Particulate matter exposure and chronic cerebral hypoperfusion promote oxidative stress and induce neuronal and oligodendrocyte apoptosis in male mice.

Chronic cerebral hypoperfusion (CCH) may amplify the neurotoxicity of nanoscale particulate matter (nPM), resulting in white matter injury. This study characterized the joint effects of nPM (diameter ≤ 200 nm) and CCH secondary to bilateral carotid artery stenosis (BCAS) exposure on neuronal and white matter injury in a murine model. nPM was collected near a highway and re-aerosolized for exposure. Ten-week-old C57BL/6 male mice were randomized into four groups: filtered air (FA), nPM, FA + BCAS, and nPM + BCAS. Mice were exposed to FA or nPM for 10 weeks. BCAS surgeries were performed. Markers of inflammation, oxidative stress, and apoptosis were examined. nPM + BCAS exposure increased brain hemisphere TNFα protein compared to FA. iNOS and HNE immunofluorescence were increased in the corpus callosum and cerebral cortex of nPM + BCAS mice compared to FA. While nPM exposure alone did not decrease cortical neuronal cell count, nPM decreased corpus callosum oligodendrocyte cell count. nPM exposure decreased mature oligodendrocyte cell count and increased oligodendrocyte precursor cell count in the corpus callosum. nPM + BCAS mice exhibited a 200% increase in cortical neuronal TUNEL staining and a 700% increase in corpus callosum oligodendrocyte TUNEL staining compared to FA. There was a supra-additive interaction between nPM and BCAS on cortical neuronal TUNEL staining (2.6× the additive effects of nPM + BCAS). nPM + BCAS exposure increased apoptosis, neuroinflammation, and oxidative stress in the cerebral cortex and corpus callosum. nPM + BCAS exposure increased neuronal apoptosis above the separate responses to each exposure. However, oligodendrocytes in the corpus callosum demonstrated a greater susceptibility to the combined neurotoxic effects of nPM + BCAS exposure.

Generation of balanced pulse pairs based on a dual-chip coupling structure.

An asymmetric Mach-Zehnder interferometer (AMZI) is an essential device to generate pulse pairs in quantum key distribution systems. An AMZI based on a dual-chip coupling structure in a silica-on-silicon planar light wave circuit platform is proposed, which includes a variable optical splitter (VOS), a delay line (DL), and a directional coupler (DC). The AMZI chip is divided into a VOS-DL part and a DC part, and the two parts are independently manufactured and then coupled. Since the DC part occupies the smallest area of the AMZI chip and is most sensitive to manufacturing errors, separate production can reduce the process difficulty and fabrication errors. In the experiment, balanced pulse pairs with a delay time of 402 ps are obtained in the condition of single photon transmission, and the excess loss is 0.8 dB. This dual-chip coupling structure can improve the yield and reduce the manufacturing cost when producing large chips.

Polarization-insensitive 90° optical hybrid using silica-based PLC.

A 90° optical hybrid (OH) based on a 4×4 multimode interference (MMI) coupler is characterized and analyzed using the silica-based planar light circuit. The OH is designed to be polarization-insensitive with an extremely low polarization-dependent loss (<0.18d B) and phase error (w i t h i n±1.3∘). The fabricated chip exhibits an excess loss of 3.4 dB and 3.8 dB for TE and TM polarizations at 1550 nm. The measured phase error is w i t h i n±7.2∘ over 50 nm in the C+L band with a polarization-dependent error w i t h i n±3.5∘. The fabrication tolerance of the MMI width and waveguide sidewall angle is analyzed, which can well explain the deviation from the theoretical calculation.

Effective Removal of Cd from Aqueous Solutions Using P-Loaded Ca-Mn-Impregnated Biochar.

Cadmium (Cd) pollution in wastewater has become an increasingly widespread concern worldwide. Studies on Cd (II) removal using phosphate-adsorbed sorbents are limited. This study aimed to elucidate the behaviors and mechanisms of Cd (II) sorption on phosphate-loaded Ca-Mn-impregnated biochar (Ps-CMBC). The Cd (II) sorption on Ps-CMBC reached equilibrium within 2 h and exhibited a higher sorption efficiency than biochar and CMBC. Additionally, the Langmuir isotherm could better describe the Cd (II) adsorption on the sorbents. P75-CMBC had a maximum Cd (II) sorption capability of 70.13 mg·g-1 when fitted by the Langmuir isotherm model, which was approximately 3.18 and 2.86 times greater than those of biochar and CMBC, respectively. Higher pH (5-7) had minimal effect on Cd (II) sorption capacity. The results of characterization analyses, such as SEM-EDS, FTIR, and XPS, suggested that there was a considerable difference in the sorption mechanisms of Cd (II) among the sorbents. The primary sorption mechanisms for biochar, CMBC, and Ps-CMBC included electrostatic attraction and surface complexation; additionally, for Ps-CMBC, Cd (II)-π interactions and coordination of Cd (II) with P=O were critical mechanisms for Cd (II) removal. The results of this study demonstrate that phosphate-loaded CMBC can be used as an effective treatment for heavy metal pollution in aqueous media.

Production of sesquiterpene patchoulol in mitochondrion-engineered Saccharomyces cerevisiae.

Patchoulol is a natural sesquiterpene, which is widely used in perfumes and cosmetics. In the work, the mitochondria of S. cerevisiae were engineered for patchoulol production. The patchoulol titer of mitochondria-compartmentalized strain (1.79 mg/L) was 2.71-fold higher than that of control strain (0.66 mg/L) using genome-integrated patchoulol synthase, indicating that mitochondria compartmentation resulted in higher concentration of FPP (farnesyl pyrophosphate) precursor for patchoulol production. Moreover, when fused FPP synthase and patchoulol synthase was overexpressed in the strain with a mitochondria-localized DMAPP (dimethylallyl diphosphate) pathway, the production of patchoulol increased significantly to 19.24 mg/L, indicating more precursors were provided for patchoulol production. Nevertheless, the introduction of excess foreign proteins into mitochondria might cause a certain stress on mitochondria and showed a negative effect on the growth of yeast cells, which could hinder the expression of foreign pathways and reduce the patchoulol production. In conclusion, mitochondria-engineered yeast cells showed important potential for the enhanced biosynthesis of patchoulol, and further engineering could be considered based on the present work.

Analysis of Degradation Kinetics and Migration Pattern of Chlorfenapyr in Celery (Apium graveliens L.) and Soil Under Greenhouse Conditions at Different Elevations.

The degradation kinetics and migration pattern of chlorfenapyr in celery and soil at Lhasa and Pengzhou were investigated. A simple, rapid analytical method for the quantification of chlorfenapyr in celery and soil was developed using gas chromatography-tandem mass spectrometer. The results indicated that the half-lives of chlorfenapyr in celeries and soils at Lhasa were 6.3 days and 12.8 days. While the half-lives of chlorfenapyr in celeries and soils at Pengzhou were 6.9 days and 20.4 days. The half-lives of chlorfenapyr in celeries and soils at Lhasa were shorter than that at Pengzhou, while the half-lives of chlorfenapyr in soils at Lhasa and Pengzhou were longer than that in celeries at Lhasa and Pengzhou. The final residues of chlorfenapyr in celeries at Lhasa and Pengzhou were 5.074 ± 0.144 mg/kg and 5.981 ± 0.234 mg/kg after 7 days of spraying, respectively. When chlofenapyr was sprayed to soils only, the average root concentration factor of chlorfenapyr were 3.57-4.02, while the average translocation factor of chlorfenapyr in leaves and stems were 0.28-0.38 and 0.20-0.25, respectively. Chlorfenapyr was easy to migrate from soil to the roots of celery, followed by leaves and stems. The limit value of chlorfenapyr in celery has not been specified in China's National MRL standard (GB 2763 in National food safety standard-maximum residue limits for pesticides in food. Standard, Beijing, 2021), this study was useful to draw up the limit values of chlorfenapyr residues in celery at different elevations.

Effects of ambient particulate matter on vascular tissue: a review.

Fine and ultra-fine particulate matter (PM) are major constituents of urban air pollution and recognized risk factors for cardiovascular diseases. This review examined the effects of PM exposure on vascular tissue. Specific mechanisms by which PM affects the vasculature include inflammation, oxidative stress, actions on vascular tone and vasomotor responses, as well as atherosclerotic plaque formation. Further, there appears to be a greater PM exposure effect on susceptible individuals with pre-existing cardiovascular conditions.

Estradiol Protects White Matter of Male C57BL6J Mice against Experimental Chronic Cerebral Hypoperfusion.

BACKGROUND AND PURPOSE: Estradiol is a sex steroid hormone known to protect the brain against damage related to transient and global cerebral ischemia. In the present study, we leverage an experimental murine model of bilateral carotid artery stenosis (BCAS) to examine the putative effects of estradiol therapy on chronic cerebral hypoperfusion. We hypothesize that long-term estradiol therapy protects against white matter injury and declarative memory deficits associated with chronic cerebral hypoperfusion. METHODS: Adult male C57BL/6J mice underwent either surgical BCAS or sham procedures. Two days after surgery, the mice were given oral estradiol (Sham+E, BCAS+E) or placebo (Sham+P, BCAS+P) treatments daily for 31-34 days. All mice underwent Novel Object Recognition (NOR) testing 31-34 days after the start of oral treatments. Following sacrifice, blood was collected and brains fixed, sliced, and prepared for histological examination of white matter injury and extracellular signal-regulated kinase (ERK) expression. RESULTS: Animals receiving long-term oral estradiol therapy (BCAS-E2 and Sham-E2) had higher plasma estradiol levels than those receiving placebo treatment (BCAS-P and Sham-P). BCAS-E2 mice demonstrated less white matter injury (Klüver-Barrera staining) and performed better on the NOR task compared to BCAS-P mice. ERK expression in the brain was increased in the BCAS compared to sham cohorts. Among the BCAS mice, the BCAS-E2 cohort had a greater number of ERK + cells. CONCLUSION: This study demonstrates a potentially protective role for oral estradiol therapy in the setting of white matter injury and declarative memory deficits secondary to murine chronic cerebral hypoperfusion.

Characterization of a novel nitrilase, BGC4, from Paraburkholderia graminis showing wide-spectrum substrate specificity, a potential versatile biocatalyst for the degradation of nitriles.

OBJECTIVE: To investigate the biodegradation of nitriles via the nitrilase-mediated pathway. RESULTS: A novel nitrilase, BGC4, was identified from proteobacteria Paraburkholderia graminis CD41M and its potential for use in biodegradation of toxic nitriles in industrial effluents was studied. BGC4 was overexpressed in Escherichia coli BL21 (DE3), the recombinant protein was purified and its enzymatic properties analysed. Maximum activity of BGC4 nitrilase was at 30 °C and pH 7.6. BGC4 has a broad substrate activity towards aliphatic, heterocyclic, and aromatic nitriles, as well as arylacetonitriles. Iminodiacetonitrile, an aliphatic nitrile, was the optimal substrate but comparable activities were also observed with phenylacetonitrile and indole-3-acetonitrile. BGC4-expressing cells degraded industrial nitriles, such as acrylonitrile, adiponitrile, benzonitrile, mandelonitrile, and 3-cyanopyridine, showing good tolerance and conversion rates. CONCLUSION: BGC4 nitrilase has wide-spectrum substrate specificity and is suitable for efficient biodegradation of toxic nitriles.

Neuroprotective delivery platforms as an adjunct to mechanical thrombectomy.

Despite the success of numerous neuroprotective strategies in animal and preclinical stroke models, none have effectively translated to clinical medicine. A multitude of influences are likely responsible. Two such factors are inefficient recanalization strategies for large vessel occlusions and suboptimal delivery methods/platforms for neuroprotective agents. The recent endovascular stroke trials have established a new paradigm for large vessel stroke treatment. The associated advent of advanced mechanical revascularization devices and new stroke technologies help address each of these existing gaps. A strategy combining effective endovascular revascularization with administration of neuroprotective therapies is now practical and could have additive, if not synergistic, effects. This review outlines past and current neuroprotective strategies assessed in acute stroke trials. The discussion focuses on delivery platforms and their potential applicability to endovascular stoke treatment.

Targeted Raman Imaging of Cells Using Graphene Oxide-Based Hybrids.

Graphene oxide (GO) is a reliable and multifunctional platform to perform cell imaging. In this work, a controllable Pt-seed-mediated method is used to prepare GO/gold nanoparticle (AuNP) hybrids, and after the covalent binding of folic acid (FA), GO/AuNP/FA hybrids are prepared. Selective labeling and Raman imaging of folate receptor (FR)-positive HeLa cells are realized using such GO-based hybrids. In this system, FA is the targeting agent, AuNPs work as surface-enhanced Raman scattering substrates, and GO takes the role of both supporting the AuNPs with FA and acting as a Raman probe. This research further extends the application of GO as a multifunctional platform in bioimaging and other biomedical processes.

The bacterial lipopeptide iturins induce Verticillium dahliae cell death by affecting fungal signalling pathways and mediate plant defence responses involved in pathogen-associated molecular pattern-triggered immunity.

Verticillium wilt in cotton caused by Verticillium dahliae is one of the most serious plant diseases worldwide. Because no known fungicides or cotton cultivars provide sufficient protection against this pathogen, V. dahliae causes major crop yield losses. Here, an isolated cotton endophytic bacterium, designated Bacillus amyloliquefaciens 41B-1, exhibited greater than 50% biocontrol efficacy against V. dahliae in cotton plants under greenhouse conditions. Through high-performance liquid chromatography and mass analysis of the filtrate, we found that the antifungal compounds present in the strain 41B-1 culture filtrate were a series of isoforms of iturins. The purified iturins suppressed V. dahliae microsclerotial germination in the absence or presence of cotton. Treatment with the iturins induced reactive oxygen species bursts, Hog1 mitogen-activated protein kinase (MAPK) activation and defects in cell wall integrity. The oxidative stress response and high-osmolarity glycerol pathway contribute to iturins resistance in V. dahliae. In contrast, the Slt2 MAPK pathway may be involved in iturins sensitivity in this fungus. In addition to antagonism, iturins could induce plant defence responses as activators and mediate pathogen-associated molecular pattern-triggered immunity. These findings suggest that iturins may affect fungal signalling pathways and mediate plant defence responses against V. dahliae.

Graphene Oxide as a Multifunctional Platform for Raman and Fluorescence Imaging of Cells.

Fluorescence and Raman bimodal imaging and Raman multifrequency imaging of Hela cells are carried out with the help of two kinds of graphene oxide-based hybrids. As a multifunctional platform, graphene oxide acts as not only a Raman probe, but also as a substrate for Raman and fluorescent probes to load on.

The impact of microplastics on sulfur REDOX processes in different soil types: A mechanism study.

Microplastics can potentially affect the physical and chemical properties of soil, as well as soil microbial communities. This could, in turn, influence soil sulfur REDOX processes and the ability of soil to supply sulfur effectively. However, the specific mechanisms driving these effects remain unclear. To explore this, soil microcosm experiments were conducted to assess the impacts of polystyrene (PS) and polyphenylene sulfide (PPS) microplastics on sulfur reduction-oxidation (REDOX) processes in black, meadow, and paddy soils. The findings revealed that PS and PPS most significantly decreased SO42- in black soil by 9.4%, elevated SO42- in meadow soil by 20.8%, and increased S2- in paddy soil by 20.5%. PS and PPS microplastics impacted the oxidation process of sulfur in soil by influencing the activity of sulfur dioxygenase, which was mediated by α-proteobacteria and γ-proteobacteria, and the oxidation process was negatively influenced by soil organic matter. PS and PPS microplastics impacted the reduction process of sulfur in soil by influencing the activity of adenosine-5'-phosphosulfate reductase, sulfite reductase, which was mediated by Desulfuromonadales and Desulfarculales, and the reduction process was positively influenced by soil organic matter. In addition to their impacts on microorganisms, it was found that PP and PPS microplastics directly influenced the structure of soil enzymes, leading to alterations in soil enzyme activity. This study sheds light on the mechanisms by which microplastics impact soil sulfur REDOX processes, providing valuable insights into how microplastics influence soil health and functioning, which is essential for optimizing crop growth and maximizing yield in future agricultural practices.

SENP2-NDR2-p21 axis modulates lung cancer cell growth.

Sentrin/small ubiquitin-like modifier (SUMO)-specific proteases (SENPs) perform pivotal roles in SUMO maturation and recycling, which modulate the balance of SUMOylation/de-SUMOylation and spatiotemporal functions of SUMOylation targets. The malfunction of SENPs often results in cellular dysfunction and various diseases. However, studies rarely investigated the correlation between SENP2 and lung cancer. This study revealed that SENP2 is a required contributor to lung cancer-cell growth and targets nuclear Dbf2-related 2 (NDR2, also known as serine/threonine kinase 38L or STK38L) for de-SUMOylation, which improves NDR2 kinase activity. This condition leads to the instability of downstream target p21 in accelerating the G1/S cell cycle transition and suggests SENP2 as a promising therapeutic target for lung cancer in the future. Specifically, astragaloside IV, an active ingredient of Jinfukang Oral Liquid (JOL, a clinical combination antilung cancer drug approved by the National Food and Drug Administration (FDA) of China), can repress lung cancer-cell growth via the SENP2-NDR2-p21 axis, which provides new insights into the molecular mechanism of JOL for lung cancer treatment.

Effect of Air Pollution Particulate Matter on Ischemic and Hemorrhagic Stroke: A Scoping Review.

Air pollution particulate matter (PM) exposure has been established as a risk factor for stroke. However, few studies have investigated the effects of PM exposure on stroke subtypes (ischemic and hemorrhagic stroke). Ischemic (IS) and hemorrhagic strokes (HS) involve distinctive pathophysiological pathways and may be differentially influenced by PM exposure. This review aims to characterize the effects of PM exposure on ischemic and hemorrhagic strokes. It also identifies subpopulations that may be uniquely vulnerable to PM toxicity. Pubmed was queried from 2000 to 2023 to identify clinical and epidemiological studies examining the association between PM exposure and stroke subtypes (ischemic and hemorrhagic stroke). Inclusion criteria were: 1) articles written in English 2) clinical and epidemiological studies 3) studies with a clear definition of stroke, IS, HS, and air pollution 4) studies reporting the effects of PM and 5) studies that included distinct analyses per stroke subtype. Two independent reviewers screened the literature for applicable studies. A total of 50 articles were included in this review. Overall, PM exposure increases ischemic stroke risk in both lightly and heavily polluted countries. The association between PM exposure and hemorrhagic stroke is variable and may be influenced by a country's ambient air pollution levels. A stronger association between PM exposure and stroke is demonstrated in older individuals and those with pre-existing diabetes. There is no clear effect of sex or hypertension on PM-associated stroke risk. Current literature suggests PM exposure increases ischemic stroke risk, with an unclear effect on hemorrhagic stroke risk. Older patients and those with pre-existing diabetes may be the most vulnerable to PM toxicity. Future investigations are needed to characterize the influence of sex and hypertension on PM-associated stroke risk.

Rapid and sensitive determination of Se and heavy metals in foods using electrothermal vaporization inductively coupled plasma mass spectrometry with a novel transportation system.

Rapid, sensitive and simultaneous determination of trace multi-elements in various plant food samples such as grain, oilseed, vegetable and tea is always a challenge thus far. In this work, a rapid determination method for Se, Cd, As and Pb in food samples by inductively coupled plasma mass spectrometry (ICP-MS) using slurry sampling electrothermal vaporization (SS-ETV) was developed. To improve the analytical sensitivity and precision as well as eliminate the memory effect, a gas turbulator line and signal delay device (SDD) were for the first time designed for the graphite furnace (GF) ETV coupled with ICP-MS. The signal acquisition parameters of ICP-MS, ashing and vaporization conditions, and the flow rates of carrier gas and gas turbulator were investigated for Se, Cd, As and Pb in food samples. Under the optimized conditions, the limits of determination (LODs) for Se, Cd, As and Pb were 0.5 ng g-1, 0.3 ng g-1, 0.3 ng g-1 and 0.6 ng g-1, respectively; the limits of quantification (LOQs) for Se, Cd, As and Pb were 1.7 ng g-1, 1.0 ng g-1, 1.0 ng g-1 and 1.9 ng g-1, respectively; linearity (R2) in the range of 1 to 4,000 ng g-1 was >0.999 using the standard addition method. This method was used to analyze 5 CRMs including rice, tea and soybeans, and the concentrations detected by this method were within the range of the certified values. The recoveries of Se, Cd, As and Pb in plant food matrices including grain, oilseed, celery, spinach, carrot and tea samples were 86-118% compared to the microwave digestion ICP-MS method; and the relative standard deviations (RSDs) were 1.2-8.9% for real food sample analysis, proving a good precision and accuracy for the simultaneous determination of multi-elements. The analysis time was less than 3 min, slurry preparation time < 5 min without sample digestion process. The proposed direct slurry sampling ICP-MS method is thus suitable for rapid and sensitive determination of Se, Cd, As and Pb in food samples with advantages such as simplicity, green and safety, as well as with a promising application potential in detecting more elements to protect food safety and human health.

Design and Experiment of a Biomimetic Duckbill-like Vibration Chain for Physical Weed Control during the Rice Tillering Stage.

The widespread use of chemical herbicides has jeopardized concerns about food safety and ecological consequences. To address these issues and reduce reliance on chemical herbicides, a physical weed control device was developed for the tillering stage in paddy fields. This device features a biomimetic duckbill-like vibration chain that effectively controls weed outbreaks. The chain penetrates the soft surface soil of the paddy field under gravity and rapidly stirs the soil through vibration, leading to the detachment of the weed roots anchored in the surface layer. Simultaneously, the device avoids mechanical damage to rice seedlings rooted in deeper soil. This study aimed to investigate the effects of chain structural parameters (the number of chain rows, vibration amplitude, and length of chains) and operational parameters (vibration frequency and working velocity) on weed control efficiency and rice seedling damage. Through a central composite regression field test, the optimal device structure and operational parameters were determined. The optimization results demonstrated that a vibration amplitude of 78.8 mm, a chain length of 93.47 cm, and 3.4 rows of chains, along with a vibration frequency and working velocity ranging from 0.5 to 1.25 m/s, achieved an optimal weeding effect. Under the optimal parameter combination, field test results demonstrated that approximately 80% of the weeds in the field were effectively cleared. This indicates that the design of the biomimetic duckbill-like vibration chain weeding device exhibits a relatively superior weeding performance, offering a practical solution for the management of weeds in rice fields.

Magnetic resonance imaging of white matter response to diesel exhaust particles.

Air pollution is associated with risks of dementia and accelerated cognitive decline. Rodent air pollution models have shown white matter vulnerability. This study uses diffusion tensor imaging (DTI) to quantify changes to white matter microstructure and tractography in multiple myelinated regions after exposure to diesel exhaust particulate (DEP). Adult C57BL/6 male mice were exposed to re-aerosolized DEP (NIST SRM 2975) at a concentration of 100 ug/m3 for 200 hours. Ex-vivo MRI analysis and fractional anisotropy (FA)-aided white matter tractography were conducted to study the effect of DEP exposure on the brain white matter tracts. Immunohistochemistry was used to assess myelin and axonal structure. DEP exposure for 8 weeks altered myelin composition in multiple regions. Diffusion tensor imaging (DTI) showed decreased FA in the corpus callosum (30%), external capsule (15%), internal capsule (15%), and cingulum (31 %). Separate immunohistochemistry analyses confirmed prior findings. Myelin basic protein (MBP) was decreased (corpus callosum: 28%, external capsule: 29%), and degraded MPB increased (corpus callosum: 32%, external capsule: 53%) in the DEP group. White matter is highly susceptible to chronic DEP exposure. This study demonstrates the utility of DTI as a neuroanatomical tool in the context of air pollution and white matter myelin vulnerability.