Direct Effect Of Radiation Research Articles

Effects of low-dose gamma radiation on DNA measured using a quartz tuning fork sensor

Despite the expected direct effects of radiation on DNA through its direct interaction with the biomolecule, research indicates that radiation also interacts with the DNA’s environment, resulting in indirect effects. Therefore, in this study, we explored the feasibility of using the quartz tuning fork (QTF) sensor system in biomedical applications, specifically in detecting DNA damage caused by low doses of gamma radiation, directly and indirectly. We differentiated between direct and indirect damage by analyzing the fork’s resonance frequency changes. This experiment was divided into three stages: before, during, and after irradiation. Each stage involved samples of pure DNA and DNA in a 60-µL aqueous solution, evaluated under identical conditions. Before irradiation, we measured frequency shifts (Δf) over a 20-min period, resulting in values of 19.34, 20.25, and 7.6 Hz for water, DNA, and DNA in water, respectively. Subsequently, the samples were irradiated with cesium-137 for the specified duration, resulting in frequency shifts of ∼ 39.21, 28.37, and 41.23 Hz for the same conditions. Our investigations showed an increase in Δf from 20.25 to 28.3 Hz at doses ranging from 7.5 to 30 µGy for pure DNA. Interestingly, DNA in aqueous solution exhibited hypersensitivity to radiation, with frequency shifts ranging from 7.6 to 41.23 Hz. Furthermore, we observed a significant difference in frequency shift after irradiation between pure DNA and DNA in water, with shifts of ∼ 70.75–98.45 Hz and 56.32–79.28 Hz for DNA and DNA in water, respectively. This result indicates a significant increase in DNA damage in aqueous environments, driven by the generation of active hydroxyl radicals (OH−), resulting in base damage and an associated increase in strand breaks. Consequently, our research indicates a lack of substantial direct impact on DNA repair owing to the absence of a conducive postirradiation environment. Therefore, QTF is a valuable biomarker for radiation sensitivity and is promising for future applications as a mass-sensitive biosensor.

Problems of late radiation injuries of the skin and possibilities of their treatment

Currently there is a problem of insufficient effectiveness of treatment of late radiation skin lesions. Possibilities of application of combined schemes of treatment of malignant neoplasms, including radiation therapy, show both good immediate and distant results, life expectancy of patients has increased. However, the issue of such remote local radiation lesions as radiation ulcers also remains relevant. Such lesions in the practice of clinical oncologists usually occur from 1-1,5 months and more after the end of the course of close-focus X-ray therapy for skin cancer. The peculiarity of radiation ulcers is that they heal extremely poorly even by secondary tension. In the pathogenesis of late radiation ulcers, along with disruption of microcirculation, the main role is played by the direct damaging effect of radiation on stem cells and, consequently, suppression of reparative processes. For this reason, such ulcerous defects are characterized by torpidity to drug and surgical treatment. The analysis of modern scientific and practical literature does not fully reveal the peculiarities of the pathogenesis of post-radiation skin lesions leading to the development of radiation ulcers. Researchers have set a goal to search for new modern methods of effective treatment of this pathology. The main purpose of the literature review was to theoretically substantiate the possibilities of including enzyme antioxidants and epidermal growth factor preparations into the complex of pathogenetic treatment of radiation skin ulcers. Superoxide dismutase (SOD) is an active enzyme-antioxidant, it neutralizes excessive free oxygen radicals, and also has a pronounced anti-inflammatory effect by means of oxidative post-radiation stress of skin tissues. Epidermal growth factor promotes cell growth and differentiation of stem cells (SC) involved in ulcer defect regeneration. Pathogenetically justified stepwise application of these drugs will improve the effectiveness of treatment of post-radiation skin ulcers. This paper presents the current information about the pathogenesis of late radiation skin ulcers, the mechanism of action of SOD, epidermal growth factor preparations, as well as the importance of the microenvironment and the homing effect in controlling the links of the pathogenesis of radiation ulcers and the possibility of their reparative regeneration.

Moving beyond the Aerosol Climatology of WRF-Solar: A Case Study over the North China Plain

Abstract Numerical weather prediction (NWP), when accessible, is a crucial input to short-term solar power forecasting. WRF-Solar, the first NWP model specifically designed for solar energy applications, has shown promising predictive capability. Nevertheless, few attempts have been made to investigate its performance under high aerosol loading, which attenuates incoming radiation significantly. The North China Plain is a polluted region due to industrialization, which constitutes a proper testbed for such investigation. In this paper, aerosol direct radiative effect (DRE) on three surface shortwave radiation components (i.e., global, beam, and diffuse) during five heavy pollution episodes is studied within the WRF-Solar framework. Results show that WRF-Solar overestimates instantaneous beam radiation up to 795.3 W m−2 when the aerosol DRE is not considered. Although such overestimation can be partially offset by an underestimation of the diffuse radiation of about 194.5 W m−2, the overestimation of the global radiation still reaches 160.2 W m−2. This undesirable bias can be reduced when WRF-Solar is powered by Copernicus Atmosphere Monitoring Service (CAMS) aerosol forecasts, which then translates to accuracy improvements in photovoltaic (PV) power forecasts. This work also compares the forecast performance of the CAMS-powered WRF-Solar with that of the European Centre for Medium-Range Weather Forecasts model. Under high aerosol loading conditions, the irradiance forecast accuracy generated by WRF-Solar increased by 53.2% and the PV power forecast accuracy increased by 6.8%. Significance Statement Numerical weather prediction (NWP) is the “go-to” approach for achieving high-performance day-ahead solar power forecasting. Integrating time-varying aerosol forecasts into NWP models effectively captures aerosol direct radiation effects, thereby enhancing the accuracy of solar irradiance forecasts in heavily polluted regions. This work not only quantifies the aerosol effects on global, beam, and diffuse irradiance but also reveals the physical mechanisms of irradiance-to-power conversion by constructing a model chain. Using the North China Plain as a testbed, the performance of WRF-Solar on solar power forecasting on five severe pollution days is analyzed. This version of WRF-Solar can outperform the European Centre for Medium-Range Weather Forecasts model, confirming the need for generating high spatial–temporal NWP.

Quantitative Assessment of the Impact of Climate Change on the Growing Season of Vegetation Gross Primary Productivity in the Middle and Lower Reaches of the Yangtze River

Quantitatively determining the direct, indirect, and comprehensive effects of climatic factors on the growing season of the vegetation GPP (GPPGS) in the middle and lower reaches of the Yangtze River at the regional and vegetation type scales can provide a scientific basis for the management and restoration of regional vegetation resources under the background of global climate change. Using MODIS GPP data, meteorological data, and vegetation type data, combined with Theil-Sen Median trend analysis and the Mann-Kendall significance test, the spatiotemporal characteristics of the GPPGS in the middle and lower reaches of the Yangtze River were investigated at different temporal and spatial scales. Path analysis was used to further reveal the direct, indirect, and comprehensive effects of climate factors on GPPGS variation in different vegetation types. The results showed that:① from 2000 to 2021, the vegetation GPPGS in the middle and lower reaches of the Yangtze River showed a fluctuating upward trend, with a rising rate (in terms of C, same below) of 2.70 g·(m2·a)-1 (P<0.01). The GPPGS of different vegetation types all showed a significant upward trend (P<0.01), with shrubs having the highest upward rate of 3.31 g·(m2·a)-1 and cultivated vegetation having the lowest upward rate of 2.54 g·(m2·a)-1. ② The proportion of the area with an upward trend in GPPGS in the middle and lower reaches of the Yangtze River was 88.11%. The proportion of the area with an upward trend in GPPGS was greater than 84% for all different vegetation types, with shrubs (49.76%) and cultivated vegetation (44.36%) having significantly higher proportions of the area with an upward trend than that in other vegetation types. ③ The path analysis results showed that precipitation and the maximum temperature had a significant positive direct effect on vegetation GPPGS (P<0.05), whereas solar radiation had a non-significant positive effect (P ≥ 0.05). The indirect effects of maximum temperature, precipitation, and solar radiation on vegetation GPPGS were all non-significantly negative (P ≥ 0.05). Under the combined effects of direct and indirect influences, precipitation and maximum temperature had a non-significant positive effect on vegetation GPPGS (P ≥ 0.05), whereas solar radiation had a non-significant negative effect on vegetation GPPGS (P ≥ 0.05). Among different vegetation types, precipitation was the main climate factor affecting the changes in GPPGS of cultivated vegetation, whereas the maximum temperature was the main climate factor affecting the changes in GPPGS of coniferous forests, broad-leaved forests, shrubs, and grasslands. ④ The changes in vegetation GPPGS in the middle and lower reaches of the Yangtze River were mainly influenced by the direct effects of maximum temperature, precipitation, and solar radiation, with the direct effect of precipitation dominating 56.72% of the changes in GPPGS. The research results can provide a reference for quantifying the carbon sequestration potential of vegetation in the middle and lower reaches of the Yangtze River and formulating ecological restoration governance policies tailored to local conditions under the background of global climate change.

Impacts of aerosol meteorological feedback on China's yield potential of soybean

AbstractChina's severe particle pollution could affect the regional climate and weather conditions that consequently threaten local to global food security. Yet, the underlying mechanisms and quantitative assessment of aerosols on crop yields remain unknown. Here, by integrating a meteorology–chemistry model and a crop model, we show the impacts of atmospheric aerosols on China's meteorology and soybean yields. We find that the potential yields of soybean would decrease in most parts of China due to direct aerosol radiation effects, while showing diverse responses in parts of the Northeast and North China Plain. Moreover, because of the high sensitivity of soybean growth to water, potential yield fluctuations are closely related to aerosol‐induced precipitation changes in most soybean‐growing regions of China. In particular, aerosols play the most important role during soybean's pod‐filling stage, in which the influence of both precipitation perturbations and negative solar radiative forcing is about 5–10 times that of air temperature on crop yield. Our study thereby identifies aerosol mitigation can bring a notable increase in crop yields, highlighting the potential for important co‐benefits in food security across polluting developing countries.

Low-dose radiation therapy for COVID-19

Background. Radiation therapy is one of the most effective treatments in patients with malignant neoplasms, it also plays an important role in the treatment of non-oncological di­seases. The coronavirus disease 2019 (COVID-19) pandemic has prompted a review of the long-forgotten idea of using low-dose radiation therapy (LDRT) in patients with lobar and interstitial pneumonia. Historically, from 1905 to the mid-1940s, LDRT was used to treat pneumonia, and evidence suggests that it might improve survival and provide rapid relief of respiratory symptoms. The purpose was to summarize current information about ­using low-dose radiation therapy in the treatment of patients with ­COVID-19. Materials and methods. A selection of publications was carried out, which covered information on the possibilities of using low-dose radiation therapy in the treatment of patients with COVID-19. At the first stage, a search was conducted for lite­rary sources using the keywords: COVID-19, low-dose radiation therapy. At the second stage, summaries of articles were studied and publications that did not meet the research criteria were excluded. At the third stage, the full texts of the selected articles were studied for compliance with the criteria for inclusion in the reference list and research relevance. Results. As of August 1, 2023, according to ClinicalTrials.gov, among 9,244 clinical trials associated with COVID-19, sixteen are currently being conduc­ted. They examine the effectiveness of LDRT in the treatment of patients with COVID-19 and already involve 1,038 patients. The largest number of studies is conducted in European countries. It has been shown that LDRT selectively attenuates oxidative stress to an inflammatory stimulus and inhibits the nitric oxide production pathway. This may contribute to its anti-inflammatory and vascular effects. At the same time, heme oxygenase 1 and other antioxidants are induced, they are mediated by Nrf2, which is the main regulator of endogenous antioxidant, anti-stress, analgesic reactions, and is also closely related to nicotinamide adenine dinucleotide phosphate and the metabolic pathway of pentose phosphate. Nrf2 may be critical for pain relief associated with edema formation and possibly plays a major role in the effects of LDRT, whereas direct functional effects of low-dose radiation on the autonomic nervous system and nociception are likely to be smaller. Conclusions. From 1905 to 1946, researchers published the results of more than 15 clinical studies on the effectiveness of radiotherapy for inflammatory lung diseases, which included more than 850 patients and demonstrated the high therapeutic effectiveness of radiation therapy in the indicated pathology. Today, there are 16 ongoing clinical trials in the world devoted to the study of LDRT effectiveness in the treatment of patients with COVID-19, in which 1,038 patients have already been involved. The risk of radiation-induced lung and breast cancer in a 25-year-old woman exposed to 1 Gy whole chest radiation may be as high as 5.9 and 5.5 %, respectively.

Changes in molecular conformation and electronic structure of DNA under 12C ions based on first-principles calculations

Fundamental studies on the interaction between ionizing radiation and deoxyribonucleic acid (DNA) can contribute to understanding the biological effects of radiation protection and radiotherapy. The transitional process from ionized and excited DNA to DNA lesions, such as strand breaks and base lesions, remains uncertain. In this study, we focused in particular on the direct effects of radiation on DNA and calculated the number of ionizations induced within 10 base pairs of DNA using the Particle and Heavy Ion Transport code System, a general-purpose Monte Carlo code for radiation transport. The electronic structure of the ionized DNA is subsequently calculated using the first-principles calculation software OpenMX. Through these calculations, we successfully identified the redox site of DNA and quantitatively evaluated the amount of molecular bond cleavage. The scientific findings of this study will elucidate the cleavage mechanism of DNA in the high-density radiation field realized by ion beam irradiation by determining the redox sites.

Roles of radiation reabsorption on flame speed and NO emission during ammonia combustion with syngas blending at elevated pressures

The radiative properties of NH3 and CO have considerable effects on ammonia-syngas flames, which has not been investigated at present. Radiation reabsorption effects on flame speed and NO production of one-dimensional premixed ammonia/syngas/air laminar flames were studied, encompassing a wide syngas content range and elevated pressures up to 25 atm. The improvement of flame speeds by radiation reabsorption reached 25.9% and decreased with rising syngas content, controlled by the direct-radiation effect and the reaction NH2 + NO = N2H + OH (R287). The relative enhancement of NO production decreased from 19.7% to 1.1% with increasing syngas content, affected by N + OH = NO + H (R273). The radiation reabsorption increased the flame speed by 25% at 18 atm. The coupling impact of high pressure and radiation reabsorption on flame speed was dominated by NH + NO = N2O + H (R279) and R287 via NH and OH radicals, respectively.

Stereotactic arrhythmia radioablation: A multicenter pre-post intervention safety evaluation of the implantable cardioverter-defibrillator function

BackgroundStereotactic arrhythmia radioablation (STAR) appears to be beneficial in selected patients with therapy-refractory ventricular tachycardia (VT). However, high-dose radiotherapy used for STAR-treatment may affect functioning of the patients’ implantable cardioverter defibrillator (ICD) by direct effects of radiation on ICD components or cardiac tissue. Currently, the effect of STAR on ICD functioning remains unknown. MethodsA retrospective pre-post multicenter study evaluating ICD functioning in the 12-month before and after STAR was performed. Patients with (non)ischemic cardiomyopathies with therapy-refractory VT and ICD who underwent STAR were included and the occurrence of ICD-related adverse events was collected. Evaluated ICD parameters included sensing, capture threshold and impedance. A linear mixed-effects model was used to investigate the association between STAR, radiotherapy dose and changes in lead parameters over time. ResultsIn total, 43 patients (88% male) were included in this study. All patients had an ICD with an additional right atrial lead in 34 (79%) and a ventricular lead in 17 (40%) patients. Median ICD-generator dose was 0.1 Gy and lead tip dose ranged from 0-32 Gy. In one patient (2%), a reset occurred during treatment, but otherwise, STAR and radiotherapy dose were not associated with clinically relevant alterations in ICD leads parameters. ConclusionsSTAR treatment did not result in major ICD malfunction. Only one radiotherapy related adverse event occurred during the study follow-up without patient harm. No clinically relevant alterations in ICD functioning were observed after STAR in any of the leads. With the reported doses STAR appears to be safe.

Dioctyl ether radiolysis under used nuclear fuel reprocessing conditions: Foundational knowledge for the development of sacrificial ligand grafts

Radiation-induced ligand destruction and concomitant degradation product formation is unavoidable under envisioned used nuclear fuel reprocessing conditions, and ultimately limits the recyclability of a given solvent system formulation. With this in mind, a novel approach to ligand innovation for advanced separations processes is in the design of tailored “protomolecules,” which when exposed to ionizing radiation undergo desired chemical transformations, thereby allowing for a reprocessing solvent system to advantageously evolve with absorbed radiation dose. Here we provide foundational knowledge for the time-resolved (electron pulse) and steady-state (cobalt-60 gamma) radiolytic behavior of dioctyl ether, a protomolecule grafting surrogate. Gamma irradiation of single-phase solutions of dioctyl ether (5–100 vol.%) in n-dodecane resulted in the loss of dioctyl ether (G ≤ −0.72 μmol J−1) and the formation of octane (G ≤ 0.11 μmol J−1) and octanol (G ≤ 0.15 μmol J−1) degradation products, the latter of which is a known reprocessing phase modifier and radioprotectant. These radiation-induced changes were attributed to direct radiation effects, for more concentrated dioctyl ether solutions, and indirect radiation effects, predominantly driven by the reaction of dioctyl ether with the dodecane radical cation, for which we report a second-order rate coefficient of k = (1.53 ± 0.05) × 1010 L mol−1 s−1. Under typical biphasic extraction (4.0 mol L−1 HNO3) and strip (0.1 mol L−1 HNO3) reprocessing conditions, gamma irradiation of 5 vol.% dioctyl ether solvent systems afforded negligible change in the rate of parent molecule destruction but promoted significant differences in the radiolytic behavior of its degradation products. These differences are attributed to their respective interactions with [dioctyl ether•HNO3•H2O] and [octanol•HNO3•H2O] adducts extracted into the organic phase. Overall, these results support the grafting of ether linkages to advanced separations ligands (e.g., modified diglycolamides).

Study on the characteristics of actinic radiation and direct aerosol radiation effects in the Pearl River Delta region

Combined air pollution prevails in the Pearl River Delta (PRD) region in recent years; large amounts of aerosols have caused a significant attenuation of actinic radiation. Solar radiation is the driving energy for photochemical reactions and plays an important role in the ozone formation. In this study, characteristics of actinic radiation and atmospheric composition in the PRD region have been analyzed based on long-term observation. The radiation transfer model (SBDART) is used to quantitatively estimate the direct radiation effect and actinic radiation effect of aerosol. Results indicate that PM2.5 concentration and atmospheric extinction coefficient have shown a downward trend. Meanwhile, ozone and Single Scattering Albedo (SSA) have increased. The average value of SSA is 0.914 ± 0.041, attaining the highest level in spring, followed by autumn and summer, and the lowest is found in winter. A linear relationship between UVA/UVB of actinic radiation flux and solar shortwave radiation has been revealed. Through the conversion formula proposed in the article, conventional radiation data can be converted into actinic radiation flux and species photolysis rate. The actinic radiation and radiation attenuation caused by aerosols shows an overall downward trend at the surface. In the ultraviolet to visible wavelength range (280–670 nm), the annual average attenuation of aerosol direct radiation and actinic radiation is 61.6 ± 31.8 W/m2 and 120.1 ± 59.7 W/m2, respectively. The radiation attenuation caused by aerosols is the largest in spring, with little difference in summer, autumn and winter, which are 92.9 ± 42.1 W/m2, 53.7 ± 21.3 W/m2, 48.0 ± 13.7 W/m2 and 52.1 ± 15.8 W/m2, respectively. The attenuation of actinic radiation caused by aerosol is the largest in spring, followed by winter, and there is little difference between summer and autumn, which are 174.8 ± 78.4 W/m2, 111.1 ± 33.1 W/m2, 98.3 ± 38.4 W/m2 and 96.7 ± 26.9 W/m2, respectively. The direct radiation effect of aerosol and the actinic radiation effect have opposite trends with increasing height. Below the aerosol scale height, the larger SSA is corresponding with greater radiant flux, and it is opposite above the aerosol scale height. SSA has the same effect on the actinic radiant flux of the entire layer: The larger SSA is in accordance with greater actinic radiant flux.

RADIOTHERAPY SIMULATION METHODS USED IN LABORATORY STUDIES OF RADIATION DAMAGE TO THE DENTITION: A SYSTEMATIC REVIEW

Objective To investigate the radiation simulation methods used in vitro and ex vivo studies to assess the direct effects of radiation on dental microhardness, chemical, and biochemical alterations. Study Design Searches were performed in PubMed, Scopus, Embase, and grey literature. Preclinical studies that examined the effect of radiation on permanent teeth were included. We used the modified CONSORT checklist of items for reporting preclinical studies to assess the risk of bias. Results Thirty-two studies met the inclusion criteria. The average radiation dose of in vitro studies was 53 (±22) Gy and 69 (±1) Gy in ex vivo studies. Twenty-two studies used five different fractionation schemes. Twenty-two of the included studies did not report the radiotherapy modality of those reporting, and 6 m-V was the energy most often used. Twenty studies used linear accelerators, and seven used Cobalt-60 with the source-surface-distance of radiation ranging from 1.5 to 100 cm. Distilled water was the most reported storage solution for the dental structure used. Conclusion The heterogeneity between radiation simulation methods used in the laboratory studies, such as radiation dose, radiotherapy modality, fractionation regime, and the storage solutions used, limit the conclusion regarding the direct effect of radiation on dental microstructure changes. To investigate the radiation simulation methods used in vitro and ex vivo studies to assess the direct effects of radiation on dental microhardness, chemical, and biochemical alterations. Searches were performed in PubMed, Scopus, Embase, and grey literature. Preclinical studies that examined the effect of radiation on permanent teeth were included. We used the modified CONSORT checklist of items for reporting preclinical studies to assess the risk of bias. Thirty-two studies met the inclusion criteria. The average radiation dose of in vitro studies was 53 (±22) Gy and 69 (±1) Gy in ex vivo studies. Twenty-two studies used five different fractionation schemes. Twenty-two of the included studies did not report the radiotherapy modality of those reporting, and 6 m-V was the energy most often used. Twenty studies used linear accelerators, and seven used Cobalt-60 with the source-surface-distance of radiation ranging from 1.5 to 100 cm. Distilled water was the most reported storage solution for the dental structure used. The heterogeneity between radiation simulation methods used in the laboratory studies, such as radiation dose, radiotherapy modality, fractionation regime, and the storage solutions used, limit the conclusion regarding the direct effect of radiation on dental microstructure changes.

Heavy Ion Radiation Directly Induced the Shift of Oral Microbiota and Increased the Cariogenicity of Streptococcus mutans.

Radiation caries is one of the most common complications of head and neck radiotherapy. A shift in the oral microbiota is the main factor of radiation caries. A new form of biosafe radiation, heavy ion radiation, is increasingly being applied in clinical treatment due to its superior depth-dose distribution and biological effects. However, how heavy ion radiation directly impacts the oral microbiota and the progress of radiation caries are unknown. Here, unstimulated saliva samples from both healthy and caries volunteers and caries-related bacteria were directly exposed to therapeutic doses of heavy ion radiation to determine the effects of radiation on oral microbiota composition and bacterial cariogenicity. Heavy ion radiation significantly decreased the richness and diversity of oral microbiota from both healthy and caries volunteers, and a higher percentage of Streptococcus was detected in radiation groups. In addition, heavy ion radiation significantly enhanced the cariogenicity of saliva-derived biofilms, including the ratios of the genus Streptococcus and biofilm formation. In the Streptococcus mutans-Streptococcus sanguinis dual-species biofilms, heavy ion radiation increased the ratio of S. mutans. Next, S. mutans was directly exposed to heavy ions, and the radiation significantly upregulated the gtfC and gtfD cariogenic virulence genes to enhance the biofilm formation and exopolysaccharides synthesis of S. mutans. Our study demonstrated, for the first time, that direct exposure to heavy ion radiation can disrupt the oral microbial diversity and balance of dual-species biofilms by increasing the virulence of S. mutans, increasing its cariogenicity, indicating a potential correlation between heavy ions and radiation caries. IMPORTANCE The oral microbiome is crucial to understanding the pathogenesis of radiation caries. Although heavy ion radiation has been used to treat head and neck cancers in some proton therapy centers, its correlation with dental caries, especially its direct effects on the oral microbiome and cariogenic pathogens, has not been reported previously. Here, we showed that the heavy ion radiation directly shifted the oral microbiota from a balanced state to a caries-associated state by increasing the cariogenic virulence of S. mutans. Our study highlighted the direct effect of heavy ion radiation on oral microbiota and the cariogenicity of oral microbes for the first time.

Fully Microfabricated Surface Acoustic Wave Tweezer for Collection of Submicron Particles and Human Blood Cells.

Precise manipulation of (sub)micron particles is key for the preparation, enrichment, and quality control in many biomedical applications. Surface acoustic waves (SAW) hold tremendous promise for manipulation of (bio)particles at the micron to nanoscale ranges. In commonly used SAW tweezers, particle manipulation relies on the direct acoustic radiation effect whose superior performance fades rapidly when progressing from micron to nanoscale particles due to the increasing dominance of a second order mechanism, termed acoustic streaming. Through reproducible and high-precision realization of stiff microchannels to reliably actuate the microchannel cross-section, here we introduce an approach that allows the otherwise competing acoustic streaming to complement the acoustic radiation effect. The synergetic effect of both mechanisms markedly enhances the manipulation of nanoparticles, down to 200 nm particles, even at relatively large wavelength (300 μm). Besides spherical particles ranging from 0.1 to 3 μm, we show collections of cells mixed with different sizes and shapes inherently existing in blood including erythrocytes, leukocytes, and thrombocytes.

Insights into dissolved organics in non-urban areas - Optical properties and sources

Brown carbon aerosols show obvious light absorption properties in the ultraviolet–visible (UV–Vis) range, which has an important impact on photochemistry and climate. In this study, experimental samples originated from the North slope of the Qinling Mountains (at two remote suburb sites) to study the optical properties of water-soluble brown carbon (WS–BrC) in PM2.5. The WS-BrC of TY (a sampling site on the edge of Tangyu of Mei county) has a stronger light absorption ability than CH (a rural sampling site, near the Cuihua Mountains scenic spot). The direct radiation effect of WS-BrC relative to elemental carbon (EC) is 6.67 ± 1.36% in TY and 24.13 ± 10.84% in CH in the UV range, respectively. In addition, two humic-like and one protein-like fluorophore components in WS-BrC were identified by fluorescence spectrum and parallel factor (EEMs-PARAFAC). Humification index (HIX), biological index (BIX) and fluorescence index (FI) together showed that the WS-BrC in the two sites may originate from fresh aerosol emissions. Potential source analysis of Positive Matrix Factorization (PMF) model show that the combustion process, vehicle, secondary formation and road dust are the main contributors to WS-BrC.

Radioprotective potential of probiotics against gastrointestinal and neuronal toxicity: a preclinical study

PurposeRadiotherapy is a critical component of cancer treatment, along with surgery and chemotherapy. Approximately, 90% of cancer patients undergoing pelvic radiotherapy show gastrointestinal (GI) toxicity, including bloody diarrhea, and gastritis, most of which are associated with gut dysbiosis. In addition to the direct effect of radiation on the brain, pelvic irradiation can alter the gut microbiome, leading to inflammation and breakdown of the gut–blood barrier. This allows toxins and bacteria to enter the bloodstream and reach the brain. Probiotics have been proven to prevent GI toxicity by producing short-chain fatty acids and exopolysaccharides beneficial for protecting mucosal integrity and oxidative stress reduction in the intestine and also shown to be beneficial in brain health. Microbiota plays a significant role in maintaining gut and brain health, so it is important to study whether bacterial supplementation will help in maintaining the gut and brain structure after radiation exposure.MethodsIn the present study, male C57BL/6 mice were divided into control, radiation, probiotics, and probiotics + radiation groups. On the 7th day, animals in the radiation and probiotics + radiation groups received a single dose of 4 Gy to whole-body. Posttreatment, mice were sacrificed, and the intestine and brain tissues were excised for histological analysis to assess GI and neuronal damage.ResultsRadiation-induced damage to the villi height and mucosal thickness was mitigated by the probiotic treatment significantly (p < 0.01). Further, radiation-induced pyknotic cell numbers in the DG, CA2, and CA3 areas were substantially reduced with bacterial supplementation (p < 0.001). Similarly, probiotics reduced neuronal inflammation induced by radiation in the cortex, CA2, and DG region (p < 0.01). Altogether, the probiotics treatment helps mitigate radiation-induced intestinal and neuronal damage.ConclusionIn conclusion, the probiotic formulation could attenuate the number of pyknotic cells in the hippocampal brain region and decrease neuroinflammation by reducing the number of microglial cells.

Neck and Upper Extremity Musculoskeletal Symptoms Secondary to Maladaptive Postures Caused by Cell Phones and Backpacks in School-Aged Children and Adolescents.

Technology is an essential part of our lives. Nowadays, it is almost impossible to leave the house without a cell phone. Despite the wide range of benefits of cell phones and handheld electronic devices, this evolution of technology has not come without a price. The pandemic of cell phone use among children and young adolescents has led to the emergence of a set of musculoskeletal (MSK) symptoms that have not been seen before in this age group. These symptoms can range from neck and shoulder discomfort to pain, peripheral neurological symptoms of the upper extremity, and long-term complications such as disk prolapse and degenerative disk disease of the cervical spine. This clinical presentation is known as "text neck syndrome." In addition to MSK symptoms, text neck syndrome could also include eye and ear symptoms, psychological problems, peripheral neurological symptoms, and poor academic performance. Multiple mechanisms have been discussed by which cell phone use causes MSK symptoms. Maladaptive postures, a decrease in physical activity leading to obesity, and the direct effect of electromagnetic radiation are some of the mechanisms by which long-term use of cell phones leads to the clinical presentation of text neck syndrome and its long-term consequences. The purpose of this article is to review the literature, discuss the epidemiology of cell phone use and MSK symptoms associated with its use in children and adolescents, describe its clinical presentation, explain the pathophysiology behind it, and provide preventative guidelines that can be used by this age group to allow for the continued use of these electronics without harmful effects on their posture and long-term health.

The ZIP9-centered androgen pathway compensates for the 2605 MHz radiofrequency electromagnetic radiation-mediated reduction in resistance to H2O2 damage in Sertoli cells of adult rats

The direct biological effects of radiofrequency electromagnetic radiation (RF-EMR) from wireless communication equipment on the testes are still unclear. Our previous study proved that long-term exposure to 2605 MHz RF-EMR gradually damage spermatogenesis and resulted in time-dependent reproductive toxicity by directly disrupting blood-testis barrier circulation. Although short-term exposure did not cause readily observable damage to fertility, whether it caused specific biological effects and how these effects contributed to the time-dependent reproductive toxicity of RF-EMR were currently unknown. Studies on this issue are important for elucidating the time-dependent reproductive toxicity of RF-EMR. The present study established a 2605 MHz RF-EMR (SAR=1.05 W/Kg) scrotal exposure model with rats and extracted primary Sertoli cells for exposure to investigate the direct biological effects of short-term RF-EMR exposure on the testis. The results showed that short-term RF-EMR exposure did not decrease sperm quality and spermatogenesis, but it increased the levels of testicular testosterone (T) and zinc transporter 9 (ZIP9) in Sertoli cells of rats. In vitro, 2605 MHz RF-EMR exposure did not increase the apoptosis rate of Sertoli cells, but it increased the apoptosis rate and MDA of Sertoli cells exposed to H2O2. T reversed these changes and increased ZIP9 level in Sertoli cells, whereas inhibiting ZIP9 expression significantly suppressed these T-mediated protective effects. Moreover, T increased the levels of phosphorylated inositol-requiring enzyme 1 (P-IRE1), phosphorylated protein kinase R (PKR)-like endoplasmic reticulum kinase (P-PERK), phosphorylated eukaryotic initiation factor 2a (P-eIF2a) and phosphorylated activating transcription factor 6 (P-ATF6) in Sertoli cells, and these effects were reversed by ZIP9 inhibition. With prolonged exposure time, testicular ZIP9 was gradually downregulated, and testicular MDA increased. ZIP9 level was negatively correlated with MDA level in the testes of exposed rats. Thus, although short-term exposure to 2605 MHz RF-EMR (SAR=1.05 W/kg) did not significantly disturb spermatogenesis, it suppressed the ability of Sertoli cells to resist external insults, which was rescued by enhancing the ZIP9-centered androgen pathway in the short term. Increasing the unfolded protein response might be an important downstream mechanism involved. These results promote a better understanding of the time-dependent reproductive toxicity of 2605 MHz RF-EMR.

Lymphocyte response and recovery to radiation therapy alone

Background: Lymphocytes are extremely radiosensitive to radiation therapy. Unfortunately the majority of the published clinical data includes chemotherapy combined with the radiation, so the direct effect of radiation alone is not clear. We report the largest published cohort of patients treated with radiation without chemotherapy.

Suicide and other causes of death among Chernobyl cleanup workers from Estonia, 1986 − 2020: an update

Mortality was studied in a cohort of 4831 men from Estonia who participated in the environmental cleanup of the radioactively contaminated areas around Chernobyl in 1986–1991. Their mortality in 1986–2020 was compared with the mortality in the Estonian male population. A total of 1503 deaths were registered among the 4812 traced men. The all-cause standardized mortality ratio (SMR) was 1.04 (95% CI 0.99–1.09). All-cancer mortality was elevated (SMR 1.16, 95% CI 1.03–1.28). Radiation-related cancers were in excess (SMR 1.20, 95% CI 1.03–1.36); however, the excesses could be attributed to tobacco and alcohol consumption. For smoking-related cancers, the SMR was 1.20 (95% CI 1.06–1.35) and for alcohol-related cancers the SMR was 1.56 (95% CI 1.26–1.86). Adjusted relative risks (ARR) of all-cause mortality were increased among workers who stayed in the Chernobyl area ≥ 92 days (ARR 1.20, 95% CI 1.08–1.34), were of non-Estonian ethnicity (ARR 1.33, 95% CI 1.19–1.47) or had lower (basic or less) education (ARR 1.63, 95% CI 1.45–1.83). Suicide mortality was increased (SMR 1.31, 95% CI 1.05–1.56), most notably among men with lower education (ARR 2.24, 95% CI 1.42–3.53). Our findings provide additional evidence that unhealthy behaviors such as alcohol and smoking play an important role in shaping cancer mortality patterns among Estonian Chernobyl cleanup workers. The excess number of suicides suggests long-term psychiatric and substance use problems tied to Chernobyl-related stressors, i.e., the psychosocial impact was greater than any direct carcinogenic effect of low-dose radiation.