Objective:To explore the distribution and clearance of 99mTc labeled diethylenetriamine pentaacetic acid(99mTc-DTPA)in different brain regions of adult rats after administration through brain extracellular space(ECS)pathway.Methods:After the injection of a volume of 2 μL and radioactive activity of about 3.7 MBq(100 μCi)of 99mTc-DTPA into the caudate nucleus and thalamus of SD rats through stereotactic positioning of rat brain,the single photon emission computed tomography/computed tomography(SPECT/CT)for small animals was used for imaging at different time points,and the dyna-mic distribution and clearance of the tracer in the whole body were observed continuously.The SD rats were injected with 99mTc-DTPA into thalamus and caudate nucleus respectively for biological distribution in vivo.They were put to death 4 h later.Their blood and urine were collected.The brain,cerebellum,heart,liver,spleen,lung,and kidney were taken and weighed by γ counter to measure its radioactivity.Results:SPECT/CT imaging results showed that after 99mTc-DTPA was administered through brain ECS,the radioactivity was concentrated in the brain,kidney and bladder.The tracer administered to the left caudate nucleus was preferentially drained to the right cerebellum,while the tracer administered to the right caudate nucleus was preferentially drained to the left cerebellum.There was a phenomenon of"con-tralateral cerebellar dominant drainage"in the caudate nucleus.The thalamic area preferentially drained to the ipsilateral cerebellum after administration.Four hours after administration via ECS,high radioac-tive uptake appeared in urine,cerebellum and brain,followed by blood and kidney.The radioactive up-take values of heart,liver,spleen and lung were low,which were mainly excreted through urinary sys-tem.Conclusion:Intracerebral ECS administration is a promising method of administration,but there are significant differences in distribution and clearance in different brain regions.This study further ex-pands the content and significance of"ECS regions",and also provides an important theoretical founda-tion for the treatment of encephalopathy and the research of new drugs through brain ECS in the future.

Objective:To explore the distribution and clearance of 99mTc labeled diethylenetriamine pentaacetic acid(99mTc-DTPA)in different brain regions of adult rats after administration through brain extracellular space(ECS)pathway.Methods:After the injection of a volume of 2 μL and radioactive activity of about 3.7 MBq(100 μCi)of 99mTc-DTPA into the caudate nucleus and thalamus of SD rats through stereotactic positioning of rat brain,the single photon emission computed tomography/computed tomography(SPECT/CT)for small animals was used for imaging at different time points,and the dyna-mic distribution and clearance of the tracer in the whole body were observed continuously.The SD rats were injected with 99mTc-DTPA into thalamus and caudate nucleus respectively for biological distribution in vivo.They were put to death 4 h later.Their blood and urine were collected.The brain,cerebellum,heart,liver,spleen,lung,and kidney were taken and weighed by γ counter to measure its radioactivity.Results:SPECT/CT imaging results showed that after 99mTc-DTPA was administered through brain ECS,the radioactivity was concentrated in the brain,kidney and bladder.The tracer administered to the left caudate nucleus was preferentially drained to the right cerebellum,while the tracer administered to the right caudate nucleus was preferentially drained to the left cerebellum.There was a phenomenon of"con-tralateral cerebellar dominant drainage"in the caudate nucleus.The thalamic area preferentially drained to the ipsilateral cerebellum after administration.Four hours after administration via ECS,high radioac-tive uptake appeared in urine,cerebellum and brain,followed by blood and kidney.The radioactive up-take values of heart,liver,spleen and lung were low,which were mainly excreted through urinary sys-tem.Conclusion:Intracerebral ECS administration is a promising method of administration,but there are significant differences in distribution and clearance in different brain regions.This study further ex-pands the content and significance of"ECS regions",and also provides an important theoretical founda-tion for the treatment of encephalopathy and the research of new drugs through brain ECS in the future.

Myocardial ischemia-reperfusion injury(MIRI)is one of the reasons for the high mortality in patients with acute myocardial infarction after percutaneous coronary intervention,which is regulated by several cell death pathways including apoptosis,autophagy,and pyroptosis.Recently,it has been found that ferroptosis,a unique programmed cell death,appears to be a therapeutic target for MIRI.However,the mechanisms remain incompletely elucidated.This re-view summarizes the latest research progress on the role of ferroptosis in MIRI,including mitochondrial dysfunction,endo-plasmic reticulum stress(ERS),oxidative stress,calcium overload,epigenetic modification,apoptosis,autophagy,etc.Moreover,the signaling pathways between ferroptosis and MIRI are elaborated,which will provide new insights for the prevention and treatment of MIRI.

Myocardial ischemia-reperfusion injury(MIRI)is one of the reasons for the high mortality in patients with acute myocardial infarction after percutaneous coronary intervention,which is regulated by several cell death pathways including apoptosis,autophagy,and pyroptosis.Recently,it has been found that ferroptosis,a unique programmed cell death,appears to be a therapeutic target for MIRI.However,the mechanisms remain incompletely elucidated.This re-view summarizes the latest research progress on the role of ferroptosis in MIRI,including mitochondrial dysfunction,endo-plasmic reticulum stress(ERS),oxidative stress,calcium overload,epigenetic modification,apoptosis,autophagy,etc.Moreover,the signaling pathways between ferroptosis and MIRI are elaborated,which will provide new insights for the prevention and treatment of MIRI.

Endometrial receptivity refers to the ability of the endometrium to allow blastocyst location, adhesion, penetration, implantation, and to promote embryo implantation and development. The study of endometrial characteristics during implantation to find markers of endometrial receptivity has long been a hot topic of research. Although progress has been made, there is still a lack of recognized markers for predicting clinical pregnancy. Recent studies have shown that aspiration of uterine fluid has no negative effect on embryo implantation and can be studied as a non-invasive test. At the same time, it was found that there were extracellular vesicles in uterine fluid, in which miRNA, protein, DNA and lipid play an important role in the reproductive process of follicle development and maturation, embryo development and implantation, etc., and it is expected to be used as endometrial receptivity markers and therapeutic targets in the future. In this article, we will review the research progress of uterine fluid extracellular vesicles in the evaluation of endometrial receptivity.

Endometrial receptivity refers to the ability of the endometrium to allow blastocyst location, adhesion, penetration, implantation, and to promote embryo implantation and development. The study of endometrial characteristics during implantation to find markers of endometrial receptivity has long been a hot topic of research. Although progress has been made, there is still a lack of recognized markers for predicting clinical pregnancy. Recent studies have shown that aspiration of uterine fluid has no negative effect on embryo implantation and can be studied as a non-invasive test. At the same time, it was found that there were extracellular vesicles in uterine fluid, in which miRNA, protein, DNA and lipid play an important role in the reproductive process of follicle development and maturation, embryo development and implantation, etc., and it is expected to be used as endometrial receptivity markers and therapeutic targets in the future. In this article, we will review the research progress of uterine fluid extracellular vesicles in the evaluation of endometrial receptivity.

Objective:To establish a method for the determination of bisphenol S in urine using dispersive liquid-liquid microextraction (DLLME) coupled with high performance liquid chromatography (HPLC) .Methods:The acetonitrile, octanol were used as extraction solvent, dispersive solvent respectively, for the preconcentration of bisphenol S. The optimal extraction conditions were optimized by single factor rotations, and methodological performance index were tested.Results:The linear correlation coefficient of bisphenol S in the range of 0.0-160 μg/L is greater than 0.999. The detection limit of this method was 0.76 μg/L, and the recovery rates were 88.06%-103.81%. The intra-and inter-day precisions were 1.78%-2.85% and 2.65%-4.25%, respectively.Conclusion:The method is reliable and sensitive. It is suitable for the determination of bisphenol S in urine samples for occupational exposure populations and non-professional.

Objective:To establish a method for the determination of bisphenol S in urine using dispersive liquid-liquid microextraction (DLLME) coupled with high performance liquid chromatography (HPLC) .Methods:The acetonitrile, octanol were used as extraction solvent, dispersive solvent respectively, for the preconcentration of bisphenol S. The optimal extraction conditions were optimized by single factor rotations, and methodological performance index were tested.Results:The linear correlation coefficient of bisphenol S in the range of 0.0-160 μg/L is greater than 0.999. The detection limit of this method was 0.76 μg/L, and the recovery rates were 88.06%-103.81%. The intra-and inter-day precisions were 1.78%-2.85% and 2.65%-4.25%, respectively.Conclusion:The method is reliable and sensitive. It is suitable for the determination of bisphenol S in urine samples for occupational exposure populations and non-professional.

Objective:To set up a new method to determine the nickel of urine in urine using dispersive liquid-liquid microextraction (DLLME) coupled with graphite furnace atomic absorption spectrometry (GFAAS) .Methods:From September 2018 to September 2019, the methanol, pyrrolidine dithiocarbamate and ionic liquid 1-hexyl-3-methyl-imidazolium hexafluorophosphate were used as dispersive solvent, the chelating agent and extraction solvent for the preconcentration of nickel, respectively. After adding into buffer solution of pH 9, ultrasonic dissolving for 10 minutes, centrifugal separation and then discarding the supernatant, the precipitate was saved. Dissolving the precipitate by methanol, mixing thoroughly on a vortex mixer, the 15 μl of the mixed solution was used for determination by graphite furnace atomic absorption spectrometry.Results:The linear correlation coefficient of urine nickel concentration in the range of 2.0-10.0 μg/L, r=0.999, with the detection limitation of 0.43 μg/L. The recovery rate and the relative standard deviations were 95.6% -103.7% and 2.53% -4.82%, respectively. Conclusion:The method, which has low detection limit, high recovery rate and good precision, is suitable for the determination of nickel in urine for the occupational populations exposure to nickel and non-occupational exposure.

Objective:To set up a new method to determine the nickel of urine in urine using dispersive liquid-liquid microextraction (DLLME) coupled with graphite furnace atomic absorption spectrometry (GFAAS) .Methods:From September 2018 to September 2019, the methanol, pyrrolidine dithiocarbamate and ionic liquid 1-hexyl-3-methyl-imidazolium hexafluorophosphate were used as dispersive solvent, the chelating agent and extraction solvent for the preconcentration of nickel, respectively. After adding into buffer solution of pH 9, ultrasonic dissolving for 10 minutes, centrifugal separation and then discarding the supernatant, the precipitate was saved. Dissolving the precipitate by methanol, mixing thoroughly on a vortex mixer, the 15 μl of the mixed solution was used for determination by graphite furnace atomic absorption spectrometry.Results:The linear correlation coefficient of urine nickel concentration in the range of 2.0-10.0 μg/L, r=0.999, with the detection limitation of 0.43 μg/L. The recovery rate and the relative standard deviations were 95.6% -103.7% and 2.53% -4.82%, respectively. Conclusion:The method, which has low detection limit, high recovery rate and good precision, is suitable for the determination of nickel in urine for the occupational populations exposure to nickel and non-occupational exposure.