Light Damage Research Articles

Data-Driven Insights Into Post-Earthquake Reconnaissance Findings: 2023 Türkiye Earthquake Sequence

Post-earthquake reconnaissance stands as a vital endeavor, encompassing a systematic survey and data collection to gain insights into the aftermath of seismic events. Grappling with a multitude of multidimensional data poses inherent challenges in the proper interpretation and extraction of hidden information. This paper unfolds in two parts. Initially, we delineate the reconnaissance mission following the February 06 Türkiye earthquake sequence, elucidating the challenges, complexities, and nature of the amassed data. Subsequently, a paradigm shift toward automated machine learning (AutoML) is embraced to ascertain the optimal model, categorize observed damages, and unveil underlying patterns within the collected data. The most accurate machine learning model is then coupled with Shapley Additive Explanations (SHAP) to explicate observations, steering away from a black-box model. SHAP values discern and prioritize factors significantly contributing to various damage levels. The results reveal a test set accuracy of 0.75 and 0.95 for multi- and binary-class problems, respectively, employing both raw and composite features. Building-related features exert more control over light damage, while earthquake-related factors dominate severe damage. In critical damage scenarios, duration- and velocity-dependent intensity measures assume significance. Furthermore, findings indicate that if column and wall indices are below 0.07 and 0.08, respectively, they positively contribute to the likelihood of critical structural damage.

PEMELIHARAAN KONSTRUKSI JALAN DENGAN METODE SDI

The Dawan-Pesinggahan Road section is one of the sections that has the status of a district road in Klungkung Regency. The Dawan Pesinggahan Road section is located in Dawan District, Dawan Village and Pesinggahan Village, which has a length of 3,300 km and an average width of 4.5 m. The Dawan – Pesinggahan Road section has existing conditions in 2021, namely 3,300 km in good condition, 0.9 km in moderate condition and there are conditions of light and heavy damage. In 2022, there will be a lot of road damage which will cause the condition of the road to decline and it is very necessary to assess the condition of the road so that we can find out what measures will be taken to restore road stability on the Dawan-Pesinggahan Road Section. Assessment of road conditions using the SDI method in Klungkung Regency was carried out on the Jl. Dawan – Stopover. The selection of this section as a sample was due to time constraints and the district road section used as a travel center in Klungkung Regency which needs to receive more attention through road management. Apart from that, the section used is a road section that visually has road damage. This research was carried out because there are still damaged roads that need to be treated quickly. This research aims to analyze road conditions, analyze the type of treatment and obtain costs for handling the road section. The data used in the research are primary data and secondary data. Primary data was obtained through a survey of road conditions by measuring road damage, while secondary data was obtained from the community development sector of the Klungkung Regency PUPRPKP Service, namely Klungkung Regency road decrees, Klungkung Regency road maps and basic Klungkung Regency road data. The research stages are, identifying road damage by taking measurements, data recapitulation by processing surveys, data analysis using the SDI method and estimating costs to repair the road. Assessment results for the Jl. Dawan – Pesinggahan Crocodile cracks at 13.54%, random cracks 18.71%, transverse cracks 17.06%, patches 14.66%, holes 12.03% and subsidence 13.24% and the estimated cost required to maintain this road section is IDR. 3,864,775,688.95

Evaluation of the Sun Protection Factor (SPF) Test for Butterfly Pea Flower (Clitoria ternatea L.) Extract Lip Tint Preparations

A lip tint is a cosmetic preparation that colors lips while shielding them from UV light and free radical damage. The butterfly pea blossom is one plant that possesses sunscreen properties and can be used as a natural dye. The purpose of this study is to ascertain how the concentration of butterfly pea flower extract affects the SPF activity of lip tint products containing this extract. This study's design is entirely random, making it an experimental investigation. The in vitro SPF test results using Uv-Vis spectrophotometry show that at a concentration of 5%, 1.618162 SPF falls into the less group; at a concentration of 10%, 4.770857 SPF falls into the medium category; and at a concentration of 15%, 6.1224069 SPF falls into the extra category. The SPF value of lip tint preparations is influenced by the varied concentrations of butterfly pea flower extract, as indicated by the statistical analysis results, which indicate significant variations between the three concentrations (p<0.05).

Inactivating Alicyclobacillus acidoterrestris spores with UVLED: Unraveling the role of turbidity, reactive oxygen species, and water dynamics

Alicyclobacillus acidoterrestris (AAT) is a spore-forming bacterium that can survive thermal pasteurization and acidic conditions. Ultraviolet light emitting diode (UVLED) has received extensive attention as a new technology to replace traditional mercury lamps for fruit juice decontamination, however, very few studies on fruit juice have been reported to investigate the sporicidal effect of UVLED on A. acidoterrestris. This research investigated for the first time the application of UVLEDs at 254 nm for the treatment of AAT in tomato juice. The optimized conditions for UVLED, achieved with the aid of Box Behnken design, were 6 cm, 12 min, and 250 mL/min. The results showed that the AAT spores in citrate buffer solution and tomato juice were inactivated by 3-log reduction with a required fluence of 53.67 mJ/cm2. Additionally, UVLED induced an exclusively cellular damage through direct absorption of UV light and direct DNA damage, and indirectly via reactive oxygen species. Besides, the deactivation of AAT spores, validated by LF-NMR analysis, indicated that the free water in AAT might be due to the rehydration of the spore core by the process of germination and then dehydration. This dehydration was further confirmed by the shrinking of spores observed through SEM and AFM imaging. These outcomes were also correlated with those of potassium ions and DPA leakage. This study emphasizes the energy-saving and resistance-reducing features of UVLED in effectively inactivating AAT.

Experimentally‐based in‐plane drift limits for the upper threshold of masonry light damage

AbstractDrift limits are useful thresholds; during design or retrofitting analyses, engineers can compare the expected behaviour of a structure to drift limits that predict when the structure will reach a certain condition. This helps ensure that structures satisfy specified performance goals when exposed to certain hazards. Masonry walls are susceptible to damage from lateral in‐plane actions such as wind or earthquake loading; ensuring that in‐plane drift remains sufficiently small will help limit this damage. Drift limits based on crack‐based damage are scarce, however, with DS1 limits being extrapolated from higher damage grades based on structural strength capacity or ductility. In this work, crack‐based damage is evaluated on a multitude of full‐scale experimental walls surveyed with digital image correlation. This method observes the initiation and propagation of cracking. Cyclically incremental in‐plane tests provide a range of drift‐damage relationships. These are explored with machine learning to determine influential predictors and ultimately establish drift limits for light damage. Two types of brick masonry are explored: fired‐clay and calcium‐silicate. For the latter, light damage begins at an in‐plane drift of 0.5 mm/m and can extend to 4.8 mm/m (or 0.48%) for the former before the masonry surpasses light damage and reaches structural damage grades. In comparison to drift limits set by other authors and (international) guidelines to characterise light damage, significant damage, or the ultimate capacity of masonry walls, the resulting drift limits for light damage from this work are set directly on the basis of experiments and are in good agreement with other authors. Most importantly, all the consulted values for ultimate capacity are much larger than the upper threshold for light damage determined herein, with limits for significant damage in the same order of magnitude. This result verifies the accuracy of the experimental crack‐based characterisation used to establish the drift thresholds.

Pistachio Consumption Increases Macular Pigment Optical Density in Healthy Adults: A Randomized Controlled Trial

BackgroundPistachios are a bioavailable source of the xanthophyll lutein. Along with zeaxanthin, these plant pigments are major components of macular pigment (MP) in the human retina. MP can be non-invasively measured and is referred to as MP optical density (MPOD). MPOD is modifiable with dietary interventions that include lutein and zeaxanthin (L/Z). Higher MPOD protects the eye from light damage and is positively associated with eye health. ObjectivesThis dietary intervention study aimed to evaluate the effect of pistachio consumption on MPOD. MethodsThis single-blinded, randomized controlled trial compared a 12-week pistachio intervention (2 oz/d) with usual diet (UD) on MPOD and serum L/Z in middle-aged to older healthy adults (n = 36) in a 1:1 randomization scheme. Participants were selected for habitually low L/Z intake and low baseline MPOD. MPOD was measured using heterochromatic flicker photometry at 4 retinal eccentricities during baseline, week 6, and week 12 study visits. Serum L/Z was analyzed using high-performance liquid chromatography. Primary statistical analysis was conducted on an intent-to-treat basis using repeated-measure analysis of variance. ResultsCompared with UD, MPOD of the participants in the pistachio intervention group (PIS) had significantly increased (P < 0.001) at all eccentricities over the initial 6-wk period. This increase was maintained at week 12. MPOD in the UD participants did not change during the 12-week period. Serum lutein concentration followed a similar pattern to MPOD; serum cis-lutein and zeaxanthin did not change in either group over the 12-wk intervention. ConclusionsThe results of our study demonstrate that a dietary intervention with pistachios is efficacious in increasing MPOD in healthy adults selected for habitually low intake of L/Z and low baseline MPOD. This suggests that pistachio consumption could be an effective dietary strategy for preserving eye health. Future studies need to evaluate the generalizability of our findings to other populations.This trial was registered at clinicaltrials.gov as NCT05283941.

Curcumin-Loaded Liposomes in Gel Protect the Skin of Mice against Oxidative Stress from Photodamage Induced by UV Irradiation.

Prolonged exposure to ultraviolet (UV) irradiation can cause oxidative stress in the skin, accompanied by rapid immunosuppressive effects, resulting in a peroxidation reaction throughout the body. Curcumin (Cur), as the bioactive compound of turmeric, is a natural polyphenol with potent antioxidant properties but is often overlooked due to its poor solubility and low bioavailability. In this study, curcumin-loaded liposomes in a sodium alginate gel complex preparation were designed to improve the bioavailability of curcumin and to study its preventive effect on photodamage. Cur-loaded liposomes (Cur-L), Cur-loaded gel (Cur-G) based on an alginate matrix, and curcumin-loaded liposomes in gel (Cur-LG) were prepared, and their antioxidant effects and drug diffusion abilities were evaluated. The antioxidant capacity of Cur, Cur-L, Cur-G, and Cur-LG was also studied in a mouse model of photodamage. Cur had the highest antioxidant activity at about 4 mg/mL. Cur-LG at this concentration showed antioxidant effects during 1,1-diphenyl-2-trinitrophenylhydrazine (DPPH) and H2O2 experiments. During the UV light damage test, Cur-LG demonstrated the ability to effectively neutralize free radicals generated as a result of lipid peroxidation in the skin, serum, and liver, thereby enhancing the overall activity of superoxide dismutase (SOD). In conclusion, using Cur-LG may protect against epidermal and cellular abnormalities induced by UV irradiation.

Cloning and Functional Analysis of a Zeaxanthin Epoxidase Gene in Ulva prolifera.

The xanthophyll cycle is a photoprotective mechanism in plants and algae, which protects the photosynthetic system from excess light damage under abiotic stress. Zeaxanthin is considered to play a pivotal role in this process. In this study, the relative content of xanthophylls was determined using HPLC-MS/MS in Ulva prolifera exposed to different salinities. The results showed that high-salt stress significantly increased the relative content of xanthophylls and led to the accumulation of zeaxanthin. It was speculated that the accumulated zeaxanthin may contribute to the response of U. prolifera to high-salt stress. Zeaxanthin epoxidase (ZEP) is a key enzyme in the xanthophyll cycle and is also involved in the synthesis of abscisic acid and carotenoids. In order to explore the biological function of ZEP, a ZEP gene was cloned and identified from U. prolifera. The CDS of UpZEP is 1122 bp and encodes 373 amino acids. Phylogenetic analysis showed that UpZEP clusters within a clade of green algae. The results of qRT-PCR showed that high-salt stress induced the expression of UpZEP. In addition, heterologous overexpression of the UpZEP gene in yeast and Chlamydomonas reinhardtii improved the salt tolerance of transgenic organisms. In conclusion, the UpZEP gene may be involved in the response of U. prolifera to high-salt stress and can improve the high-salt tolerance of transgenic organisms.

Near-infrared light induced cathodic photoelectrochemical biosensor for duplex-specific nuclease mediated detection of miRNA166-a

The photoelectrochemical (PEC) biosensor is a new sensing platform which has the merits of low background signal, low cost, easy miniaturization and so on. However, at present, most PEC biosensors utilize visible light or ultraviolet light as the excitation light source. This type of light has high energy and may cause some light damage to the detected object and some photoelectric materials, thus limiting its application scope. Herein, based on NaYF4:Yb,Tm/BiOBr0.8I0.2 a cathode PEC biosensor that can be excited by near-infrared light was constructed to avoid the occurrence of anode false positives and light damage. Through two cycles of the miRNA cycle assisted by Duplex-Specific Nuclease (DSN) and the dissolved oxygen cycle assisted by gold nanoparticles during the detection process, the detection signal was amplified and miRNA166-a was sensitively detected. By using up-conversion materials, the near-infrared light of 980 nm can be converted into ultraviolet light and visible light, thus exciting the photogenerated carriers of BiOBr0.8I0.2. The photocurrent reaction shows a positive correlation with the quantity of gold nanoparticles present on the electrode surface, which are derived from the reporter molecules produced by the hybridization of miRNA166-a and H1. It has a good linear relationship and selectivity towards miRNA166-a, and the detection limit is 0.32 fM. This sensing method provides a cathode PEC biosensor, which can be excited by near-infrared light. The overall light damage of the system is low, and the possibility of false positive of anode PEC biosensor can be avoided, which has certain significance.

Effect of Climate Change on Identification of Delayed Chilling Damage of Rice in China’s Cold Region

This study analyzed temperature and yield data from 34 meteorological stations in Heilongjiang Province during 1961–2020. Four climate averages (P1, P2, P3, and P4) were determined based on their respective time distributions (1961–1990, 1971–2000, 1981–2010, and 1991–2020). The national standard temperature anomaly index was used to identify delayed chilling damage in rice cultivation compared to these climate averages. Climate tendency rate analysis, Mann–Kendall detection, and linear regression methods were employed to examine the relationship between temperature anomaly and rice yield from May to September. The results showed that there were noticeable differences in recognizing delayed chilling damage across different climate averages from 1961 to 2020. The average duration of chilling damage under P1, P2, P3, and P4 was, respectively, estimated as 8.5 years, 13.3 years, 21.4 years, and 30.9 years, with severe cold damage accounting for a significant portion (68.2–76.0%) of the total chilling damage period. The occurrence of severe cold damage increased significantly over time while light and moderate cold damage did not show a clear increasing or decreasing trend. Based on the test results, P3 was found to be the most suitable climate average for identifying delayed chilling damage in rice cultivation from 1961 to 2020. Moreover, the incidence of chilling damage revealed declining trend over time. There was a high incidence of chilling damage in the 1960s and 1970s, followed by a decrease from the 1980s to the mid 1990s, and finally a low-incidence period after the mid-1990s. Spatially, the western regions experienced greater occurrence of chilling damage than the eastern regions. Additionally, there was a highly significant positive correlation (p &lt; 0.01) between temperature anomalies from May to September and relative meteorological yield of rice. As temperature anomalies decreased during this period, there was an observed downward trend in relative meteorological yield of rice, indicating that delayed cold injury had a negative impact on rice production.

Mechanisms of Senescence and Anti-Senescence Strategies in the Skin.

The skin is the layer of tissue that covers the largest part of the body in vertebrates, and its main function is to act as a protective barrier against external environmental factors, such as microorganisms, ultraviolet light and mechanical damage. Due to its important function, investigating the factors that lead to skin aging and age-related diseases, as well as understanding the biology of this process, is of high importance. Indeed, it has been reported that several external and internal stressors contribute to skin aging, similar to the aging of other tissues. Moreover, during aging, senescent cells accumulate in the skin and express senescence-associated factors, which act in a paracrine manner on neighboring healthy cells and tissues. In this review, we will present the factors that lead to skin aging and cellular senescence, as well as ways to study senescence in vitro and in vivo. We will further discuss the adverse effects of the accumulation of chronic senescent cells and therapeutic agents and tools to selectively target and eliminate them.

Investigation of singlet-oxygen-responsive genes in the cyanobacterium Synechocystis PCC 6803.

Singlet oxygen (1O2) is an important reactive oxygen species whose formation by the type-II, light-dependent, photodynamic reaction is inevitable during photosynthetic processes. In the last decades, the recognition that 1O2 is not only a damaging agent, but can also affect gene expression and participates in signal transduction pathways has received increasing attention. However, contrary to several other taxa, 1O2-responsive genes have not been identified in the important cyanobacterial model organism Synechocystis PCC 6803. By using global transcript analysis we have identified a large set of Synechocystis genes, whose transcript levels were either enhanced or repressed in the presence of 1O2. Characteristic 1O2 responses were observed in several light-inducible genes of Synechocystis, especially in the hli (or scp) family encoding HLIP/SCP proteins involved in photoprotection. Other important 1O2-induced genes include components of the Photosystem II repair machinery (psbA2 and ftsH2, ftsH3), iron homeostasis genes isiA and idiA, the group 2 sigma factor sigD, some components of the transcriptomes induced by salt-, hyperosmotic and cold-stress, as well as several genes of unknown function. The most pronounced 1O2-induced upregulation was observed for the hliB and the co-transcribed lilA genes, whose deletion induced enhanced sensitivity against 1O2-mediated light damage. A bioreporter Synechocystis strain was created by fusing the hliB promoter to the bacterial luciferase (lux), which showed its utility for continuous monitoring of 1O2 concentrations inside the cell.

Elimination of splash damage for smaller scribe widths in next-gen memory devices via stealth dicing

Scattered light damage (splash) is one of the common defects that can be observed from the stealth dicing process, and it is mainly due to the interaction of the pulsed laser beam with the micro-crack and modified layer formed. This might cause thermal damage on the active layer of the die and degrade the reliability and yield of the device. The development of new technology node for memory devices aims to reduce scribe width, thereby increasing the number of dies per wafer. The ongoing trend towards scribe width reduction from 120 μm to current sub-60 μm, results in increased throughput and decreased cost per die. Furthermore, this reduction allows for greater functionality integration within a confined space, thereby enhancing overall device performance. Hence, the elimination of splash during the SD process is imperative to enable further shrinking of scribe width. This paper focuses on the impact of pulse pitch and distance from 1st focal depth to silicon (Si) frontside on the maximum splash distance. Lower pulse pitch and lower distance from 1st focal depth to Si frontside will introduce higher splash distance. An empirical model for splash elimination was established to determine the critical distance from 1st focal depth to Si frontside as a function of pulse pitch.

Detection of emerald ash borer damage using an improved change detection method: Integrating host phenology and pest life history

Invasive Emerald Ash Borer (EAB) damage pose significant challenges for sustainable forest management, necessitating accurate mapping of damaged ash trees. Traditional change detection methods, using time-series imagery, are essential for monitoring forest disturbances but complicated by abnormal fluctuations in original time-series features. Tree phenology also complicates this process by masking the reflectance characteristics indicative of EAB infestation. To address these challenges, we propose an improved change detection method integrating patterns from host tree phenology and EAB life history. This improved method includes: (1) select the indices with time stability to enhance detection reliability by partial least squares method (PLS); (2) correction on negative change values before and positive change values after the phenological peak based on known patterns of tree phenology and EAB life history. Result confirms that this method effectively reflects the seasonal growth and decline dynamics of ash trees, revealing the impacts of phenology and EAB infestation. EAB-damaged trees exhibited slower growth in May and premature decline in July compared with healthy tree, with the damage severity influencing the rate of leaf decline. This proposed method achieved an overall accuracy of 53.4%-76.7% across different months for ash trees with health, light and severe damage. This study highlights the capabilities of integrating pest life history and phenology in change detection method and provide a new method to monitor individual tree health across large areas by high-resolution satellite imagery.

Earthquake-Resistant and Environmental Advantages of DIAGRID Systems in High Seismicity Zones

A comparison of the seismic response and environmental impact potential of two building systems is presented. Both buildings have 24 floors and a total height of 114 m, and are located in the Lake Zone of Mexico City. The first building, denominated traditional, uses composite (steel and reinforced concrete) moment-resisting frames and concentric diagonals. The second one, denominated innovative, is structured with steel perimetral diagonal grids and steel frames. Despite its lower weight, and smaller lateral strength and stiffness, the innovative system exhibits a superior seismic performance characterized by light damage on approximately 8% of its seismic-resistant elements for the design seismic excitation. In addition, the construction of the innovative system reduces emission of greenhouse gases by two thirds compared to its traditional counterpart. The example presented here provides an idea of the benefits that the use of innovative systems can bring to the Mexican design and building practices.

Cytokines IL-1β and IL-10 are required for Müller glia proliferation following light damage in the adult zebrafish retina

Zebrafish possess the ability to regenerate dying neurons in response to retinal injury, with both Müller glia and microglia playing integral roles in this response. Resident Müller glia respond to damage by reprogramming and undergoing an asymmetric cell division to generate a neuronal progenitor cell, which continues to proliferate and differentiate into the lost neurons. In contrast, microglia become reactive, phagocytose dying cells, and release inflammatory signals into the surrounding tissue following damage. In recent years, there has been increased attention on elucidating the role that microglia play in regulating retinal regeneration. Here we demonstrate that inflammatory cytokines are differentially expressed during retinal regeneration, with the expression of a subset of pro-inflammatory cytokine genes upregulated shortly after light damage and the expression of a different subset of cytokine genes subsequently increasing. We demonstrate that both cytokine IL-1β and IL-10 are essential for Müller glia proliferation in the light-damaged retina. While IL-1β is sufficient to induce Müller glia proliferation in an undamaged retina, expression of IL-10 in undamaged retinas only induces Müller glia to express gliotic markers. Together, these findings demonstrate the essential role of inflammatory cytokines IL-1β and IL-10 on Müller glia proliferation following light damage in adult zebrafish.

Differences between long- and short-wavelength light–induced retinal damage and the role of PARP-1 in retinal injury induced by blue light

Photobiomodulation (PBM) therapy uses light of different wavelengths to treat various retinal degeneration diseases, but the potential damage to the retina caused by long-term light irradiation is still unclear. This study were designed to detect the difference between long- and short-wavelength light (650-nm red light and 450-nm blue light, 2.55 mW/cm2, reference intensity in PBM)–induced injury. In addition, a comparative study was conducted to investigate the differences in retinal light damage induced by different irradiation protocols (short periods of repeated irradiation and a long period of constant irradiation). Furthermore, the protective role of PARP-1 inhibition on the molecular mechanism of blue light-induced injury was confirmed by a gene knockdown technique or a specific inhibitor through in vitro and in vivo experiments. The results showed that the susceptibility to retinal damage caused by irradiation with long- and short-wavelength light is different. Shorter wavelength lights, such as blue light, induce more severe retinal damage, while the retina exhibits better resistance to longer wavelength lights, such as red light. In addition, repeated irradiation for short periods induces less retinal damage than constant exposure over a long period. PARP-1 plays a critical role in the molecular mechanism of blue light-induced damage in photoreceptors and retina, and inhibiting PARP-1 can significantly protect the retina against blue light damage. This study lays an experimental foundation for assessing the safety of phototherapy products and for developing target drugs to protect the retina from light damage.

Chemotherapy plus therapeutic plasmapheresis with 4% human albumin solution in multiple myeloma patients with acute kidney injury: a prospective, open-label, proof-of-concept study

As no unified treatment protocol or evidence yet exists for plasmapheresis without plasma, this study explored the outcomes of using 4% human albumin (ALB) solution as a replacement solution in patients undergoing plasma exchange for multiple myeloma (MM) patients with acute kidney injury (AKI). This study was prospectively registered (ChiCTR2000030640 and NCT05251896). Bortezomib-based chemotherapy plus therapeutic plasmapheresis (TPP) with 4% human ALB solution was assessed for three years in patients with MM aged >18 years, with AKI according to the Kidney Disease Improving Global Outcomes criteria, and without previous renal impairment from other causes. The primary endpoints were changes in renal function over 18 weeks and survival outcomes at 36 months. The secondary endpoints were the incidence of adverse reactions and symptom improvement. Among the 119 patients included in the analysis, 108 experienced renal reactions. The M protein (absolute changes: median −12.12%, interquartile ranges (IQRs) −18.62 to −5.626) and creatine (median −46.91 μmol/L, IQR −64.70 to −29.12) levels decreased, whereas the estimated glomerular filtration rate (eGFR) increased (median 20.66 mL/(min·1.73 m2), IQR 16.03–25.29). Regarding patient survival, 68.1% and 35.3% of patients survived for >12 and >36 months, respectively. The three symptoms with the greatest relief were urine foam, poor appetite, and blurred vision. All 11 patients (7.6%) who experienced mild adverse reactions achieved remission. In conclusion, in MM patients with AKI, plasma-free plasmapheresis with 4% human ALB solution and bortezomib-based chemotherapy effectively alleviated light chain damage to kidney function while improving patient quality of life.

Study on the failure mechanism of deep roadways considering gradient stress and the control technology of CFST supports

The surrounding rocks showed gradient failure after excavation. And according to the different stress states, the surrounding rock of the excavated roadway is divided into severe damage area, moderate damage area and light damage area. An indoor triaxial unloading test was designed to simulate the damage of surrounding rock under different stress states. It was found that it has the composite failure characteristics of splitting and shearing, and the peak stress is also between the conventional uniaxial and triaxial test results. The relative stress gradient was introduced, and a mechanical model of gradient failure in deep tunnels was proposed and established based on the stress field strength method. Based on the gradient damage mechanism, a combined support scheme of annular concrete-filled steel tube support is proposed, which has a better effect on controlling the deformation of the roadway in the field.

Prohibitin 2 deficiency in photoreceptors leads to progressive retinal degeneration and facilitated Müller glia engulfing microglia debris

Müller glia and microglia are capable of phagocytosing fragments of retinal cells in response to retinal injury or degeneration. However, the direct evidence for their mutual interactions between Müller glia and microglia in the progression of retinal degeneration (RD) remains largely unclear. This study aims to construct a progressive RD mouse model and investigate the activated pattern of Müller glia and the interplay between Müller glia and microglia in the early stage or progression of RD. A Prohibitin 2 (Phb2) photoreceptor-specific knockout (RKO) mouse model was generated by crossing Phb2flox/flox mice with Rhodopsin-Cre mice. Optical Coherence Tomography (OCT), histological staining, and Electroretinography (ERG) assessed retinal structure and function, and RKO mice exhibited progressive RD from six weeks of age. In detail, six-week-old RKO mice showed no significant retinal impairment, but severe vision dysfunction and retina thinning were shown in ten-week-old RKO mice. Furthermore, RKO mice were sensitive to Light Damage (LD) and showed severe RD at an early age after light exposure. Bulk retina RNA-seq analysis from six-week-old control (Ctrl) and RKO mice showed reactive retinal glia in RKO mice. The activated pattern of Müller glia and the interplay between Müller glia and microglia was visualized by immunohistology and 3D reconstruction. In six-week-old RKO mice or light-exposed Ctrl mice, Müller glia were initially activated at the edge of the retina. Moreover, in ten-week-old RKO mice or light-exposed six-week-old RKO mice with severe photoreceptor degeneration, abundant Müller glia were activated across the whole retinas. With the progression of RD, phagocytosis of microglia debris by activated Müller glia were remarkably increased. Altogether, our study establishes a Phb2 photoreceptor-specific knockout mouse model, which is a novel mouse model of RD and can well demonstrate the phenotype of progressive RD. We also report that Müller glia in the peripheral retina is more sensitive to the early damage of photoreceptors. Our study provides more direct evidence for Müller glia engulfing microglia debris in the progression of RD due to photoreceptor Phb2 deficiency.