Application of fractional factorial design for green synthesis of cyano-modified silica nanoparticles: Chemometrics and multifarious response optimization

Cyano-functionalized spherical silica nanoparticles (SNPs) were synthesized via Stöber method. A 2?^k-p_IV–fractional factorial design (2^k-p_IV–FFD) was used to smartly prepare monodispersed evenly distributed SNPs. Six factors were considered; concentrations of tetraethylorthosilicate (TEOS), 3-Cyanopropyltriethoxysilane (CPTS), water, and ammonia, reaction time (RT) and stirring time (ST). Two responses; particle size (PS, measured by SEM) and particle-size distribution (PSD, calculated as standard deviation, ±SD) were measured. Control charts were used to decide on impacts of linear and two-way interactions on both responses. Derringer’s function was used to consolidate these multifarious responses into a uniform execution characteristic. Both screening and optimization were always accompanied by ANOVA testing at a 95.0% confidence interval (CI). The ideal synthetic conditions were obtained from the composite desirability plots. Cyano-functionalized SNPs with an average PS of 474.04?±?86.71?nm were produced. Raman spectroscopy and FTIR were used to confirm the functionalization process. Thermogravimetric analysis (TGA) was used to evaluate the thermal behavior of synthesized particles.     

Impact of sodium chloride on Escherichia coli O157:H7 and Staphylococcus aureus analysed using transmission electron microscopy

Abundant literature information is available on sodium chloride, NaCl, as an antimicrobial and a preservative, however, information on NaCl effects on bacterial cell morphology is lacking. The effect of NaCl, on Escherichia coli O157:H7 and Staphylococcus aureus cells individually grown in a laboratory medium was examined using transmission electron microscopy (TEM). Cultures were grown in brain heart infusion (BHI) broth containing dissolved 0%, 5%, or 10% (w/v) commercially obtained fine (FN) and extra coarse (EC) grade granular NaCl. The pathogens were incubated at 35 degrees C for 12 and 24 h. Then, a mixture of five strains of each pathogen per treatment was prepared. Samples were centrifuged, pellets collected, fixed immediately with glutaraldehyde, and prepared for TEM examination. Cells morphology on TEM micrographs verified that the magnitude of morphological damage to E. coli O157:H7 cells was significantly greater than that of S. aureus cells. More cell injury occurred as NaCl concentration increased from 5% to 10%. Generally, S. aureus maintained its cellular structure and no severe cell wall or plasma membrane damage and/or shrinkage was observed. At 10% NaCl, the damage to E. coli O157:H7 cells was extensive, and the pathogen seemed to have lost its cellular integrity. Although NaCl affected the morphology of E. coli O157:H7 and S. aureus, the coarse grade of NaCl seemed to have a milder effect with respect to cell damage, especially on S. aureus. The 24 h-old cultures were more susceptible to NaCl treatment compared to the 12 h-old cells. Thus, the age of the cells has an impact on their resistance to salt--the environmental stressor.     

Dictatorial Transaction Processing: Atomic Commitment Without Veto Right

The current standard in governing distributed transaction termination is the so-called Two-Phase Commit protocol (2PC). The first phase of 2PC is a voting phase, where the participants in the transaction are given an ultimate right to abort that transaction. Giving up that veto right from all participants reduces the overhead of the atomic commitment protocol but also imposes some restrictions on the concurrency control and recovery protocols employed by the participants in the transaction.This paper gives, for the first time, a precise abstract specification of the Dictatorial Atomic Commitment (DAC) problem, resulting from removing veto rights from the traditional Atomic Commitment (AC) problem. We characterize transactional systems that are compatible with that specification in terms of necessary and sufficient conditions on concurrency control and recovery protocols, and discuss the practical impacts of those conditions. From this study, we capitalize on existing protocols that solve the DAC problem, and propose a new protocol that broadens the applicability of dictatorial transaction processing in order to meet the requirements of today's distributed environments. We point out interesting performance tradeoffs, and describe the implementation of our protocol in the context of current transactional standards, initially designed with 2PC in mind.     

Inter-Calibration Between Plasma Instruments Onboard DEMETER

The in-situ measurements of the ionospheric plasma that we use come from two instruments of the scientific payload of the satellite DEMETER; the plasma analyser IAP （Instrument d＇analyse du plasma） and the Langmuir probe ISL （Instrument Sonde de Langmuir）. DEMETER is a micro-satellite realized by the CNES（Centre National d＇Etudes Spatiales, France） with a principal objective to seek a possible influence of the seismic activity on the electromagnetic waves in the ionosphere and on the ionospheric plasma. The satellite was placed on June 29, 2004, in a circular and quasi helio-synchronous orbit at -710 km altitude. The experiments function primarily at mid-latitudes （from ＋60° to -60°）. The IAP data were analysed to deduce the ion population （densities of the dominant ions, i.e. generally O^＋, H^＋ and He^＋） therefore the total ion density. The use of data IAP thus requires some precaution to make sure that the electric equilibrium conditions of the satellite, such as the satellite potential （Фsat）, are obtained during the treatment of routine, does not induce an error of measurement. When this potential is negative, the minority light ions H^＋ and He^＋ can be measured in a reliable way when their proportion is above 3% to 5% of that of O^＋. The critical limitation is： under certain conditions, the satellite potential becomes positive and reach a value about -0.5 V so that it becomes impossible to measure H^＋ ions. This is likely to involve a significant error on the composition and the density of the plasma. Therefore we carried out a calibration to estimate the missing density. The ISL experiment （Langmuir probe） provided the collected current/polarized tension characteristics of a cylindrical probe from which both electron density Ne and temperature Te were obtained. In some situations it is necessary to examine the accuracy of the electron density using another technique, for instance the high frequency （HF） spectrogram, provided by ICE （instrument champ     

Antimicrobial Activity of Essential Oils Isolated from Phlomis crinita Cav. ssp. mauritanica Munby

The essential oil extracted from the leaves and flowers of Phlomis crinita Cav. ssp. mauritanica Munby were obtained by steam distillation and analyzed by gas chromatography coupled with mass spectrometry. The major constituents of flower oil were β-caryophyllene (58.1%) and germacrene D (35.1%). This oil inhibited the growth of Staphylococcus aureus, Enterococcus faecalis, and Salmonella typhimurium with minimal inhibition concentrations (MIC) varying between 39 and 625 μg/ml. The essential oil obtained from the leaves was mainly composed of trans-caryophyllene (40.8%) and germacrene D (39.1%) and exhibited an antimicrobial profile against the same strains mentioned above with MIC between 156 μg/ml and 2.5 mg/ml.     

Survival of Salmonella and Escherichia coli O157:H7 in chorizos

Mexican-style raw meat sausages (chorizos) are not regulated in California when they are produced in small ethnic food markets. These sausages are sold uncooked, but their formulation imparts a color that may lead the consumer to assume that they are already cooked, and thus the chorizos may sometimes be eaten without proper cooking. If pathogens are present in such cases, illness may result. Survival of Salmonella and Escherichia coli O157:H7 in chorizos was evaluated under different storage conditions selected based on an initial survey of uninspected chorizos in California. Chorizos were formulated with five different initial water activity (aw) values (0.85, 0.90, 0.93, 0.95, and 0.97), stored under four conditions (refrigeration at 6 to 8 degrees C, room temperature at 24 to 26 degrees C, under a hood at 24 to 26 degrees C with forced air circulation, and incubation at 30 to 31 degrees C with convective air circulation), and sampled after 1, 2, 4, and 7 days. The initial pH was 4.8 and remained near 5.0 from day 1 of the sampling period. Two separate studies of packs inoculated with five-strain cocktails of Salmonella and of E. coli O157:H7 were performed twice for each initial aw. The three lowest aw values (0.85, 0.90, and 0.93) and the incubation and hood storage conditions were more effective (P < or = 0.05) at reducing the target pathogen levels in chorizos than were the two highest aw values (0.95 and 0.97) and the refrigeration storage condition, regardless of storage time. These results provide a scientific basis for guidelines given to producers of uninspected chorizo and should reduce the probability of foodborne illness associated with these products.     

Effect of Geobacter sulfurreducens on the microbial corrosion of mild steel, ferritic and austenitic stainless steels

The influence of Geobacter sulfurreducens was tested on the anaerobic corrosion of four different steels: mild steel 1145, ferritic steel 403 and austenitic steels 304L and 316L. Within a few hours, the presence of cells induced a free potential (E_oc) ennoblement around +0.3 V on 1145 mild steel, 403 ferritic steel and 304L austenitic steels and slightly less on 316L. The kinetics of E_oc ennoblement depended on the amount of bacteria in the inoculum, but the final potential value depended essentially on the nature of the material. This effect was due to the capacity of G. sulfurreducens to create a direct cathodic reaction on steel surfaces, extracting the electrons directly from material. The presence of bacterial cells modified the corrosion features of mild steel and ferritic steel, so that corrosion attacks were gathered in determined zones of the surface. Local corrosion was significantly enhanced on ferritic steel. Potential ennoblement was not sufficient to induce corrosion on austenitic steels. In contrast G. sulfurreducens delayed the occurrence of pitting on 304L steel because of its capability to oxidize acetate at high potential values. The electrochemical behaviour of 304L steel was not affected by the concentration of soluble electron donor (acetate, 1–10 mM) or the amount of planktonic cells; it was directly linked to the biofilm coverage. After polarization pitting curves had been recorded, microscopic observations showed that pits propagated only in the surface zones where cell settlement was the densest. The study evidenced that Geobacter sulfurreducens can control the electrochemical behaviour of steels in complex ways that can lead to severe corrosion. As Geobacteraceae are ubiquitous species in sediments and soils they should now be considered as possible crucial actors in the microbial corrosion of buried equipment.     

Camel milk composition by breed,season, publication year,and country: A global systematic review,meta-analysis,and meta-regression

Camel milk consists of an essential macro/micronutrient for human nutrition in the arid and urban regions. This review study aimed to use meta-analysis statistical techniques for assessment and correction of publication bias, exploration of heterogeneity between studies, and detailed assessment of the effect of a comprehensive set of moderators including breed, season, country, year of publication, and the interaction between composition elements. This could provide a single synthesis of the camel milk composition to warrant strong generalizability of results, examine variability between available studies, and analyze differences in camel milk composition among different exposures. Such a finding will aid future researchers and health professionals in acquiring a more precise understanding of camel milk composition and drawing more clinical implications. Six searching databases and bibliographic were used including PubMed/MEDLINE, ScienceDirect, Springer, EBSCOhost, Scopus, and Web of Science from January 1980 to December 2021. The DerSimonian–Laird estimator was used to create the current random-effects meta-analysis. This systematic review and meta-analysis included a total of 7298 camel milk samples from 23 countries. This review comprises 79 studies published in the English language on or after 1980, including a subgroup of 117 analyses consisting of seasons, sub-breeds, and countries. The contents of macro/micronutrients in camel milk were identified as follows: protein, 3.17%; fat, 3.47%; lactose, 4.28%; ash, 0.78%; and total solids, 11.31%; calcium, 112.93 mg/100 g; iron, 0.45 mg/100 g; potassium, 116.13 mg/100 g; magnesium, 9.65 mg/100 g; sodium, 53.10 mg/100 g; zinc, 1.68 mg/100 g; vitamin C, 5.38 mg/100 g; vitamin A, 0.36 mg/100 g; vitamin B₁,0.05 mg/100 g; vitamin B₂, 0.13 mg/100 g; vitamin B₃, 0.51 mg/100 g; vitamin B₆, 0.09 mg/100 g; and vitamin B₁₂, 0.0039 mg/100 g. Our meta-regression analysis found that fat and total solids were statistically significant moderators of protein; moreover, total solids content is a statistically significant moderator of fat. Discrepancies observed in camel milk profiles are dependent upon several factors, including number of included studies, number of samples, different analytical techniques, feeding patterns, camel's breeds, geographical locations, and seasonal variations.     

La-doped NaTaO3 perovskite nanocrystals supported with α-Fe2O3 for sustainable visible-light-driven elimination of ciprofloxacin in water

To date, the emergence of antibiotic waste in water has become an important issue for humans and other living organisms. The spread of such waste will influence human health and the effectiveness of such antibiotics. Accordingly, several research approaches are offered for the clean and safe elimination of such waste. Herein, we present a facile synthesis of visible-light-activated La-doped NaTaO₃ perovskite nanocrystals (LNTO) supported with small amounts (1.0–4.0 wt %) of Fe₂O₃ (FO) nanoparticles to produce x%FO@LNTO nanocomposites. These FO@LNTO samples exhibited a mesostructured crystalline surface with a high surface area (200–230 m² g^?1). Additionally, the loading of FO nanoparticles onto LNTO resulted in a broad visible-light absorption and reduction of the bandgap (E_g) to 2.35 eV compared to 4.40 eV for the parent LNTO. The produced nanocomposite was tested for the photodegradation of ciprofloxacin (CIP) as an emerging probe of antibiotic waste in water. The 3% FO@LNTO displayed a total elimination of 10 ppm CIP after 90 min of visible-light illumination with sustainable recyclability. This fascinating action of FO@LNTO is referred to as the formation of a close heterojunction between FO and LNTO that decreases the E_g value and enhances photocharge separation. This work implies the use of perovskite-based photocatalysts for reasonable elimination of antibiotic waste in water.