tools;

  3. 3.

    Taking the local availability of data into account when setting data quality requirements;

  4. 4.

    Adapting the rules for data collection and quality to allow for more precise adaptations;

  5. 5.

    Including in the PEFCR development, supporting studies for products manufactured outside the EU and/or in a geography with unusual conditions; and

  6. 6.

    Updating existing rules specific for certain product categories regularly.

  相似文献   

14.
This study used molecular dynamics (MD) simulation to investigate the passage of water molecules through a composite graphene/Au nano-nozzle. Our focus was on the degree to which system temperature, extrusion speed, and nozzle diameter affect jet dynamics and the associated transient phenomena. Our findings show that high pressure and spatial confinement cause the nanojet from a small nozzle diameter (1.0?nm) to bend and twist, whereas the jets from a nozzle with a diameter of 1.5?nm present columns of greater stability. At 100?K, the H2O nanojet froze at the outlet of the nozzle in the form of condensed icicles. At 500?K, the H2O nanojet formed a loose spray and gaseous clusters. High extrusion speed of 55.824?m/s produced recirculating flow downstream from the nanojet with the appearance of an erupting volcano, which further prompted the jet column to thicken. Lower extrusion speeds produced jets with flow velocity insufficient to overcome the capillary force at the outlet of the nozzle, which subsequently manifests as unstable fluctuations in the flow rate.

  • HIGHLIGHTS
  • Water molecules through a composite graphene/Au nano-nozzle forming a nanojet is investigated.

  • High pressure and spatial confinement cause the nanojet from a small nozzle diameter (≤1.0?nm) to bend and twist.

  • High extrusion speed (≧55.824?m/s) produced recirculating flow downstream from the nanojet.

  • Figure abstract: Schematic of the H2O nano-jet through a nano-nozzle of graphene/Au

  相似文献   

15.
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Highlights
  • •Flow cytometry analysis is used to isolate ASC speck(+) NPC cells.
  • •Proteome analysis of ASC speck(+) NPC cells reveals enriched mitochondrial OxPhos proteins.
  • •OxPhos proteins mediate NLRP3 inflammasome activation through mtROS.
  • •OxPhos proteins, NDUFB8 and ATP5B are correlated with NPC local recurrence.
  相似文献   

16.
Chemical signals known as strigolactones (SLs) were discovered more than 50 years ago as host-derived germination stimulants of parasitic plants in the Orobanchaceae. Strigolactone-responsive germination is an essential adaptation of obligate parasites in this family, which depend upon a host for survival. Several species of obligate parasites, including witchweeds (Striga, Alectra spp.) and broomrapes (Orobanche, Phelipanche spp.), are highly destructive agricultural weeds that pose a significant threat to global food security. Understanding how parasites sense SLs and other host-derived stimulants will catalyze the development of innovative chemical and biological control methods. This review synthesizes the recent discoveries of strigolactone receptors in parasitic Orobanchaceae, their signaling mechanism, and key steps in their evolution.

A family of receptors that evolved in the Orobanchaceae family enable seeds of parasitic plants to sense strigolactones from a nearby host root and germinate.

Advances
  • Strigolactone perception by parasite seed is mediated by a clade of neofunctionalized KAI2d proteins that evolved from a receptor that mediates karrikin responses in other plants.
  • KAI2d proteins use a similar mechanism to perceive SLs as D14, which mediates growth responses to SLs in nonparasites, but activate different signaling pathways.
  • Crystal structure analyses and chemical probes reveal features of KAI2d ligand-binding pockets that contribute to their specificity.
  相似文献   

17.
Abstract

GROWTH OF PERICARP, SEED, ENDOSPERM, AND EMBRYO IN PRUNUS AMYGDALUS STOKES. — The fruits of an almond-tree growing at Bari were collected weekly from February 22nd to July 11th and on August 16th 1960. The material was kept in fixative; the growth of the various organs was studied both from a morphological and a quantitative point of view. Special attention was given to growth of the endosperm, especially during the nuclear stage and at the beginning of cellularisation (Figg. 1-14), and to the developement of the embryo until it reaches the « heart-shaped » stage (Figg. 15–22). From a quantitative point of view, the volume and main diameters of pericarp and seed, and whenever possible endosperm and embryo, were measured for each fruit. Most of the data are given in Tables I to V and Figg. 23 and 24.

If reference is made to the 3 phases of fruit growth established for other species (notably peaches and cherries), the main conclusions are that:
  1. phase I (growth of pericarp, testa and nucellus) is clearly recognisable; it ends after the micropylar portion of the endosperm has become cellular and the embryo heart shaped;

  2. phase II is also present: during this phase most of the growth of endosperm and embryo takes place; while the seed has reached its definite size at the end of phase I, the pericarp undergoes a period of greatly reduced growth;

  3. two weeks after the beginning of phase II the pericarp seems to resume growth just for a very short period, judging at least by the weekly values of the ratio pericarp volume to seed volume (see Fig. 23); this seems to indicate the existence of a new phase, that is phase III, which in fleshy fruits of the genus Prunus corresponds to a much longer and important process of pericarp growth than in the almond;

  4. as in the peaches and cherries therefore a crisis in pericarp growth occurs during the period of maximum rate of growth of the cellular endosperm and embryo;

  5. the sequence: cellularisation of the endosperm, growth of endosperm and embryo, ceasing of seed growth, and reduction in pericarp growth is very clear, particularly if we take into account growth in length rather than in volume; both morphological and quantitative data would indicate the importance of the endosperm not only for the beginning of embryo development, but also for the control of pericarp growth.

  相似文献   

18.
The quantitative determination of sarcosine is of great importance in clinical chemistry, food and fermentation industries. Elevated sarcosine levels are associated with Alzheimer, dementia, prostate cancer, colorectal cancer, stomach cancer and sarcosinemia. This review summarizes the various methods for quantitative analysis of sarcosine with special emphasis on various strategies of biosensors and their analytical performance. The current bio sensing methods have overcome the drawbacks of conventional methods. Sarcosine biosensors work optimally at pH 7.0 to 8.0 in the linear range of 0.1 to 100?μM within 2 to 17?s and between 25 and 37?°C, within a limit of detection (LOD) between 0.008 and 500?mM. The formulated biosensors can be reused within a stability period of 3–180?days. Future research could be focused to modify existing sarcosine biosensors, leading to simple, reliable, and economical sensors ideally suited for point-of-care treatment.
  • Clinical significance
  • Elevated sarcosine levels are associated with prostate and colorectal cancer, Alzheimer, dementia, stomach cancer and sarcosinemia.

  • Quantitative determination of sarcosine is of great importance in clinical chemistry as well as food and fermentation industries.

  • Attempts made in development of sarcosine biosensors have been reviewed with their advantages and disadvantages, so that scientist and clinicians can improvise the methods of developing more potent sarcosine biosensor applicable in multitudinous fields.

  • This is the first comprehensive review which compares the various immobilization methods, sensing principles, strategies used in biosensors and their analytical performance in detail.

  相似文献   

19.
Ecological risk actually refers to two separate things. First, risk to the environment as a result of human activity. Contaminated sites are an example. Second, risk to the biota—flora, fauna, and people—as a result of environmental hazards. Geophysical risk arising from natural hazards is an example. Risk is a combination of likelihoods and consequences. This article examines methods used to quantify the consequences. At the general level, such methods are linked to the methods used to quantify the likelihoods and thus to quantify the risks. It is possible to use the existing frameworks of risk management, health risk assessment, and ecological risk analysis to develop a risk management framework that is suitable for ecological risk assessment. The framework consists of the following steps:
  1. Determine concernsby using risk assessment techniques for various scenarios.

  2. Identify the consequences by systematically identifying hazards.

  3. Undertake calculations by using relevant models.

  4. Evaluate certainties, uncertainties, and probabilities involved in the calculations of the vulnerability and of the exposure.

  5. Compare with criteriato assess the need for further action.

  6. Determine and act on options to control, mitigate, and adapt to the risk.

  7. Communicatethe results to those who need to know.

  相似文献   

20.
  1. Download : Download high-res image (175KB)
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Highlights
  • •Several proteins were found to be unique to each male type.
  • •Expression levels of seven proteins trended downward in teratospermic males.
  • •Several proteins were related to sperm motility and subsequent oocyte binding.
  相似文献   

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