Significance of phosphate adsorbed on the cellular surface as a storage pool and its regulation in marine microalgae.

The increasing prevalence of phosphorus limitation in coastal waters has drawn attention to the bioavailability of cellular surface-adsorbed phosphorus (SP) as a reservoir of phosphorus in phytoplankton. This study examined the storage, utilization, and regulation of SP in the coastal waters of the East China Sea, as well as three cultivated algal bloom species (Skeletonema marinoi, Prorocentrum shikokuense, and Karenia mikimotoi) prevalent in the area. SP accounted for 14.3%-45.5% of particulate phosphorus in the field and laboratory species. After the depletion of external phosphate, the studied species can rapidly transport SP within 3-24 h. The storage of SP is regulated by both external phosphate conditions and the internal growth stage of cells, but it is not influenced by the various cellular surface structures of the studied species. This study highlights the significance of SP as a crucial phosphorus reservoir and the potential use of the SP level as an indicator of phosphorus deficiency in phytoplankton.

Triazine herbicide reduced the toxicity of the harmful dinoflagellate Karenia mikimotoi by impairing its photosynthetic systems.

Triazine herbicides are common contaminants in coastal waters, and they are recognized as inhibitors of photosystem II, causing significant hinderance to the growth and reproduction of phytoplankton. However, the influence of these herbicides on microalgal toxin production remains unclear. This study aimed to examine this relationship by conducting a comprehensive physiological and 4D label-free quantitative proteomic analysis on the harmful dinoflagellate Karenia mikimotoi in the presence of the triazine herbicide dipropetryn. The findings demonstrated a significant decrease in photosynthetic activity and pigment content, as well as reduced levels of unsaturated fatty acids, reactive oxygen species (ROS), and hemolytic toxins in K. mikimotoi when exposed to dipropetryn. The proteomic analysis revealed a down-regulation in proteins associated with photosynthesis, ROS response, and energy metabolism, such as fatty acid biosynthesis, chlorophyll metabolism, and nitrogen metabolism. In contrast, an up-regulation of proteins related to energy-producing processes, such as fatty acid ß-oxidation, glycolysis, and the tricarboxylic acid cycle, was observed. This study demonstrated that dipropetryn disrupts the photosynthetic systems of K. mikimotoi, resulting in a notable decrease in algal toxin production. These findings provide valuable insights into the underlying mechanisms of toxin production in toxigenic microalgae and explore the potential effect of herbicide pollution on harmful algal blooms in coastal environments.

Membrane lipid remodeling and autophagy to cope with phosphorus deficiency in the dinoflagellate Prorocentrum shikokuense.

Dinoflagellates, which are responsible for more than 80% of harmful algal blooms in coastal waters, are competitive in low-phosphate environments. However, the specific acclimated phosphorus strategies to adapt to phosphorus deficiency in dinoflagellates, particularly through intracellular phosphorus metabolism, remain largely unknown. Comprehensive physiological, biochemical, and transcriptomic analyses were conducted to investigate intracellular phosphorus modulation in a model dinoflagellate, Prorocentrum shikokuense, with a specific focus on membrane lipid remodeling and autophagy in response to phosphorus deficiency. Under phosphorus deficiency, P. shikokuense exhibited a preference to spare phospholipids with nonphospholipids. The major phospholipid classes of phosphatidylcholine and phosphatidylethanolamine decreased in content, whereas the betaine lipid class of diacylglyceryl carboxyhydroxymethylcholine increased in content. Furthermore, under phosphorus deficiency, P. shikokuense induced autophagy as a mechanism to conserve and recycle cellular phosphorus resources. The present study highlights the effective modulation of intracellular phosphorus in P. shikokuense through membrane phospholipid remodeling and autophagy and contributes to a comprehensive understanding of the acclimation strategies to low-phosphorus conditions in dinoflagellates.

[Spatio-temporal Characteristics and Influencing Factors of Ozone Suppression Events Under High Temperature in China].

Temperature is a key meteorological factor affecting ozone formation. In general, a positive correlation is observed between ozone and temperature, that is, ozone concentration increases with the increase in temperature. However, this relationship may change at extremely high temperatures. When the temperature exceeds a threshold value, the ozone concentration tends to decrease, which is referred to as an ozone suppression event. Ozone suppression events lead to greater uncertainties in the prediction of future air quality under climate change. Based on the national air quality monitoring data, reanalysis data, and meteorological observation data, this study used the Z test to systematically analyze the spatio-temporal characteristics of the critical temperature(Tx) and frequency of ozone suppression events in China during the warm season(April to September) from 2013 to 2020 and further analyzed the possible influencing factors for the occurrence of ozone suppression events. The results showed that approximately 18% of the sites in China experienced ozone suppression events in the warm season from 2013 to 2020. The sites with a high frequency of ozone suppression events were mainly distributed in the central and western regions of China, such as Sichuan, Xinjiang, and Shaanxi, with an average frequency of ten times per year. The critical temperature(Tx) ranged from 19.2 to 39.3℃, and the Tx of most sites showed an increasing trend from 2013 to 2020. The high values of Tx were mainly distributed in the central and western regions such as Sichuan, Chongqing, Hunan, and Hubei, whereas the low values of Tx were concentrated in the Qinghai-Tibet Plateau. Contrary to the interannual trend of Tx, the frequency of ozone suppression events decreased significantly in the Beijing-Tianjin-Hebei Region and exhibited a characteristic of "increase-decrease-increase" in the Fenwei Plain, the Yangtze River Delta, and the Chengdu-Chongqing regions. The most significant effect of extreme high temperature on ozone suppresion was found in the Pearl River Delta Region. In addition, ozone precursors(e.g., NO2) and meteorological conditions(wind speed and direction) were possible factors affecting the occurrence of ozone suppression events.

[Impact of Accelerated Electrification Under the Low Carbon Path in Dongguan City on the Coordinated Emission Reduction of CO2 and Pollutants].

Cities are the center of energy consumption. Electrification integrates urban energy structure and achieves the efficient use of clean energy. Exploring the urban impact of accelerated electrification under the low-carbon path is crucial to reducing urban pollution and carbon. Based on the Long-range Energy Alternative Planning System(LEAP-DG), this study set up three scenarios, including the baseline, low-carbon, and accelerated electrification scenarios, to evaluate the emission reduction potential of electrification under different power structures, quantify the contribution of key sectors, and discuss the coordinated emission reduction effect of Dongguan, a typical manufacturing city in Guangdong. The results showed that accelerated electrification under the low-carbon path would reduce the emission intensity of power pollutants, and in 2050, Dongguan will further reduce CO2, NOx, VOC, and CO by 7.35×106, 1.28×104, 1.62×104, and 8.13×104 t; SO2 and PM2.5 emission reductions on the consumption side and increased emissions on the production side had been balanced. Accelerated electrification in the industrial and transportation sectors would reduce CO2 and air pollutant emissions at the same time, and the transportation sector would benefit from the high conversion efficiency of fuel vehicles and electric vehicles, reducing CO2, CO, VOC, and NOx by 5.42×106, 7.76×104, 1.43×104, and 1.06×104 t, respectively, in 2050. In the building sector with high electrification rates, coal power was higher in extra electricity, increasing CO2 and pollutant emissions. Under the optimization of power supply structure, cities can reasonably adjust the electrification of different departments to achieve targeted pollution prevention and control.

Variation in intracellular polyphosphate and associated gene expression in response to different phosphorus conditions in the dinoflagellate Karenia mikimotoi.

Polyphosphate (polyP) has long been recognized as a crucial intracellular reservoir for phosphorus in microorganisms. However, the dynamics of polyP and its regulatory mechanism in eukaryotic phytoplankton in response to variations in external phosphorus conditions remain poorly understood. A comprehensive investigation was conducted to examine the intracellular polyP-associated metabolic response of the dinoflagellate Karenia mikimotoi, a harmful algal bloom species, through integrated physiological, biochemical, and transcriptional analyses under varying external phosphorus conditions. Comparable growth curves and Fv/Fm between phosphorus-replete conditions and phosphorus-depleted conditions suggested that K. mikimotoi has a strong capability to mobilize the intracellular phosphorus pool for growth under phosphorus deficiency. Intracellular phosphate (IPi) and polyP contributed approximately 6-23 % and 1-3 %, respectively, to the overall particulate phosphorus (PP) content under different phosphorus conditions. The significant decrease in PP and increase in polyP:PP suggested that cellular phosphorus components other than polyP are preferred for utilization under phosphorus deficiency. Genes involved in polyP synthesis and hydrolysis were upregulated to maintain phosphorus homeostasis in K. mikimotoi. These findings provide novel insights into the specific cellular strategies for phosphorus storage and the transcriptional response in intracellular polyP metabolism in K. mikimotoi. Additionally, these results also indicate that polyP may not play a crucial role in cellular phosphorus storage in phytoplankton, at least in dinoflagellates.

Efficient modulation of cellular phosphorus components in response to phosphorus deficiency in the dinoflagellate Karenia mikimotoi.

IMPORTANCE: Dinoflagellates are the most common phytoplankton group and account for more than 75% of harmful algal blooms in coastal waters. In recent decades, dinoflagellates seem to prevail in phosphate-depleted waters. However, the underlying acclimation mechanisms and competitive strategies of dinoflagellates in response to phosphorus deficiency are poorly understood, especially in terms of intracellular phosphorus modulation and recycling. Here, we focused on the response of intracellular phosphorus metabolism to phosphorus deficiency in the model dinoflagellate Karenia mikimotoi. Our work reveals the strong capability of K. mikimotoi to efficiently regulate intracellular phosphorus resources, particularly through membrane phospholipid remodeling and miRNA regulation of energy metabolism. Our research improved the understanding of intracellular phosphorus metabolism in marine phytoplankton and underscored the advantageous strategies of dinoflagellates in the efficient modulation of internal phosphorus resources to maintain active physiological activity and growth under unsuitable phosphorus conditions, which help them outcompete other species in coastal phosphate-depleted environments.

Integrative analysis uncovers response mechanism of Pirata subpiraticus to chronic cadmium stress.

Soil cadmium (Cd) pollution is global environmental pollution and adversely affects paddy field organisms. Wolf spider grants a new insight to evaluate the toxicity triggered by Cd, yet the impact of chronic Cd exposure on the spider and its molecular mechanism remains unclear. The present study found that the wolf spider Pirata subpiraticus fed with Cd-accumulated flies for 5 weeks presented lower catalase, peroxidase, and acetylcholinesterase activities and higher malonaldehyde content than the control spiders (p < 0.05). An in-depth transcriptomic analysis yielded a total of 5995 differentially expressed genes (DEGs, with 3857 up-regulated and 2138 down-regulated genes) from the comparison, and 19 DEGs encoding three enzymatic indicators were down-regulated. Further enrichment analysis indicated that Cd stress could inhibit the expression of cuticle and chitin-encoding genes via the down-regulation of several key enzymes, such as chitin synthase, glutamine-fructose-6-phosphate transaminase, and chitinase. In addition, our findings suggested that hedgehog and FoxO signaling pathways might play an essential role in regulating survival, cell cycle, and autophagy process in spiders, which were primarily down-regulated under Cd stress. An intensely interactive network displayed that Cd exposure could repress key biological processes in P. subpiraticus, particularly peptide metabolic process and peptide biosynthetic process. To sum up, this integrative investigation confirmed an effective bioindicator for assessing Cd-induced toxicity; provided a mass of genes, proteins, and enzymes for further validation; and granted novel perspectives to uncover the molecular responses of spiders to Cd pollution.

Periodontitis Exacerbates and Promotes the Progression of Chronic Kidney Disease Through Oral Flora, Cytokines, and Oxidative Stress.

Periodontitis is a type of systemic immune inflammation that is caused by the complex infection of a variety of microorganisms in the subgingival plaque and the imbalance of the microbial ecological environment in the mouth. Periodontitis and chronic kidney disease (CKD) share many risk factors, such as obesity, smoking, and age. A growing body of data supports a strong correlation between periodontitis and kidney disease. Evidence supports the role of periodontal inflammation and elevated serum inflammatory mediators in renal atherosclerosis, renal deterioration, and end-stage renal disease (ESRD) development. Periodontitis is a risk factor for kidney disease. However, to our knowledge, there are few studies detailing the possible link between periodontitis and CKD. This review summarizes the possible mechanisms underlying periodontitis and CKD. More importantly, it highlights novel and potential pathogenic factors for CKD, including bacteria, pro-inflammatory mediators and oxidative stress. However, most research on the relationship between periodontitis and systemic disease has not determined causality, and these diseases are largely linked by bidirectional associations. Future research will focus on exploring these links to contribute to new treatments for CKD.

Light-harvesting protein Lhcx3 is essential for high light acclimation of Phaeodactylum tricornutum.

The light-harvesting protein complexes (Lhc) play key roles in the processes of light absorption and protection in diatoms. However, different Lhc protein carries out distinct function in photosynthesis. For now, roles of many Lhc proteins in light acclimation are largely unknown. Here, function of Lhcx3 in marine diatom Phaeodactylum tricornutum was examined by using reverse genetic technologies. The overexpression of Lhcx3 led to increased diadinoxanthin + diatoxanthin content and elevated non-photochemical fluorescence quenching (NPQ) while knockdown of Lhcx3 reduced NPQ level. In addition, the expression of Lhcx3 could be induced by blue light but not by red light. After addition of the photosynthetic inhibitor, upregulation of Lhcx3 transcript in high light could be inhibited by NH4Cl, but not by DCMU (3-(3,4-dichlorophenyl)-l,l-dim ethylurea). In contrast, DCMU addition increased expression of Lhcx3 in high light. In combination with changes of NPQ after addition of inhibitor, we concluded that the Lhcx3 played key roles in high light acclimation of diatoms. This finding will provide new clues for genetic improvement of P. tricornutum with an aim to cultivate new strains with high growth rate.

Transcriptome data of Prorocentrum donghaiense Lu under nitrogen and phosphorus limitation.

Prorocentrum donghaiense Lu is one of the most frequently occurred harmful algae in the coastal waters of China. The growth of P. donghaiense can be limited by nitrogen or phosphorus in marine environment. However, molecular mechanism of P. donghaiense in response to nitrogen and phosphorus limitation is poorly understood. In this study, we summarized the transcriptome datasets of P. donghaiense in response to nitrogen or phosphorus depletion. Raw data of approximately 19 GB in size were generated from IlluminaHiSeqTM 4000 sequencer. From 250, 539, 604 raw reads, 211, 394, 052 clean reads were obtained. The raw data were deposited into SRA database with the BioProject ID 436946. Our dataset will provide more scientific and valuable information for analyses of gene expression related to metabolic processes in P. donghaiense.

Identification of the dwarf gene GmDW1 in soybean (Glycine max L.) by combining mapping-by-sequencing and linkage analysis.

KEY MESSAGE: GmDW1 encodes an ent-kaurene synthase (KS) acting at the early step of the biosynthesis pathway for gibberellins (GAs) and regulates the development of plant height in soybean. Plant height is an important component of plant architecture, and significantly affects crop breeding practices and yield. Here, we report the characterization of an EMS-induced dwarf mutant (dw) of the soybean cultivar Zhongpin 661 (ZDD23893). The dw mutant displayed reduced plant height and shortened internodes, both of which were mainly attributed to the longitudinally decreased cell length. The bioactive GA1 (gibberellin A1) and GA4 (gibberellin A4) were not detectable in the stem of dw, and the dwarf phenotype could be rescued by treatment with exogenous GA3. Genetic analysis showed that the dwarf trait of dw was controlled by a recessive nuclear gene. By combining linkage analysis and mapping-by-sequencing, we mapped the GmDW1 gene to an approximately 460-kb region on chromosome (Chr.) 8, containing 36 annotated genes in the reference Willliams 82 genome. Of these genes, we identified two nonsynonymous single nucleotide polymorphisms (SNPs) that are present in the encoding regions of Gmdw1 and Glyma.08G165100 in dw, respectively. However, only the SNP mutation (T>A) at nucleotide 1224 in Gmdw1 cosegregated with the dwarf phenotype. GmDW1 encodes an ent-kaurene synthase, and was expressed in various tissues including root, stem, and leaf. Further phenotypic analysis of the allelic variations in soybean accessions strongly indicated that GmDW1 is responsible for the dwarf phenotype in dw. Our results provide important information for improving our understanding of the genetics of soybean plant height and crop breeding.

Detection of Genomic DNA Damage from Radiated Nasopharyngeal Carcinoma Cells Using Surface-Enhanced Raman Spectroscopy (SERS).

Structural changes and chemical modifications in DNA during interactions with X-ray radiation are still not clear within 48 h of incubation. We investigate genomic DNA from the radiated CNE2 cell line within 48 h of incubation using surface-enhanced Raman spectroscopy (SERS). Multivariate methods including principal component analysis (PCA) and random forest are proposed to explore the statistical significance before and after radiation. Our results show that intensities of several bands change after radiation, which indicates backbone damage and base-unstacking. Biological effects from DNA damage repairing process may be simultaneously stimulated and different from incubation time. Under doses of 10 Gy (with 24 and 48 h of incubation) and 20 Gy (with 48 h of incubation), the relative contents of C against T and A against G deviate obviously from the control level. Statistical results strengthen significantly the idea that modification in DNA bases is associated with the disruption of base-stacking in the DNA duplex. Our findings provide vital information for radiation-induced the DNA damage at the molecular level, which may provide insight into the effect and mechanism of anticarcinogens in tumor therapy.

Raman spectral analysis of nasopharyngeal carcinoma cell line CNE2 after microwave radiation.

This study aimed to study the effects of microwave radiation on the nasopharyngeal carcinoma cell line CNE2 by Raman spectroscopy. The cells were separated into a control group and radiated groups with radiation times of 2, 5, 10, and 25 min, respectively. Both principal components analysis and support vector machine were employed for statistical analysis of Raman spectra. The results show that the relative content of C-H deformation and amide I begin to change when the radiation time is over 10 min, and principal components analysis further confirms there are significant differences after 10 min of radiation. Moreover, support vector machine is simultaneously used to classify radiated samples from control samples. The classification accuracy is low until the radiation time reaches over 10 min. In conclusion, this study reveals the Raman spectral characteristics of CNE2 under different microwave radiation exposure timesand demonstrates Raman spectroscopy can be a potential method to explore cellular characterization after radiation. The final results may help in elucidating the mechanism by which microwave radiation interacts with tumor cells.

Induction of nucleoside phosphorylase in Enterobacter aerogenes and enzymatic synthesis of adenine arabinoside.

Nucleoside phosphorylases (NPases) were found to be induced in Enterobacter aerogenes DGO-04, and cytidine and cytidine 5'-monophosphate (CMP) were the best inducers. Five mmol/L to fifteen mmol/L cytidine or CMP could distinctly increase the activities of purine nucleoside phosphorylase (PNPase), uridine phosphorylase (UPase) and thymidine phosphorylase (TPase) when they were added into medium from 0 to 8 h. In the process of enzymatic synthesis of adenine arabinoside from adenine and uracil arabinoside with wet cells of Enterobacter aerogenes DGO-04 induced by cytidine or CMP, the reaction time could be shortened from 36 to 6 h. After enzymatic reaction the activity of NPase in the cells induced remained higher than that in the cells uninduced.

[FT-raman spectra study of Platymonas subcordiformis].

FT-Raman spectroscopy was adopted to investigate the Raman spectrum of Platymonas subcordiformis. The result shows that the optimal experiment condition is making sample lose solvent with centrifuge, exciting laser power set at 360 mW and accumulating 70 times. The main peaks of the spectra are 381-432, 552-556, 611-613, 710, 873, 953-964, 1 108-1119, 1457, 1523-1527 and 2986 cm(-1). They belong to protein, insaturation acid and ester, etc, which are the main composition of Platymonas subcordiformis. The precise measurements of algae Raman spectra could be used for developing a new optical taxonomic methodology to distinguish between different algae species, and a rapid, non-destructive detection way of stress effects.

[Surgical treatment of apical chest tumor in 27 patients].

OBJECTIVE: To explore the "hemi-clamshell" approach to the resection of the apical chest tumors, and to evaluate its advantages of operative safety and completeness. METHODS: We conducted a retrospective review of the records of 27 patients undergoing resection of the primary apical chest tumors from January 1995 to January 2001. Tumor type included NSCLC, sarcoma, neurofibromatosis, esophageal carcinoma. Data collected included clinical presentation, tumor type and involvement, type of resection, complication, and survival. RESULTS: A clinical operation for gross-total resection of tumors and invaded structures was performed on six patients by means of a successful anterior approach. Among other 21 patients on whom a clinical operation was performed by posterior approach, only 13 patients obtained gross-total resection. There were significant difference between the two groups (P < 0.01). The mean duration for follow-up was 29 months, and the overall median survival was 21 months. Median survival in patients undergoing gross-total resection was 29 months, and this is significantly better than in incomplete resection group (P < 0.01). CONCLUSIONS: The anterior "hemi-clamshell" approach is a successful technique for the exposure and resection of these tumors and invaded structures. Release of symptoms and long-term survival is acceptable if complete resection can be performed.

Surgical treatment of apical chest tumor in 27 patients / 中华外科杂志

<p><b>OBJECTIVE</b>To explore the "hemi-clamshell" approach to the resection of the apical chest tumors, and to evaluate its advantages of operative safety and completeness.</p><p><b>METHODS</b>We conducted a retrospective review of the records of 27 patients undergoing resection of the primary apical chest tumors from January 1995 to January 2001. Tumor type included NSCLC, sarcoma, neurofibromatosis, esophageal carcinoma. Data collected included clinical presentation, tumor type and involvement, type of resection, complication, and survival.</p><p><b>RESULTS</b>A clinical operation for gross-total resection of tumors and invaded structures was performed on six patients by means of a successful anterior approach. Among other 21 patients on whom a clinical operation was performed by posterior approach, only 13 patients obtained gross-total resection. There were significant difference between the two groups (P < 0.01). The mean duration for follow-up was 29 months, and the overall median survival was 21 months. Median survival in patients undergoing gross-total resection was 29 months, and this is significantly better than in incomplete resection group (P < 0.01).</p><p><b>CONCLUSIONS</b>The anterior "hemi-clamshell" approach is a successful technique for the exposure and resection of these tumors and invaded structures. Release of symptoms and long-term survival is acceptable if complete resection can be performed.</p>