Secondhand Smoking and the Fetus: A Bibliometric Analysis

Background

Bibliometric analysis may indicate the most active specialist, authors, and journals in a given research field. To the authors' knowledge, there is no bibliometric analysis to provide a macroscopic overview in the field of secondhand smoke that harms non-smoker.

Methods

Using the bibliometric method, 644 articles that were present in the Scopus database between 1973-2020 on the subject were considered. The data were analyzed by two visualization and science-mapping software called Bibliometrix and VoS Viewer. Also, reference publication year stereoscopy and Co-Citation historiography were used. In the qualitative analysis, 52 articles were selected that had the most citation and were analyzed.

Results

In this paper, the findings show that the documents were published in 364 sources with an average citation per document of 25.14 and more than 3 authors or nearly 4 authors per document. The peak reference publication year stereoscopy happened in the year 199 with 974 references. The countries with the highest number of MCP were the USA, China, and Spain. The "International Journal of Environmental Research" and "Public Health", has raised their publications in the field of secondhand smoke and pregnancy rapidly since 2003. Among the titles, "passive smoking" was the most used.

Conclusion

The study highlights the importance of understanding the harmful effects of secondhand smoke on the developing fetus. The findings also shed light on key research trends, influential authors, and active research areas, which can guide future studies and support evidence-based decision-making in the field of maternal and child health.

Triggering apoptosis in cancer cells with an analogue of cribrostatin 6 that elevates intracellular ROS

Elevation of reactive oxygen species (ROS) is both a consequence and driver of the upregulated metabolism and proliferation of transformed cells. The resulting increase in oxidative stress is postulated to saturate the cellular antioxidant machinery, leaving cancer cells susceptible to agents that further elevate their intracellular oxidative stress. Several small molecules, including the marine natural product cribrostatin 6, have been demonstrated to trigger apoptosis in cancer cells by increasing intracellular ROS. Here, we report the modular synthesis of a series of cribrostatin 6 derivatives, and assessment of their activity in a number of cell lines. We establish that placing a phenyl ring on carbon 8 of cribrostatin 6 leads to increased potency, and observe a window of selectivity towards cancer cells. The mechanism of activity of this more potent analogue is assessed and demonstrated to induce apoptosis in cancer cells by increasing ROS. Our results demonstrate the potential for targeting tumors with molecules that enhance intracellular oxidative stress.

The half Heusler system Ti1+xFe1.33−xSb–TiCoSb with Sb/Sn substitution: phase relations, crystal structures and thermoelectric properties

Phase equilibria for Heusler Phase Ti_1+xFe_1.33−xSb at 800 °C and calculated isosurfaces (ϒ = 0.42) of the electron localization function in TiFe_1.25Sb.

Post-translational control of protein function with light using a LOV-intein fusion protein

Methods for the post-translational control of protein function with light hold much value as tools in cell biology. To this end, we report a fusion protein that consists of DnaE split-inteins, flanking the light sensitive LOV2 domain of Avena sativa. The resulting chimera combines the activities of these two unrelated proteins to enable controlled formation of a functional protein via upregulation of intein splicing with blue light in bacterial and human cells.

Probing the epigenetic regulation of HIF-1α transcription in developing tissue

HIF-1-mediated hypoxia signalling in embryonic tissue is probed by assessing the methylation status of the HIF-1α and EPO HRE promoters using bisulfite sequencing.

HIF-1 promotes the expression of its α-subunit via an epigenetically regulated transactivation loop

A HIF-1 protein–protein interaction inhibitor is used to establish the presence of a HIF-1α transactivation loop in hypoxia.

Microbial transformation of citral by Penicillium sp

Thymol is present in the essential oils from herbs and spices, such as thyme. It is produced by these plant species as a chemical defense against phytopathogenic microorganisms. Therefore, this compound has attracted great attention in food industry, i.e., it has been used as a natural preservative in foods such as cheese to prevent fungal growth. Previous studies concerning the biotransformation of nerol by Penicillium sp. and microbial transformation of citral by sporulated surface cultures method (SSCM) of Penicillium digitatum have been reported. The objective of this research was to study the pathway involved during biotransformation of citral by Penicillium sp. using two methods. The culture preparation was done using different microbial methods and incubation periods to obtain Penicillium for citral biotransformation. The biotransformation products were identified by gas chromatography (GC) and gas chromatography/mass spectroscopy (GC/MS). A comparison of the two methods showed that SSCM was more effective, its major products were thymol (21.5 %), geranial (18.6 %) and nerol (13.7 %). LM produced only one compound — thymol — with a low efficiency.

Eye movements selective for spatial frequency and orientation during active visual search

Visual search can simply be defined as the task of looking for objects of interest in cluttered visual environments. Typically, the human visual system succeeds at this by making a series of rapid eye movements called saccades, interleaved by discrete fixations. However, very little is known on how the brain programs saccades and selects fixation loci in such naturalistic tasks. In the current study, we use a technique developed in our laboratory based on reverse-correlation(1) and stimuli that emulate the natural visual environment to examine observers' strategies when seeking low-contrast targets of various spatial frequency and orientation characteristics. We present four major findings. First, we provide strong evidence of visual guidance in saccadic targeting characterized by saccadic selectivity for spatial frequencies and orientations close to that of the search target. Second, we show that observers exhibit inaccuracies and biases in their estimates of target features. Third, a complementarity effect is generally observed: the absence of certain frequency components in distracters affects whether they are fixated or mistakenly selected as the target. Finally, an unusual phenomenon is observed whereby distracters containing close-to-vertical structures are fixated in searches for nonvertically oriented targets. Our results provide evidence for the involvement of band-pass mechanisms along feature dimensions (spatial frequency and orientation) during visual search.

Flow-injection analysis of nitrate by reduction to nitrite and gas-phase molecular absorption spectrometry

Two flow-injection manifolds have been investigated for the determination of nitrate. These manifolds are based on the reduction of nitrate to nitrite and determination of nitrite by gas-phase molecular absorption spectrophotometry. Nitrate sample solution (300 microL) which is injected to the flow line, is reduced to nitrite by reaction with hydrazine or passage through the on-line copperized cadmium (Cd-Cu) reduction column. The nitrite produced reacts with a stream of hydrochloric acid and the evolved gases are purged into the stream of O2 carrier gas. The gaseous phase is separated from the liquid phase using a gas-liquid separator and then swept into a flow-through cell which has been positioned in the cell compartment of an UV-visible spectrophotometer. The absorbance of the gaseous phase is measured at 204.7 nm. A linear relationship was obtained between the intensity of absorption signals and concentration of nitrate when Cd-Cu reduction method was used, but a logarithmic relationship was obtained when the hydrazine reduction method was used. By use of the Cd-Cu reduction method, up to 330 microg of nitrate was determined. The limit of detection was 2.97 microg nitrate and the relative standard deviations for the determination of 12.0, 30.0 and 150 microg nitrate were 3.32, 3.87 and 3.6%, respectively. Maximum sampling rate was approximately 30 samples per hour. The Cd-Cu reduction method was applied to the determination of nitrate and the simultaneous determination of nitrate and nitrite in meat products, vegetables, urine, and a water sample.

Transplantation in utero of fetal human hematopoietic stem cells into mice results in hematopoietic chimerism

Allogeneic and xenogeneic hematolymphoid chimerism has been achieved in large and small animals using varied techniques to circumvent immune mediated graft rejection by the recipient. We show here the establishment of long-term chimerism in normal mice transplanted in utero with human fetal hematopoietic stem cells (HSC). HSCs from fetal (13-20 weeks' gestation) human livers were injected into fetal mouse peritoneal cavities on days 11-13 of gestation. Histologic examination demonstrated human chimerism in 29% of 38 live born mice using fluorescein conjugated antibodies to both the CD45 and CD14 antigens present on human peripheral blood (PB) cells. Further investigation using flow cytometric analysis of cells from 70 mice transplanted in utero revealed 28% of mice greater than 16 weeks of age contained human cells in at least one organ at the following frequencies: 14% PB, 8% bone marrow, 8% spleen and 12% thymus. These data indicate that human fetal HSC can be engrafted into mouse fetuses. Additionally, the identification of circulating human cells 18 months following transplantation supports the engraftment and proliferation of a primitive hematopoietic progenitor.

Microbial transformation of citral by Penicillium sp

Thymol is present in the essential oils from herbs and spices, such as thyme. It is produced by these plant species as a chemical defense against phytopathogenic microorganisms. Therefore, this compound has attracted great attention in food industry, i.e., it has been used as a natural preservative in foods such as cheese to prevent fungal growth. Previous studies concerning the biotransformation of nerol by Penicillium sp. and microbial transformation of citral by sporulated surface cultures method (SSCM) of Penicillium digitatum have been reported. The objective of this research was to study the pathway involved during biotransformation of citral by Penicillium sp. using two methods. The culture preparation was done using different microbial methods and incubation periods to obtain Penicillium for citral biotransformation. The biotransformation products were identified by gas chromatography (GC) and gas chromatography/mass spectroscopy (GC/MS). A comparison of the two methods showed that SSCM was more effective, its major products were thymol (21.5 %), geranial (18.6 %) and nerol (13.7 %). LM produced only one compound — thymol — with a low efficiency.