Corneal wound healing following infrared laser irradiation at the wavelengths of 1.319 and 10.6 µm.

OBJECTIVES: To investigate the wound healing of rabbit cornea following infrared laser irradiations at the wavelengths of 1.319 and 10.6 µm. MATERIALS AND METHODS: Twelve New Zealand rabbits were selected to establish a corneal injury model. The right and left eyes were irradiated with a neodymium-doped yttrium aluminum garnet laser at the wavelength of 1.319 µm (140 J/cm2 ) for 0.7 s and a CO2 laser at the wavelength of 10.6 µm (5.94 J/cm2 ) for 0.14 s, respectively. The incident spot diameter was 3 mm. Optical coherence tomography (OCT) was used to monitor injuries at 0 h, 0.5 h, 1 h, 3 h, 6 h, 12 h, 18 h, 24 h, 30 h, 36 h, 42 h, 48 h, 54 h, 60 h, 66 h, 3 d, 7 d, 14 d, 28 d, 3 m, and 6 m postexposure. Meanwhile, slit-lamp microscopy and histopathology were performed at 6 h, 24 h, 3 d, 7 d, 14 d, 28 d, 3 m, and 6 m postexposure. RESULTS: After the two types of infrared laser injuries, distinct white circular lesions on the corneal surface were directly observed. Deeper corneal injury, more severe edema, and faster migration of new epithelium were found for the wavelength of 1.319 µm, compared to the wavelength of 10.6 µm. CONCLUSIONS: OCT combined with histopathology and slit-lamp microscopy can clearly observe the dynamic process of corneal wound healing after infrared laser irradiation. The damage characteristics for the two different wavelengths were visibly different, but the whole wound healing process was similar. The obtained results may provide references for the diagnosis, treatment, and evaluation of laser-induced damages.

Corneal damage threshold induced by supercontinuum source: A further study.

OBJECTIVES: Previous report shows that corneal spot size is an important influence factor on damage threshold induced by supercontinumm (SC) source. However, damage thresholds were determined for the spot size of only 0.37 mm due to the low output of the employed SC source at that time. The objectives of this study are to determine the lowest possible corneal damage threshold at a large corneal spot size using a more powerful SC source and provide data for the future possible refinements of laser safety standards. MATERIALS AND METHODS: A series of experiments was conducted in the New Zealand white rabbit model to determine the corneal damage threshold induced by a 900-2000 nm SC source, with corneal 1/e beam diameter of about 1.2 mm. Slit-lamp biomicroscope was employed to reveal the corneal damage characteristics. By employing the action spectra determined through the analysis of current laser safety guidelines and standards, the effective damage threshold could be calculated. RESULTS: The determined damage threshold given in terms of the peak radiant exposure for the exposure duration of 0.14 s was 44.3 J/cm2 . At threshold level, corneal damages involved the epithelium and the shallower stroma. The safety factor between the effective damage threshold and the corresponding maximum permissible exposure (MPE) was about 45. CONCLUSIONS: Present corneal MPEs in the wavelength range of 700-1200 nm may be conservative and corneal damage thresholds for the infrared A wavelengths should be determined in future studies.

Characterization of histone deacetylases and their roles in response to abiotic and PAMPs stresses in Sorghum bicolor.

BACKGROUND: Histone deacetylases (HDACs) play an important role in the regulation of gene expression, which is indispensable in plant growth, development, and responses to environmental stresses. In Arabidopsis and rice, the molecular functions of HDACs have been well-described. However, systematic analysis of the HDAC gene family and gene expression in response to biotic and abiotic stresses has not been reported for sorghum. RESULTS: We conducted a systematic analysis of the sorghum HDAC gene family and identified 19 SbHDACs mainly distributed on eight chromosomes. Phylogenetic tree analysis of SbHDACs showed that the gene family was divided into three subfamilies: RPD3/HDA1, SIR2, and HD2. Tissue-specific expression results showed that SbHDACs displayed different expression patterns in different tissues, indicating that these genes may perform different functions in growth and development. The expression pattern of SbHDACs under different stresses (high and low temperature, drought, osmotic and salt) and pathogen-associated molecular model (PAMPs) elf18, chitin, and flg22) indicated that SbHDAC genes may participate in adversity responses and biological stress defenses. Overexpression of SbHDA1, SbHDA3, SbHDT2 and SbSRT2 in Escherichia coli promoted the growth of recombinant cells under abiotic stress. Interestingly, we also showed that the sorghum acetylation level was enhanced when plants were under cold, heat, drought, osmotic and salt stresses. The findings will help us to understand the HDAC gene family in sorghum, and illuminate the molecular mechanism of the responses to abiotic and biotic stresses. CONCLUSION: We have identified and classified 19 HDAC genes in sorghum. Our data provides insights into the evolution of the HDAC gene family and further support the hypothesis that these genes are important for the plant responses to abiotic and biotic stresses.

First report of Diplodia mutila causing leaf blight on Magnolia grandiflora in China.

Magnolia grandiflora is a widely cultivated ornamental tree in China. In June 2020, a leaf blight disease was observed on M. grandiflora in Guizhou University (26° 44' 57'' N, 106° 65' 94'' E) in Guiyang, China. The initial symptoms on leaves were expanding round necrotic lesions with a grey center and dark brown edge, and twigs were withered when the disease was serious. Of the 100 plants surveyed 65% had symptoms. To isolate the potential causal pathogen, diseased leaves were collected from an M. grandiflora tree at Guizhou University. Isolations from made form the junction between healthy and symptomatic tissue and disinfested by immersing in 75% ethanol for 30 seconds, 3% NaOCl for 2 minutes, and then washed 3 times in sterile distilled water. Symptomatic tissue was then plated on potato dextrose agar (PDA) and incubated at 25ºC with 12-hour light for 3-5 days. Three isolates (GUCC 21235.1, GUCC 21235.2 and GUCC 21235.3) were obtained. Colonies on PDA after 7 d were dark brown, pycnidia embedded in the mydelium were dark brown to black, single and separated. Conidiophores were transparent measuring 7-12.5 × 2.5-4.5 µm (mean = 9.5 × 3.6 µm, n = 30) in length. Conidia were transparent becoming brown when mature with a diaphragm, with round ends measuring, 21-27 × 10-15 µm (mean = 23.6 × 12.6 µm, n = 30). To confirm the pathogen by molecular characterization, four genes or DNA fragments, ITS, LSU, tef1 and ß-tubulin, were amplified using the following primer pairs: ITS4-F/ ITS5-R (White et al., 1990), LR0R/ LR5 (Rehner & Samuels, 1994), EF1-688F/ EF1-986R (Carbone & Kohn, 1999) and Bt2a/ Bt2b (O'Donnell & Cigelnik, 1997). The sequences of four PCR fragments of GUCC 21235.1 were deposited in GenBank, and the accession numbers were MZ519778 (ITS), MZ520367 (LSU), MZ508428 (tef1) and MZ542354 (ß-tubulin). Bayesian inference was performed based on a concatenated dataset of ITS, LSU, tef1 and ß-tubulin gene using MrBayes 3.2.10, and the isolates GUCC 21235.1 formed a single clade with the reference isolates of Diplodia mutila (Diplodia mutila strain CBS 112553). BLASTn analysis indicated that the sequences of ITS, LSU, tef1 and ß-tubulin revealed 100% (546/546 nucleotides), 99.82% (568/569 nucleotides), 100% (302/302 nucleotides), and 100% (437/437 nucleotides) similarity with that of D. mutila in GenBank (AY259093, AY928049, AY573219 and DQ458850), respectively. For confirmation of the pathogenicity of this fungus, a conidial suspension (1×105 conidia mL-1) was prepared from GUCC 21235.1, and healthy leaves of M. grandiflora trees were surface-disinfested by 75% ethanol, rinsed with sterilized distilled water and dried by absorbent paper. Small pieces of filter paper (5 mm ×5 mm), dipped with 20 µL conidial suspension (1×105 conidia mL-1) or sterilized distilled water (as control), were placed on the bottom-left of the leaves for inoculation. Then the leaves were sprayed with sterile distilled water, wrapped with a plastic film and tin foil successively to maintain high humidity in the dark dark. After 36 h, the plastic film and tin foil on the leaves was removed, and the leaves were sprayed with distilled water three times each day at natural condition (average temperature was about 25 °C, 14 h light/10 h dark). After 10 days of inoculation, the same leaf blight began to appear on the leaves inoculated with conidial suspension. No lesion was appeared on the control leaves. The fungus was re-isolated from the symptomatic tissue. Based on the morphological information and molecular characterization, the isolate GUCC 21235.1 is D. mutila. Previous reports indicated that D. mutila infects a broad host range and gives rise to a canker disease of olive, apple and jujube (Úrbez-Torres et al., 2013; Úrbez-Torres et al., 2016; Feng et al., 2019). This is the first report of leaf blight on M. grandiflora caused by D. mutila in China.

A new strain of Volutella citrinella with nematode predation and nematicidal activity, isolated from the cysts of potato cyst nematodes in China.

BACKGROUND: Plant parasitic nematodes (PPNs) are responsible for causing many plant diseases and are extremely difficult to control at present. Currently, due to the negative effects of chemical agents on the environment and human health, the development of new biological pesticides has become an important part of plant nematode control. Nematophagous fungi refers to a class of fungi that kill plant nematodes. Notably, a large number of nematophagous fungi resources remain to be studied. The objective of our study was to use in vitro screening to identify nematophagous fungi and select strains that were highly active against nematodes, providing a primary research for the development and utilization of new nematophagous fungi. RESULTS: A new nematophagous fungal strain (GUCC2219) was isolated from cysts of possibly Globodera spp. and Heterodera spp., identified as Volutella citrinella. The hyphae of V. citrinella produced ring structures of variable size and exhibited predatory and nematicidal activity. The hyphal predation rates (in vitro) against three species of nematodes, Aphelenchoides besseyi, Bursaphelenchus xylophilus, and Ditylenchus destructor, averaged 59.45, 33.35, and 50.95%, respectively, while the fermentation broth produced by the fungus exhibited mortality rates of 100, 100, and 55.63%, respectively, after 72 h. CONCLUSION: V. citrinella is a new strain with nematophagous properties, which are a novel discovery. At the same time, this is the first report of nematicidal and nematode predation activity in the genus Volutella.

Toxicity of soil antimony to earthworm Eisenia fetida (Savingy) before and after the aging process.

Information on soil antimony (Sb) toxicity to earthworm Eisenia fetida (Savingy) is limited. This ecotoxicology study was designed to quantify the soil Sb toxicity to earthworm E. fetida before and after aging process, establishing dose-effect relationship between Sb content and mortality. Results of the avoidance test and acute test showed that the values of net avoidance response, escape rate and mortality were generally decreased in aged treatment compared to that in fresh treatment, respectively from 93.33% to 66.67%, 36.67% to 13.33% and 100% to 53.33% (15 d) taking TL800 (treatment level of 800 mg/kg) for example, meanwhile the values of median lethal content (LC50) at 72 h, 7 d and 15 d were respectively increased from 355.27 mg/kg to 2324.55 mg/kg, 322.19 mg/kg and 1743.19 mg/kg and 282.74 mg/kg to 745.94 mg/kg, indicating that aging process could reduce the Sb acute toxicity to earthworm. According to a three-step sequential extraction procedure, the bioavailable Sb ranged from 24.45% to 43.24% and 16.97% to 27.70% in fresh treatment and aged treatment, respectively, and the mortality of earthworm for 24 h decreased with the decrease of the content of mild acid-soluble antimony (which decreased averagely from 23.09% to 14.00%), which was more suited to assess Sb toxicity. This is the first report that confirms the toxicity of soil Sb to earthworm E. fetida as well as the considering of aging process and speciation.

Corneal Damage Effects Induced by a 770-2,500 nm Supercontinuum Light Source.

BACKGROUND AND OBJECTIVES: Widespread applications of supercontinuum (SC) source lead to the possibility of ocular damages. However, the corneal damage effects induced by SC have not been explored before. The objectives of this study are to determine the rabbit corneal injury threshold for SC radiation and to examine whether the existing safety guidelines and standards are suitable for the hazard evaluation of this new kind of light source. STUDY DESIGN/MATERIALS AND METHODS: A series of experiments was conducted in the New Zealand white rabbit model to determine the corneal damage thresholds induced by a 770-2,500 nm SC source, with a corneal 1/e beam diameter of 0.37 mm. Through slit-lamp biomicroscope, optical coherence tomography (OCT), and histopathology the corneal damage characteristics at the threshold level were revealed. By employing the action spectra determined through the analysis of safety guidelines and standards, the damage thresholds for SC source could be compared with the corresponding exposure limits. RESULTS: The determined damage thresholds given in terms of the peak radiant exposure for exposure durations of 2.0 and 10.0 seconds were 2.1 × 103 and 7.4 × 103 J/cm2 , respectively. At threshold level, corneal damages involved the epithelium and the shallower stroma, and no obvious changes could be found in the deep stroma, Descemet's membrane, and endothelium. CONCLUSIONS: The exposure limits for the anterior parts of the eye in the wavelength range of 700-1,200 nm are overly conservative. The obtained results contribute to the knowledge base for the hazard evaluation of SC source. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc.

Effect of multi-walled carbon nanotubes on extractability of Sb and Cd in contaminated soil.

The interaction between multi-walled carbon nanotubes (MWCNTs) and soil heavy metals was rarely studied. With the convenience of detecting multiple metal elements by ICP-AES, this paper examined the potential effectiveness of MWCNTs on extractability of antimony (Sb) and cadmium (Cd) in contaminated soil. Three-step sequential extraction procedure, toxicity characteristic leaching procedure, bioaccessibility and CaCl2 single extraction were employed to evaluate Sb and Cd speciations and their extractabilities. According to our results, only at low Sb content level of 100 mg/kg, antimony bioavailability reduced with MWCNTs addition of 0.3% and 0.9% by 22.97% and 20.74%, respectively, which might due to the increase of adsorption point, nevertheless, the excess Sb(OH)6- was not adsorbed more efficiently. Secondly, due to the difference in effective specific surface area, only under the condition of high content level and MWCNTs addition of 0.1%, the mild acid-soluble fraction increased at most by 15.40% for Sb and 9.40% for Cd, respectively. However, in terms of TCLP-extractable Sb and Cd and CaCl2-extractable Sb and Cd, no significant, continuous, regular extractability pattern were found. Overall, MWCNTs were selective on extractability of soil heavy metals due to mechanisms of physical adsorption. This paper provides data reference for the interaction between MWCNTs and soil heavy metals extractability.

Retinal injury thresholds for 532, 578, and 630 nm lasers in connection to photodynamic therapy for choroidal neovascularization.

BACKGROUND AND OBJECTIVES: The purpose of this study was to explore the retinal injury thresholds in rabbits and evaluate the influence of retinal pigmentation on threshold irradiance at laser wavelengths of 532, 578, and 630 nm which might be involved in hypocrellin B (HB) and hematoporphyrin monomethyl ether (HMME) photodynamic therapy (PDT) for choroidal neovascularization (CNV). MATERIALS AND METHODS: The eyes of pigmented and non-pigmented rabbits were exposed to 532, 578, and 630 nm lasers coupled to a slit lamp biological microscope. The exposure duration was 100 seconds and the retinal spot size was 2 mm throughout the experiment. The minimum visible lesions were detected by funduscopy at 1 and 24 hours post exposure. Bliss probit analysis was performed to determine the ED50 thresholds, fiducial limits and probit slope. RESULTS: In pigmented rabbits, the 24-hour retinal threshold irradiances at 532, 578, and 630 nm were 1,003, 1,475, and 1,720 mW/cm(2) , respectively. In non-pigmented rabbits, the 24-hour threshold irradiances were 1,657, 1,865, and 15,360 mW/cm(2) , respectively. The ED50 for 24-hour observation differed very little from the ED50 for 1-hour observation. The non-pigmented rabbits required a ninefold increase in threshold irradiance at 630 nm comparing to the pigmented rabbits. CONCLUSION: This study will contribute to the knowledge base for the limits of laser irradiance in application of HB or HMME PDT for CNV.

Combined toxicity of polyethylene microplastics and nickel oxide nanoparticle on earthworm (Eisenia andrei): oxidative stress responses, bioavailability and joint effect.

The co-occurrence of heavy metals and microplastics (MPs) is an emerging issue that has attracted considerable attention. However, the interaction of nickel oxide nanoparticle (nano-NiO) combined with MPs in soil was poorly researched. Here, experiments were conducted to study the influence of nano-NiO (200 mg/kg) and polyethylene (PE) MPs with different concentrations (0.1, 1, and 10%) and sizes (13, 50, and 500 µm) on earthworms for 28 days. Compared to control, the damage was induced by PE and nano-NiO, which was evaluated by biomarker Integrated Biomarker Response index: version 2 (IBRv2) based on six biomarkers including SOD, POD, CAT, MDA, AChE, Na+/K+-ATPase and cellulase. The majority of the chosen biomarkers showed significant but complicated responses with increasing contaminant concentrations after 28 days of exposure. Moreover, the joint effect was assessed as antagonism by the effect addition index (EAI). Overall, this work expands our understanding of the combined toxicity of PE and nano-NiO in soil ecosystems.

Morphological and molecular characterization of Heterodera ripae, a new record cyst nematode in the rhizosphere soil of Fagopyrum esculentum.

Numerous plant parasitic nematodes (PPNs) have the potential to inflict considerable damage on agricultural crops. Through a comprehensive survey aimed at identifying PPNs affecting crops, cyst nematodes were isolated from the rhizosphere soil of buckwheat (Fagopyrum esculentum). Employing both molecular and morphological techniques, this cyst nematode was conclusively identified as Heterodera ripae. Notably, this represents the first documented occurrence of this particular cyst nematode species within the rhizosphere soil of F. esculentum.

The completed mitochondrial genomes of Globodera vulgaris reveals new insights into the genus Globodera phylogeny.

Due to the highly conserved structure, animal mitochondrial genome (mtDNA) is widely used in classification, evolution, phylogeny, population genetic structure and other fields. We reported on the five circle multipartite mtDNAs of a newly described species of Globodera, Globodera vulgaris (Gv) from potatoes in China. The results showed that the mtDNA of Gv was obtained through second- and third-generation sequencing, with a total length of 42,995 bp. It contained 12 protein-coding genes, two rRNA genes and 17 tRNA genes, which were distributed in different subgenomic circles. Comparison of the differences in mtDNA among Gv, G. rostochiensis, G. pallida and G. ellingtonae showed that the size and arrangement of the genes in the mtDNA of the genus Globodera were variable and not conserved. The codon usage bias of the mitochondrial protein-coding gene of Gv showed that Gv might have originated from locally and more primitive group of existing Globodera. Based on the cytochrome c oxidase subunits I genes (COX1) and the nicotinamide adenine dinucleotide dehydrogenase subunits I genes (ND1), and the results showed that Gv was clustered with Globodera spp. according to the COX1 and ND1 in scmtDNA-V, while Gv was clustered with Meloidogyne spp. according to ND1 in scmtDNA-III. The results of this study provided a new basis for understanding the multipartite structure of mtDNA as a phylogenetic and taxonomic feature of the genus Globodera. The number of subgenomic circles is a diagnostic feature of species and the arrangement order and size of mitochondrial protein-coding genes also have important application value in species identification within the genus.

Diversity of Fungi Isolated from Potato Nematode Cysts in Guizhou Province, China.

Potatoes rank third in terms of human consumption after rice and wheat. Globodera spp. are significant pests of potato crop worldwide. Globodera rostochiensis was found in Weining County, Guizhou Province, China, in 2019. We collected soil from the rhizosphere zone from infected potato plants and separated mature cysts through simple floatation and sieving methods. The selected cysts were surface-sterilized, and the colonized fungi were isolated and purified. At the same time, the preliminary identification of fungi and fungi parasites on the cysts of nematodes was carried out. This study aimed to define the species and frequency of fungi-colonizing cysts of G. rostochiensis collected from Weining County, Guizhou Province, China, and provide a basis for the control of G. rostochiensis. As a result, 139 strains of colonized fungi were successfully isolated. Multigene analyses showed that these isolates included 11 orders, 17 families, and 23 genera. The genera Fusarium (with a separation frequency of 59%), Penicillium (11%), Edenia (3.6%), and Paraphaeosphaeria (3.6%) were the most frequently occurring. Among the 44 strains, 27 had a colonization rate of 100% on the cysts of G. rostochiensis. Meanwhile, the functional annotation of 23 genera indicated that some fungi have multitrophic lifestyles combining endophytic, pathogenic, and saprophytic behavior. In conclusion, this study showed the species composition and lifestyle diversity of colonized fungi from G. rostochiensis and demonstrated these isolates as potential sources of biocontrol agents. Colonized fungi were isolated from G. rostochiensis for the first time in China, and the taxonomic diversity of fungi from G. rostochiensis was clarified.

Two strains Neocosmosporastercicola (Sordariomycetes, Nectriaceae) with high nematicidal activity, isolated from the cysts of Globodera sp. (Heteroderidae) in China.

Plant-parasitic nematodes (PPNs) are significant pests that result in considerable economic losses in global crop production. Due to the high toxicity of chemical nematicides, there is a need to develop new strategies for nematode control. In this context, nematophagous fungi may offer a viable option for biological control. Two fungal strains (GUCC2212 and GUCC2232) were isolated from cysts of Globodera sp., identified as Neocosmosporastercicola. The fungal filtrates of the strains were evaluated for their nematicidal activity against three species of PPNs: Aphelenchoidesbesseyi, Bursaphelenchusxylophilus and Ditylenchusdestructor. The fermentation filtrates of two strains exhibited substantial toxicity towards the evaluated nematodes, with mortality rates reaching up to 100% within 72 h. Concurrently, N.stercicola also demonstrated predatory and parasitic behavior. The eggs of Globodera sp. were parasitized by the two strains. N.stercicola represents a newly recorded species in China and a novel nematophagous species. In conclusion, the two strains of N.stercicola show promise as biocontrol agents for PPNs management.

Isolation, Identification, and Evaluation of the Predatory Activity of Chinese Arthrobotrys Species towards Economically Important Plant-Parasitic Nematodes.

The current investigation aimed to isolate and identify predatory fungal strains and evaluate their efficacy in mitigating the effects of plant-parasitic nematodes. We successfully isolated three distinct nematophagous fungal strains from soil samples, identified as Arthrobotrys megalosporus, A. oligospora, and A. sinensis, using conventional and molecular identification methodologies. In vitro trials illustrated the high capture efficiency of these fungi against plant-parasitic nematodes. Over an exposure period of 48 h to Aphelenchoides besseyi, Bursaphelenchus xylophilus, and Ditylenchus destructor, A. megalosporus (GUCC220044) displayed predation rates of 99.7%, 83.0%, and 21.1%, respectively. A. oligospora (GUCC220045) demonstrated predation rates of 97.3%, 97.3%, and 54.6%, and A. sinensis (GUCC220046) showed rates of 85.1%, 68.3%, and 19.0% against the same cohort of nematodes. The experimental outcomes substantiate that all three identified fungal strains demonstrate predatory activity against the tested nematodes, albeit with varying efficiencies.

Toxicity of titanate nanotubes in earthworm (Eisenia fetida): Growth inhibition and integrated biomarker response.

Widely use of Titanate Nanotubes (TNTs) as remediation materials for heavy metal polluted water and soil lead to their release into the soil environment, persistently threatening faunal biodiversity and the entire environment. Growth inhibition rates (GIR) and specific growth rates (SGR) are used to evaluate the effect of TNTs on earthworm growth, and the integrated biomarker response (IBR) index is used to comprehensively evaluate the toxicity of eight biomarkers (Protein-body mass ratio, MDA, SOD, CAT, POD, Cellulase, AChE, and Na+/K+-ATPase) on earthworms exposed to TNTs contaminated soil by concentrations of CK, 50, 250, 500 and 2500 mg TNTs/kg dry soil. Results show that TNTs significantly inhibit the growth of earthworms (p < 0.05), and GIR reaches up to 52.34 % at 2500 mg TNTs/kg dry soil for 28 days. IBR index has a dose-time relationship, which indicates that exposure time and concentration of TNTs contaminated soil affect the toxicity degree of contaminant to earthworms.

Effects of one-dimensional nanomaterial polyaniline nanorods on earthworm biomarkers and soil enzymes.

Polyaniline nanorods (PANRs) are typical one-dimensional nanomaterials (1D NMs), which are widely used in medicine, batteries and water treatment, etc. Applications of PANRs will eventually enter the soil environment, but their ecotoxicity has been barely reported. Therefore, we measured earthworm biomass, earthworm biomarkers and soil enzymes to investigate the ecotoxicity of PANRs. The result of positive and increasing growth inhibition rates (GIR) showed that PANRs inhibited earthworm growth. As for earthworm biomarkers, PANRs caused a decrease in protein content, indicating that PANRs stress would increase earthworm energy consumption. Except for the 7th day, the activities of SOD, CAT and POD consistently increased, suggesting that PANRs activated the earthworm antioxidant system. The continually augment of MDA content indicated that PANRs stress would cause earthworm lipid damage. Na+-K+-ATPase increased with an excellent dose-time relationship. Differently, cellulase and AChE activities promoted at low concentrations and inhibited at high concentrations. The positive and dose-dependent IBRv2 indicated that the higher the concentrations of PANRs, the greater the ecotoxicity to earthworms. PANRs inhibited the soil enzyme activities such as sucrase, neutral phosphatase, protease and urease, while induced catalase activity in a dose-dependent manner. Earthworm addition reduced catalase activity by 10.74-29.99%, but improved other soil enzymes activities, demonstrating that earthworms played a positive role in regulating soil enzyme activity. GMean and T-SQI consistently increased due to earthworm activity, meaning a higher soil microbial functional diversity. Generally, this study provided data support for future PANRs toxicity studies, but their toxicity mechanisms still need to be further studied.

Identification, characterization, and expression profiling of the putative U-box E3 ubiquitin ligase gene family in Sorghum bicolor.

The U-box family is one of the main E3 ubiquitin ligase families in plants. The U-box family has been characterized in several species. However, genome-wide gene identification and expression profiling of the U-box family in response to abiotic stress in Sorghum bicolor remain unclear. In this study, we broadly identified 68 U-box genes in the sorghum genome, including 2 CHIP genes, and 1 typical UFD2 (Ub fusion degradation 2) gene. The U-box gene family was divided into eight subclasses based on homology and conserved domain characteristics. Evolutionary analysis identified 14, 66, and 82 U-box collinear gene pairs in sorghum compared with arabidopsis, rice, and maize, respectively, and a unique tandem repeat pair (SbPUB26/SbPUB27) is present in the sorghum genome. Gene Ontology (GO) enrichment analysis showed that U-box proteins were mainly related to ubiquitination and modification, and various stress responses. Comprehensive analysis of promoters, expression profiling, and gene co-regulation networks also revealed that many sorghum U-box genes may be correlated with multiple stress responses. In summary, our results showed that sorghum contains 68 U-box genes, which may be involved in multiple abiotic stress responses. The findings will support future gene functional studies related to ubiquitination in sorghum.

A comparative study on ocular damage induced by 1319nm laser radiation.

BACKGROUND AND OBJECTIVES: High energy loss of 1,319 nm laser due to pre-retinal water absorption makes the ocular axial length more critical, while the relative low absorbance of melanin makes retinal pigmented epithelium less contributing, to retinal damage threshold. However, both have never been illustrated experimentally. Here we determined and compared the retinal damage thresholds at this wavelength in three species with different axial lengths and retinal pigmentations. The corneal damage threshold was also determined for further comparative analysis. MATERIALS AND METHODS: The retinal damage thresholds of albino rat, non-pigmented and pigmented rabbit, and the corneal damage threshold of non-pigmented rabbit were determined for 0.2 and/or 0.4-second exposure durations. The incident beam diameter on cornea was 5 mm for rabbit retinal and 2 mm for rat retinal and rabbit corneal lesion. Minimum visible lesions were examined 1- and 24-hour post-exposure. Probit analysis was used to establish the estimated damage threshold for 50% of exposures (ED(50) ). The direct transmittance of pre-retinal eye media was used for further comparative analysis. RESULTS: The retinal ED(50) of albino rat for 0.2 seconds, non-pigmented rabbit for 0.2 seconds, 0.4 seconds, pigmented rabbit for 0.4 seconds was 8.8, 12.1, 22.5, 18.5 J/cm(2) (0.28, 2.4, 4.4, 3.6 J in total intraocular energy (TIE)). The corneal ED(50) was 86.1 J/cm(2) . Under the condition of 5 mm beam diameter and 0.4-second exposure duration, the calculated retinal ED(50) of human was higher, while that of rhesus monkey was lower than the corneal ED(50) . CONCLUSION: For 1,319 nm laser radiation, the ocular axial length has great, while the retinal pigmentation has only slight influence on retinal damage threshold. The relative lower direct transmittance of human eye media makes the retina more resistant to laser lesion, which should be considered when deriving human maximum permissible exposure (MPE).

Efficient Kidney Exchange with Dichotomous Preferences.

This paper studies a general kidney exchange model with compatible patient-donor pairs, incompatible patient-donor pairs, single donors, and patients on the waiting list. We derive an explicit formula of the maximal number of feasible kidney transplants under several sizes of cycles and chains of exchange, analyze the effect of different ways of exchange on efficiency, and provide substantial simulation results based on the USA data. Our results further show that kidney exchange can be decentralized for relatively large populations, and that allowing compatible pairs and single donors to exchange with incompatible pairs can significantly increase the number of feasible kidney transplants. A more general model of two-category type-compatible exchanges is also established.