Valine is an essential amino acid and a type of branched-chain amino acid. Due to the involvement of branchedchain amino acids in various metabolic pathways, there has been a surge of interests in valine nutrition and...Valine is an essential amino acid and a type of branched-chain amino acid. Due to the involvement of branchedchain amino acids in various metabolic pathways, there has been a surge of interests in valine nutrition and its role in animal physiology. In pigs, the interactions between valine and other branched-chain amino acids or aromatic amino acids are complex. In this review, we delve into the interaction mechanism, metabolic pathways, and biological functions of valine. Appropriate valine supplementation not only enhances growth and reproductive performances, but also modulates gut microbiota and immune functions. Based on past observations and interpretations, we provide recommended feed levels of valine for weaned piglets, growing pigs, gilts, lactating sows, barrows and entire males. The summarized valine nutrient requirements for pigs at different stages offer valuable insights for future research and practical applications in animal husbandry.展开更多
Dairy products have become one of the most prevalent daily foods worldwide,but safety concerns are rising.In dairy farming,unscrupulous traders misuse antibiotics to treat some diseases such as mastitis in cows,leadin...Dairy products have become one of the most prevalent daily foods worldwide,but safety concerns are rising.In dairy farming,unscrupulous traders misuse antibiotics to treat some diseases such as mastitis in cows,leading to antibiotic residues in dairy products.Rapid,sensitive,and simple detection methods for antibiotic residues are particularly important for food safety in dairy products.Traditional detection technology can effectively detect antibiotics,but there are defects such as complicated pre-treatment and high cost.Biosensors are widely used in food safety due to fast detection speed,low detection cost,strong anti-interference ability,and suitability for the field application.Nevertheless,these sensors often fail to trigger the signal conversion output due to low target concentration.To cope with this issue,some high-efficiency signal amplification systems can be introduced to improve the detection sensitivity and linear range of biosensors.In this review,we focused on:(i)Sources and toxicity of major antibiotics in animal-derived foods.(ii)Nanomaterial-mediated biosensors for real-time detection of target antibiotics in animal-derived foods.(iii)Signal amplification techniques to increase the sensitivity of biosensors.Finally,future prospects and challenges in this research field are discussed.展开更多
The original online version of this article (Kitadokoro, K., Matsui, S., Osokoshi, R., Nakata, K. and Kamitani, S. (2018) Expression, Purification and Crystallization of Thermostable Mutant of Cutinase Est1 from Therm...The original online version of this article (Kitadokoro, K., Matsui, S., Osokoshi, R., Nakata, K. and Kamitani, S. (2018) Expression, Purification and Crystallization of Thermostable Mutant of Cutinase Est1 from Thermobifida alba. Advances in Bioscience and Biotechnology, 9, 215-223. https://doi.org/10.4236/abb.2018.95015) unfortunately contains some mistakes. The author wishes to correct the errors.展开更多
Coronavirus disease 2019(COVID-19)infection caused by the severe acute respiratory syndrome coronavirus 2 virus,its symptoms,treatment,and post-COVID-19 effects have been a major focus of research since 2020.In additi...Coronavirus disease 2019(COVID-19)infection caused by the severe acute respiratory syndrome coronavirus 2 virus,its symptoms,treatment,and post-COVID-19 effects have been a major focus of research since 2020.In addition to respiratory symptoms,different clinical variants of the virus have been associated with dynamic symptoms and multiorgan diseases,including liver abnormalities.The release of cytokines by the activation of innate immune cells during viral infection and the high doses of drugs used for COVID-19 treatment are considered major drivers of liver injury in COVID-19 patients.The degree of hepatic inflammation in patients suffering from chronic liver disease and having COVID-19 could be severe and can be estimated through different liver chemistry abnormality markers.Gut microbiota influences liver chemistry through its metabolites.Gut dysbiosis during COVID-19 treatment can promote liver inflammation.Here,we highlighted the bidirectional association of liver physiology and gut microbiota(gut-liver axis)and its potential to manipulate drug-induced chemical abnormalities in the livers of COVID-19 patients.展开更多
Scope:High-fat diet(HFD)induces imbalance in the small intestine environment,where fat digestion and absorption mainly take place.This study aimed to elucidate the mechanisms by which Lonicera caerulea polyphenols(LCP...Scope:High-fat diet(HFD)induces imbalance in the small intestine environment,where fat digestion and absorption mainly take place.This study aimed to elucidate the mechanisms by which Lonicera caerulea polyphenols(LCP)might inhibit fat absorption,from the perspective of small intestine microbiota and epithelial barrier integrity.Methods and results:Male Sprague-Dawley rats were given HFD with or without co-administration of LCP for 8 weeks.The results showed that LCP supplementation significantly decreased the levels of serum triglycerides(TG),total cholesterol(TC),and low-density lipoprotein cholesterol(LDL-C),and increased the contents of fecal sterols,in HFD rats.LCP also inhibited the dysfunction of the small intestine epithelial barrier,via alleviating the oxidative stress activated by Nrf2-ARE pathway,and by modulating the expressions of pro-inflammatory factors such as tumor necrosis factor-α(TNF-α),interleukin-6(IL-6),cyclooxygenase-2(COX-2),nuclear factor kappa-B p65(NF-κB p65)and inducible nitric oxide synthase(iNOS)in the small intestine.Additionally,LCP administration restored the balance in small intestine microbiota and increased the abundance of the specific bacteria,such as Lactobacillus,involved in fat absorption.Conclusion:Our results demonstrated that LCP may be beneficial to inhibit fat absorption.The mechanism seems to be associated with the protection of the epithelial barrier integrity and the modulation of specific bacteria in the small intestine.展开更多
Nono is a traditionally fermented milk drink commonly consumed in the Northern parts of Nigeria. It is produced through the spontaneous fermentation of raw cow milk by Lactic Acid Bacteria (LAB), a process that could ...Nono is a traditionally fermented milk drink commonly consumed in the Northern parts of Nigeria. It is produced through the spontaneous fermentation of raw cow milk by Lactic Acid Bacteria (LAB), a process that could result to the contamination of the product with such pathogenic organisms as Clostridia spp. The aim of this research was therefore to determine the incidence of Clostridia species in thirty-two (32) ready-to-drink nono samples collected directly from a number of Fulani vendors in randomly selected locations within the Federal Capital Territory (FCT), Abuja, Nigeria. Isolated organisms were further subjected to some morphological and biochemical characterizations using standard microbiological procedures. The results obtained indicate that fourteen (14) isolates were putatively identified to be Clostridium sp., out of which five (5) isolates were confirmed to be Clostridium sporogens by a BLAST analysis of their respective 16SrRNA nucleotide sequence. It was concluded that, the detection of these pathogenic strains in frequently consumed product like nono could pose a public health risk and proactive measures to prevent an outbreak of food borne illness from nono consumption, were recommended.展开更多
As a crucial protein kinase,the mammalian target of rapamycin(mTOR)intimately controls essential cellular processes like cell development,proliferation,metabolism,and other crucial activities.Different cancers and dis...As a crucial protein kinase,the mammalian target of rapamycin(mTOR)intimately controls essential cellular processes like cell development,proliferation,metabolism,and other crucial activities.Different cancers and disorders have been linked to imbalances in mTOR's regulatory systems.Multiple mTOR inhibitor therapy has recently acquired popularity as a method of treating cancers brought on by abnormal signal transduction pathways.We also explore potential processes behind tumor cell resistance to mTOR inhibitors and suggest workarounds to overcome this challenge.We hold the potential to pioneer cutting-edge methods for tumor therapy by methodically examining the complex mTOR signaling system and its regulatory complexity.Increasing our knowledge of mTOR-related mechanisms not only creates opportunities for cutting-edge methods to target and treat cancers but also has the potential to improve patient outcomes and general quality of life significantly.This review paper explores the most recent developments in understanding mTOR signaling pathways and the use of mTOR inhibitors in treating tumors.展开更多
Alzheimer’s disease(AD)is a neurodegenerative condition that disrupts nerve cell function due to the misfolding and buildup of proteins,resulting in cognitive loss and aberrant behavior.Microglia cellsare one of the ...Alzheimer’s disease(AD)is a neurodegenerative condition that disrupts nerve cell function due to the misfolding and buildup of proteins,resulting in cognitive loss and aberrant behavior.Microglia cellsare one of the crucial immune cells in the central nervous system.Depending on their activation levels,microglia cells in the degenerative phase of AD can serve either neuroprotective or neurotoxic roles.Microglia cells express several neurotransmitter receptors that play distinct functions in the degenerative progression of AD.These receptors facilitate bidirectional communication between microglia and nerve cells.The neurotransmitter receptors on microglia cells can mediate or affect the neuroprotective or toxic effects of microglia cells,thereby affecting AD pathology.This paper focuses on the gamma-aminobutyric acid,glutaminergic,cannabinoid,cholinergic,and adrenergic receptors on microglia cells and their relationship with AD.Understanding how neurotransmitter receptors on microglia function in AD will be crucial for identifying potential treatment targets.展开更多
The use of rare earth for inducing plant resistance was reviewed. The important developments in recent years were described, and rare earth can alleviate the pollution of acid rain, ozone, pesticide, heavy metals etc....The use of rare earth for inducing plant resistance was reviewed. The important developments in recent years were described, and rare earth can alleviate the pollution of acid rain, ozone, pesticide, heavy metals etc. in environment. The authors suggest that the mechanism of rare earth to inducing plant resistance and reducing plant injury is to control biochemical metabolism web in plant cell, to adjust its protection system of free radical, to maintain its photosynthesis, to protect cell membrane system and to carry through its function on mineral metabolism. Meanwhile some problems in the field were discussed as well.展开更多
The methylotrophic yeast Pichia pastoris is a highly successful system for production of a variety of heterologous proteins due to its unique features/abilities for effective protein expression, and tremendous efforts...The methylotrophic yeast Pichia pastoris is a highly successful system for production of a variety of heterologous proteins due to its unique features/abilities for effective protein expression, and tremendous efforts have been made to increase heterologous protein productivity by P. pastoris in recent years. When new engineered yeast strains are constructed and are ready to use for industrial protein production, process control and optimization techniques should be applied to improve the fermentation performance in the following aspects: (1) increase recombinant cell concentrations in fermentor to high density during growth phase; (2) effectively induce heterologous proteins by enhancing/stabilizing titers or concentrations of the proteins during induction phase; (3) decrease operation costs by relieving the working loads of heat-exchange and oxygen supply. This article reviews and discusses the key and commonly used techniques in heterologous protein production by P. pastoris, with the focus on optimizations of fermentation media and basic operation conditions, development of optimal glycerol feeding strategies for achieving high density cultivation of P. pastoris and effective heterologous protein induction methods by regulating specific growth rate, methanol concentration, temperatures, mixture ratio of multi-carbon substrates, etc. Metabolic analysis for recombinant protein production by P. pastoris is also introduced to interpret the mechanism of sub-optimal heterologous protein production and to explore further optimal expression methods.展开更多
Effect of cerium (Ce^3+) on growth and photosynthesis in rape seedlings exposed to two levels of ultraviolet-B radiation (UV-B, 280 - 320 nm) was studied with hydroponics under laboratory conditions. The growth o...Effect of cerium (Ce^3+) on growth and photosynthesis in rape seedlings exposed to two levels of ultraviolet-B radiation (UV-B, 280 - 320 nm) was studied with hydroponics under laboratory conditions. The growth of rape seedlings exposed to two levels of UV-B irradiation (0.15 and 0.35 W· m^-2/T2) was both heavily restrained. The aboveground growth indices including stem (plant) height, leaf number, leaf area, leaf fresh/dry weight and stem fresh/dry weight were obviously decreased by 13.2% - 44.1% (T1) and 21 .4% - 49.3% (T2). Compared to CK, and except active absorption area of roots, the belowground indices main root length, root volume and fresh/dry weight by 14.1% -35.6% (T1) and 20.3% - 42.6% (T2), respectively. For Ce + UV-B treatments, the aboveground and belowground growth indices were decreased by 4.1% - 23.6%, 5.2% -23.3% (Ce+T1) and 10.8% -28.4%, 7.0% -27.8% (Ce +T2), lower than those of UV-B treatments mentioned above. These results show that Ce has protective effect on plant against injury of UV-B radiation. Furthermore, the protective effect of Ce on seedlings exposed to T1 level of UV-B radiation is superior to T2 level. Chlorophyll content, net photosynthesis rate, transpiration rate, stomatal conductance and water use efficiency in UV-B treatments decrease dramatically, whereas intercellular CO2 concentration increases. Although these indices in Ce + UV-B treatments decrease compared with those of CK, the decrease in Ce + UV-B treatments are lower than those in UV-B treatment. This phenomenon indicates that the ecophysiological protective effect of Ce is based on improving photosynthesis in plants. The dynamic curves of photosynthesis indices show that the course of light-repair is shortened and the injury to rape seedlings by UV-B radiation stress is alleviated by Ce.展开更多
The hydroponic culture experiments of soybean bean seedlings were conducted to investigate the effect of lanthanum (La) on nitrogen metabolism under two different levels of elevated UV-B radiation (UV-B, 280-320 nm...The hydroponic culture experiments of soybean bean seedlings were conducted to investigate the effect of lanthanum (La) on nitrogen metabolism under two different levels of elevated UV-B radiation (UV-B, 280-320 nm). The whole process of nitrogen metabolism involves uptake and transport of nitrate, nitrate assimilation, ammonium assimilation, amino acid biosynthesis, and protein synthesis. Compared with the control, UV-B radiation with the intensity of low level 0.15 W/m^2 and high level 0.45 W/m^2 significantly affected the whole nitrogen metabolism in soybean seedlings (p 〈 0.05). It restricted uptake and transport of NO3^-, inhibited activity of some key nitrogen-metabolism-related enzymes, such as: nitrate reductase (NR) to the nitrate reduction, glutamine systhetase (GS) and glutamine synthase (GOGAT) to the ammonia assimilation, while it increased the content of free amino acids and decreased that of soluble protein as well. The damage effect of high level of UV-B radiation on nitrogen metabolism was greater than that of low level. And UV-B radiation promoted the activity of the anti-adversity enzyme glutamate dehydrogenase (GDH), which reduced the toxicity of excess ammonia in plant. After pretreatment with the optimum concentration of La (20 mg/L), La could increase the activity of NR, GS, GOGAT, and GDH, and ammonia assimilation, but decrease nitrate and ammonia accumulation. In conclusion, La could relieve the damage effect of UV-B radiation on plant by regulating nitrogen metabolism process, and its alleviating effect under low level was better than that under the high one.展开更多
The effect of La on flavonoids, chlorophyll contents, and phenylalanine ammonia-lyase (PAL) activity in soybean seedlings under supplementary ultraviolet-B radiation (UV-B, 280 - 320 nm) was studied. The results s...The effect of La on flavonoids, chlorophyll contents, and phenylalanine ammonia-lyase (PAL) activity in soybean seedlings under supplementary ultraviolet-B radiation (UV-B, 280 - 320 nm) was studied. The results show that PAL activity, contents of flavonoids and chlorophyll in the plants pretreated with La (20 mg·L^- 1 ) are higher than those in CK. UV-B radiation could result in an increase in flavonoid content and PAL activity, associated with a decrease in chlorophyll content. However, the increase in the range of PAL activity and flavonoid content in UV-B treatment are lesser than those in the La treatment. The changes of flavonoid contents and PAL activity in La + UV-B treatment are similar to those in UV-B treatment, and the increase in their range is higher than those in UV-B treatment. This shows that La can enhance the resistance of soybean seedling to UV-B radiation and alleviate the damage of UV-B radiation by increasing flavonoid content, chlorophyll content, and PAL activity.展开更多
The effect of lanthanum (Ⅲ) on reactive oxygen metabolism of soybean seedlings under elevated ultraviolet-B radiation(UV-B:280~320 nm)at 0.15 and 0.45 W·cm-2 levels respectively was studied through hydropon...The effect of lanthanum (Ⅲ) on reactive oxygen metabolism of soybean seedlings under elevated ultraviolet-B radiation(UV-B:280~320 nm)at 0.15 and 0.45 W·cm-2 levels respectively was studied through hydroponics in the laboratory.Plasmolemma permeability and contents of malonadialdehyde(MDA),hydrogen peroxide(H2O2),and proline gradually increased during the imposition of UV-B radiation and subsequently decreased during recovery from UV-B stress.The dynamic tendency of catalase(CAT)activity was similar to that of the above four indices.The activity of peroxidase(POD)initially increased,then remained at a high level,and finally dropped steeply when soybean seedlings were exposed to a low dosage of UV-B radiation.However,POD activity rose throughout and declined slightly on the eleventh day when soybean seedlings were stressed by a high dosage.With the addition of La (Ⅲ) of 20 mg·L-1,the rising tendency of plasmolemma permeability and contents of MDA,H2O2,and proline were slowed down during the stress period,whereas the declining speed was accelerated during the recovery period.The activities of CAT and POD were higher than those without La (Ⅲ) in all experiments.It suggested that the regulative effect of La (Ⅲ) on antioxidant enzymes such as CAT and POD could strengthen their capacities to scavenge reactive oxygen species(ROS),decrease contents of MDA and proline,and maintain normal plasmolemma permeability.Further more,the protective potential of La (Ⅲ) was better under low UV-B radiation than under a high one.展开更多
In order to investigate the effects of lanthanum(Ⅲ) on cell ultrastructure of soybean leaves under elevated ultraviolet-B irradiation (UV-B, 280-320 nm), the chloroplast ultrastructure of soybean seedlings was st...In order to investigate the effects of lanthanum(Ⅲ) on cell ultrastructure of soybean leaves under elevated ultraviolet-B irradiation (UV-B, 280-320 nm), the chloroplast ultrastructure of soybean seedlings was studied by hydroponics under laboratory conditions. The resuits showed that the thylakoid in chloroplast was orderly and clearly as soybean leaves were pretreated by La(Ⅲ). The thylakoid was indis- tinctly disordered, expanded and even indiscoverable in the chloroplast under UV-B stress. The impact on the thylakoid by the high intensity UV-B irradiation (T2) was bigger than that by the low intensity UV-B irradiation (T1). However, the destruction of the chloroplast structure caused by UV-B stress was alleviated by La(Ⅲ), and the arrangement of the thylakoid in the chloroplast became orderly and clearly. The effect of the alleviation by La(Ⅲ) under the low intensity UV-B irradiation (T1) was better than that under the high intensity UV-B irradiation (T2).展开更多
Solid state bio-processing of wheat straw was carried out through an indigenous fungal strain Pleurotus ostreatus IBL-02 under pre-optimized fermentation conditions. The maximum activity, 692±12 U/mL, of the indu...Solid state bio-processing of wheat straw was carried out through an indigenous fungal strain Pleurotus ostreatus IBL-02 under pre-optimized fermentation conditions. The maximum activity, 692±12 U/mL, of the industrially important manganese peroxidase (MnP) enzyme was recorded after five days of still culture incubation. The crude MnP was 2.1-fold purified with a specific activity of 860 U/mg after purification on a Sephadex-G-100 gel column. On native and SDS-PAGE electrophoresis gels, the purified MnP fraction was a single homogenous band of 45 kDa. An active fraction of MnP was immobilized using hydrophobic sol-gel entrapment comprising tetramethoxysilane (T) and propyltrimethoxysilane (P) at different T:P molar ratios. Characterization revealed that after 24 h incubation at varying pH and temperatures, the MnP fraction immobilized at a T:P ratio of 1:2 in the sol-gel retained 82% and 75% of its original activity at pH4 and 70 ℃, respectively. The optimally active fraction at a 1:2 T:P ratio was tested against MnSO4 as a substrate to determine the kinetic catalytic constants KM and Vmax . To explore the industrial applicability of P. ostreatus IBL-02 MnP, both the free and immobilized MnP were used for the decolorization of four different textile industrial effluents. A maximum of 100% decolorization was achieved for the different textile effluents within the shortest time period. A lower KM , higher Vmax , hyper-activation, and enhanced acidic and thermal resistance up to 70 ℃ were the novel catalytic features of the sol-gel immobilized MnP, suggesting that it may be a potential candidate for biotechnological applications particularly for textile bioremediation purposes.展开更多
基金supported by Postdoctoral Innovation Talents’ Support Programthe National Natural Science Foundation of China (32130099)+1 种基金the Tianjin Synthetic Biotechnology Innovation Capacity Improvement Project (TSBICIP-CXRC-038)Laboratory of Lingnan Modern Agriculture Project (NT2021005)。
文摘Valine is an essential amino acid and a type of branched-chain amino acid. Due to the involvement of branchedchain amino acids in various metabolic pathways, there has been a surge of interests in valine nutrition and its role in animal physiology. In pigs, the interactions between valine and other branched-chain amino acids or aromatic amino acids are complex. In this review, we delve into the interaction mechanism, metabolic pathways, and biological functions of valine. Appropriate valine supplementation not only enhances growth and reproductive performances, but also modulates gut microbiota and immune functions. Based on past observations and interpretations, we provide recommended feed levels of valine for weaned piglets, growing pigs, gilts, lactating sows, barrows and entire males. The summarized valine nutrient requirements for pigs at different stages offer valuable insights for future research and practical applications in animal husbandry.
基金We thank the Natural Science Foundation of Hubei Province of China(2023AFB330)the China Postdoctoral Science Foundation(2022M721275)the Hubei Provincial Market Supervision Administration Science and Technology Program Project(Hbscjg-KJ2021002)for financial support.
文摘Dairy products have become one of the most prevalent daily foods worldwide,but safety concerns are rising.In dairy farming,unscrupulous traders misuse antibiotics to treat some diseases such as mastitis in cows,leading to antibiotic residues in dairy products.Rapid,sensitive,and simple detection methods for antibiotic residues are particularly important for food safety in dairy products.Traditional detection technology can effectively detect antibiotics,but there are defects such as complicated pre-treatment and high cost.Biosensors are widely used in food safety due to fast detection speed,low detection cost,strong anti-interference ability,and suitability for the field application.Nevertheless,these sensors often fail to trigger the signal conversion output due to low target concentration.To cope with this issue,some high-efficiency signal amplification systems can be introduced to improve the detection sensitivity and linear range of biosensors.In this review,we focused on:(i)Sources and toxicity of major antibiotics in animal-derived foods.(ii)Nanomaterial-mediated biosensors for real-time detection of target antibiotics in animal-derived foods.(iii)Signal amplification techniques to increase the sensitivity of biosensors.Finally,future prospects and challenges in this research field are discussed.
文摘The original online version of this article (Kitadokoro, K., Matsui, S., Osokoshi, R., Nakata, K. and Kamitani, S. (2018) Expression, Purification and Crystallization of Thermostable Mutant of Cutinase Est1 from Thermobifida alba. Advances in Bioscience and Biotechnology, 9, 215-223. https://doi.org/10.4236/abb.2018.95015) unfortunately contains some mistakes. The author wishes to correct the errors.
基金Supported by United Arab Emirates University UPAR 2022 Research Grant,No.12S094.
文摘Coronavirus disease 2019(COVID-19)infection caused by the severe acute respiratory syndrome coronavirus 2 virus,its symptoms,treatment,and post-COVID-19 effects have been a major focus of research since 2020.In addition to respiratory symptoms,different clinical variants of the virus have been associated with dynamic symptoms and multiorgan diseases,including liver abnormalities.The release of cytokines by the activation of innate immune cells during viral infection and the high doses of drugs used for COVID-19 treatment are considered major drivers of liver injury in COVID-19 patients.The degree of hepatic inflammation in patients suffering from chronic liver disease and having COVID-19 could be severe and can be estimated through different liver chemistry abnormality markers.Gut microbiota influences liver chemistry through its metabolites.Gut dysbiosis during COVID-19 treatment can promote liver inflammation.Here,we highlighted the bidirectional association of liver physiology and gut microbiota(gut-liver axis)and its potential to manipulate drug-induced chemical abnormalities in the livers of COVID-19 patients.
基金supported by the National Natural Science Foundation of China(32001685)the Guidance Plan of Liaoning Natural Science Foundation(20180550776)the Research Initiation Fund of Shenyang Agricultural University(880418026).
文摘Scope:High-fat diet(HFD)induces imbalance in the small intestine environment,where fat digestion and absorption mainly take place.This study aimed to elucidate the mechanisms by which Lonicera caerulea polyphenols(LCP)might inhibit fat absorption,from the perspective of small intestine microbiota and epithelial barrier integrity.Methods and results:Male Sprague-Dawley rats were given HFD with or without co-administration of LCP for 8 weeks.The results showed that LCP supplementation significantly decreased the levels of serum triglycerides(TG),total cholesterol(TC),and low-density lipoprotein cholesterol(LDL-C),and increased the contents of fecal sterols,in HFD rats.LCP also inhibited the dysfunction of the small intestine epithelial barrier,via alleviating the oxidative stress activated by Nrf2-ARE pathway,and by modulating the expressions of pro-inflammatory factors such as tumor necrosis factor-α(TNF-α),interleukin-6(IL-6),cyclooxygenase-2(COX-2),nuclear factor kappa-B p65(NF-κB p65)and inducible nitric oxide synthase(iNOS)in the small intestine.Additionally,LCP administration restored the balance in small intestine microbiota and increased the abundance of the specific bacteria,such as Lactobacillus,involved in fat absorption.Conclusion:Our results demonstrated that LCP may be beneficial to inhibit fat absorption.The mechanism seems to be associated with the protection of the epithelial barrier integrity and the modulation of specific bacteria in the small intestine.
文摘Nono is a traditionally fermented milk drink commonly consumed in the Northern parts of Nigeria. It is produced through the spontaneous fermentation of raw cow milk by Lactic Acid Bacteria (LAB), a process that could result to the contamination of the product with such pathogenic organisms as Clostridia spp. The aim of this research was therefore to determine the incidence of Clostridia species in thirty-two (32) ready-to-drink nono samples collected directly from a number of Fulani vendors in randomly selected locations within the Federal Capital Territory (FCT), Abuja, Nigeria. Isolated organisms were further subjected to some morphological and biochemical characterizations using standard microbiological procedures. The results obtained indicate that fourteen (14) isolates were putatively identified to be Clostridium sp., out of which five (5) isolates were confirmed to be Clostridium sporogens by a BLAST analysis of their respective 16SrRNA nucleotide sequence. It was concluded that, the detection of these pathogenic strains in frequently consumed product like nono could pose a public health risk and proactive measures to prevent an outbreak of food borne illness from nono consumption, were recommended.
文摘As a crucial protein kinase,the mammalian target of rapamycin(mTOR)intimately controls essential cellular processes like cell development,proliferation,metabolism,and other crucial activities.Different cancers and disorders have been linked to imbalances in mTOR's regulatory systems.Multiple mTOR inhibitor therapy has recently acquired popularity as a method of treating cancers brought on by abnormal signal transduction pathways.We also explore potential processes behind tumor cell resistance to mTOR inhibitors and suggest workarounds to overcome this challenge.We hold the potential to pioneer cutting-edge methods for tumor therapy by methodically examining the complex mTOR signaling system and its regulatory complexity.Increasing our knowledge of mTOR-related mechanisms not only creates opportunities for cutting-edge methods to target and treat cancers but also has the potential to improve patient outcomes and general quality of life significantly.This review paper explores the most recent developments in understanding mTOR signaling pathways and the use of mTOR inhibitors in treating tumors.
文摘Alzheimer’s disease(AD)is a neurodegenerative condition that disrupts nerve cell function due to the misfolding and buildup of proteins,resulting in cognitive loss and aberrant behavior.Microglia cellsare one of the crucial immune cells in the central nervous system.Depending on their activation levels,microglia cells in the degenerative phase of AD can serve either neuroprotective or neurotoxic roles.Microglia cells express several neurotransmitter receptors that play distinct functions in the degenerative progression of AD.These receptors facilitate bidirectional communication between microglia and nerve cells.The neurotransmitter receptors on microglia cells can mediate or affect the neuroprotective or toxic effects of microglia cells,thereby affecting AD pathology.This paper focuses on the gamma-aminobutyric acid,glutaminergic,cannabinoid,cholinergic,and adrenergic receptors on microglia cells and their relationship with AD.Understanding how neurotransmitter receptors on microglia function in AD will be crucial for identifying potential treatment targets.
基金Project supported by the National Natural Science Foundation of China ( 20471030 ) the Foundation of State Planning Committee (GFZ040628)
文摘The use of rare earth for inducing plant resistance was reviewed. The important developments in recent years were described, and rare earth can alleviate the pollution of acid rain, ozone, pesticide, heavy metals etc. in environment. The authors suggest that the mechanism of rare earth to inducing plant resistance and reducing plant injury is to control biochemical metabolism web in plant cell, to adjust its protection system of free radical, to maintain its photosynthesis, to protect cell membrane system and to carry through its function on mineral metabolism. Meanwhile some problems in the field were discussed as well.
基金Supported by the Key Agricultral Technology Program of Shanghai Science & Technology Committee(073919108)MajorState Basic Research Development Program of China(2007CB714303)
文摘The methylotrophic yeast Pichia pastoris is a highly successful system for production of a variety of heterologous proteins due to its unique features/abilities for effective protein expression, and tremendous efforts have been made to increase heterologous protein productivity by P. pastoris in recent years. When new engineered yeast strains are constructed and are ready to use for industrial protein production, process control and optimization techniques should be applied to improve the fermentation performance in the following aspects: (1) increase recombinant cell concentrations in fermentor to high density during growth phase; (2) effectively induce heterologous proteins by enhancing/stabilizing titers or concentrations of the proteins during induction phase; (3) decrease operation costs by relieving the working loads of heat-exchange and oxygen supply. This article reviews and discusses the key and commonly used techniques in heterologous protein production by P. pastoris, with the focus on optimizations of fermentation media and basic operation conditions, development of optimal glycerol feeding strategies for achieving high density cultivation of P. pastoris and effective heterologous protein induction methods by regulating specific growth rate, methanol concentration, temperatures, mixture ratio of multi-carbon substrates, etc. Metabolic analysis for recombinant protein production by P. pastoris is also introduced to interpret the mechanism of sub-optimal heterologous protein production and to explore further optimal expression methods.
文摘Effect of cerium (Ce^3+) on growth and photosynthesis in rape seedlings exposed to two levels of ultraviolet-B radiation (UV-B, 280 - 320 nm) was studied with hydroponics under laboratory conditions. The growth of rape seedlings exposed to two levels of UV-B irradiation (0.15 and 0.35 W· m^-2/T2) was both heavily restrained. The aboveground growth indices including stem (plant) height, leaf number, leaf area, leaf fresh/dry weight and stem fresh/dry weight were obviously decreased by 13.2% - 44.1% (T1) and 21 .4% - 49.3% (T2). Compared to CK, and except active absorption area of roots, the belowground indices main root length, root volume and fresh/dry weight by 14.1% -35.6% (T1) and 20.3% - 42.6% (T2), respectively. For Ce + UV-B treatments, the aboveground and belowground growth indices were decreased by 4.1% - 23.6%, 5.2% -23.3% (Ce+T1) and 10.8% -28.4%, 7.0% -27.8% (Ce +T2), lower than those of UV-B treatments mentioned above. These results show that Ce has protective effect on plant against injury of UV-B radiation. Furthermore, the protective effect of Ce on seedlings exposed to T1 level of UV-B radiation is superior to T2 level. Chlorophyll content, net photosynthesis rate, transpiration rate, stomatal conductance and water use efficiency in UV-B treatments decrease dramatically, whereas intercellular CO2 concentration increases. Although these indices in Ce + UV-B treatments decrease compared with those of CK, the decrease in Ce + UV-B treatments are lower than those in UV-B treatment. This phenomenon indicates that the ecophysiological protective effect of Ce is based on improving photosynthesis in plants. The dynamic curves of photosynthesis indices show that the course of light-repair is shortened and the injury to rape seedlings by UV-B radiation stress is alleviated by Ce.
基金Project supported by the National Natural Science Foundation of China(No.30570323)Foundation of State Developing and Reforming Committee(No.IFZ20051210)
文摘The hydroponic culture experiments of soybean bean seedlings were conducted to investigate the effect of lanthanum (La) on nitrogen metabolism under two different levels of elevated UV-B radiation (UV-B, 280-320 nm). The whole process of nitrogen metabolism involves uptake and transport of nitrate, nitrate assimilation, ammonium assimilation, amino acid biosynthesis, and protein synthesis. Compared with the control, UV-B radiation with the intensity of low level 0.15 W/m^2 and high level 0.45 W/m^2 significantly affected the whole nitrogen metabolism in soybean seedlings (p 〈 0.05). It restricted uptake and transport of NO3^-, inhibited activity of some key nitrogen-metabolism-related enzymes, such as: nitrate reductase (NR) to the nitrate reduction, glutamine systhetase (GS) and glutamine synthase (GOGAT) to the ammonia assimilation, while it increased the content of free amino acids and decreased that of soluble protein as well. The damage effect of high level of UV-B radiation on nitrogen metabolism was greater than that of low level. And UV-B radiation promoted the activity of the anti-adversity enzyme glutamate dehydrogenase (GDH), which reduced the toxicity of excess ammonia in plant. After pretreatment with the optimum concentration of La (20 mg/L), La could increase the activity of NR, GS, GOGAT, and GDH, and ammonia assimilation, but decrease nitrate and ammonia accumulation. In conclusion, La could relieve the damage effect of UV-B radiation on plant by regulating nitrogen metabolism process, and its alleviating effect under low level was better than that under the high one.
基金Project supported by the National Natural Science Foundation of China (20471030)the Foundation of State PlanningCommittee (IFZ20051210)
文摘The effect of La on flavonoids, chlorophyll contents, and phenylalanine ammonia-lyase (PAL) activity in soybean seedlings under supplementary ultraviolet-B radiation (UV-B, 280 - 320 nm) was studied. The results show that PAL activity, contents of flavonoids and chlorophyll in the plants pretreated with La (20 mg·L^- 1 ) are higher than those in CK. UV-B radiation could result in an increase in flavonoid content and PAL activity, associated with a decrease in chlorophyll content. However, the increase in the range of PAL activity and flavonoid content in UV-B treatment are lesser than those in the La treatment. The changes of flavonoid contents and PAL activity in La + UV-B treatment are similar to those in UV-B treatment, and the increase in their range is higher than those in UV-B treatment. This shows that La can enhance the resistance of soybean seedling to UV-B radiation and alleviate the damage of UV-B radiation by increasing flavonoid content, chlorophyll content, and PAL activity.
基金Project supported by the National Natural Science Foundation of China(30570323)the Foundation of State Developingand Reforming Committee(IFZ20051210)
文摘The effect of lanthanum (Ⅲ) on reactive oxygen metabolism of soybean seedlings under elevated ultraviolet-B radiation(UV-B:280~320 nm)at 0.15 and 0.45 W·cm-2 levels respectively was studied through hydroponics in the laboratory.Plasmolemma permeability and contents of malonadialdehyde(MDA),hydrogen peroxide(H2O2),and proline gradually increased during the imposition of UV-B radiation and subsequently decreased during recovery from UV-B stress.The dynamic tendency of catalase(CAT)activity was similar to that of the above four indices.The activity of peroxidase(POD)initially increased,then remained at a high level,and finally dropped steeply when soybean seedlings were exposed to a low dosage of UV-B radiation.However,POD activity rose throughout and declined slightly on the eleventh day when soybean seedlings were stressed by a high dosage.With the addition of La (Ⅲ) of 20 mg·L-1,the rising tendency of plasmolemma permeability and contents of MDA,H2O2,and proline were slowed down during the stress period,whereas the declining speed was accelerated during the recovery period.The activities of CAT and POD were higher than those without La (Ⅲ) in all experiments.It suggested that the regulative effect of La (Ⅲ) on antioxidant enzymes such as CAT and POD could strengthen their capacities to scavenge reactive oxygen species(ROS),decrease contents of MDA and proline,and maintain normal plasmolemma permeability.Further more,the protective potential of La (Ⅲ) was better under low UV-B radiation than under a high one.
基金supported by the National Natural Science Foundation of China (30570323)the Special Foundation for Rare Earth of State Planning Committee (IFZ20051210)
文摘In order to investigate the effects of lanthanum(Ⅲ) on cell ultrastructure of soybean leaves under elevated ultraviolet-B irradiation (UV-B, 280-320 nm), the chloroplast ultrastructure of soybean seedlings was studied by hydroponics under laboratory conditions. The resuits showed that the thylakoid in chloroplast was orderly and clearly as soybean leaves were pretreated by La(Ⅲ). The thylakoid was indis- tinctly disordered, expanded and even indiscoverable in the chloroplast under UV-B stress. The impact on the thylakoid by the high intensity UV-B irradiation (T2) was bigger than that by the low intensity UV-B irradiation (T1). However, the destruction of the chloroplast structure caused by UV-B stress was alleviated by La(Ⅲ), and the arrangement of the thylakoid in the chloroplast became orderly and clearly. The effect of the alleviation by La(Ⅲ) under the low intensity UV-B irradiation (T1) was better than that under the high intensity UV-B irradiation (T2).
基金a part of a research project entitled “the development of immobilized ligninolytic enzymes for industrial applications” supported by Higher Education Commission (HEC), Islamabad, Pakistan
文摘Solid state bio-processing of wheat straw was carried out through an indigenous fungal strain Pleurotus ostreatus IBL-02 under pre-optimized fermentation conditions. The maximum activity, 692±12 U/mL, of the industrially important manganese peroxidase (MnP) enzyme was recorded after five days of still culture incubation. The crude MnP was 2.1-fold purified with a specific activity of 860 U/mg after purification on a Sephadex-G-100 gel column. On native and SDS-PAGE electrophoresis gels, the purified MnP fraction was a single homogenous band of 45 kDa. An active fraction of MnP was immobilized using hydrophobic sol-gel entrapment comprising tetramethoxysilane (T) and propyltrimethoxysilane (P) at different T:P molar ratios. Characterization revealed that after 24 h incubation at varying pH and temperatures, the MnP fraction immobilized at a T:P ratio of 1:2 in the sol-gel retained 82% and 75% of its original activity at pH4 and 70 ℃, respectively. The optimally active fraction at a 1:2 T:P ratio was tested against MnSO4 as a substrate to determine the kinetic catalytic constants KM and Vmax . To explore the industrial applicability of P. ostreatus IBL-02 MnP, both the free and immobilized MnP were used for the decolorization of four different textile industrial effluents. A maximum of 100% decolorization was achieved for the different textile effluents within the shortest time period. A lower KM , higher Vmax , hyper-activation, and enhanced acidic and thermal resistance up to 70 ℃ were the novel catalytic features of the sol-gel immobilized MnP, suggesting that it may be a potential candidate for biotechnological applications particularly for textile bioremediation purposes.