Pregnant outcomes of patients with positive anticentromere antibodies receiving in vitro fertilization-embryo transfer. / æŠ—ç€ä¸ç‚¹æŠ—ä½“é˜³æ€§æ‚£è€ ä½“å¤–å—ç²¾ç»“å±€åˆ†æž.

OBJECTIVES: To analyze the pregnant outcomes in patients with positive anti-centromere antibody (ACA) receiving in vitro fertilization (IVF) -embryo transfer (ET) and natural conception. METHODS: A case-control study was used to retrospectively analyze the clinical data of 3955 patients who received in vitro fertilization-embryo transfer therapy and had the results of antinuclear antibody (ANA) spectrum at Zhejiang Provincial People's Hospital from June 2016 to June 2023. Patients with positive ACA and negative ACA were matched at a ratio of 1∶3 using propensity score matching. Embryo outcomes of IVF were compared between the two groups, and the impact of different fertilization methods and the use of immunosuppressants on pregnant outcomes were analyzed using self-matching analysis. The natural conception and disease progress were followed up for ACA-positive patients after IVF failure. RESULTS: The ACA-positive patients accounted for 0.86% of all IVF patients (34/3955) and 2.51% of total ANA-positive IVF patients. Regardless of whether patients received conventional IVF (c-IVF) or intracytoplasmic sperm injection (ICSI), the ACA-positive group exhibited significant differences in oocyte maturity and fertilization compared to the ACA-negative group (both P<0.01). Moreover, the ACA-positive group had a decreased number of D3 suboptimal embryos and D3 optimal embryos (both P<0.05). In 5 cases of ACA-positive patients who underwent ICSI cycles, the double pronuclei rate did not increase compared to c-IVF cycles (P>0.05), and there was a decrease in the number of D3 high-quality embryos and D3 suboptimal embryos (both P<0.05). After 1-2 months of immunosuppressant treatment, 12 ACA-positive patients underwent c-IVF/ICSI again, and there were no changes in egg retrieval and fertilization before and after medication (both P>0.05), but there was an improvement in the 2PN embryo cleavage rate (P<0.05). The number of embryos transferred was similar between the ACA-positive and negative groups, but the ACA-positive group had significantly lower embryo implantation rate and clinical pregnancy rate compared to the ACA-negative group (both P<0.05), with no significant difference in miscarriage rate between the two groups (P>0.05). Twenty-seven ACA-positive patients attempted natural conception or artificial insemination after IVF failure, resulting in a total of 7 cases of clinical pregnancy. CONCLUSIONS: Serum ACA positivity may disrupt oocyte maturation and normal fertilization processes, with no improvement observed with ICSI and immunosuppressant use. However, ACA-positive patients may still achieve natural pregnancy.

Spatialtemporal evolution characteristics of ozone in China and its response to urbanization.

Based on the background of urbanization in China, we used the dynamic spatial panel Durbin model to study the driving mechanism of ozone pollution empirically. We also analyzed the spatial distribution of ozone driving factors using the GTWR. The results show that: i) The average annual increase of ozone concentration in ambient air in China from 2015 to 2019 was 1.68µg/m3, and 8.39µg/m3 elevated the year 2019 compared with 2015. ii) The Moran's I value of ozone in ambient air was 0.027 in 2015 and 0.209 in 2019, showing the spatial distribution characteristics of "east heavy and west light" and "south low and north high". iii) Per capita GDP industrial structure, population density, land expansion, and urbanization rate have significant spillover effects on ozone concentration, and the regional spillover effect is greater than the local effect. R&D intensity and education level have a significant negative impact on ozone concentration. iv) There is a decreasing trend in the inhibitory effect of educational attainment and R&D intensity on ozone concentration, and an increasing trend in the promotional effect of population urbanization rate, land expansion, and economic development on ozone concentration. Empirical results suggest a twofold policy meaning: i) to explore the causes behind the distribution of ozone from the new perspective of urbanization, and to further the atmospheric environmental protection system and ii) to eliminate the adverse impacts of ozone pollution on nature and harmonious social development.

Novel MEI1 mutations cause chromosomal and DNA methylation abnormalities leading to embryonic arrest and implantation failure.

This study presents a case of a female infertile patient suffering from embryonic arrest and recurrent implantation failure. The primary objective was to assess the copy number variations (CNVs) and DNA methylation of her embryos. Genetic diagnosis was conducted by whole-exome sequencing and validated through Sanger sequencing. CNV evaluation of two cleavage stage embryos was performed using whole-genome sequencing, while DNA methylation and CNV assessment of two blastocysts were carried out using whole-genome bisulfite sequencing. We identified two novel pathogenic frameshift variants in the MEI1 gene (NM_152513.3, c.3002delC, c.2264_2268 + 11delGTGAGGTATGGACCAC) in the proband. These two variants were inherited from her heterozygous parents, consistent with autosomal recessive genetic transmission. Notably, two Day 3 embryos and two Day 6 blastocysts were all aneuploid, with numerous monosomy and trisomy events. Moreover, global methylation levels greatly deviated from the optimized window of 0.25-0.27, measuring 0.344 and 0.168 for the respective blastocysts. This study expands the mutational spectrum of MEI1 and is the first to document both aneuploidy and abnormal methylation levels in embryos from a MEI1-affected female patient presenting with embryonic arrest. Given that females affected by MEI1 mutations might experience either embryonic arrest or monospermic androgenetic hydatidiform moles due to the extrusion of all maternal chromosomes, the genetic makeup of the arrested embryos of MEI1 patients provides important clues for understanding the different disease mechanisms of the two phenotypes.

Impacts of water surge from mountain railroad tunnels on ecological environments based on the RSEI model.

Tunnels play a significant role in mountain railroad routes and increase the efficiency of railroad traffic. However, water surge from tunnels can seriously impact the ecological environment during the construction period. This study selected a typical mountain railroad tunnel in southwest China and used the remote sensing ecological index (RSEI) to evaluate the changes in the ecological environment along the tunnel surge water path and relate the impacts to the main influencing factors throughout the whole tunnel construction cycle. The following conclusions were obtained: (1) The RSEI from 2005 to 2020 mostly ranged within 0.25-0.75. The most severe ecological disturbances occurred in areas directly affected by tunnel construction and along the water surge path. (2) In addition to affecting the surrounding ecological environment during the construction period, tunnel surge water continued to adversely affect the environment during the post-construction period. (3) In the post-construction period, the areas 300-450 m and 750-850 m from the tunnel exit had the largest changes in RSEI. This study provides scientific evidence to support environmental planning for mountain railroad tunnel construction, which is necessary to achieve both efficient tunnel construction and environmental protection.

Dazomet changes microbial communities and improves morel mushroom yield under continuous cropping.

Morels (Morchella spp.) are highly prized and popular edible mushrooms. The outdoor cultivation of morels in China first developed at the beginning of the 21st century. Several species, such as Morchella sextelata, M. eximia, and M. importuna, have been commercially cultivated in greenhouses. However, the detriments and obstacles associated with continuous cropping have become increasingly serious, reducing yields and even leading to a complete lack of fructification. It has been reported that the obstacles encountered with continuous morel cropping may be related to changes in the soil microbial community. To study the effect of dazomet treatment on the cultivation of morel under continuous cropping, soil was fumigated with dazomet before morel sowing. Alpha diversity and beta diversity analysis results showed that dazomet treatment altered the microbial communities in continuous cropping soil, which decreased the relative abundance of soil-borne fungal pathogens, including Paecilomyces, Trichoderma, Fusarium, Penicillium, and Acremonium, increased the relative abundance of beneficial soil bacteria, including Bacillius and Pseudomonas. In addition, the dazomet treatment significantly increased the relative abundance of morel mycelia in the soil and significantly improved morel yield under continuous cropping. These results verified the relationship between the obstacles associated with continuous cropping in morels and the soil microbial community and elucidated the mechanism by which the obstacle is alleviated when using dazomet treatment.

Corrigendum: milR20 negatively regulates the development of fruit bodies in Pleurotus cornucopiae.

[This corrects the article DOI: 10.3389/fmicb.2023.1177820.].

milR20 negatively regulates the development of fruit bodies in Pleurotus cornucopiae.

The mechanism underlying the development of fruit bodies in edible mushroom is a widely studied topic. In this study, the role of milRNAs in the development of fruit bodies of Pleurotus cornucopiae was studied by comparative analyses of the mRNAs and milRNAs at different stages of development. The genes that play a crucial role in the expression and function of milRNAs were identified and subsequently expressed and silenced at different stages of development. The total number of differentially expressed genes (DEGs) and differentially expressed milRNAs (DEMs) at different stages of development was determined to be 7,934 and 20, respectively. Comparison of the DEGs and DEMs across the different development stages revealed that DEMs and its target DEGs involved in the mitogen-activated protein kinase (MAPK) signaling pathway, protein processing in endoplasmic reticulum, endocytosis, aminoacyl-tRNA biosynthesis, RNA transport, and other metabolism pathways, which may play important roles in the development of the fruit bodies of P. cornucopiae. The function of milR20, which targeted pheromone A receptor g8971 and was involved in the MAPK signaling pathway, was further verified by overexpression and silencing in P. cornucopiae. The results demonstrated that the overexpression of milR20 reduced the growth rate of mycelia and prolonged the development of the fruit bodies, while milR20 silencing had an opposite effect. These findings indicated that milR20 plays a negative role in the development of P. cornucopiae. This study provides novel insights into the molecular mechanism underlying the development of fruit bodies in P. cornucopiae.

Innovation network structure, government R&D investment and regional innovation efficiency: Evidence from China.

Based on the panel data of 30 provinces in China from 2011 to 2019, this paper uses a two-stage DEA model to measure regional innovation efficiency, then non-parametric test is used to examine the impact of innovation network structure and government R&D investment on regional innovation efficiency. The results show that, at the provincial level, innovation efficiency of regional R&D is not necessarily in direct proportion to the innovation efficiency in the commercialization stage. Commercialization efficiency is not necessarily high in provinces with high technical R&D efficiency. At the national level, the innovation efficiency gap between our country's R&D and commercialization stage is small, indicating that the development of the national innovation efficiency is more and more balanced. Innovation network structure can promote the R&D efficiency, but has no significant effect on the commercialization efficiency. Government R&D investment helps to improve the R&D efficiency, but it is not conducive to the improvement of commercialization efficiency. The interaction between innovation network structure and government R&D investment will have compound effects on regional innovation efficiency; the region with underdeveloped innovation network structure can increase the government R&D investment to make it have a higher level of R&D. This paper provides insights into how to improve innovation efficiency in different social networks and policy environments.

Financial development, technological innovation and urban-rural income gap: Time series evidence from China.

The main purpose of the paper is to investigate the relationship between technological innovation and income inequality for China based on the financial Kuznets curve (FKC) hypothesis. The study uses time-series data from 1985 to 2019. We employ the Johansen cointegration, ARDL model and VECM Granger causality techniques to analyze the links between the variables. We also use the DOLS, FMOLS and CCR mechanisms to estimate the long-run parameters. The paper finds that the FKC is valid for China's economy in the long run. Technological innovation positively affects the urban-rural income gap, while there is an inverted-U shaped between financial development and the urban-rural income gap. The relationship between financial development and the urban-rural income gap is bi-directional causality. Technological innovation and the urban-rural income gap cause each other. Empirical results suggest a twofold policy meaning: i) to further the financial system and ii) to eliminate the adverse impacts of technological innovations on income distribution.

Preventing Growth Stagnation and Premature LH Surge Are the Keys to Obtaining a Viable Embryo in Monofollicular IVF Cycles: A Retrospective Cohort Study.

How LH levels influenced the outcomes of monofollicular IVF cycles using different stimulation protocols was controversial. In this single-center, retrospective study, we analyzed 815 monofollicular IVF cycles between 2016−2022 using natural cycle (NC), medroxyprogesterone acetate (MPA) or clomiphene citrate (CC) in addition to human menopausal gonadotropin (hMG), with or without GnRH antagonist. A viable embryo was obtained in 35.7% of all cycles. Growth stagnation and premature LH surge are two markedly negative factors for obtaining viable embryos (odds ratios of 0.12 [0.08−0.65], p < 0.0001 and 0.33 [0.26,0.42], p < 0.0001, respectively). NC/hMG cycles are prone to premature LH surge (40.4%), yielding a significantly lower opportunity of obtaining embryos (24.7%, p = 0.029). The administration of GnRH antagonist on the background of MPA resulted in a significant decrease in LH levels (from 2.26 IU/L to −0.89 IU/L relative to baseline, p = 0.000214), leading to a higher risk of growth stagnation (18.6%, p = 0.007). We hypothesized that the abrupt decline of LH might increase the risk of apoptosis in granulosa cells. We proposed a "marginal effect" framework to emphasize that the change of LH was the key to its bioactivity, rather than the traditional "window" concept with fixed cutoff values of a threshold and a ceiling.

Status of maternal serum B vitamins and pregnancy outcomes: New insights from in vitro fertilization and embryo transfer (IVF-ET) treatment.

The influence of B vitamins on human fertility and infertility treatments remains elusive. Therefore, this study investigated the association of most B vitamins with IVF-ET outcomes. A total of 216 subjects aged <35 year in their first oocyte retrieval cycle were recruited. Blood samples from the participants were collected before the oocyte pick-up procedure, and serum levels of riboflavin, niacin, pantothenic acid, vitamin B6 (including PA and PLP), folate, and methylmalonic acid (MMA) were detected using high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Endpoints were classified into three groups according to tertiles (lower, middle, and upper) of each vitamin index, and the association of the serum vitamin status with intermediate and clinical outcomes was analyzed using a generalized estimating equation model. Higher riboflavin levels were associated with elevated probabilities of high-quality embryos, as well as clinical pregnancy after embryo transfer. A greater likelihood of transferable embryos was found in the middle tertile of serum folate. Similarly, a negative correlation of serum MMA, a marker of vitamin B12 deficiency, with high-quality embryos was identified. No significance was observed for other vitamins in terms of all endpoints. Therefore, sufficient levels of pre-conception riboflavin, folate, and vitamin B12 are recommended for successful infertility treatment and pregnancy planning; further evidence is needed to confirm our conclusion.

Nitric Oxide Negatively Regulates the Rapid Formation of Pleurotus ostreatus Primordia by Inhibiting the Mitochondrial aco Gene.

Nitric oxide (NO) is as a signaling molecule that participates in the regulation of plant development and in a number of physiological processes. However, the function and regulatory pathway of NO in the growth and development of edible mushrooms are still unknown. This study found that NO played a negative role in the transformation of Pleurotus ostreatus from vegetative growth to reproductive growth by the exogenous addition of NO donors and scavengers. Further studies showed that NO can inhibit the gene expression and enzyme activity of aconitase (ACO). Moreover, the overexpression (OE) of mitochondrial aco and RNA interference (RNAi) confirmed that ACO participates in the regulation of the primordia formation rate. The effects of aco OE and RNAi on the tricarboxylic acid (TCA) cycle and energy metabolism were further measured. The results showed that RNAi-aco mutant strains can affect the enzyme activities of isocitrate dehydrogenase of mitochondria (ICDHm) and α-ketoglutarate dehydrogenase (α-KGDH) in the TCA cycle, thereby reducing the production of nicotinamide adenine dinucleotide (NADH) in the TCA cycle, decreasing the contents of adenosine triphosphate (ATP) and hydrogen peroxide (H2O2), and negatively regulating the rapid formation of primordia. In addition, H2O2 was significantly increased during the transformation from vegetative growth to reproductive growth of P. ostreatus. Additionally, the exogenous addition of H2O2 and its scavengers further confirmed the positive regulation by H2O2 in primordia formation. This study shows that during the growth and development of P. ostreatus, NO can inhibit the expression of the mitochondrial aco gene and ACO protein in the TCA cycle, reduce the production of ATP and H2O2 in the respiratory chain, and negatively regulate the rate of primordia formation.

Cross-Border Accessibility and Spatial Effects of China-Mongolia-Russia Economic Corridor under the Background of High-Speed Rail Environment.

Under the background of "the Belt and Road" and "China-Mongolia-Russia economic corridor" initiatives, we studied the urban accessibility level and regional spatial effect of the west line and east line of China-Mongolia-Russia economic corridor in the high-speed rail (HSR) environment. The results are as following. (1) The operation of China-Mongolia-Russia HSR will greatly improve the urban accessibility level, which will shorten the whole journey time to two days along China-Mongolia-Russia economic corridor. The regional space-time convergence effect will be very strong in the China-Mongolia-Russia HSR environment. (2) The accessibility level and its improvement degree of the China-Mongolia-Russia east line are stronger than those of the west line. The accessibility level of different countries differs: China > Russia > Mongolia. The accessibility improvement degree of different countries also differs: Mongolia > Russia > China. Spatially, the accessibility improvement degree of the cities, which are located in the middle of the line is stronger than those cities at the beginning and end of the line. (3) Affected by the China-Mongolia-Russia HSR environment, the spatial polarization effect of China-Mongolia-Russia HSR axial belt will be further enhanced. The internal boundary effect of the China-Mongolia-Russia HSR axial belt will disappear. New HSR economic growth poles will occur, promoting the formation of point-axis system. China-Mongolia-Russia cross-border trade creation and transfer effects will be deepened.

Spatiotemporal evolution characteristics of coordinated development of urbanization and ecological environment in eastern Russia-Perspectives from the 3D global trend and 2D plane analysis.

Under the background of "the Belt and Road" and "the economic corridor of China, Mongolia and Russia" initiatives, it has great value to study the temporal and spatial evolution characteristics of the coordinated development between the urbanization and ecological environment in eastern Russia (the Siberian Federal District and the Far East Federal District). In this paper, we studied the urbanization development level, eco-environment development level, and their coupling coordinated development degree during 2005-2018 in the eastern Russia from the perspectives of the 3D global trend and 2D plane analysis. First, combining with the Population-Economic-Sociology and Pressure-State-Response models, the urbanization development level and eco-environment development level were calculated by the comprehensive weighting method of entropy weight and variation coefficient for eastern Russia. Second, the coupling coordinated development degree of the urbanization development level and eco-environment development level was measured by the coupling coordination model for eastern Russia. Finally, the spatial differentiation of the urbanization development level, the eco-environment development level and their coupling coordinated development degree was performed respectively by the 3D global trend and 2D plane analysis using ArcGIS. The results are as following. First, the comprehensive urbanization development level of eastern Russia has increased from 2005 to 2018, and the economic urbanization is the main factor that affects the urbanization development in eastern Russia. The comprehensive eco-environment development level of eastern Russia has decreased from 2005 to 2018, and the eco-environment pressure is the main factor that affects the eco-environment development in eastern Russia. The coupling coordination degree of the urbanization development and eco-environment development has increased from 2005 to 2018. However, it is still in the uncoordinated stage. Second, from 2005 to 2018, the urbanization development level of the Siberian Federal District is higher than that of the Far East Federal District. The eco-environment development level of the Siberian Federal District is balanced to that of the Far East Federal District. The coupling coordination degree of the Siberian Federal District is higher than that of the Far East Federal District. Among the Siberian and Far East Federal Districts, most of the federal subjects belong to the uncoordinated stage of the urbanization development and the eco-environment development. Third, the urbanization development level, the eco-environment development level, and their coupling coordinated development level are all spatially imbalanced in the eastern Russia, which show the "High West, Low East" and "High Center, Low North and Low South" spatial pattern from the perspectives of the 3D global trend and 2D plane analysis. The areas with high levels are concentrated in the Novosibirsk Region, Altay Territory, Kemerovo Region, Krasnoyarsk Territory, and Irkutsk Region. The areas with low ones are mostly in the Republic of Altay and Chukotka Autonomous Area. Finally, we suggest policies and strategies that can boost the growth and development of the urbanization and the eco-environment in the Sino-Russian border areas.

The outcomes of sequential embryo transfer in patients undergoing in vitro fertilization with frozen-thawed embryos: A retrospective study.

AIM: To explore whether sequential embryo transfer benefits patients with repeated implantation failure (RIF) undergoing frozen-thawed embryo transfer (FET) cycles. METHODS: We included 311 patients with a history of RIF in this retrospective study. We did sequential transfers with a cleavage embryo on day 3 and a blastocyst on day 5 in 77 patients; blastocyst transfers with two blastocysts on day 5 in 80 patients; and cleavage embryo transfers with two cleavage embryos on day 3 in 154 patients. We compared clinical outcomes between the three groups. RESULTS: The clinical pregnancy rate was comparable between the blastocyst transfer group (48.8%), the sequential transfer group(48.1%) and the cleavage embryo transfer group (48.1%). There was no statistically significant difference found (p > 0.05). The ongoing pregnancy and multipregnancy rates were also comparable between the three groups (p > 0.05). The early miscarriage rate was significantly higher in the sequential transfer group (32.4%) compared with the blastocyst group (12.8%) and the cleavage embryo group (12.2%) (p < 0.05). However, after adjusting for confounders, there was no significant difference in early miscarriage rates in the sequential transfer group compared with the blastocyst group (odds ratio [OR], 2.97; 95% confidence interval [CI], 0.85-9.24; p = 0.07) and the cleavage embryo group (OR, 3.03; 95% CI, 0.94-8.06; p = 0.08). CONCLUSIONS: Sequential embryo transfer failed to improve clinical outcomes for patients with RIF.

Case Management Improves Satisfaction, Anxiety, and Depression of Patients with Pregnancy Loss after In Vitro Fertilization and Embryo Transfer.

Objective: Pregnancy loss has negative impacts on both the physical and the mental health of expectant mothers, which calls for an in-depth investigation. In this study, we examined the effects of case management on patients with pregnancy loss after in vitro fertilization and embryo transfer (IVF-ET). Methods: 100 participants that had suffered pregnancy loss after IVF-ET-assisted pregnancy from January 2019 to March 2020 were divided into routine care and case management groups, each with 50 cases. For the routine care group, a doctor led the diagnostic and treatment processes and a nurse assisted with the treatment. For the case management group, a nurse led the patient diagnostic and treatment processes and a doctor controlled the diagnosis and treatment plan formulation. Case management models were established according to the comprehensive peripregnancy loss care of patients with pregnancy loss after IVF-ET-assisted pregnancy. The participants' outcomes (satisfaction, anxiety, and depression) were assessed at the time of pregnancy loss and 1 and 3 months after pregnancy loss during follow-up of the routine care and case management groups. Results: There was no statistical difference between the patients in the two groups with regard to their general information statistics (P > 0.05) or their satisfaction, anxiety, and depression at the time of pregnancy loss (P > 0.05). One month after pregnancy loss, there was no statistical difference in anxiety between the two groups (P > 0.05), but satisfaction was greater and depression was significantly reduced in the case management group compared with the routine care group (P < 0.05). Conclusion: Case management care can have a positive effect on improving the satisfaction, anxiety, and depression of patients that have had pregnancy loss after IVF-ET.

Spatiotemporal evolution characteristics of urbanization and its coupling coordination degree in Russia - perspectives from the population, economy, society, and eco-environment.

Under the background of "the Belt and Road" and "the economic corridor of China, Mongolia and Russia" initiatives, it is of great significance to study the temporal and spatial evolution characteristics of urbanization in Russia. This paper studied the population urbanization level, economic urbanization level, social urbanization level, eco-environment urbanization level, and their coupling coordination development degree during 2005-2020 in Russia. First, combining with the Population-Economic-Sociology-Eco-environment model, the paper constructed the index systems to evaluate the urbanization development levels in Russia. Second, based on the comprehensive weighting method of entropy weight and variation coefficient, this paper calculated the population urbanization level, economic urbanization level, social urbanization level, and eco-environment urbanization level in Russia. Third, this paper used the coupling coordination model to measure the coupling coordination degree of the urbanization development levels in Russia. Finally, the spatial differentiation of the population urbanization level, economic urbanization level, social urbanization level, eco-environment urbanization level, and their coupling coupling-coordination degree was performed, respectively, by using ArcGIS. The results are as the following. First, from 2005 to 2020, the economic urbanization level and eco-urbanization level have shown the increasing trend in Russia. The population urbanization level and social urbanization level have shown the stable changing trend in Russia. The eco-environment urbanization and economic urbanization contribute larger share to the urbanization system compared with the population urbanization and social urbanization. The coupling coordination development degree of population urbanization level, economic urbanization level, social urbanization level, and eco-environment urbanization level has showed a slight increasing trend. However, the overall situation of the urbanization in Russia is still in the moderate uncoordinated recession stage. Second, the federal subjects with high urbanization development levels are mainly distributed in Moscow city, Moscow Region, Sverdlovsk Region, Tumen Region, Saint-Petersburg city, Republic of Tatarstan, Krasnoyarsk Territory, Republic of Bashkortostan, Chelyabinsk Region, Nizhny Novgorod Region, Krasnodar Territory, Rostov Region, and Khanty-Mansiysky Autonomous Area. The federal subjects with low ones are mainly located in Republic of Khakasia, Republic of Marii El, Republic of Kabardino-Balkaria, Republic of Tyva, Republic of Karachaevo-Cherkessia, Republic of Kalmykia, Republic of Altay, Jewish Autonomous Area, and Republic of Ingushetia. Third, spatially, from 2005 to 2020, the urbanization pattern of population, economy, society, eco-environment, and their coupling coordination degree in Russia all show unbalanced development characteristics. The population urbanization pattern and the social urbanization pattern have not changed significantly, showing the spatial characteristics of "high west, low east," and "high middle, low north, low south." The economic urbanization pattern has been increasing significantly, showing the spatial characteristics of "high core, low edge." The eco-environment urbanization pattern has not changed significantly, showing the spatial characteristics of "high north, low south." The coupling coordinated development degree of urbanization pattern has showed a slight increasing trend, showing the spatial characteristics of "high middle, low north, low south," "high west, low east". Finally, we suggest policies and strategies that can boost the growth and development of the urbanization in Russia.

Evolution characteristics of temporal and spatial pattern of Russian economic differences since the 21st century.

Under the background of "the Belt and Road" and "the economic corridor of China, Mongolia and Russia" initiatives, it is of great significance to study the temporal and spatial economic pattern in the Russian Federation. Based on the economic development difference index, regional economic grade index, global trend analysis tool and spatial autocorrelation model, this paper analyzes the temporal and spatial pattern evolution characteristics of Russian economic differences from 2002 to 2020. The results are as following. First, although the economic imbalance among various federal subjects has been decreasing, the economic polarization has been still severe between the prosperous developed regions and the stagnant backward regions during 2002-2020. Russia's economy shows a trend of changing from significant positive correlation in strong agglomeration space to positive correlation in weak agglomeration space, and then to random distribution. Second, there has been great differences of the economic development among various federal subjects. The economic grade of the Russian federal subjects presents a significant spatial differentiation pattern. The Russian Federation's economic resources are concentrated in the first-class federal subject (Moscow City), second-class federal subjects (Tumen Region, Moscow Region and Saint-Petersburg city) and a few third-class federal subjects (Yamalo-Nenetsky Autonomous Area, Khanty-Mansiysky Autonomous Area, Republic of Tatarstan, Krasnodar Territory, Sverdlovsk Region, etc). Third, the Russian Federation's economy presents "High Core, Low Periphery", "High West, Low East" and "High south, Low north" spatial differentiation pattern. The economic hot regions coincide with the high-class economic regions, which are mainly distributed in the contiguous areas of Ural Federal District and Volga Federal District, as well as the Moscow City, Moscow Region, Saint-Petersburg city, Krasnodar Territory and Rostov Region. The economic cold regions coincide with the low-class economic regions, which are mainly located in the Far East Federal District, the east of Siberian Federal District, the north of North West Federal District and the south of North-Caucasian Federal District. Finally, we suggest the recommendation for policy makers in Russia. And we propose the future research ideas.

Physiological mechanisms by which gypsum increases the growth and yield of Lentinula edodes.

Lentinula edodes is one of the most important commercially cultivated edible mushrooms. It is well known that gypsum (CaSO4·2H2O) supplementation in sawdust medium increases the yield of L. edodes, while the physiological mechanisms remain unclear. Our previous study showed that the acidification of the medium to pH 3.5-4.0 was essential for the growth of L. edodes. In this study, it was found that the oxalic acid excreted by L. edodes was responsible for the acidification of the medium. The biosynthesis of oxalic acid was regulated by the ambient pH and buffer capacity of the medium. To acidify the sawdust medium, the concentrations of total and soluble oxalate were 51.1 mmol/kg and 10.8 mmol/kg, respectively. However, when the concentration of soluble oxalate was 8.0 mmol/kg, the mycelial growth rate decreased by 29% compared with the control. Soluble oxalate was toxic to L. edodes, while soluble sulfate was nontoxic. CaSO4 reacted with soluble oxalate to form nontoxic insoluble CaC2O4 and the strong acid H2SO4. When the CaSO4 supplemented in sawdust medium was more than 25 mmol/kg, the soluble oxalate decreased to less than 1 mmol/kg, and the mycelial growth rate increased by 32% compared with the control. In conclusion, gypsum improved the growth and yield by relieving the toxicity of oxalate and facilitating the acidification of sawdust medium. KEY POINTS: • L. edodes excretes oxalic acid to acidify the ambient environment for growth. • Soluble oxalate is toxic to L. edodes. • Gypsum increases growth by reacting with oxalate to relieve its toxicity.

Isolation and identification of pigments from oyster mushrooms with black, yellow and pink caps.

The genus Pleurotus, namely oyster mushroom, is widely cultivated and consumed worldwide. Cap color is an important commercial trait for oyster mushroom. Diverse color is determined by various pigment constituents. However, the pigments of oyster mushrooms are still ambiguous. In this study, we extracted and identified pigments of oyster mushroom species with black, yellow and pink cap color. The extracted pigments appearing the three color types correspondingly to the cap color, which were all identified as melanin using a panel of spectroscopic and physical/imaging techniques. Nevertheless, HPLC and elemental analysis indicated that the melanin in oyster mushrooms was actually a mixture of eumelanin and phaeomelanin. Differences in the quantities and relative proportions of eumelanin and phaeomelanin resulted in the color variation in oyster mushroom caps. Electron microscopy studies showed that the melanin units are likely located in the cell wall, as reported in other fungi. The pigments in oyster mushrooms with three different cap color were extracted and identified for the first time in this study, which provided fundamental knowledge for future studies on the mechanism of color formation in mushrooms.