Free Samples Research Articles

Anion-Assisted Delivery of Multivalent Cations to Inert Electrodes.

To understand and control key electrochemical processes-metal plating, corrosion, intercalation, etc.-requires molecular-scale details of the active species at electrochemical interfaces and their mechanisms for desolvation from the electrolyte. Using free energy sampling techniques we reveal the interfacial speciation of divalent cations in ether-based electrolytes and mechanisms for their delivery to an inert graphene electrode interface. Surprisingly, we find that anion solvophobicity drives a high population of anion-containing species to the interface that facilitate the delivery of divalent cations, even to negatively charged electrodes. Our simulations indicate that cation desolvation is greatly facilitated by cation-anion coupling. We propose anion solvophobicity as a molecular-level descriptor for rational design of electrolytes with increased efficiency for electrochemical processes limited by multivalent cation desolvation.

Residual stress reduction of LPBF-processed CM247LC samples via multi laser beam strategies

Based on SLM parameters from previous works, which guarantee fully dense and crack free CM247LC samples, multi laser beam strategies have been pursued to reduce residual stresses or rather distortion during LPBF processing. By using a second post heating and non-melting laser source with a defocused laser beam and lateral offset, cantilever distortion is reduced more than 7.5%, compared to the reference. Based on pre-tests with 9 different offset parameters, the optimum offset has been identified. Also, an upper limit for the laser power of 65 W is identified for the second heat laser beam with a spot diameter of 380 μm, to avoid re-melting and creating new defects. A theoretical “two bar model,” to explain the residual stress behavior and reduction with multi laser beam offset strategy during the LPBF process, is presented. Furthermore, re-melting cracks, defects, and microstructure are analyzed in conjunction with the second defocused offset laser, in case of a 200 W laser power, an increased scan speed of 1300 mms/s, and a reduced hatch distance. Secondary electron signal (SE) images of re-melting cracks are analyzed and compared to SE-image of hot cracks (solidification cracks). Based on electron backscatter diffraction (EBSD), the results of the microstructure from the last mentioned multi laser beam approach, which creates re-melting cracks, are presented and analyzed.

Prediction of higher heating value (HHV) based on the structural composition for biomass

Higher heating values (HHV), as well as carbon, hydrogen, sulphur, nitrogen, chlorine, ash, lignin and extractives contents have been experimentally determined for initial, extractives free, extractives and lignin free samples of pine, alder and rape straw.HHV of cellulose, hemicellulose, lignin, extractives for softwood, hardwood and plants are recommended. Systematization and analysis of 30 equations for prediction HHV of the biomass based on the structural composition were carried out. For 20 equations, a relationship between the coefficients correcting for the contributions of lignin and extractives was established.Two equations for predicting HHV of the biomass based on the lignin and carbon contents with an error no worse than 2.7 % are proposed.

In situ formation of Si3N4–SiC nanocomposites through polymer-derived SiAlCN ceramics and spark plasma sintering

In this paper, fully dense Si3N4/SiC nano-composites were fabricated through polymer-derived ceramics (PDCs) method and spark plasma sintering technique. Polymer-derived SiAlCN ceramic was synthesized by using polysilazane as preceramic precursor, aluminum tri-sec-butoxide as Al source. Then Si3N4/SiC composites with nanometer sized Si3N4 and SiC phases were formed spontaneously during spark plasma sintering through in-situ phase separation of amorphous SiAlCN ceramics. It's found that with the increasement of Al contents, the densification rate was accelerated significantly and serious degradation of Si3N4 phase was avoided by restricting carbothermal reaction. At the same time, Al contained composites show excellent oxidation/corrosion resistance at 1350 °C and 50% H2O - 50% O2 water vapor environment than that of Al free samples. The Si3N4/SiC composites derived from Al contained PDCs overcomes the trade-off between abnormal grain growth and serious degradation of Si3N4 phase, which is a very tough problem for traditional PDC route (without Al) to fabricate Si3N4/SiC composites. For traditional PDC route, (I) if with traditional sintering additives, abnormal grain growth occurs, nano grains cannot be achieved; (II) if without traditional sintering additives, serious degradation of Si3N4 occurs, Si3N4 and SiC composite cannot be formed. Therefore, Al contained polymer-derived ceramics route opens a promising avenue to fabricate Si3N4/SiC nano-composites with fine grain size, uniform microstructure and excellent oxidation/corrosion resistance.

A quest for the healthy lifestyle and learning experiences in olive oil tourism

ABSTRACT Olive oil tourism is an emerging form of tourism and it has recently garnered attention owing to health-related benefits of olive oil. Prior research has investigated olive oil tourists’ characteristics, their motivations for olive oil tourism and drivers for satisfaction in the context of traditional markets, such as Spain and Italy. However, there is scant research understanding olive oil tourists’ experiences in emerging markets, such as the US. This void is important to fill as olive oil tourists in emerging markets may be different from those in traditional markets in terms of their knowledge in and consumption of olive oil. Drawing on the experience economy framework, the authors show that education (vs. aesthetics, entertainment, and escapist) experience is more closely related to satisfaction among US olive oil tourists. Olive oil tourism marketers may want to emphasize learning aspects of olive oil tourism via open-house tastings at olive mills, production tours, free sampling of various olive oils and food pairings.

Some machining and handtool properties of tetuya koroi (Albizia odoratissima) wood

The study was conducted to determine the suitability of tetuya koroi (Albizia odoratissima) wood for furniture manufacturing i.e., planing, shaping, boring, mortising, turning, etc machining and handtool property tests of this species grown in south-east Bangladesh.. The evaluation in both machining and handtool property tests was based on the frequency of the defect-free sample. Finishing property was also determined by implementing two types of polishing materials, viz.: carpa and shellac. The defects of the sample were estimated by visual and tactile observation. The percentage of defect free samples was evaluated for each property operation and classified based on five quality grades. The study's findings mainly introduced good working properties, and tetuya koroi wood may be suitable for furniture. All properties exhibited 63 % to 76 % grade 1 and 95 % to 100 % qualified grade. The finishing property of this wood showed good quality as well.

In-situ formation of TiN during the hot-pressing of TiC–AlN ceramics

In this investigation, various amounts of AlN (0, 3.5, and 7 vol%) were added to TiC, and the resulted ceramics were studied in terms of microstructures and mechanical properties. The hot-pressing technique was employed as the sintering process at 2000 °C for 2 h under 35 MPa. Though a relative density of ~ 97% was obtained for the AlN free sample, the composite introduced by 7 vol% AlN reached its full density. The precipitation of carbon from the TiC matrix was proved by both X-ray diffractometry and microstructural observations. The deposited graphite contributed to removing the TiO2 surface impurity over sintering. Moreover, TiO2 reacted with AlN additive, generating in-situ TiN. Such a phase mainly dissolved into the AlN phase, leading to the formation of (Al,Ti)N solid solution. The highest Vickers hardness of 2745 HV0.5kg was attained for the monolithic ceramic, thanks to the lack of AlN as a softer phase. Finally, incorporating 7 vol% AlN increased the flexural strength of TiC by almost 33% as a result of porosity removal and fine-grain, standing at 790 MPa.

The Impact of Formula Industry Marketing on Breastfeeding Rates in Native and Migrant Mothers.

Introduction: Lifelong benefits of breastfeeding are far-reaching. However, optimal breastfeeding practices may be negatively affected by the marketing of different forms of breast milk substitutes. In addition, whether market factors have a different impact on migrants' breastfeeding practices when compared to natives has been poorly investigated. Objectives: Our study's aims are (1) to assess the effect of market factors on breastfeeding discontinuation (any and exclusive), (2) comparing migrant and native women. Methods: A longitudinal study was conducted within baMBINO, a nationwide project on perinatal health among migrant women in Portugal. Our final sample included 1,251 migrants and 1,150 natives recruited between April 2017 and March 2019 in 32 public maternities. Cox regression analysis was performed, adjusting for important confounders, and interactions were tested. Results: Market factors were associated with any and exclusive breastfeeding discontinuation. Participants receiving free formula samples from a health professional were more likely to stop exclusive breastfeeding (adjusted hazard ratios [aHR] = 1.37, 95% confidence intervals [95% CI] = 1.13-1.66, p = 0.002). Reporting exposure to formula discounts was associated with discontinuation of exclusive (aHR = 1.22, 95% CI = 1.09-1.38, p = 0.001) and any breastfeeding (aHR = 1.21, 95% CI = 1.00-1.46, p = 0.046). No interactions were found between being migrant and exposure to market factors. Conclusions: Market factors influence discontinuation of any and exclusive breastfeeding. The impact of marketing does not differ between native and migrant women.

Electrosprayed whey protein nanocarriers containing natural phenolics; thermal and antioxidant properties, release behavior and stability

In this study, a one-step and convenient electrospraying strategy was investigated to encapsulate olive leaf extract (OLE) within whey protein concentrate (WPC) nanoparticles and they were characterized via differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). Furthermore, the release properties, antioxidant activity, thermal/oxidative stability, and color profiles of the nanoparticles were also evaluated. WPC offered good capability in re-ordering into spherical nanoparticles and encapsulating OLE into its amphiphilic core. The DSC results suggested a higher denaturation and glass transition temperature (Tg) of WPC due to an increase in the concentration of phenolics and a reduction in the melting temperature compared with free OLE and WPC samples; the highest and lowest Tg values were corresponding to WPC (at 160 °C) and WPC20OLE500 (at 140 °C), respectively. The coated phenolics were completely and almost uniformly released into the medium of higher pH. The WPC30 sample (30% protein) had the highest free radical inhibition at both OLE levels (45.26 and 46.68%). The WPC30OLE500 with oxidative stability of 43.5 h possessed the highest oxidative stability index. In conclusion, the electrosprayed WPC nanoparticles might be engineered as a promising nanodelivery cargo for promoting the release profile and thermochemical properties of bioactive agents.

New Products

![Figure][1]</img> ZEISS has introduced a compact microscope for digital teaching and routine lab work. ZEISS Primostar 3 is a robust upright light microscope developed for daily work in a classroom or in a lab for tissue and sample examination in histology, cell biology, food, or microbiology, etc. It is designed for long-term use and extreme durability. The unit is simple to operate, so that students and laboratory staff can spend more of their time exploring rather than fiddling with knobs. It is easy to learn, and the setup is quick and convenient with a plug-and-play installation. Users can choose either a 30-W halogen bulb or an energy-saving LED bulb with a stable color temperature and illumination intensity. Or, they can add on the fluorescence tube and turn ZEISS Primostar 3 into an LED fluorescence microscope. ZEISS Primostar 3 offers the advantages of an integrated 8-megapixel microscope camera. With the ZEISS Labscope imaging app, it is easy to connect microscopes in classrooms to each other. Used with Olympus confocal laser scanning microscopes, such as the FLUOVIEW FV3000 system, NoviSight 3D cell analysis software provides images of cell clusters down to the nuclei. The software's True 3D technology uses multiple microplate images to provide accurate morphology data and the ability to quantitatively analyze the effect of medications, including growth suppression and cell-survival rates. A range of parameters can be easily and precisely measured, enabling researchers to count the number of cells that have suppressed growth, proliferated, or died. NoviSight 3D also makes it easy to compare the effects of different medications at various concentrations. Results—including recognition, analysis, and statistics—are displayed on a single screen. Users can view the quantitative data as a scatterplot, heat map, or graph, and click on a point in the graphical display to automatically open the corresponding image. It is easy to switch between 2D and 3D views of the sample, and data are easily exported as CSV or FCS files for further analysis. MitoView Fix 640 is a new far-red fluorescent live-cell mitochondrial stain that retains crisp and specific staining after fixation for downstream immunofluorescence protocols. The nontoxic, cell membrane–permeant dye rapidly accumulates in the mitochondria of live cells and has a reactive group that covalently attaches to proteins inside the mitochondria. This results in stable mitochondria staining that lasts for days in live cultures, is well retained after fixation with formaldehyde or methanol, and withstands permeabilization. Staining with MitoView Fix 640 shows better specificity after fixation as compared to MitoTracker Deep Red and other mitochondrial stains currently available. MitoView Fix 640 is ideal for the Cy5 channel and is offered in 1 or 10 units of 50 μg. ibidi's top-selling, all-in-one 8-well chamber slide, the µ-Slide 8 Well, now has extra-high individual walls to keep cross-contamination between wells as low as possible when performing high-resolution, cost-effective cell-culture experiments. With its thin ibidi Polymer Coverslip bottom, the µ-Slide 8 Well high allows for excellent cell adhesion onto the tissue culture–treated surface. In addition, it has the highest optical quality and is ideally suited for a variety of microscopic techniques, such as widefield fluorescence, confocal microscopy, and differential interference contrast (DIC). For scientists who perform special microscopic applications, such as total internal reflection fluorescence (TIRF) and superresolution microscopy, ibidi has created the µ-Slide 8 Well high Glass Bottom with a #1.5H D 263 M Schott glass. It is also available as a sticky-Slide 8 Well high without any bottom, enabling the researcher to mount any chosen substrate. The entire µ-Slide 8 Well high family is ideal for experiments with small cell numbers and low reagent volumes. Scientists who would like to test one of the µ-Slide 8 Well high variations with their own experiments can request free samples. The HoloStim-3D is an all-optical solution that facilitates simultaneous imaging and photostimulation of hundreds of individual cells in 3D, enabling novel insights into the roles of neural subtypes and individual neurons in brain circuits and behavior. A compact module, the HoloStim-3D seamlessly integrates with Scientifica's HyperScope, a multiphoton imaging system, creating a fully integrated spatial light modulator (SLM)-based photostimulation solution. With its industry-leading resolution, cell bodies and subcellular structures can be specifically targeted with less off-target activation than other systems on the market, generating cleaner, more accurate data. HyperScope and HoloStim-3D allow different imaging and stimulation wavelengths to freely combine for excitation and imaging of target cells expressing different opsins. Full integration with ScanImage software means that the HoloStim-3D is easier to adopt than ever before, making it an excellent choice for researchers who want to start experimenting right away. [1]: pending:yes

Kinetic Modeling for Photo-Assisted Penicillin G Degradation of (Mn0.5Zn0.5)[CdxFe2-x]O4 (x ≤ 0.05) Nanospinel Ferrites.

Penicillin G is an old and widely used antibiotic. Its persistence in the environment started to appear in many environmental samples and food chains. The removal of these emerging pollutants has been a challenging task for scientists in the last decades. The photocatalytic properties of Cd2+ doped Manganese- Zinc NSFs with chemical formula (Mn0.5Zn0.5)[CdxFe2−x]O4 (0.0 ≤ x ≤ 0.05) NSFs are herein evaluated. The Manganese- Zinc N.S.F.s nanomaterials were deeply characterized, utilizing UV-Vis (reflectance) spectroscopy, X-ray diffraction, N2 adsorption isotherm measurements, and S.E.M., SEM-EDX mapping, and T.E.M. The Kinetic model for the photodegradation of penicillin G (as a model molecule) is investigated using visible light as a source of energy. The kinetic study shows that our results fit well with the modified pseudo-first-order model. The Pen G degradation are 88.73%, 66.65%, 44.70%, 37.62% and 24.68% for x = 0.5, 0.4, 0.3, 0.2 and 0.1, respectively, against 14.68% for the free Cd spinel sample. The pseudo-rate constant is bandgap dependent. From the intra-diffusion rate constant (Kd), we developed an intra-diffusion time (τ) model, which decreases exponentially as a function of (x) and mainly shows the existence of three different domains versus cadmium coordination in spinel ferrite samples. Hence, Cadmium’s presence generates spontaneous polarization with a strong opportunity to monitor the charge separation and then open the route to a new generation of “assisted” photocatalysts under visible light.

Monte Carlo approach for calculation of mass energy absorption coefficients of some amino acids

This study offers a Monte Carlo alternative for computing mass energy absorption coefficients of any material through calculation of photon energy deposited per mass of the sample and the energy flux obtained inside a sample volume. This approach is applied in this study to evaluate mass energy absorption coefficients of some amino acids found in human body at twenty-eight different photon energies between 10 keV and 20 MeV. The simulations involved a pencil beam source modeled to emit a parallel beam of mono-energetic photons toward a 1 mean free path thick sample of rectangular parallelepiped geometry. All the components in the problem geometry were surrounded by a 100 cm vacuum sphere to avoid any interactions in materials other than the absorber itself. The results computed using the Monte Carlo radiation transport packages MCNP6.2 and GAMOS5.1 were checked against the theoretical values available from the tables of XMUDAT database. These comparisons indicate very good agreement and support the conclusion that Monte Carlo technique utilized in this fashion may be used as a computational tool for determining the mass energy absorption coefficients of any material whose data are not available in the literature.

Models for predicting the suction of heaving compacted soils using geotechnical properties

Soil suction is the major property that controls the behaviour of unsaturated soils. Suction estimation is challenging both in the lab and the field. Various instruments to measure the suction have been developed with the recent technological advancements. Nonetheless, there are still limitations in regards to the reliability, cost, suction range, accessibility, scope of activity, and appropriateness for use either within the field or lab settings. The filter paper method is probably the simplest procedure to measure the suction for the entire range both in the field and the lab. Nevertheless, the procedure takes time. To alleviate the requirement for conducting this test, it becomes imperative to develop mathematical predictive models for soil suction. In this study, a detailed survey was carried out across the Free State province, South Africa, and sampling points identified. Samples were tested for their geotechnical properties. The influence of the geotechnical properties on soil suction was studied. Multivariate regression analysis was carried out utilizing MINITAB 18 program to develop the mathematical predictive models.

Electrical and Mechanical Effects of Carbon Powder in F and C Class Fly Ash Reinforced Mortars

This study was carried out to investigate the effects of carbon powder on the electrical conductivity and mechanical properties of fly ash reinforced mortars used as mineral additives. Samples were created by replacing CEM I 42.5 R cement, water and Cen standard sand with 0.5%, 1%, 3% carbon powder by weight. Class F and Class C fly ash were added separately at the rate of 10% and 20% by weight of cement to the formed carbon dust series. 20 different series were created with the reference sample. Electrical resistivity measurements were made to the oven dry and natural humid conditions of the samples that completed their 7,28 and 56 days curing period. The physical properties of the samples were determined and bending and compressive strength tests were made. The results obtained were evaluated and it was observed that with the increase of the carbon dust ratio compared to the reference sample, the electrical conductivity ratio increased, but the conductivity decreased depending on the time. It has been observed that the F class fly ash combination series are more conductive than the C class combination series. It was observed that the compressive and tensile strength values ​​of F and C class fly ash carbon dust free samples increased with time. Carbon dust has been shown to increase compressive strength in fly ashless series. There was an increase in the 56th day reading in the tensile strength. It was observed that F class increased tensile and compressive strength in fly ash and carbon dust combination series. Keywords: Carbon dust, F class fly ash, C class fly ash, Electrical conductivity. DOI: 10.7176/CER/13-2-02 Publication date: April 30 th 2021

Optical Excitations with Electron Beams: ChallengesandOpportunities.

Free electron beams such as those employed in electron microscopes have evolved into powerful tools to investigate photonic nanostructures with an unrivaled combination of spatial and spectral precision through the analysis of electron energy losses and cathodoluminescence light emission. In combination with ultrafast optics, the emerging field of ultrafast electron microscopy utilizes synchronized femtosecond electron and light pulses that are aimed at the sampled structures, holding the promise to bring simultaneous sub-Å–sub-fs–sub-meV space–time–energy resolution to the study of material and optical-field dynamics. In addition, these advances enable the manipulation of the wave function of individual free electrons in unprecedented ways, opening sound prospects to probe and control quantum excitations at the nanoscale. Here, we provide an overview of photonics research based on free electrons, supplemented by original theoretical insights and discussion of several stimulating challenges and opportunities. In particular, we show that the excitation probability by a single electron is independent of its wave function, apart from a classical average over the transverse beam density profile, whereas the probability for two or more modulated electrons depends on their relative spatial arrangement, thus reflecting the quantum nature of their interactions. We derive first-principles analytical expressions that embody these results and have general validity for arbitrarily shaped electrons and any type of electron–sample interaction. We conclude with some perspectives on various exciting directions that include disruptive approaches to noninvasive spectroscopy and microscopy, the possibility of sampling the nonlinear optical response at the nanoscale, the manipulation of the density matrices associated with free electrons and optical sample modes, and appealing applications in optical modulation of electron beams, all of which could potentially revolutionize the use of free electrons in photonics.

Prevalence Of Cigarette Smoking Phenomenon In Iraqi University Students And Factors Affecting Its Cessation An Observational Epidemiologic Study

Smoking is one of the negative pests spread all over the world. The most valuable thing a person has is his health which is destroyed by smoking. Smoking results in many negative effects on society, so we must get rid of it so that we can live in a clean and vital environment. Programs designed to combat cigarette smoking should be targeted mainly to university students, males, heavy smokers and urban areas. More of cigarette smoking combating programs should be against manufactured cigarettes (for example, applying higher taxis). Efforts should be done to announce the problem of passive cigarette mainly in university community, among nonsmokers, females and urban areas. Enforcement of Anti-cigarette information came from health warnings on cigarette package followed by health care provider followed by the media (especially newspapers or magazines). Encouraging the smokers to consult the HCP should be considered. Attention should be paid to cigarette advertising sites specially advertisements in stores, Free samples Sale prices, noticed cigarette promotions, free gifts/discounts on other products, Clothing/item with brand name or logo, Coupons and Mail promoting cigarette. Encouraging the ways of high or moderate efficacy that help smoking cessation as the willpower, nicotine patch, changing habits, nicotine gum, cessation program, and exercise.

Do online reviews have different effects on consumers’ sampling behaviour across product types? Evidence from the software industry

Previous research shows that online reviews may have different effects for search goods and experience goods. However, as a typical type of experience goods, software can be further divided into different categories based on product characteristics. Little research has been conducted regarding the different effects of online reviews for different types of software. Furthermore, to offer free samples is another common practice of software firms to alleviate consumer uncertainty prior to purchase. To fill the corresponding research gap, this research focuses on the interaction effects between online reviews and free samples for different types of software. Through our empirical analysis, we find that user ratings significantly increase consumers’ sample downloads. Furthermore, consumers download more samples for some categories than for others. Finally, user and editor ratings might have differential effects for different types of software.

Lignin – Derived antioxidants as value-added products obtained under cavitation treatments of the wheat straw processing for sugar production

Most of biorefinery technologies are focused on the utilization of plant polysaccharides into chemicals, whereas lignin, the second most abundant natural polymer, is commonly used as a resource to generate power. This is the first report on flavones-bound lignin obtained by wheat straw (WS) pretreatment under low-frequency ultrasound (US) and hydrodynamic cavitation (HC) in sugar production processing. US and HC procedures carried out in aqueous 0.2–0.4% NaOH solutions and various liquid/biomass ratios strongly decreased the lignin content in the solid fraction by 30–45% and 25%, respectively, compared to non-treated WS. Moreover, НС pretreatment increased (approximately tenfold) the portion of ordered cellulose in residual biomass that could hinder the further enzymatic hydrolysis of WS. By means of sequential HC and US pretreatment the ordered cellulose content in solid fraction significantly decreased, compared to the HC alone. Furthermore, it was demonstrated that, after US pretreatment, hemicelluloses and oligomeric fragments of lignin and ligno-carbohydrate complexes were transferred into the liquid phase. In particular, tricin derivatives were detected in liquid fractions with a concentration of 30–35% on o.v.d. ash free sample, and more than 50 compounds associated with low-molecular-weight lignin fragments. These compounds were tentatively identified using high-resolution mass spectrometry (HR-MS) based fragmentation (sequencing) and a self-made database, showing that 16 out of 50 identified compounds belonged to the fragments of model lignin structural units. Tricin and low molecular weight lignin derivatives may find applications as strong antioxidants (i.e. lipidic systems). These findings proved that waste lignin streams obtained after cavitational processes could be a source of value-added products from WS conversion.

Predictors of exclusive breastfeeding in the first six months: four consecutive surveys in a tertiary hospital in Lithuania

BackgroundThere are little up-to-date data available on the duration of exclusive breastfeeding in Lithuania. The aim of our study was to examine the factors that could influence exclusive breastfeeding during the first 6 months of life.MethodsIn 2016, a survey was conducted at the Obstetrics and Gynecology Clinic of Vilnius University Hospital, Santaros Klinikos. Women in postnatal wards were opportunistically offered questionnaires and later followed up by telephone interviews at 6 weeks, 3 months, and 6 months postpartum. We used binary logistic regression to determine the factors that impacted exclusive breastfeeding during the first 6 months following childbirth.ResultsOf 475 eligible women that were approached, a total of 447 women were recruited, with response rates of 76.1, 71.4 and 67.0% at 6 weeks, 3 months, and 6 months postpartum, respectively. The prevalence of exclusive breastfeeding through the 6 month postpartum period was 39.8%. Exclusive breastfeeding during days 2 to 4 postpartum was positively influenced by factors such as a natural childbirth, the practice of breastfeeding on demand and maternal self-confidence in breastfeeding. Subsequently, exclusive breastfeeding on demand in the immediate postpartum period and exclusive breastfeeding for up to 3 months were associated with successful exclusive breastfeeding up to 6 months. However, the adverse factors that limited the success and duration of exclusive breastfeeding included free samples of human milk substitutes or advertising at primary healthcare centers 6 weeks after childbirth, pacifier use 6 months after childbirth, as well as amniotomy for labor induction.ConclusionsOur research demonstrated that exclusive breastfeeding is impacted in both directions by a range of factors during particular periods after delivery. One of the novel findings was the adverse influence of amniotomy for labor induction on exclusive breastfeeding rates. Taking into account diverse factors influencing exclusive breastfeeding and the absence of a single way to promote it, there is a crucial need to increase the incidence of exclusive breastfeeding until infants reach the age of 6 months.

Activity, stability, and binding capacity of β-galactosidase immobilized on electrospun nylon-6 fiber membrane

In this research, we explored various immobilized enzyme support materials, including the novel nylon-6 fiber membrane (NFM), and evaluated the increase in surface area and its effect on enzyme binding potential. We also manipulated incubation and reaction conditions and assessed the subsequent effects on activity and stability of β-galactosidase, with comparisons between various solid support materials and free (dissolved) enzyme. Nylon-6 fiber membranes were created by electrospinning and were compared with other materials as solid supports for enzyme binding. The other materials included polyvinylidene fluoride 5-kDa nanofiltration dairy membranes, nylon-6 pellets, and silica glass beads. Scanning electron microscopy revealed the large surface area of NFM, which correlated with greater enzyme activity compared with the relatively flatter surfaces of the other solid support materials. Enzyme activity was measured spectrophotometrically with the color-changing substrate o-nitrophenyl-β-d-galactopyranoside. Compared with the other solid supports, NFM had greater maximum enzyme binding potential. Across pH conditions ranging from 3.5 to 6.0 (including the optimal pH of 4.0-5.0), enzyme activity was maintained on the membrane-immobilized samples, whereas free enzyme did not maintain activity. Altering the storage temperature (4, 22, and 50°C) affected enzyme stability (i.e., the ability of the enzyme to maintain activity over time) of free and polyvinylidene fluoride membrane samples. However, NFM samples maintained stability across the varying storage temperatures. Increasing the immobilization solution enzyme concentration above the maximum enzyme binding capacity had no significant effect on enzyme stability for membrane-immobilized samples; however, both had lower mean stability than free enzyme by approximately 74%. With further development, β-galactosidase immobilized on NFM or other membranes could be used in continuous processing in the dairy industry for a combination of filtration and lactose hydrolysis-creating products that are reduced in lactose and increased in sweetness, with no requirement for "added sugars" on the nutrition label and no enzyme listed as final product ingredient.