The development of chemoresistance which results in a poor prognosis often renders current treatments for colorectal cancer(CRC).In this study,we identified reduced microvessel density(MVD)and vascular immaturity resu...The development of chemoresistance which results in a poor prognosis often renders current treatments for colorectal cancer(CRC).In this study,we identified reduced microvessel density(MVD)and vascular immaturity resulting from endothelial apoptosis as therapeutic targets for overcoming chemoresistance.We focused on the effect of metformin on MVD,vascular maturity,and endothelial apoptosis of CRCs with a non-angiogenic phenotype,and further investigated its effect in overcoming chemoresistance.In situ transplanted cancer models were established to compare MVD,endothelial apoptosis and vascular maturity,and function in tumors from metformin-and vehicle-treated mice.An in vitro co-culture system was used to observe the effects of metformin on tumor cell-induced endothelial apoptosis.Transcriptome sequencing was performed for genetic screening.Non-angiogenic CRC developed independently of angiogenesis and was characterized by vascular leakage,immaturity,reduced MVD,and non-hypoxia.This phenomenon had also been observed in human CRC.Furthermore,non-angiogenic CRCs showed a worse response to chemotherapeutic drugs in vivo than in vitro.By suppressing endothelial apoptosis,metformin sensitized non-angiogenic CRCs to chemo-drugs via elevation of MVD and improvement of vascular maturity.Further results showed that endothelial apoptosis was induced by tumor cells via activation of caspase signaling,which was abrogated by metformin administration.These findings provide pre-clinical evidence for the involvement of endothelial apoptosis and subsequent vascular immaturity in the chemoresistance of non-angiogenic CRC.By suppressing endothelial apoptosis,metformin restores vascular maturity and function and sensitizes CRC to chemotherapeutic drugs via a vascular mechanism.展开更多
The capacity of the central nervous system for structural plasticity and regeneration is commonly believed to show a decreasing progression from“small and simple”brains to the larger,more complex brains of mammals.H...The capacity of the central nervous system for structural plasticity and regeneration is commonly believed to show a decreasing progression from“small and simple”brains to the larger,more complex brains of mammals.However,recent findings revealed that some forms of neural plasticity can show a reverse trend.Although plasticity is a well-preserved,transversal feature across the animal world,a variety of cell populations and mechanisms seem to have evolved to enable structural modifications to take place in widely different brains,likely as adaptations to selective pressures.Increasing evidence now indicates that a trade-off has occurred between regenerative(mostly stem cell–driven)plasticity and developmental(mostly juvenile)remodeling,with the latter primarily aimed not at brain repair but rather at“sculpting”the neural circuits based on experience.In particular,an evolutionary trade-off has occurred between neurogenic processes intended to support the possibility of recruiting new neurons throughout life and the different ways of obtaining new neurons,and between the different brain locations in which plasticity occurs.This review first briefly surveys the different types of plasticity and the complexity of their possible outcomes and then focuses on recent findings showing that the mammalian brain has a stem cell–independent integration of new neurons into pre-existing(mature)neural circuits.This process is still largely unknown but involves neuronal cells that have been blocked in arrested maturation since their embryonic origin(also termed“immature”or“dormant”neurons).These cells can then restart maturation throughout the animal's lifespan to become functional neurons in brain regions,such as the cerebral cortex and amygdala,that are relevant to high-order cognition and emotions.Unlike stem cell–driven postnatal/adult neurogenesis,which significantly decreases from small-brained,short-living species to large-brained ones,immature neurons are particularly abundant in large-brained,long-living mammals,including humans.The immature neural cell populations hosted in these complex brains are an interesting example of an“enlarged road”in the phylogenetic trend of plastic potential decreases commonly observed in the animal world.The topic of dormant neurons that covary with brain size and gyrencephaly represents a prospective turning point in the field of neuroplasticity,with important translational outcomes.These cells can represent a reservoir of undifferentiated neurons,potentially granting plasticity within the high-order circuits subserving the most sophisticated cognitive skills that are important in the growing brains of young,healthy individuals and are frequently affected by debilitating neurodevelopmental and degenerative disorders.展开更多
BACKGROUND Immature ovarian teratoma is a rare and aggressive neoplasm that affects young women.This report is the first to describe the development of immature teratoma after ovarian cystectomy for mature teratoma of...BACKGROUND Immature ovarian teratoma is a rare and aggressive neoplasm that affects young women.This report is the first to describe the development of immature teratoma after ovarian cystectomy for mature teratoma of the ovary in an adolescent female with a family history of ovarian teratoma.CASE SUMMARY A 16-year-old girl who had undergone bilateral ovarian cystectomy for mature teratomas 3 years ago showed bilateral adnexal tumors during her regular ultrasonography follow-up every 6 months.She received laparoscopic bilateral ovarian cystectomy,and final histopathology showed grade-1 immature teratoma of the left ovary and mature teratoma of the right ovary.Laparoscopic left salpingo-oophorectomy and staging procedures were performed again.Her mother,maternal aunt,and maternal grandmother had also received surgeries for mature ovarian teratomas.CONCLUSION It is important to have guidance on management of patient and family members with familial ovarian teratomas.展开更多
Common or bread wheat ( Triticum aestivum L., AABBDD, 2n=42) originated ca. 8 000 years ago from hybridization of tetraploid wheat ( Triticum turgidum L., AABB, 2n=28) and diploid Aegilops tauschii Coss. (DD...Common or bread wheat ( Triticum aestivum L., AABBDD, 2n=42) originated ca. 8 000 years ago from hybridization of tetraploid wheat ( Triticum turgidum L., AABB, 2n=28) and diploid Aegilops tauschii Coss. (DD, 2n=14). An essential prerequisite for this evolutionary step is that the natural hybrids between tetraploid wheat and diploid Aegilops tauschii can produce relatively many filled seeds which germinated well. In this study, without special techniques, e.g. immature embryo culture, out of 22 Ae. tauschii accessions, the genotype AS60 produced relatively many filled seeds which germinated well. The seed germination percentages in the crosses of Ae. tauschii ×tetraploid wheat, tetraploid wheat× Ae. tauschii and Ae. tauschii ×common wheat were, respectively, 50.0%, 57.1% and 45.5%. It seems that Ae. tauschii accession AS60 has a unique genotype which facilitate hybrid seed development and viability, and which meets with the prerequisite for wheat evolutionary. Furthermore, the significance of this finding for common wheat improvement and evolution was discussed.展开更多
In this experiment, floral development from tissue culture of bread wheat (Triticum aestivum L.) was investigated. Immature embryos of 45 wheat cultivars were cultured, and 11.1% of the genotypes regenerated floral or...In this experiment, floral development from tissue culture of bread wheat (Triticum aestivum L.) was investigated. Immature embryos of 45 wheat cultivars were cultured, and 11.1% of the genotypes regenerated floral organs from the calli near the bases of the green buds or plantlets regenerated. The floral buds were morphologically incomplete with the appearances of unisexual pistillate flowers which were naked, clustered with normal ovaries and exuberant feather-like stigmas, but without stamens, paleas, lemmas and glumes. The histological examination showed that the pistils originated from the meristematic cells near the green buds or plantlets, and the clustered pistils were formed by secondary pistillate regeneration. The development of the feather-like structures was earlier than that of the ovules. Biovule developed from an ovary besides normal uniovule. Statistical analysis by X 2 test for independency demonstrated highly significant difference of flower regeneration among the tested genotypes. Wheat cultivar YA-1 revealed higher percentage (44.4%) than other genotypes, and the response could well be repeated in different years. It was indicated that the floral regeneration of immature embryo explants of YA-1 is relatively stable. The frequency of floral regeneration was mainly regulated by the components in the subculture media, compared with the response of the dedifferentiation media, despite the obviously different components involving basal medium type, inorganic Fe2+ concentration and plant growth regulators. The results suggested the combination of 6-benzylaminopurine, alpha-naphthalene acetic-acid and doubled inorganic Fe2+ might be more beneficial to inducing the floral development than that of 2,4-D and normal inorganic Fe2+ concentration in subculture medium. However, both immature inflorescence and mature embryo, as cultured explants of YA-1, did not regenerate any flower organs. It is believed that the immature embryo culture of YA-1 can be used to establish ideal experimental system for the study of floral developmental mechanism in wheat.展开更多
The line of T240-6 was selected from 32 SC 2 lines of immature embryo culture of T240 (common wheat (Triticum aestivum L.)× Wheat-Haynaldia villosa (L.) Schur. 6D/6V substitution line) through powdery mildew ch...The line of T240-6 was selected from 32 SC 2 lines of immature embryo culture of T240 (common wheat (Triticum aestivum L.)× Wheat-Haynaldia villosa (L.) Schur. 6D/6V substitution line) through powdery mildew characterization, glutamate oxaloacetate transaminase (GOT) enzyme and gliadin (Gli) analyses and in situ hybridization. All of the individual plants resistant to powdery mildew lacked the locus of GOT at 6VL arm (GOT-V 2) and had gliadin locus at 6VS arm (Gli-V 2) of Haynaldia villosa. All the plants resistant to powdery mildew had one or two telocentric chromosomes that did not pair with wheat chromosomes but paired between themselves. T240-6 was identified as a telocentric line through in situ hybridization.展开更多
[Objective] The aim was to explore the conditions of high frequency induction of embryonic callus and plant regeneration of maize. [Method] Immature embryos of maize inbred lines were used as explants to study the eff...[Objective] The aim was to explore the conditions of high frequency induction of embryonic callus and plant regeneration of maize. [Method] Immature embryos of maize inbred lines were used as explants to study the effect of different 2,4-D concentrations on the induction of callus,the effect of different 6-BA concentrations on the differentiation of test-tube plantlet,as well as the effect of different IBA concentrations on the rooting of test-tube plantlet. [Result] 2,4-D showed obvious effect on the induction of inducement rate of maize,and the optimum induction medium was：N6 ＋ 2 mg/L of 2,4-D ＋ 500 mg/L of CH ＋ 500 mg/L of Pro ＋10 mg/L of AgNO3; the optimum differentiation medium was：N6 ＋ 0.5 mg/L of BA ＋ 500 mg/L of Pro; the optimum for the rooting of test-tube plantlet was 1/2 MS ＋ 0.5 mg/L of IBA. [Conclusion] The study had provided basis for the genetic transformation of maize.展开更多
Studies were carried out to establish an efficient regeneration system of three bread wheat cultivars. Results showed induction medium containing 2,4-dichlorophenoxyacetic acid (2,4-D) had a higher plantlet regenerati...Studies were carried out to establish an efficient regeneration system of three bread wheat cultivars. Results showed induction medium containing 2,4-dichlorophenoxyacetic acid (2,4-D) had a higher plantlet regeneration frequency than Piclorm, with an average frequency of 54% in all treatments. Optimal condition for different genotypic rice was as following: induction medium (MSS 3AA/2) with 0.5 mg L-1 2,4-D, regeneration medium (R) with 0.01 mg L-1 2,4-D and 3 mg L-1 KT. The average regeneration frequency reached 83.3% under the condition. Correlation analysis showed that root differentiation, in different level, correlated with green spot regeneration, and with the number of regenerated plants per callus. No correlation was found between green spots regenerated and the numbers of plants regenerated per callus.展开更多
Immature stages of 3 species of the tribe Ozophorini from China are described for the first time, they are Bryanellocoris orientalis Hidaka (3rd^5th instars), Primierus longispinus Zheng (4th^5th instars) and Vertoman...Immature stages of 3 species of the tribe Ozophorini from China are described for the first time, they are Bryanellocoris orientalis Hidaka (3rd^5th instars), Primierus longispinus Zheng (4th^5th instars) and Vertomannus brevicollum Zheng (4th^5th instars). Abrief study on fine structure of pale spots on head, pronotum and abdomen of 5th instar nymph of Bryanellocoris orientalis Hidaka was also given.展开更多
In this paper the morphology of adult female of Kuwania bipora Borchsenius, 1960 is redescribed. The morphologies of adult male and all immature stages of both sexes are firstly described and illustrated. A key to all...In this paper the morphology of adult female of Kuwania bipora Borchsenius, 1960 is redescribed. The morphologies of adult male and all immature stages of both sexes are firstly described and illustrated. A key to all stages of K. bipora is provided.展开更多
In this paper, the crawler, second instar female and male, prepupa, pupa and adult male of Cryptococcus ulmi are described and illustrated for the first time; adult female is redescribed; a key to all stages is gi...In this paper, the crawler, second instar female and male, prepupa, pupa and adult male of Cryptococcus ulmi are described and illustrated for the first time; adult female is redescribed; a key to all stages is given and the biology is briefly repor ted.展开更多
This research explores emerging concepts of tourism education,training,and entrepreneurship development.Nowadays,the discourses on this theme have been growing in both developed and developing countries,especially to ...This research explores emerging concepts of tourism education,training,and entrepreneurship development.Nowadays,the discourses on this theme have been growing in both developed and developing countries,especially to reduce unemployment rates through the education of young people.For this purpose,this study uses secondary data sources to analyze individual rationality and the creativity of educated young people for entrepreneurship development in the business sector.The analytical framework begins from the investigation of the tourism industry and the processes for empowering those people since tourism industry is considered as one of the agents of economic changes in developing countries,such as Nepal.However,skilled and trained manpower are required to operate well.The main theme of this study is that the aforesaid manpower can be developed with entrepreneurship skills by providing education and training in this business.This study entirely agrees that once the tourism industry is well run by removing the hurdles seen in this sector,there would be an increase in employment opportunities and a raise in the country’s revenue in addition to solving many other social problems.展开更多
Petroleum geochemistry contributes to exploration successes by providing key constraints for geological models and critical input to exploration scenarios. One of the most important tasks in a typical exploration pr...Petroleum geochemistry contributes to exploration successes by providing key constraints for geological models and critical input to exploration scenarios. One of the most important tasks in a typical exploration program is to identify the most effective source intervals or kitchens in a basin, through oil-source correlation. The results of correlation are valid only if the geochemical parameters used address adequately the genetic characteristics of the source rocks as well as the mass transport and mixing processes of hydrocarbon fluids occurring in the carrier beds and reservoirs. This manuscript discusses four of the major contentious petroleum geochemical issues in China’s sedimentary basins. It is suggested that marine incursions played a significant role in the formation of prolific petroleum source rocks in the gigantic, dominantly freshwater, Songliao Basin. Several models are proposed to account for the occurrence of immature oils in the Cathaysian rift system including the Bohai Bay Basin, thus immature source rocks are considered a mere minor contributor to the known economic immature oil resources. Both geological and geochemical evidence are reviewed to refute a dominantly coaly source for the petroleum discovered in the Turpan Basin. Results of case studies are presented to demonstrate the importance of recognizing petroleum fluid mixing to solve the oil-source correlation issues in the structurally complex Tarim Basin. In addressing the fundamental assumptions and potential flaws of the molecular geochemical parameters commonly used for oil-source correlation, the need of a mass fraction approach is proposed to deal with such contentious issues as marine versus lacustrine, coal versus lacustrine, and mature versus immature oils.展开更多
Background/aims: To determine whether the 17-hydroxyprogesterone (17-OHP)/cortisol ratio as a marker of immature11-beta hydroxylase activity can predict severe systemic hypotension in preterm neonates. Methods: Serum ...Background/aims: To determine whether the 17-hydroxyprogesterone (17-OHP)/cortisol ratio as a marker of immature11-beta hydroxylase activity can predict severe systemic hypotension in preterm neonates. Methods: Serum cortisol and 17-OHP concentrations were measured in capillary blood deposited on blotter paper on day 3 post-natal age (Day 3) in infants less than 32 weeks postmenstrual age (PMA). The predictive value of 17-OHP/cortisol ratio for a first episode of systemic hypotension occurring after Day 3 (FESH) was evaluated. Results: Of 105 infants included, 14 patients (13%) presented a FESH. Neither the 17-OHP/cortisol ratio, nor the 17-OHP or cortisol concentrations were associated with the occurrence of a FESH when adjusted for potential confounding factors. 17-OHP and cortisol were inversely associated to PMA (r = ﹣0.36 and ﹣0.40, respectively). Cortisol, but not 17-OHP, was associated with the type of hospitalization unit, the respiratory support and the presence of a patent ductus arteriosus. The 17-OHP/cortisol ratio was associated with the type of hospitalization unit only. Conclusions: The 17-OHP/ cortisol ratio at Day 3 did not predict the occurrence of a first episode of systemic hypotension after Day3 inpreterm neonates.展开更多
According to the study on the peripheral orogenic belts of the Junggar basin and combined with the interpretation of geophysical data, this paper points out that there is an Early Paleozoic basement of immature contin...According to the study on the peripheral orogenic belts of the Junggar basin and combined with the interpretation of geophysical data, this paper points out that there is an Early Paleozoic basement of immature continental crust in the Junggar area, which is mainly composed of Neoproterozoic-Ordovician oceanic crust and weakly metamorphosed covering sedimentary rocks. The Late Paleozoic tectonism and mineralization were developed on the basement of the Early Paleozoic immature continental crust. The Junggar metallogenic province is dominated by Cr, Cu, Ni and Au mineralization. Those large and medium-scale deposits are mainly distributed along the deep faults and particularly near the ophiolitic melange zones, and formed in the Late Paleozoic with the peak of mineralization occurring in the Carboniferous-Permian post-collisional stage. The intrusions related to Cu, Ni and Au mineralization generally have low Is, and positive εNd(t) values. The δ34S values of the ore deposits are mostly near zero, and the lead isotopes are mostly of normal lead. All these indicate that the ore-forming material comes either directly from the mantle-derived magma (for chromite and Cu-Ni deposits) or from recirculation of the basement material of the Early Paleozoic immature crust (for most Cu and Au deposits).展开更多
Based on a detailed survey of the distribution and organic geochemical characteristics of potential source rocks in the South Slope of the Niuzhuang Sag, Bohai Bay Basin, eastern China, a new approach to assess the am...Based on a detailed survey of the distribution and organic geochemical characteristics of potential source rocks in the South Slope of the Niuzhuang Sag, Bohai Bay Basin, eastern China, a new approach to assess the amount of hydrocarbons generated and expelled has been developed. The approach is applicable to evaluate hydrocarbons with different genetic mechanisms. The results show that the models for hydrocarbon generation and expulsion vary with potential source rocks, depending on thermal maturity, types of organic matter and paleoenvironment. Hydrocarbons are mostly generated and expelled from source rocks within the normal oil window. It was calculated that the special interval (algal-rich shales of the ES4 member formed in brackish environments) in the South Slope of the Niuzhuang Sag has a much higher potential of immature oil generation than the other intervals in the area. This suggests that hydrocarbons can definitely be generated in early diagenesis, especially under certain special geological settings. The proportion of hydrocarbons generated and expelled from the ES4 shales in the early diagenetic stage is up to 26.75% and 17.36%, respectively. It was also observed that laminated shales have a much higher expulsion efficiency than massive mudstones. In contrast, the special interval of the ES4 shales proposed from previous studies is probably not the whole rock for oil in the South Slope of the Niuzhuang Sag because of the small proportion of the gross volume and corresponding low percentage of hydrocarbons generated and expelled. A much lower expulsion efficiency of the source rock during the early stage relative to that within the normal oil window has been calculated. Our results indicate that the ES4 mudstones rather than the shales deposited in the Niuzhuang and Guangli Sag are the main source rocks for the oil discovered.展开更多
Revascularization of immature necrotic teeth is a reliable treatment alternative to conventional apexogenesis or apexification. In case 1, a 12-year-old boy had his necrotic, immature mandibular left second premolar t...Revascularization of immature necrotic teeth is a reliable treatment alternative to conventional apexogenesis or apexification. In case 1, a 12-year-old boy had his necrotic, immature mandibular left second premolar treated with a revascularization technique. At a 24-month follow-up, periapical radiolucency had disappeared and thickening of the root wall was observed. In cases 2 and 3, a lO-year-old boy had his necrotic, immature, bilateral mandibular second premolars treated with the same modality. At 48-month （in case 2） and 42-month （in case 3） follow-ups, loss of periapical radiolucencies and increases in the root wall thickness were also observed.展开更多
Recent detailed organic geochemical and geological investigation indicate that oils of the Bamianhe oilfield, Bohai Bay Basin, East China are the mixture of less mature oils and normal oils derived from the ES4 mudsto...Recent detailed organic geochemical and geological investigation indicate that oils of the Bamianhe oilfield, Bohai Bay Basin, East China are the mixture of less mature oils and normal oils derived from the ES4 mudstones and shales with a wide range of thermal maturity from immature to middle-maturity, and most of the oils were proved to be sourced from the depocenter of the Niuzhuang Sag immediately adjacent to the Bamianhe oilfield. Two approaches to quantify the amount of immature oils mixed through quantitative biomarkers were established. One is a relatively simple way only through organic geochemical analysis while the other is to be combined with basin modeling. Selecting biomarkers as proxies is the crucial point in both of them. The results show that the less mature oils mixed in the Bamianhe oilfield is less than 10% and 18% respectively based on the two approaches, which coincide with the results of oil-source rock correlation.展开更多
The main active components extracted from Panax notoginseng are total saponins. They have been shown to inhibit platelet aggregation, increase cerebral blood flow, improve neurological behavior, decrease infarct volum...The main active components extracted from Panax notoginseng are total saponins. They have been shown to inhibit platelet aggregation, increase cerebral blood flow, improve neurological behavior, decrease infarct volume and promote proliferation and differentiation of neural stem cells in the hippocampus and lateral ventricles. However, there is a lack of studies on whether total saponins of Panax notoginsertg have potential benefits on immature neuroblasts in the olfactory bulb following ischemia and reperfusion. This study established a rat model of global cerebral ischemia and reperfusion using four-vessel occlusion. Rats were administered total sa- ponins of Panax notoginseng at 75 mg/kg intraperitoneally 30 minutes after ischemia then once a day, for either 7 or 14 days. Total saponins of Panax notoginseng enhanced the number of dou- blecortin （DCX）＋ neural progenitor ceils and increased co-localization of DCX with neuronal nuclei and phosphorylated cAMP response element-binding/DCX＋ neural progenitor cells in the olfactory bulb at 7 and 14 days post ischemia. These findings indicate that following global brain ischemia/reperfusion, total saponins of Panax notoginseng promote differentiation of DCX＋ cells expressing immature neuroblasts in the olfactory bulb and the underlying mechanism is related to the activation of the signaling pathway of cyclic adenosine monophosphate response element binding protein.展开更多
Wheat, one of the most important food crops, has been extensively studied with respects to plant regeneration and transformation employing the immature embryos as recipient tissues. However, the transformed tissues of...Wheat, one of the most important food crops, has been extensively studied with respects to plant regeneration and transformation employing the immature embryos as recipient tissues. However, the transformed tissues often become severely necrotic after co-cultivation with Agrobacterium, which is one of the major obstacles in gene delivery. In this study, wheat varieties CB037, Kenong 199, Xinchun 9, Lunxuan 987, and Shi 4185 showed desirable culture potential or high infection ability in Agrobacterium-mediated transformation. Similarly, optimal regeneration conditions were determined by testing their ability to inhibit the cell necrosis and cell death phenotype. Two auxins of 2,4-dichlorophenoxyacetic acid （2,4-D） and 3,6-dichloro-o-anisic acid （dicamba） were evaluated for highly significant effect on both callus and plantlet production, although they were genotype-dependent in wheat. Substitution of 2,4-D by dicamba enhanced the growth and regeneration ability of callus from the immature embryos of most genotypes tested. The callus growth state couldn’t be modified by adding antioxidants such as ascorbic acid, cysteine, and silver nitrate or organic additives such as thiamine HCl and asparagine to the media. On the contrary, the best tissue statement and plant regeneration was achieved by employing the media containing the simplest MS （Murashige and Skoog） components and dicamba without organic components and vitamins. Thereby, our results are thought to inhibit wheat cell necrosis effectively and suggested to be used for more wheat genotypes.展开更多
基金supported by grants from the National Natural Science Foundation of China(Grant No.:81972811)the Key Research and Development Foundation of Shaanxi Province(Grant Nos.:2018SF-099,S2021SF-136,2021JM-273,and 2022JQ-848)+1 种基金the Fundamental Research Funds for the Central Universities(Grant No.:xzy012022094)the Provincial Science and Technology Rising Star(Grant No.:2021KJXX-03).
文摘The development of chemoresistance which results in a poor prognosis often renders current treatments for colorectal cancer(CRC).In this study,we identified reduced microvessel density(MVD)and vascular immaturity resulting from endothelial apoptosis as therapeutic targets for overcoming chemoresistance.We focused on the effect of metformin on MVD,vascular maturity,and endothelial apoptosis of CRCs with a non-angiogenic phenotype,and further investigated its effect in overcoming chemoresistance.In situ transplanted cancer models were established to compare MVD,endothelial apoptosis and vascular maturity,and function in tumors from metformin-and vehicle-treated mice.An in vitro co-culture system was used to observe the effects of metformin on tumor cell-induced endothelial apoptosis.Transcriptome sequencing was performed for genetic screening.Non-angiogenic CRC developed independently of angiogenesis and was characterized by vascular leakage,immaturity,reduced MVD,and non-hypoxia.This phenomenon had also been observed in human CRC.Furthermore,non-angiogenic CRCs showed a worse response to chemotherapeutic drugs in vivo than in vitro.By suppressing endothelial apoptosis,metformin sensitized non-angiogenic CRCs to chemo-drugs via elevation of MVD and improvement of vascular maturity.Further results showed that endothelial apoptosis was induced by tumor cells via activation of caspase signaling,which was abrogated by metformin administration.These findings provide pre-clinical evidence for the involvement of endothelial apoptosis and subsequent vascular immaturity in the chemoresistance of non-angiogenic CRC.By suppressing endothelial apoptosis,metformin restores vascular maturity and function and sensitizes CRC to chemotherapeutic drugs via a vascular mechanism.
基金supported by Progetto Trapezio,Compagnia di San Paolo(67935-2021.2174),to LBFondazione CRT(Cassa di Risparmio di Torino,RF=2022.0618),to LBPRIN2022(grant 2022LB4X3N),to LB。
文摘The capacity of the central nervous system for structural plasticity and regeneration is commonly believed to show a decreasing progression from“small and simple”brains to the larger,more complex brains of mammals.However,recent findings revealed that some forms of neural plasticity can show a reverse trend.Although plasticity is a well-preserved,transversal feature across the animal world,a variety of cell populations and mechanisms seem to have evolved to enable structural modifications to take place in widely different brains,likely as adaptations to selective pressures.Increasing evidence now indicates that a trade-off has occurred between regenerative(mostly stem cell–driven)plasticity and developmental(mostly juvenile)remodeling,with the latter primarily aimed not at brain repair but rather at“sculpting”the neural circuits based on experience.In particular,an evolutionary trade-off has occurred between neurogenic processes intended to support the possibility of recruiting new neurons throughout life and the different ways of obtaining new neurons,and between the different brain locations in which plasticity occurs.This review first briefly surveys the different types of plasticity and the complexity of their possible outcomes and then focuses on recent findings showing that the mammalian brain has a stem cell–independent integration of new neurons into pre-existing(mature)neural circuits.This process is still largely unknown but involves neuronal cells that have been blocked in arrested maturation since their embryonic origin(also termed“immature”or“dormant”neurons).These cells can then restart maturation throughout the animal's lifespan to become functional neurons in brain regions,such as the cerebral cortex and amygdala,that are relevant to high-order cognition and emotions.Unlike stem cell–driven postnatal/adult neurogenesis,which significantly decreases from small-brained,short-living species to large-brained ones,immature neurons are particularly abundant in large-brained,long-living mammals,including humans.The immature neural cell populations hosted in these complex brains are an interesting example of an“enlarged road”in the phylogenetic trend of plastic potential decreases commonly observed in the animal world.The topic of dormant neurons that covary with brain size and gyrencephaly represents a prospective turning point in the field of neuroplasticity,with important translational outcomes.These cells can represent a reservoir of undifferentiated neurons,potentially granting plasticity within the high-order circuits subserving the most sophisticated cognitive skills that are important in the growing brains of young,healthy individuals and are frequently affected by debilitating neurodevelopmental and degenerative disorders.
文摘BACKGROUND Immature ovarian teratoma is a rare and aggressive neoplasm that affects young women.This report is the first to describe the development of immature teratoma after ovarian cystectomy for mature teratoma of the ovary in an adolescent female with a family history of ovarian teratoma.CASE SUMMARY A 16-year-old girl who had undergone bilateral ovarian cystectomy for mature teratomas 3 years ago showed bilateral adnexal tumors during her regular ultrasonography follow-up every 6 months.She received laparoscopic bilateral ovarian cystectomy,and final histopathology showed grade-1 immature teratoma of the left ovary and mature teratoma of the right ovary.Laparoscopic left salpingo-oophorectomy and staging procedures were performed again.Her mother,maternal aunt,and maternal grandmother had also received surgeries for mature ovarian teratomas.CONCLUSION It is important to have guidance on management of patient and family members with familial ovarian teratomas.
文摘Common or bread wheat ( Triticum aestivum L., AABBDD, 2n=42) originated ca. 8 000 years ago from hybridization of tetraploid wheat ( Triticum turgidum L., AABB, 2n=28) and diploid Aegilops tauschii Coss. (DD, 2n=14). An essential prerequisite for this evolutionary step is that the natural hybrids between tetraploid wheat and diploid Aegilops tauschii can produce relatively many filled seeds which germinated well. In this study, without special techniques, e.g. immature embryo culture, out of 22 Ae. tauschii accessions, the genotype AS60 produced relatively many filled seeds which germinated well. The seed germination percentages in the crosses of Ae. tauschii ×tetraploid wheat, tetraploid wheat× Ae. tauschii and Ae. tauschii ×common wheat were, respectively, 50.0%, 57.1% and 45.5%. It seems that Ae. tauschii accession AS60 has a unique genotype which facilitate hybrid seed development and viability, and which meets with the prerequisite for wheat evolutionary. Furthermore, the significance of this finding for common wheat improvement and evolution was discussed.
文摘In this experiment, floral development from tissue culture of bread wheat (Triticum aestivum L.) was investigated. Immature embryos of 45 wheat cultivars were cultured, and 11.1% of the genotypes regenerated floral organs from the calli near the bases of the green buds or plantlets regenerated. The floral buds were morphologically incomplete with the appearances of unisexual pistillate flowers which were naked, clustered with normal ovaries and exuberant feather-like stigmas, but without stamens, paleas, lemmas and glumes. The histological examination showed that the pistils originated from the meristematic cells near the green buds or plantlets, and the clustered pistils were formed by secondary pistillate regeneration. The development of the feather-like structures was earlier than that of the ovules. Biovule developed from an ovary besides normal uniovule. Statistical analysis by X 2 test for independency demonstrated highly significant difference of flower regeneration among the tested genotypes. Wheat cultivar YA-1 revealed higher percentage (44.4%) than other genotypes, and the response could well be repeated in different years. It was indicated that the floral regeneration of immature embryo explants of YA-1 is relatively stable. The frequency of floral regeneration was mainly regulated by the components in the subculture media, compared with the response of the dedifferentiation media, despite the obviously different components involving basal medium type, inorganic Fe2+ concentration and plant growth regulators. The results suggested the combination of 6-benzylaminopurine, alpha-naphthalene acetic-acid and doubled inorganic Fe2+ might be more beneficial to inducing the floral development than that of 2,4-D and normal inorganic Fe2+ concentration in subculture medium. However, both immature inflorescence and mature embryo, as cultured explants of YA-1, did not regenerate any flower organs. It is believed that the immature embryo culture of YA-1 can be used to establish ideal experimental system for the study of floral developmental mechanism in wheat.
文摘The line of T240-6 was selected from 32 SC 2 lines of immature embryo culture of T240 (common wheat (Triticum aestivum L.)× Wheat-Haynaldia villosa (L.) Schur. 6D/6V substitution line) through powdery mildew characterization, glutamate oxaloacetate transaminase (GOT) enzyme and gliadin (Gli) analyses and in situ hybridization. All of the individual plants resistant to powdery mildew lacked the locus of GOT at 6VL arm (GOT-V 2) and had gliadin locus at 6VS arm (Gli-V 2) of Haynaldia villosa. All the plants resistant to powdery mildew had one or two telocentric chromosomes that did not pair with wheat chromosomes but paired between themselves. T240-6 was identified as a telocentric line through in situ hybridization.
基金Supported by Natural Science Foundation of Guangxi Province(Guikezi 0991096)~~
文摘[Objective] The aim was to explore the conditions of high frequency induction of embryonic callus and plant regeneration of maize. [Method] Immature embryos of maize inbred lines were used as explants to study the effect of different 2,4-D concentrations on the induction of callus,the effect of different 6-BA concentrations on the differentiation of test-tube plantlet,as well as the effect of different IBA concentrations on the rooting of test-tube plantlet. [Result] 2,4-D showed obvious effect on the induction of inducement rate of maize,and the optimum induction medium was：N6 ＋ 2 mg/L of 2,4-D ＋ 500 mg/L of CH ＋ 500 mg/L of Pro ＋10 mg/L of AgNO3; the optimum differentiation medium was：N6 ＋ 0.5 mg/L of BA ＋ 500 mg/L of Pro; the optimum for the rooting of test-tube plantlet was 1/2 MS ＋ 0.5 mg/L of IBA. [Conclusion] The study had provided basis for the genetic transformation of maize.
文摘Studies were carried out to establish an efficient regeneration system of three bread wheat cultivars. Results showed induction medium containing 2,4-dichlorophenoxyacetic acid (2,4-D) had a higher plantlet regeneration frequency than Piclorm, with an average frequency of 54% in all treatments. Optimal condition for different genotypic rice was as following: induction medium (MSS 3AA/2) with 0.5 mg L-1 2,4-D, regeneration medium (R) with 0.01 mg L-1 2,4-D and 3 mg L-1 KT. The average regeneration frequency reached 83.3% under the condition. Correlation analysis showed that root differentiation, in different level, correlated with green spot regeneration, and with the number of regenerated plants per callus. No correlation was found between green spots regenerated and the numbers of plants regenerated per callus.
基金The project was supported by "Education Grant" of National Natural SciencesFoundation of China (No. 108)
文摘Immature stages of 3 species of the tribe Ozophorini from China are described for the first time, they are Bryanellocoris orientalis Hidaka (3rd^5th instars), Primierus longispinus Zheng (4th^5th instars) and Vertomannus brevicollum Zheng (4th^5th instars). Abrief study on fine structure of pale spots on head, pronotum and abdomen of 5th instar nymph of Bryanellocoris orientalis Hidaka was also given.
基金the National Natural Science Foundation of China (30670235)
文摘In this paper the morphology of adult female of Kuwania bipora Borchsenius, 1960 is redescribed. The morphologies of adult male and all immature stages of both sexes are firstly described and illustrated. A key to all stages of K. bipora is provided.
文摘In this paper, the crawler, second instar female and male, prepupa, pupa and adult male of Cryptococcus ulmi are described and illustrated for the first time; adult female is redescribed; a key to all stages is given and the biology is briefly repor ted.
文摘This research explores emerging concepts of tourism education,training,and entrepreneurship development.Nowadays,the discourses on this theme have been growing in both developed and developing countries,especially to reduce unemployment rates through the education of young people.For this purpose,this study uses secondary data sources to analyze individual rationality and the creativity of educated young people for entrepreneurship development in the business sector.The analytical framework begins from the investigation of the tourism industry and the processes for empowering those people since tourism industry is considered as one of the agents of economic changes in developing countries,such as Nepal.However,skilled and trained manpower are required to operate well.The main theme of this study is that the aforesaid manpower can be developed with entrepreneurship skills by providing education and training in this business.This study entirely agrees that once the tourism industry is well run by removing the hurdles seen in this sector,there would be an increase in employment opportunities and a raise in the country’s revenue in addition to solving many other social problems.
文摘Petroleum geochemistry contributes to exploration successes by providing key constraints for geological models and critical input to exploration scenarios. One of the most important tasks in a typical exploration program is to identify the most effective source intervals or kitchens in a basin, through oil-source correlation. The results of correlation are valid only if the geochemical parameters used address adequately the genetic characteristics of the source rocks as well as the mass transport and mixing processes of hydrocarbon fluids occurring in the carrier beds and reservoirs. This manuscript discusses four of the major contentious petroleum geochemical issues in China’s sedimentary basins. It is suggested that marine incursions played a significant role in the formation of prolific petroleum source rocks in the gigantic, dominantly freshwater, Songliao Basin. Several models are proposed to account for the occurrence of immature oils in the Cathaysian rift system including the Bohai Bay Basin, thus immature source rocks are considered a mere minor contributor to the known economic immature oil resources. Both geological and geochemical evidence are reviewed to refute a dominantly coaly source for the petroleum discovered in the Turpan Basin. Results of case studies are presented to demonstrate the importance of recognizing petroleum fluid mixing to solve the oil-source correlation issues in the structurally complex Tarim Basin. In addressing the fundamental assumptions and potential flaws of the molecular geochemical parameters commonly used for oil-source correlation, the need of a mass fraction approach is proposed to deal with such contentious issues as marine versus lacustrine, coal versus lacustrine, and mature versus immature oils.
基金the French National Registry(Direction Generale de la Sante)with the following number:DGS 2005/0503
文摘Background/aims: To determine whether the 17-hydroxyprogesterone (17-OHP)/cortisol ratio as a marker of immature11-beta hydroxylase activity can predict severe systemic hypotension in preterm neonates. Methods: Serum cortisol and 17-OHP concentrations were measured in capillary blood deposited on blotter paper on day 3 post-natal age (Day 3) in infants less than 32 weeks postmenstrual age (PMA). The predictive value of 17-OHP/cortisol ratio for a first episode of systemic hypotension occurring after Day 3 (FESH) was evaluated. Results: Of 105 infants included, 14 patients (13%) presented a FESH. Neither the 17-OHP/cortisol ratio, nor the 17-OHP or cortisol concentrations were associated with the occurrence of a FESH when adjusted for potential confounding factors. 17-OHP and cortisol were inversely associated to PMA (r = ﹣0.36 and ﹣0.40, respectively). Cortisol, but not 17-OHP, was associated with the type of hospitalization unit, the respiratory support and the presence of a patent ductus arteriosus. The 17-OHP/cortisol ratio was associated with the type of hospitalization unit only. Conclusions: The 17-OHP/ cortisol ratio at Day 3 did not predict the occurrence of a first episode of systemic hypotension after Day3 inpreterm neonates.
基金the Major State Basic Research Programs of the People’s Republic of China(No.2001CB409806).
文摘According to the study on the peripheral orogenic belts of the Junggar basin and combined with the interpretation of geophysical data, this paper points out that there is an Early Paleozoic basement of immature continental crust in the Junggar area, which is mainly composed of Neoproterozoic-Ordovician oceanic crust and weakly metamorphosed covering sedimentary rocks. The Late Paleozoic tectonism and mineralization were developed on the basement of the Early Paleozoic immature continental crust. The Junggar metallogenic province is dominated by Cr, Cu, Ni and Au mineralization. Those large and medium-scale deposits are mainly distributed along the deep faults and particularly near the ophiolitic melange zones, and formed in the Late Paleozoic with the peak of mineralization occurring in the Carboniferous-Permian post-collisional stage. The intrusions related to Cu, Ni and Au mineralization generally have low Is, and positive εNd(t) values. The δ34S values of the ore deposits are mostly near zero, and the lead isotopes are mostly of normal lead. All these indicate that the ore-forming material comes either directly from the mantle-derived magma (for chromite and Cu-Ni deposits) or from recirculation of the basement material of the Early Paleozoic immature crust (for most Cu and Au deposits).
基金This study is part of the China National“973”Key Research and Development Program#G199943310a Professional Enhancement Program of the Natural Resources of Canada Earth Science Sector,under the collaborative research agreement between the Geological Survey of Canada(Calgary)and the University of Petroleum(Beijing)+1 种基金The funding for this project was provided by the National Natural Science Foundation of China(under the“973”National Key Research and Development Program of China#G1999043310)the Geological Survey of Canada and the Chinese National Petrochemical Corporation.
文摘Based on a detailed survey of the distribution and organic geochemical characteristics of potential source rocks in the South Slope of the Niuzhuang Sag, Bohai Bay Basin, eastern China, a new approach to assess the amount of hydrocarbons generated and expelled has been developed. The approach is applicable to evaluate hydrocarbons with different genetic mechanisms. The results show that the models for hydrocarbon generation and expulsion vary with potential source rocks, depending on thermal maturity, types of organic matter and paleoenvironment. Hydrocarbons are mostly generated and expelled from source rocks within the normal oil window. It was calculated that the special interval (algal-rich shales of the ES4 member formed in brackish environments) in the South Slope of the Niuzhuang Sag has a much higher potential of immature oil generation than the other intervals in the area. This suggests that hydrocarbons can definitely be generated in early diagenesis, especially under certain special geological settings. The proportion of hydrocarbons generated and expelled from the ES4 shales in the early diagenetic stage is up to 26.75% and 17.36%, respectively. It was also observed that laminated shales have a much higher expulsion efficiency than massive mudstones. In contrast, the special interval of the ES4 shales proposed from previous studies is probably not the whole rock for oil in the South Slope of the Niuzhuang Sag because of the small proportion of the gross volume and corresponding low percentage of hydrocarbons generated and expelled. A much lower expulsion efficiency of the source rock during the early stage relative to that within the normal oil window has been calculated. Our results indicate that the ES4 mudstones rather than the shales deposited in the Niuzhuang and Guangli Sag are the main source rocks for the oil discovered.
文摘Revascularization of immature necrotic teeth is a reliable treatment alternative to conventional apexogenesis or apexification. In case 1, a 12-year-old boy had his necrotic, immature mandibular left second premolar treated with a revascularization technique. At a 24-month follow-up, periapical radiolucency had disappeared and thickening of the root wall was observed. In cases 2 and 3, a lO-year-old boy had his necrotic, immature, bilateral mandibular second premolars treated with the same modality. At 48-month （in case 2） and 42-month （in case 3） follow-ups, loss of periapical radiolucencies and increases in the root wall thickness were also observed.
基金Results in this study were obtained as part of the China 973 National Key Research and Development Program(#G199943310)a Professional Enhancement Program of Natural Resources Canada's Earth Science Sector,under the collaborative research agreement between the Geological Survey of Canada(Calgary)and the University of Petroleum(Bejjing)+1 种基金The funding for this project was provided by the National Natural Science Foundation of China(under the“973”National Key Research and Development Program China#G1999043310)Geological Survey of Canada and Chinese National Petrochemical Corporation.
文摘Recent detailed organic geochemical and geological investigation indicate that oils of the Bamianhe oilfield, Bohai Bay Basin, East China are the mixture of less mature oils and normal oils derived from the ES4 mudstones and shales with a wide range of thermal maturity from immature to middle-maturity, and most of the oils were proved to be sourced from the depocenter of the Niuzhuang Sag immediately adjacent to the Bamianhe oilfield. Two approaches to quantify the amount of immature oils mixed through quantitative biomarkers were established. One is a relatively simple way only through organic geochemical analysis while the other is to be combined with basin modeling. Selecting biomarkers as proxies is the crucial point in both of them. The results show that the less mature oils mixed in the Bamianhe oilfield is less than 10% and 18% respectively based on the two approaches, which coincide with the results of oil-source rock correlation.
基金supported by the Hunan Provincial Innovation Foundation for Postgraduate in China,No.CX2014B099(to XH)the Science Foundation of Hunan Provincial Education Department of China,No.11C1264(to FJD),13C958(to XH)
文摘The main active components extracted from Panax notoginseng are total saponins. They have been shown to inhibit platelet aggregation, increase cerebral blood flow, improve neurological behavior, decrease infarct volume and promote proliferation and differentiation of neural stem cells in the hippocampus and lateral ventricles. However, there is a lack of studies on whether total saponins of Panax notoginsertg have potential benefits on immature neuroblasts in the olfactory bulb following ischemia and reperfusion. This study established a rat model of global cerebral ischemia and reperfusion using four-vessel occlusion. Rats were administered total sa- ponins of Panax notoginseng at 75 mg/kg intraperitoneally 30 minutes after ischemia then once a day, for either 7 or 14 days. Total saponins of Panax notoginseng enhanced the number of dou- blecortin （DCX）＋ neural progenitor ceils and increased co-localization of DCX with neuronal nuclei and phosphorylated cAMP response element-binding/DCX＋ neural progenitor cells in the olfactory bulb at 7 and 14 days post ischemia. These findings indicate that following global brain ischemia/reperfusion, total saponins of Panax notoginseng promote differentiation of DCX＋ cells expressing immature neuroblasts in the olfactory bulb and the underlying mechanism is related to the activation of the signaling pathway of cyclic adenosine monophosphate response element binding protein.
基金supported by the National Natural Science Foundation of China (30971776)the National Transgenic Specialized Research Program of China (2008ZX08010-004)
文摘Wheat, one of the most important food crops, has been extensively studied with respects to plant regeneration and transformation employing the immature embryos as recipient tissues. However, the transformed tissues often become severely necrotic after co-cultivation with Agrobacterium, which is one of the major obstacles in gene delivery. In this study, wheat varieties CB037, Kenong 199, Xinchun 9, Lunxuan 987, and Shi 4185 showed desirable culture potential or high infection ability in Agrobacterium-mediated transformation. Similarly, optimal regeneration conditions were determined by testing their ability to inhibit the cell necrosis and cell death phenotype. Two auxins of 2,4-dichlorophenoxyacetic acid （2,4-D） and 3,6-dichloro-o-anisic acid （dicamba） were evaluated for highly significant effect on both callus and plantlet production, although they were genotype-dependent in wheat. Substitution of 2,4-D by dicamba enhanced the growth and regeneration ability of callus from the immature embryos of most genotypes tested. The callus growth state couldn’t be modified by adding antioxidants such as ascorbic acid, cysteine, and silver nitrate or organic additives such as thiamine HCl and asparagine to the media. On the contrary, the best tissue statement and plant regeneration was achieved by employing the media containing the simplest MS （Murashige and Skoog） components and dicamba without organic components and vitamins. Thereby, our results are thought to inhibit wheat cell necrosis effectively and suggested to be used for more wheat genotypes.
