Evaluation of twin fetal exposure to radiofrequency field during magnetic resonance imaging.

Fetal development is essential to the human lifespan. As more and more multifetal gestations have been reported recently, clinical diagnosis using magnetic resonance imaging (MRI), which introduced radiofrequency (RF) exposure, raised public concerns. The present study developed two whole-body pregnant models of 31 and 32 gestational weeks (GWs) with twin fetuses and explored RF exposure by 1.5 and 3.0 T MRI. Differences in the relative position of the fetus and changes in fetal weight can cause differences in fetal peak local specific absorption rate averaged over 10 g tissue (pSAR10g). Variation of pSAR10g due to different fetal positions can be ~35%. Numerically, twin and singleton fetal pSAR10g results were not significantly different, however twin results exceeded the limit in some cases (e.g. fetuses of 31 GW at 1.5 T), which indicated the necessity for further research employing anatomically correct twin-fetal models coming from various GWs and particular sequence to be applied.

Evaluation of laboratory and environmental exposure systems for protein modification upon gas pollutants and environmental factors.

Chemical modifications of proteins induced by ambient ozone (O3) and nitrogen oxides (NOx) are of public health concerns due to their potential to trigger respiratory diseases. The laboratory and environmental exposure systems have been widely used to investigate their relevant mechanism in the atmosphere. Using bovine serum albumin (BSA) as a model protein, we evaluated the two systems and aimed to reduce the uncertainties of both the reactants and products in the corresponding kinetic study. In the laboratory simulation system, the generated gaseous pollutants showed negligible losses. Ten layers of BSA were coated on the flow tube with protein extraction recovery of 87.4%. For environmental exposure experiment, quartz fiber filter was selected as the upper filter with low gaseous O3 (8.0%) and NO2 (1.7%) losses, and cellulose acetate filter was appropriate for the lower filter with protein extraction efficiency of 95.2%. The protein degradation process was observed without the exposure to atmospheric oxidants and contributed to the loss of protein monomer mass fractions, while environmental factors (e.g., molecular oxygen and ultraviolet) may cause greater protein monomer losses. Based on the evaluation, the study exemplarily applied the two systems to protein modification and both showed that O3 promotes the protein oligomerization and nitration, while increased temperature can accelerate the oligomerization and increased relative humidity can inhibit the nitration in the environmental exposure samples. The developed laboratory and environmental systems are suitable for studying protein modifications formed under different atmospheric conditions. A combination of the two will further reveal the actual mechanism of protein modifications.

Occurrence, distribution, and sources of organophosphate esters (OPEs) in the air of the Indo-China Peninsula Based on a Passive Air Monitoring Network.

Organophosphate esters (OPEs) are a class of emerging and ubiquitous contaminants that are attracting increasing attention, and their large-scale use as flame retardants and plasticizers has led to their pervasive presence in the environment, although their broader impacts remain unknown. In this study, 11 OPEs were measured in the atmosphere of Southeast Asia and Southwest China during 2016. The ∑11OPEs were higher in this region (78.0-1670 pg/m3, mean 458 pg/m3) than in many remote areas, lower than in developed regions, and comparable to levels in many developing country cities. Generally, the ∑11OPEs were higher in urban (105-1670 pg/m3, mean 538 pg/m3) than in suburban (78.0-1350 pg/m3, mean 388 pg/m3). Seasonal variations of OPEs in the air were more pronounced in Cambodia and Laos, especially for Triphenyl Phosphate (TPHP). Seasonal variations of ∑11OPEs in most regions correspond to changes in temperature and rainfall. Biomass burning may be also a factor in facilitating OPE emissions from biomass materials or soil into the atmosphere of Southeast Asia. The random forest analysis showed that among these, rainfall had the greatest effect on the seasonal variation of atmospheric OPE concentrations, followed by biomass burning and temperature. The inter-regional variation of ∑11OPEs in Southeast Asia was related to population and economic development in each region. Airflow trajectories indicated that the OPEs in this region were mainly from local sources. The health risk assessment revealed that the inhalation exposure risks of OPEs to the residents in the study areas were very low during the sampling period, but may be increasing.

Single Nucleotide Polymorphism in Cell Adhesion Molecule L1 Affects Learning and Memory in a Mouse Model of Traumatic Brain Injury.

The L1 cell adhesion molecule (L1) has demonstrated a range of beneficial effects in animal models of spinal cord injury, neurodegenerative disease, and ischemia; however, the role of L1 in TBI has not been fully examined. Mutations in the L1 gene affecting the extracellular domain of this type 1 transmembrane glycoprotein have been identified in patients with L1 syndrome. These patients suffer from hydrocephalus, MASA (mental retardation, adducted thumbs, shuffling gait, aphasia) symptoms, and corpus callosum agenesis. Clinicians have observed that recovery post-traumatic brain injury (TBI) varies among the population. This variability may be explained by the genetic differences present in the general population. In this study, we utilized a novel mouse model of L1 syndrome with a mutation at aspartic acid position 201 in the extracellular domain of L1 (L1-201). We assessed the impact of this specific single nucleotide polymorphism (SNP) localized to the X-chromosome L1 gene on recovery outcomes following TBI by comparing the L1-201 mouse mutants with their wild-type littermates. We demonstrate that male L1-201 mice exhibit significantly worse learning and memory outcomes in the Morris water maze after lateral fluid percussion (LFP) injury compared to male wild-type mice and a trend to worse motor function on the rotarod. However, no significant changes were observed in markers for inflammatory responses or apoptosis after TBI.

Near-Infrared, Organic Chiroptic Switch with High Dissymmetry Factors.

Here we unveil a chiral molecular redox switch derived from PDI-based twistacenes─chPDI[2] that has the remarkable attributes of high-intensity and a broadband chiral response. This material exhibits facile, stable, and reversible multistate chiroptical switching behavior over a broad active wavelength range close to 700 nm, encompassing ultraviolet, visible, and near-infrared regions. Upon reduction, chPDI[2] exhibits a substantial increase in the amplitude of its circular dichroic response, with an outstanding |ΔΔε| > 300 M-1 cm-1 and a high dissymmetry factor of 3 × 10-2 at 960 nm. DFT calculations suggest that the long wavelength CD signal for doubly reduced chPDI[2] originates from excitation of the PDI backbone to the π* orbital of the bridging alkene. Importantly, the dimer's molecular contortion facilitates ionic diffusion, enabling chiral switching in solid state films. The high dissymmetry factors and near-infrared response establish chPDI[2] as a unique chiroptic switch.

Unexpectedly high levels and health risks of atmospheric polychlorinated biphenyls in modern mechanical dismantling of obsolete electrical equipment: Investigations in a large integrated e-waste dismantling industrial estate.

Large industrial estates for electrical and electronic waste (e-waste) mechanical dismantling and recycling are gradually replacing outmoded small factories and intensive domestic workshops for e-waste manual and chemical dismantling. However, the air pollution and health risks of persistent organic pollutants during the modern mechanical processing of e-waste, especially obsolete electrical equipment, still remain unclear. Here, unexpectedly high levels (409.3 ng/m3) and health risks of airborne polychlorinated biphenyls (PCBs) were found during the mechanical processing of obsolete electric equipment or parts in a large integrated dismantling industrial estate, which is comparable to or a dozen times higher than those reported during chemical processing. In contrast, the levels (936.0 pg/m3) and health risks of particulate polybrominated diphenyl ethers (PBDEs) were all lower than those of previous studies. PCB emissions (44.9-3300.5 ng/m3) varied significantly across six mechanical dismantling places specifically treating waste motors, electrical appliances, hardware, transformers, and metals, respectively. The high PCB content and mass processing number of obsolete electrical equipment probably result in the highest PCB emissions from the mechanical dismantling of obsolete motors, followed by waste electrical appliances and metals. The PCB non-cancer and cancer risks associated with inhalation and dermal exposure in different mechanical dismantling places were all above the given potential risk limits. In particular, the health risks of dismantling obsolete motor exceeded the definite risk levels. Little difference in PCB emissions and health risks between working and non-working time suggested the importance of PCB volatilization from most e-waste. Such high PCB emissions and health risks of PCBs undoubtedly posed a severe threat to frontline workers, but fortunately, they decreased significantly with the increasing distance from the industrial estate. We highlight that PCB emissions and associated health risks from obsolete electrical equipment with high PCB content during mechanical dismantling activities should be of great concern.

A study on the correlation between MTHFR and folic acid combined with trace elements for the prevention of fetal malformations in the first trimester of pregnancy.

This study aims to elucidate and examine the intricate interrelation between 5,10-methylenetetrahydrofolate reductase (MTHFR), combined folic acid (FA), and trace element supplementation as a preventive strategy against fetal malformations during the inaugural trimester of pregnancy. Eighty pregnant women selected from our hospital's early obstetrics department from May 2021 to August 2021. Pregnant women are divided into the MTHFR combined group, FA, and trace element group. Comparing the basic data of patients, analyzing adverse reactions in pregnant women, and total birth risk situation, detecting MTHFR gene polymorphisms, and analyzing the correlation between MTHFR and FA in the prevention of fetal malformations in early pregnancy. Compared with the north, the southern region is more prone to FA deficiency. MTHFR degree of the MTHFR combined group was positively correlated with fetal malformations. The deformity rate was negatively correlated with FA and trace elements. Pregnant women in the first trimester may have fetal malformations, and the malformation rate is negatively correlated with FA and positively correlated with MTHFR level. Importantly, the inverse relationship between FA supplementation and malformation incidence underscores its significance as a preventive measure.

YOLOv8-Peas: a lightweight drought tolerance method for peas based on seed germination vigor.

Introduction: Drought stress has become an important factor affecting global food production. Screening and breeding new varieties of peas (Pisum sativum L.) for drought-tolerant is of critical importance to ensure sustainable agricultural production and global food security. Germination rate and germination index are important indicators of seed germination vigor, and the level of germination vigor of pea seeds directly affects their yield and quality. The traditional manual germination detection can hardly meet the demand of full-time sequence nondestructive detection. We propose YOLOv8-Peas, an improved YOLOv8-n based method for the detection of pea germination vigor. Methods: We constructed a pea germination dataset and used multiple data augmentation methods to improve the robustness of the model in real-world scenarios. By introducing the C2f-Ghost structure and depth-separable convolution, the model computational complexity is reduced and the model size is compressed. In addition, the original detector head is replaced by the self-designed PDetect detector head, which significantly improves the computational efficiency of the model. The Coordinate Attention (CA) mechanism is added to the backbone network to enhance the model's ability to localize and extract features from critical regions. The neck used a lightweight Content-Aware ReAssembly of FEatures (CARAFE) upsampling operator to capture and retain detailed features at low levels. The Adam optimizer is used to improve the model's learning ability in complex parameter spaces, thus improving the model's detection performance. Results: The experimental results showed that the Params, FLOPs, and Weight Size of YOLOv8-Peas were 1.17M, 3.2G, and 2.7MB, respectively, which decreased by 61.2%, 61%, and 56.5% compared with the original YOLOv8-n. The mAP of YOLOv8-Peas was on par with that of YOLOv8-n, reaching 98.7%, and achieved a detection speed of 116.2FPS. We used PEG6000 to simulate different drought environments and YOLOv8-Peas to analyze and quantify the germination vigor of different genotypes of peas, and screened for the best drought-resistant pea varieties. Discussion: Our model effectively reduces deployment costs, improves detection efficiency, and provides a scientific theoretical basis for drought-resistant genotype screening in pea.

Dynamic analysis of the subsea production system with lazy-wave risers attached to FPSO.

The lazy-wave riser is an input and output riser for a flexible development system, which is widely used in all the riser and pipeline systems. Because of the influence of various factors, its configuration description, control and motion which have a strong nonlinear character are complex during the running process of the lazy-wave riser. Reference to the specific structure and environmental parameters of a certain lazy-wave risers system with a 300 thousand tons FPSO, with the basis of the specific process of the flexible riser system at work, the lazy-wave risers were discretized into lumped mass models, combined with AQWA, the simplified dynamic model of the whole system at the depth of 2100m has been established by the large hydrodynamic analysis software OrcaFlex. The dynamic response characteristics of the lazy-wave risers have been given by using time domain coupling method. With and without the consideration of the 2nd wave drift load in the simulation process, the effects of the 2nd wave drift load on the results are obtained. The simulation results reveal the difficulty of simulation convergence caused by a large number of risers and flexible components. The 2nd order wave drift loads have a significant effect on the riser system, resulting in the increasement of the effective tension at each end of each riser. To counteract the magnitude of the FPSO response caused by such loads, the number of mooring lines needed to be increased or combined with dynamic positioning techniques to optimize the design.

Dynamic analysis of towed cable with variable length during turning maneuvers.

The configuration of marine towing cable changes significantly during the turning process, with the rotating procedure with fixed cable length being the most frequent. To overcome these challenges, the configuration and dynamic properties of the marine towing cable must be addressed. However, under some particular operating situations, the tugboat must release the marine towed cable during rotation, resulting in a constant change in the length of the marine cable. In view of this, the towed cable is discretized into a lumped mass model based on the lumped mass method, and the dynamic analysis model of the rotation process of towed cable with variable length under different release speeds and different depths is established. This is done with reference to the specific parameters of a towed system, combined with the specific sea conditions of a particular sea area. Time-domain coupling analysis is used to determine the dynamic changes in configuration and stress of marine towing cable at various release speeds and depths. The results of the calculations have some guiding relevance for a certain engineering practice.

Fusing perylene diimide with helicenes.

Incorporating perylene diimide (PDI) units into helicene structures has become a useful strategy for giving access to non-planar electron acceptors as well as a method of creating molecules with unique and intriguing chiroptical properties. This minireview describes this fusion of PDIs with helicenes.

Pyramiding of Multiple Genes to Improve Rice Blast Resistance of Photo-Thermo Sensitive Male Sterile Line, without Yield Penalty in Hybrid Rice Production.

Rice blast caused by pathogenic fungus Magnaporthe oryzae is one of the most serious diseases in rice. The pyramiding of effective resistance genes into rice varieties is a potential approach to reduce the damage of blast disease. In this study, combinations of three resistance genes, Pigm, Pi48 and Pi49, were introduced into a thermo-sensitive genic male sterile (PTGMS) line Chuang5S through marker-assisted selection. The results showed that the blast resistance of improved lines increased significantly compared with Chuang5S, and the three gene pyramiding lines (Pigm + Pi48 + Pi49) had higher rice blast resistance level than monogenic line and digenic lines (Pigm +Pi48, Pigm + Pi49). The genetic backgrounds of the improved lines were highly similar (>90%) to the recurrent parent Chuang5S by using the RICE10K SNP chip. In addition, agronomic traits evaluation also showed pyramiding lines with two or three genes similar to Chuang5S. The yields of the hybrids developed from improved PTGMS lines and Chuang5S are not significantly different. The newly developed PTGMS lines can be practically used for the breeding of parental lines and hybrid varieties with broad spectrum blast resistance.

Mapping the Contribution of Biomass Burning to Persistent Organic Pollutants in the Air of the Indo-China Peninsula Based on a Passive Air Monitoring Network.

Biomass burning (BB) is an important source of atmospheric persistent organic pollutants (POPs) across the world. However, there are few field-based regional studies regarding the POPs released from BB. Due to the current limitations of emission factors and satellites, the contribution of BB to airborne POPs is still not well understood. In this study, with the simultaneous monitoring of BB biomarkers and POPs based on polyurethane foam-based passive air sampling technique, we mapped the contribution of BB to polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in the Indo-China Peninsula. Spearman correlations between levoglucosan and 16 PCBs (rs = 0.264-0.767, p < 0.05) and 2 OCPs (rs = 0.250-0.328, p < 0.05) confirmed that BB may facilitate POP emissions. Source apportionment indicated that BB contributed 9.3% to the total PCB and OCP mass. The high contribution of positive matrix factorization-resolved BB to PCBs and OCPs was almost consistent with their concentration distributions in the open BB season but not completely consistent with those in the pre-monsoon and/or monsoon seasons. Their contribution distributions may reflect the use history and geographic distribution in secondary sources of POPs. The field-based contribution dataset of BB to POPs is significant in improving regional BB emission inventories and model prediction.

Regional monitoring of biomass burning using passive air sampling technique reveals the importance of MODIS unresolved fires.

Field-based sampling can provide more accurate evaluation than MODIS in regional biomass burning (BB) emissions given the limitations of MODIS on unresolved fires. Polyurethane foam-based passive air samplers (PUF-PASs) are a promising tool for collecting atmospheric monosaccharides. Here, we deployed PUF-PASs to monitor monosaccharides and other BB-related biomarkers and presented a dataset of 31 atmospheric BB-related biomarkers in the Indo-China Peninsula (ICP) and Southwest China. The peak concentrations of monosaccharides in the ICP occurred before monsoon season. The highest concentrations were in the eastern Mekong plain, while the lowest were along the eastern coast. BB-related biomarkers displayed elevated concentrations after April, particularly in the monsoon season; however, fewer active fires were recorded by MODIS. This revealed the importance of MODIS unresolved fires (e.g., indoor biofuel combustion, small-scale BB incidents, and charcoal fires) to the regional atmosphere. The PAS derived levoglucosan concentrations indicated that, with the inclusion of MODIS unresolved fires, the estimated top-down emissions of PM (4194-4974 Gg/yr), OC (1234-1719 Gg/yr) and EC (52-384 Gg/yr) would be higher than previous bottom-up estimations in the ICP. Future studies on these MODIS unresolved fires and regional monitoring data of BB are vital for improving the modeling of regional BB emissions.

Remote Control of Dynamic Twistacene Chirality.

We report a reliable way to manipulate the dynamic, axial chirality in perylene diimide (PDI)-based twistacenes. Specifically, we reveal how chiral substituents on the imide position induce the helicity in a series of PDI-based twistacenes. We demonstrate that this remote chirality is able to control the helicity of flexible [4]helicene subunits by UV-vis, CD spectroscopy, X-ray crystallography, and TDDFT calculations. Furthermore, we have discovered that both the chiral substituent and the solvent each has a strong impact on the sign and intensity of the CD signals, highlighting the control of the dynamic helicity in this flexible system. DFT calculations suggest that the steric interaction of the chiral substituents is the important factor in how well a particular group is at inducing a preferred helicity.

Single-Handed Helicene Nanoribbons via Transfer of Chiral Information.

Here we show the access to single-handed helicene nanoribbons by utilizing a [6]helicene building block to induce diastereoselective, photochemical formation of [5]helicene units. Specifically, we have synthesized nanoribbons P1 and P2 with different ratios of [6]helicene "sergeants" to [5]helicene "soldiers", which on average consist of between ∼50 and 60 ortho-annulated benzene rings. These are the longest, optically active helicene backbones that have been prepared to date. The chiroptic properties of P1 and P2 reveal the transfer of stereochemical information from "sergeants" to "soldiers". To gain further insight into the stereo-information relay, we apply the same molecular design to discrete, model oligomers 1-5 and confirm that they also preferentially adopt homochiral geometries.

Simultaneous measurement of energy spectrum and fluence of neutrons using a diamond detector.

Due to the excellent radiation hardness and high-temperature endurance, diamond detectors are suitable for intense neutron measurements and promising for neutron diagnostics of scientific fusion devices. In the present work, simultaneous measurement of energy spectrum and fluence of neutrons using a diamond detector was realized for the first time. The absolute response matrix of the diamond detector was simulated based on detailed analysis of the nuclear reactions and the proper selection of nuclear reaction data. Neutron energy spectra as well as neutron fluences for 5.0, 5.5, 8.5, 9.5 and 10.5 MeV neutrons from d-d reaction were measured using the diamond detector based on the absolute response matrix. The measured neutron energy spectra and neutron fluences are reasonable compared with those detected using a EJ-309 liquid scintillator and a 238U fission chamber, respectively, which verifies the reliability of the present work. Furthermore, the energy spectrum and fluence of a 14.2 MeV d-t neutron source were also measured using the diamond detector. The present work demonstrates the ability of simultaneous measurement of energy spectrum and fluence as well as for both d-d and d-t neutrons using a diamond detector, which is of great significance for neutron diagnostics of scientific fusion devices.

An MRI radiomics approach to predict survival and tumour-infiltrating macrophages in gliomas.

Preoperative MRI is one of the most important clinical results for the diagnosis and treatment of glioma patients. The objective of this study was to construct a stable and validatable preoperative T2-weighted MRI-based radiomics model for predicting the survival of gliomas. A total of 652 glioma patients across three independent cohorts were covered in this study including their preoperative T2-weighted MRI images, RNA-seq and clinical data. Radiomic features (1731) were extracted from preoperative T2-weighted MRI images of 167 gliomas (discovery cohort) collected from Beijing Tiantan Hospital and then used to develop a radiomics prediction model through a machine learning-based method. The performance of the radiomics prediction model was validated in two independent cohorts including 261 gliomas from the The Cancer Genomae Atlas database (external validation cohort) and 224 gliomas collected in the prospective study from Beijing Tiantan Hospital (prospective validation cohort). RNA-seq data of gliomas from discovery and external validation cohorts were applied to establish the relationship between biological function and the key radiomics features, which were further validated by single-cell sequencing and immunohistochemical staining. The 14 radiomic features-based prediction model was constructed from preoperative T2-weighted MRI images in the discovery cohort, and showed highly robust predictive power for overall survival of gliomas in external and prospective validation cohorts. The radiomic features in the prediction model were associated with immune response, especially tumour macrophage infiltration. The preoperative T2-weighted MRI radiomics prediction model can stably predict the survival of glioma patients and assist in preoperatively assessing the extent of macrophage infiltration in glioma tumours.

Oxidative potential of solvent-extractable organic matter of ambient total suspended particulate in Bangkok, Thailand.

Oxidative stress is a key mechanism by which ambient particulate matter induces adverse health effects. Most studies have focused on the oxidative potential (OP) of water-soluble constituents, while there has been limited work on the OP of solvent-extractable organic matter (EOM OP). In this study, the EOM OP of ambient total suspended particulate (TSP) from Bangkok, Thailand, was determined using the dithiothreitol (DTT) assay. Positive matrix factorization (PMF), combined with chemical analysis of molecular markers, was employed to apportion the contributions of various emission sources to EOM OP. The volume-normalized OP initially increased with organic carbon (OC) concentration and plateaued gradually, while the mass-normalized OP fitted well with OC concentration using a power function. Fossil fuel combustion (62%) and plastic waste burning (23%) were the major contributors to EOM OP, while biomass burning demonstrated only a limited contribution. EOM OP correlated well with each group of polycyclic aromatic hydrocarbons (PAHs), suggesting that secondary formation of quinones associated with fossil fuel combustion and plastic waste burning could be an important pathway of TSP toxicity. This study underscores the importance of considering different emission sources when evaluating potential health impacts and the implementation of air pollution regulations.

Modulation of Sleep Architecture by Whole-Body Static Magnetic Exposure: A Study Based on EEG-Based Automatic Sleep Staging.

A steady increase in sleep problems has been observed along with the development of society. Overnight exposure to a static magnetic field has been found to improve sleep quality; however, such studies were mainly based on subjective evaluation. Thus, the presented data cannot be used to infer sleep architecture in detail. In this study, the subjects slept on a magneto-static mattress for four nights, and self-reported scales and electroencephalogram (EEG) were used to determine the effect of static magnetic field exposure (SMFE) on sleep. Machine learning operators, i.e., decision tree and supporting vector machine, were trained and optimized with the open access sleep EEG dataset to automatically discriminate the individual sleep stages, determined experimentally. SMEF was found to decrease light sleep duration (N2%) by 3.51%, and sleep onset latency (SOL) by 15.83%, while it increased deep sleep duration (N3%) by 8.43%, compared with the sham SMFE group. Further, the overall sleep efficiency (SE) was also enhanced by SMFE. It is the first study, to the best of our knowledge, where the change in sleep architecture was explored by SMFE. Our findings will be useful in developing a non-invasive sleep-facilitating instrument.