When tunnelling through low-permeability saturated ground,the pore pressure decreases in the vicinity of the cavity.In certain instances of deep tunnels crossing weak rocks,the pore pressure may even become negative.A...When tunnelling through low-permeability saturated ground,the pore pressure decreases in the vicinity of the cavity.In certain instances of deep tunnels crossing weak rocks,the pore pressure may even become negative.All existing analytical solutions for the undrained ground response curve(GRC)in the literature assume that the ground fully retains its saturation,in which case the development of negative pore pressures has a stabilising effect e it results in increased effective stresses,and thus shearing resistance,which in turn leads to reduced deformations and plastification.In practice,however,negative pore pressures can induce partial or complete ground desaturation,which may even invalidate the premise of undrained conditions and lead to considerably increased deformations and plastification.In such cases,existing solutions are unsafe for design.The present paper aims to address this shortcoming,by presenting a novel analytical solution for the undrained GRC which incorporates the effect of the excavation-induced desaturation.The solution is derived under the assumption that the ground desaturates completely and immediately under negative pore pressures,which provides the upper bound of deformations and plastification for cases of partial desaturation.The rock is considered to be a linear elastic,brittle-plastic material,obeying a non-associated Mohr-Coulomb(MC)yield criterion.Nevertheless,the solution is also applicable to perfectly plastic rocks via a simple modification of the input parameters.Although the solution is in general semi-analytical,simple closed-form expressions are obtained in the special case of non-dilatant rocks.These expressions are also applicable to rocks exhibiting limited dilatancy,which is usually the case.An application example,based on the planned deep geological repository for radioactive waste in Switzerland,demonstrates the significant practical value and usefulness of the novel solution and underscores its necessity in cases where existing solutions that disregard desaturation are rendered thoroughly unsafe for design.展开更多
BACKGROUND: Rapid sequence induction and intubation(RSII) is an emergency airway management technique for patients with a risk of pulmonary aspiration. It involves preoxygenation, administration of predetermined doses...BACKGROUND: Rapid sequence induction and intubation(RSII) is an emergency airway management technique for patients with a risk of pulmonary aspiration. It involves preoxygenation, administration of predetermined doses of induction and paralytic drugs, avoidance of mask ventilation, and laryngoscopy followed by tracheal intubation and keeping cricoid pressure applied till endotracheal tube cuff be inflated. Oxygen desaturation has been seen during RSII. We assessed the incidence of oxygen desaturation during RSII.METHODS: An institution-based observational study was conducted from March 3 to May 4, 2014 in our hospital. All patients who were operated upon under general anesthesia with RSII during the study period were included. A checklist was prepared for data collection.RESULTS: A total of 153 patients were included in this study with a response rate of 91.6%. Appropriate drugs for RSII, equipments for RSII, equipments for diffi cult intubation, suction machine with a catheter, a monitor and an oxygen backup such as ambu bag were not prepared for 41(26.8%), 50(32.7%), 51(33.3%), 38(24.8%) and 25(16.3%) patients respectively. Cricoid pressure was not applied at all for 17(11.1%) patients and 53(34.6%) patients were ventilated after induction of anesthesia but before intubation and endotracheal cuff inflation. A total of 55(35.9%) patients desaturated during RSII(SPO2<95%). The minimum, maximum and mean oxygen desaturations were 26%, 94% and 70.9% respectively. The oxygen desaturation was in the range of <50%, 50%–64%, 65%–74%, 75%–84%, 85%–89 % and 90%–94% for 6(3.9%), 7(4.6%), 5(3.3%), 10(6.5%), 13(8.5%) and 14(9.2%) patients respectively.CONCLUSION: The incidence of oxygen desaturation during RSII was high in our hospital. Preoperative patient optimization and training about the techniques of RSII should be emphasized.展开更多
Catalytic oxidative alkane desaturation by base metals with benign oxidants under mild conditions is highly attractive,as it could enable an efficient way to produce valuable olefin products.Here we report the design ...Catalytic oxidative alkane desaturation by base metals with benign oxidants under mild conditions is highly attractive,as it could enable an efficient way to produce valuable olefin products.Here we report the design and synthesis of macrocyclic and molecular cage copper complexes in catalyzing highly selective cyclohexane desaturation with H_(2)O_(2)/O_(2).The macrocycles and cages possess two to three phenanthroline units connected by versatile binary linkers or tripodal caps.These compounds readily formed bi-and tri-nuclear copper complexes with confined cavities and adaptive coordination environments,as suggested by X-ray single crystal analysis.In the catalytic oxidation of cyclohexane,a considerable yield of cyclohexene with unprecedented dehydrogenation/oxygenation selectivity up to 6.1:1 was achieved with the optimal cage compound C3.Control and mechanistic experiments suggested a pronounced cage effect and radical-mediated processes.The high selectivity was attributed to a cooperative effect between the copper centers,which facilitated the second hydrogen atom abstraction on the trapped cyclohexyl radical and the inhibition of the Fenton process within the shielding cavity environment.展开更多
The purpose of the study was to investigate the relationship between sleep disordered breathing (SDB) and degree of heart failure (HF) in patients with coronary heart disease (CHD). A total of 3017 patients (77.4% men...The purpose of the study was to investigate the relationship between sleep disordered breathing (SDB) and degree of heart failure (HF) in patients with coronary heart disease (CHD). A total of 3017 patients (77.4% men and 22.6% women) were included in the study. Clinical examination and echocardiography for evaluation of HF using NYHA functional classification and sleep polysomnography were performed. The study demonstrated that SDB is more common in CHD patients with higher NYHA functional class. The prevalence of central sleep apneas against obstructive apneas was observed in patients with mild and moderate HF. The number of central apneas was strongly related to the severity of heart failure. More frequent appearance of central sleep apneas is predominantly due to instability of ventilatory control systems during sleep because of impaired cardiac function in HF patients. Sleep architecture was more disturbed in CHD patients with higher NYHA functional class. A gradual increase of stage 1 and wakefulness after sleep onset and a decrease of sleep stages 3-4 and REM sleep as well as a diminution of sleep efficiency with worsening of NYHA functional class were observed. We suggest that both SDB and disturbed sleep variables independently significantly correlate with manifestation of HF.展开更多
To investigate the possible correlation between obstructive sleep apnea(OSA) and central retinal vein occlusion(CRVO). Thirty consecutive patients with a recent(<3 mo)CRVO and an age-and sex-matched group of 30 con...To investigate the possible correlation between obstructive sleep apnea(OSA) and central retinal vein occlusion(CRVO). Thirty consecutive patients with a recent(<3 mo)CRVO and an age-and sex-matched group of 30 control subjects were recruited. All subjects underwent full-night polysomnography to measure apnea-hypopnea index(AHI)and oxygen desaturation index(ODI). The average AHI and ODI were significantly higher in CRVO patients(AHI:13.86±8.63, ODI: 9.21±4.47) than in control subjects(AHI:8.51±6.36, ODI: 5.87±3.18;P=0.008 and 0.001 respectively).Additionally, the AHI was positively correlated with body mass index(BMI;r=0.476, P=0.017) and ODI(r=0.921,P<0.01) in both CRVO and control subjects. According to AHI scores, twenty-two(73.33%) CRVO patients had OSA and 12(40.00%) control subjects had OSA, a difference that was statistically significant(P=0.019). OSA may be a risk factor for or a trigger of CRVO development.展开更多
Soil liquefaction is a major geo-hazard.As liquefaction could occur anywhere in a sand layer and result in large-scale lateral spreading,treatment for liquefaction needs to be carried out over a large extent.The cost-...Soil liquefaction is a major geo-hazard.As liquefaction could occur anywhere in a sand layer and result in large-scale lateral spreading,treatment for liquefaction needs to be carried out over a large extent.The cost-effectiveness of the treatment then becomes a major consideration.With the development of microbial geotechnologies,some new approaches for liquefaction mitigation have been developed.Some of the methods offer more advantages over the existing methods.This paper gives an overview of the recent progress in bio related soil liquefaction mitigation methods.These include both bio-cementation and biogas desaturation.The mechanisms of bio-cementation and biogas desaturation are discussed.Recent up-scaled model tests and field trials are also reviewed.The studies so far have demonstrated that there is a great potential for some of liquefaction mitigation methods to be adopted in practice,although there are still challenges that need to be studied further.These include treatment efficiency,long-term sustainability,and biosafety.A brief introduction to some emerging technologies for liquefaction mitigation such as bio-gelation and use of fungi are also introduced.展开更多
The deep geological repository for radioactive waste in Switzerland will be embedded in an approximately 100 m thick layer of Opalinus Clay.The emplacement drifts for high-level waste(approximately 3.5 m diameter)are ...The deep geological repository for radioactive waste in Switzerland will be embedded in an approximately 100 m thick layer of Opalinus Clay.The emplacement drifts for high-level waste(approximately 3.5 m diameter)are planned to be excavated with a shielded tunnel boring machine(TBM)and supported by a segmental lining.At the repository depth of 900 m in the designated siting region Nordlich Lagern,squeezing conditions may be encountered due to the rock strength and the high hydrostatic pressure(90 bar).This paper presents a detailed assessment of the shield jamming and lining overstressing hazards,considering a stiff lining(resistance principle)and a deformable lining(yielding principle),and proposes conceptual design solutions.The assessment is based on three-dimensional transient hydromechanical simulations,which additionally consider the effects of ground anisotropy and the desaturation that may occur under negative pore pressures generated during the drift excavation.By addressing these design issues,the paper takes the opportunity to analyse some more fundamental aspects related to the influences of anisotropy and desaturation on the development of rock convergences and pressures over time,and their markedly different effects on the two lining systems.The results demonstrate that,regardless of these effects,shield jamming can be avoided with a moderate TBM overcut,however overstressing of a stiff lining may be critical depending on whether the ground desaturates.This uncertainty is eliminated using a deformable system with reasonable dimensions of yielding elements,which can also accommodate thermal strains generated due to the high temperature of the disposal canisters.展开更多
Colorization is the practice of adding appropriate chromatic values to monochrome photographs or videos.A real-valued luminance image can be mapped to a three-dimensional color image.However,it is a severely ill-defin...Colorization is the practice of adding appropriate chromatic values to monochrome photographs or videos.A real-valued luminance image can be mapped to a three-dimensional color image.However,it is a severely ill-defined problem and not has a single solution.In this paper,an encoder-decoder Convolutional Neural Network(CNN)model is used for colorizing gray images where the encoder is a Densely Connected Convolutional Network(DenseNet)and the decoder is a conventional CNN.The DenseNet extracts image features from gray images and the conventional CNN outputs a^(*)b^(*)color channels.Due to a large number of desaturated color components compared to saturated color components in the training images,the saturated color components have a strong tendency towards desaturated color components in the predicted a^(*)b^(*)channel.To solve the problems,we rebalance the predicted a^(*)b^(*)color channel by smoothing every subregion individually using the average filter.2 stage k-means clustering technique is applied to divide the subregions.Then we apply Gamma transformation in the entire a^(*)b^(*)channel to saturate the image.We compare our proposed method with several existing methods.From the experimental results,we see that our proposed method has made some notable improvements over the existing methods and color representation of gray-scale images by our proposed method is more plausible to visualize.Additionally,our suggested approach beats other approaches in terms of Peak Signal-to-Noise Ratio(PSNR),Structural Similarity Index Measure(SSIM)and Histogram.展开更多
Background Mastitis is known to alter milk lipid yield,but its effects on lipid composition in blood and milk remain less understood.This study investigated changes in fatty acid(FA)composition in blood lipid fraction...Background Mastitis is known to alter milk lipid yield,but its effects on lipid composition in blood and milk remain less understood.This study investigated changes in fatty acid(FA)composition in blood lipid fractions and milk of dairy cows following an intramammary lipopolysaccharide(LPS)challenge and explored potential links associated with these changes.We hypothesized that intramammary LPS infusion would alter the FA composition of blood lipid fractions,and that milk FA composition would reflect these changes.Furthermore,we hypothesized that prostaglandin E2(PGE2)would be associated with changes in both blood and milk FA composition,functioning as a potential mediator of these changes.Results Ten lactating cows were split into two groups.The treatment group received intramammary infusions of 50μg Escherichia coli LPS in both quarters of one udder half to induce clinical mastitis,and saline infusions in the quarters of the opposite udder half;the control group received saline infusions in one udder half only.Blood and foremilk were collected from individual cows or glands at−1,3,6,12,and 24 h post-infusion.Blood lipids were fractionated into cholesterol esters,free fatty acids(FFA),phospholipids(PL),and triacylglycerides(TAG).The FA composition was analyzed via gas-liquid chromatography.Total plasma TAG,FFA,and PGE2 concentrations were measured by colorimetric assay or ELISA.Statistical significance was determined using mixed models with Tukey's test.Lipopolysaccharide infusion did not affect total plasma TAG and FFA concentrations but increased plasma PGE2 concentrations andΔ9 desaturation indices in plasma TAG.A distinct shift in FA composition in plasma phospholipids and TAG was observed between the treatment and control groups at 6 and 12 h post-infusion.Specifically,LPS increased the proportion of n-6 polyunsaturated FA(18:2,18:3,20:3,20:4,20:5)and FA with less than 16 carbons while decreasing the saturated FA(18:0 and 20:0)in plasma TAG at 6 and 12 h.However,the milk FA composition remained unchanged.Conclusion Our findings indicate that transient intramammary LPS challenge influences systemic lipid metabolism without altering the milk FA composition,suggesting that mammary inflammatory responses affect blood lipids independently of milk lipid secretion.展开更多
文摘When tunnelling through low-permeability saturated ground,the pore pressure decreases in the vicinity of the cavity.In certain instances of deep tunnels crossing weak rocks,the pore pressure may even become negative.All existing analytical solutions for the undrained ground response curve(GRC)in the literature assume that the ground fully retains its saturation,in which case the development of negative pore pressures has a stabilising effect e it results in increased effective stresses,and thus shearing resistance,which in turn leads to reduced deformations and plastification.In practice,however,negative pore pressures can induce partial or complete ground desaturation,which may even invalidate the premise of undrained conditions and lead to considerably increased deformations and plastification.In such cases,existing solutions are unsafe for design.The present paper aims to address this shortcoming,by presenting a novel analytical solution for the undrained GRC which incorporates the effect of the excavation-induced desaturation.The solution is derived under the assumption that the ground desaturates completely and immediately under negative pore pressures,which provides the upper bound of deformations and plastification for cases of partial desaturation.The rock is considered to be a linear elastic,brittle-plastic material,obeying a non-associated Mohr-Coulomb(MC)yield criterion.Nevertheless,the solution is also applicable to perfectly plastic rocks via a simple modification of the input parameters.Although the solution is in general semi-analytical,simple closed-form expressions are obtained in the special case of non-dilatant rocks.These expressions are also applicable to rocks exhibiting limited dilatancy,which is usually the case.An application example,based on the planned deep geological repository for radioactive waste in Switzerland,demonstrates the significant practical value and usefulness of the novel solution and underscores its necessity in cases where existing solutions that disregard desaturation are rendered thoroughly unsafe for design.
文摘BACKGROUND: Rapid sequence induction and intubation(RSII) is an emergency airway management technique for patients with a risk of pulmonary aspiration. It involves preoxygenation, administration of predetermined doses of induction and paralytic drugs, avoidance of mask ventilation, and laryngoscopy followed by tracheal intubation and keeping cricoid pressure applied till endotracheal tube cuff be inflated. Oxygen desaturation has been seen during RSII. We assessed the incidence of oxygen desaturation during RSII.METHODS: An institution-based observational study was conducted from March 3 to May 4, 2014 in our hospital. All patients who were operated upon under general anesthesia with RSII during the study period were included. A checklist was prepared for data collection.RESULTS: A total of 153 patients were included in this study with a response rate of 91.6%. Appropriate drugs for RSII, equipments for RSII, equipments for diffi cult intubation, suction machine with a catheter, a monitor and an oxygen backup such as ambu bag were not prepared for 41(26.8%), 50(32.7%), 51(33.3%), 38(24.8%) and 25(16.3%) patients respectively. Cricoid pressure was not applied at all for 17(11.1%) patients and 53(34.6%) patients were ventilated after induction of anesthesia but before intubation and endotracheal cuff inflation. A total of 55(35.9%) patients desaturated during RSII(SPO2<95%). The minimum, maximum and mean oxygen desaturations were 26%, 94% and 70.9% respectively. The oxygen desaturation was in the range of <50%, 50%–64%, 65%–74%, 75%–84%, 85%–89 % and 90%–94% for 6(3.9%), 7(4.6%), 5(3.3%), 10(6.5%), 13(8.5%) and 14(9.2%) patients respectively.CONCLUSION: The incidence of oxygen desaturation during RSII was high in our hospital. Preoperative patient optimization and training about the techniques of RSII should be emphasized.
基金the National Key R&D Program of China(grant no.2021YFA1501600)the National Natural Science Foundation of China(grant nos.22022112 and 21521002).
文摘Catalytic oxidative alkane desaturation by base metals with benign oxidants under mild conditions is highly attractive,as it could enable an efficient way to produce valuable olefin products.Here we report the design and synthesis of macrocyclic and molecular cage copper complexes in catalyzing highly selective cyclohexane desaturation with H_(2)O_(2)/O_(2).The macrocycles and cages possess two to three phenanthroline units connected by versatile binary linkers or tripodal caps.These compounds readily formed bi-and tri-nuclear copper complexes with confined cavities and adaptive coordination environments,as suggested by X-ray single crystal analysis.In the catalytic oxidation of cyclohexane,a considerable yield of cyclohexene with unprecedented dehydrogenation/oxygenation selectivity up to 6.1:1 was achieved with the optimal cage compound C3.Control and mechanistic experiments suggested a pronounced cage effect and radical-mediated processes.The high selectivity was attributed to a cooperative effect between the copper centers,which facilitated the second hydrogen atom abstraction on the trapped cyclohexyl radical and the inhibition of the Fenton process within the shielding cavity environment.
文摘The purpose of the study was to investigate the relationship between sleep disordered breathing (SDB) and degree of heart failure (HF) in patients with coronary heart disease (CHD). A total of 3017 patients (77.4% men and 22.6% women) were included in the study. Clinical examination and echocardiography for evaluation of HF using NYHA functional classification and sleep polysomnography were performed. The study demonstrated that SDB is more common in CHD patients with higher NYHA functional class. The prevalence of central sleep apneas against obstructive apneas was observed in patients with mild and moderate HF. The number of central apneas was strongly related to the severity of heart failure. More frequent appearance of central sleep apneas is predominantly due to instability of ventilatory control systems during sleep because of impaired cardiac function in HF patients. Sleep architecture was more disturbed in CHD patients with higher NYHA functional class. A gradual increase of stage 1 and wakefulness after sleep onset and a decrease of sleep stages 3-4 and REM sleep as well as a diminution of sleep efficiency with worsening of NYHA functional class were observed. We suggest that both SDB and disturbed sleep variables independently significantly correlate with manifestation of HF.
基金Supported by Planned Science and Technology Project of Xi’an City, China [No.2017116SF/YX010(9)]
文摘To investigate the possible correlation between obstructive sleep apnea(OSA) and central retinal vein occlusion(CRVO). Thirty consecutive patients with a recent(<3 mo)CRVO and an age-and sex-matched group of 30 control subjects were recruited. All subjects underwent full-night polysomnography to measure apnea-hypopnea index(AHI)and oxygen desaturation index(ODI). The average AHI and ODI were significantly higher in CRVO patients(AHI:13.86±8.63, ODI: 9.21±4.47) than in control subjects(AHI:8.51±6.36, ODI: 5.87±3.18;P=0.008 and 0.001 respectively).Additionally, the AHI was positively correlated with body mass index(BMI;r=0.476, P=0.017) and ODI(r=0.921,P<0.01) in both CRVO and control subjects. According to AHI scores, twenty-two(73.33%) CRVO patients had OSA and 12(40.00%) control subjects had OSA, a difference that was statistically significant(P=0.019). OSA may be a risk factor for or a trigger of CRVO development.
基金support from National Research Foundation of Singapore under the Grant No.COT-V1-2020-4,and the support from JTC Corporation,Singapore.
文摘Soil liquefaction is a major geo-hazard.As liquefaction could occur anywhere in a sand layer and result in large-scale lateral spreading,treatment for liquefaction needs to be carried out over a large extent.The cost-effectiveness of the treatment then becomes a major consideration.With the development of microbial geotechnologies,some new approaches for liquefaction mitigation have been developed.Some of the methods offer more advantages over the existing methods.This paper gives an overview of the recent progress in bio related soil liquefaction mitigation methods.These include both bio-cementation and biogas desaturation.The mechanisms of bio-cementation and biogas desaturation are discussed.Recent up-scaled model tests and field trials are also reviewed.The studies so far have demonstrated that there is a great potential for some of liquefaction mitigation methods to be adopted in practice,although there are still challenges that need to be studied further.These include treatment efficiency,long-term sustainability,and biosafety.A brief introduction to some emerging technologies for liquefaction mitigation such as bio-gelation and use of fungi are also introduced.
文摘The deep geological repository for radioactive waste in Switzerland will be embedded in an approximately 100 m thick layer of Opalinus Clay.The emplacement drifts for high-level waste(approximately 3.5 m diameter)are planned to be excavated with a shielded tunnel boring machine(TBM)and supported by a segmental lining.At the repository depth of 900 m in the designated siting region Nordlich Lagern,squeezing conditions may be encountered due to the rock strength and the high hydrostatic pressure(90 bar).This paper presents a detailed assessment of the shield jamming and lining overstressing hazards,considering a stiff lining(resistance principle)and a deformable lining(yielding principle),and proposes conceptual design solutions.The assessment is based on three-dimensional transient hydromechanical simulations,which additionally consider the effects of ground anisotropy and the desaturation that may occur under negative pore pressures generated during the drift excavation.By addressing these design issues,the paper takes the opportunity to analyse some more fundamental aspects related to the influences of anisotropy and desaturation on the development of rock convergences and pressures over time,and their markedly different effects on the two lining systems.The results demonstrate that,regardless of these effects,shield jamming can be avoided with a moderate TBM overcut,however overstressing of a stiff lining may be critical depending on whether the ground desaturates.This uncertainty is eliminated using a deformable system with reasonable dimensions of yielding elements,which can also accommodate thermal strains generated due to the high temperature of the disposal canisters.
基金Taif University Researchers Supporting Project Number(TURSP-2020/10),Taif University,Taif,Saudi Arabia.
文摘Colorization is the practice of adding appropriate chromatic values to monochrome photographs or videos.A real-valued luminance image can be mapped to a three-dimensional color image.However,it is a severely ill-defined problem and not has a single solution.In this paper,an encoder-decoder Convolutional Neural Network(CNN)model is used for colorizing gray images where the encoder is a Densely Connected Convolutional Network(DenseNet)and the decoder is a conventional CNN.The DenseNet extracts image features from gray images and the conventional CNN outputs a^(*)b^(*)color channels.Due to a large number of desaturated color components compared to saturated color components in the training images,the saturated color components have a strong tendency towards desaturated color components in the predicted a^(*)b^(*)channel.To solve the problems,we rebalance the predicted a^(*)b^(*)color channel by smoothing every subregion individually using the average filter.2 stage k-means clustering technique is applied to divide the subregions.Then we apply Gamma transformation in the entire a^(*)b^(*)channel to saturate the image.We compare our proposed method with several existing methods.From the experimental results,we see that our proposed method has made some notable improvements over the existing methods and color representation of gray-scale images by our proposed method is more plausible to visualize.Additionally,our suggested approach beats other approaches in terms of Peak Signal-to-Noise Ratio(PSNR),Structural Similarity Index Measure(SSIM)and Histogram.
基金partly funded by Agriculture and Food Research Initiative Competitive Grant no. 2016-09363 from the USDA National Institute of Food and Agriculture (Washington, DC) to FQZby the USDA National Institute of Food and Agriculture Hatch grant VT-H02503 to JK.
文摘Background Mastitis is known to alter milk lipid yield,but its effects on lipid composition in blood and milk remain less understood.This study investigated changes in fatty acid(FA)composition in blood lipid fractions and milk of dairy cows following an intramammary lipopolysaccharide(LPS)challenge and explored potential links associated with these changes.We hypothesized that intramammary LPS infusion would alter the FA composition of blood lipid fractions,and that milk FA composition would reflect these changes.Furthermore,we hypothesized that prostaglandin E2(PGE2)would be associated with changes in both blood and milk FA composition,functioning as a potential mediator of these changes.Results Ten lactating cows were split into two groups.The treatment group received intramammary infusions of 50μg Escherichia coli LPS in both quarters of one udder half to induce clinical mastitis,and saline infusions in the quarters of the opposite udder half;the control group received saline infusions in one udder half only.Blood and foremilk were collected from individual cows or glands at−1,3,6,12,and 24 h post-infusion.Blood lipids were fractionated into cholesterol esters,free fatty acids(FFA),phospholipids(PL),and triacylglycerides(TAG).The FA composition was analyzed via gas-liquid chromatography.Total plasma TAG,FFA,and PGE2 concentrations were measured by colorimetric assay or ELISA.Statistical significance was determined using mixed models with Tukey's test.Lipopolysaccharide infusion did not affect total plasma TAG and FFA concentrations but increased plasma PGE2 concentrations andΔ9 desaturation indices in plasma TAG.A distinct shift in FA composition in plasma phospholipids and TAG was observed between the treatment and control groups at 6 and 12 h post-infusion.Specifically,LPS increased the proportion of n-6 polyunsaturated FA(18:2,18:3,20:3,20:4,20:5)and FA with less than 16 carbons while decreasing the saturated FA(18:0 and 20:0)in plasma TAG at 6 and 12 h.However,the milk FA composition remained unchanged.Conclusion Our findings indicate that transient intramammary LPS challenge influences systemic lipid metabolism without altering the milk FA composition,suggesting that mammary inflammatory responses affect blood lipids independently of milk lipid secretion.
