In this study, we investigated the effect of exogenous sodium benzoate on wheat seedlings(Yangmai 16) grown under heavy metal stress. The results showed that 2.4 mmol kg-1 of heavy metals significantly inhibited growt...In this study, we investigated the effect of exogenous sodium benzoate on wheat seedlings(Yangmai 16) grown under heavy metal stress. The results showed that 2.4 mmol kg-1 of heavy metals significantly inhibited growth and delayed emergence of wheat seedlings. Under compound heavy metal stress, application of 2-4 g L^-1 sodium benzoate significantly increased(P<0.01) chlorophyll content and chlorophyll fluorescence parameters Fv/Fm and Fv/Fo of wheat, compared to the control(water treatment). Further analysis showed that application of 2-4 g L^-1 sodium benzoate alleviated osmotic stress by promoting the accumulation of osmolytes such as soluble proteins and free proline, increased the activity of superoxide dismutase(SOD) and reduced malondialdehyde content(MDA). In contrast, higher concentrations of sodium benzoate solution(>6 g L^-1) inhibited the growth of wheat seedlings and even caused damage to seedlings. Correlation analysis showed that when the sodium benzoate concentration was in the range of 1.97-3.12 g L^-1(2016) and 1.58-3.27 g L^-1(2017), values of chlorophyll and its components, root activity, SOD activity, soluble protein, and free proline content were the highest. When the sodium benzoate concentration was raised to 2.59 g L^-1(2016) or 3.02 g L^-1(2017), MDA content was the lowest. Ultimately, exogenous sodium benzoate(2-4 g L^-1) facilitates root development and improves the root activity of wheat seedlings grown under compound heavy metals stress, thereby effectively alleviating the damage of compound heavy metal stress in wheat seedlings.展开更多
With the widespread adoption of ultrasound guidance,Seldinger puncture techniques,and intracardiac electrical positioning technology for the placement of peripherally inserted central catheters in recent years,an incr...With the widespread adoption of ultrasound guidance,Seldinger puncture techniques,and intracardiac electrical positioning technology for the placement of peripherally inserted central catheters in recent years,an increasing number of medical staff and patients now accept peripheral placement of totally implantable venous access devices(TIVADs)in the upper arm.This approach has the advantage of completely avoiding the risks of hemothorax,pneumothorax,and neck and chest scarring.Medical specialties presently engaged in this study in China include internal medicine,surgery,anesthesiology,and interventional departments.However,command over implantation techniques,treatment of complications,and proper use and maintenance of TIVAD remain uneven among different medical units.Moreover,currently,there are no established quality control standards for implantation techniques or specifications for handling complications.Thus,this expert consensus is proposed to improve the success rate of TIVAD implantation via the upper-arm approach,reduce complication rates,and ensure patient safety.This consensus elaborates on the technical indications and contraindications,procedures and technical points,treatment of complications,and the use and maintenance of upper-arm TIVAD,thus providing a practical reference for medical staff.展开更多
BACKGROUND： Rho GTPase family members have been shown to participate in neurite growth by regulating the neuronal cytoskeleton. However, there are very few reports of developmental roles of signaling molecules relate...BACKGROUND： Rho GTPase family members have been shown to participate in neurite growth by regulating the neuronal cytoskeleton. However, there are very few reports of developmental roles of signaling molecules related to Rho GTPases. OBJECTIVE： To investigate messenger ribonucleic acid mRNA expression of signaling molecules associated with Rho GTPases, including Rho-A, Rac-1, collapsin response mediator protein 1 （CRMP-1）, and tubulin 133 （Tub/33） during rat hippocampus development. DESIGN, TIME AND SETTING- A non-randomized, controlled, animal experiment, based on different developmental stages of the rat hippocampus, was performed at the Guangdong Key Laboratory of Tissue Construction and Detection, Institute of Clinical Anatomy, Southern Medical University between December 2005 and July 2007. MATERIALS： Trizol reagent was purchased from Invitrogen, USA. RNA PCR kit （AMV） Ver 3.0 and 150 bp DNA Ladder Marker were purchased from TaKaRa, Japan. Unless otherwise specified, all other reagents were purchased from Sigma-Aldrich, USA. METHODS： Twenty-five Sprague Dawley rats were assigned to five groups （n = 5） according to developmental stages： embryonic （embryonic 15 days）, neonatal （postnatal 5 days）, juvenile （postnatal 1 month）, adult （postnatal 3 months）, and senile （postnatal 18 months）. MAIN OUTCOME MEASURES： Detection of mRNA expression of Rho-A, Rac-1, CRMP-1, and Tub β3 during various hippocampal developmental stages by reverse-transcription polymerase chain reaction. RESULTS： Hippocampal mRNA expression of Rho-A, as well as Rac-1, reached peak levels at embryonic, juvenile, and senile stages, and was relatively less during neonatal and adult stages. mRNA expression of Rac-1 was greater than Rho-A during each hippocampal developmental stage. CRMP-1 mRNA expression levels were as follows： embryonic 〉 neonatal 〉 juvenile 〉 adult 〈 senile, while Tubβ3 mRNA expression was embryonic 〉 neonatal 〉 juvenile 〉 adult = senile. CONCLUSION： Rho-A and Rac-1 shared similar expression profiles, which demonstrated similar variations during the entire rat hippocampus developmental process. However, Rac-1 mRNA expression remained greater than Rho-A. Both CRMP-1 and Tubβ3 mRNA expression profiles gradually declined during hippocampal development from embryonic to adult stages. Tubβ3 mRNA expression arrested during the adult stage, and CRMP-1 mRNA expression increased during the senile stage.展开更多
基金supported by the National Key Research and Development Program of China(2017YFD0201306)the National Natural Science Foundation of China(31671613,31471435)+2 种基金the Ph D Programs Foundation of Jiangsu Province,China(1601116C)the Priority Academic Program Development of Jiangsu Higher Education Institutions,Chinathe Top-Notch Academic Programs Project of Jiangsu Higher Education Institutions,China(PPZY2015A060)。
文摘In this study, we investigated the effect of exogenous sodium benzoate on wheat seedlings(Yangmai 16) grown under heavy metal stress. The results showed that 2.4 mmol kg-1 of heavy metals significantly inhibited growth and delayed emergence of wheat seedlings. Under compound heavy metal stress, application of 2-4 g L^-1 sodium benzoate significantly increased(P<0.01) chlorophyll content and chlorophyll fluorescence parameters Fv/Fm and Fv/Fo of wheat, compared to the control(water treatment). Further analysis showed that application of 2-4 g L^-1 sodium benzoate alleviated osmotic stress by promoting the accumulation of osmolytes such as soluble proteins and free proline, increased the activity of superoxide dismutase(SOD) and reduced malondialdehyde content(MDA). In contrast, higher concentrations of sodium benzoate solution(>6 g L^-1) inhibited the growth of wheat seedlings and even caused damage to seedlings. Correlation analysis showed that when the sodium benzoate concentration was in the range of 1.97-3.12 g L^-1(2016) and 1.58-3.27 g L^-1(2017), values of chlorophyll and its components, root activity, SOD activity, soluble protein, and free proline content were the highest. When the sodium benzoate concentration was raised to 2.59 g L^-1(2016) or 3.02 g L^-1(2017), MDA content was the lowest. Ultimately, exogenous sodium benzoate(2-4 g L^-1) facilitates root development and improves the root activity of wheat seedlings grown under compound heavy metals stress, thereby effectively alleviating the damage of compound heavy metal stress in wheat seedlings.
文摘With the widespread adoption of ultrasound guidance,Seldinger puncture techniques,and intracardiac electrical positioning technology for the placement of peripherally inserted central catheters in recent years,an increasing number of medical staff and patients now accept peripheral placement of totally implantable venous access devices(TIVADs)in the upper arm.This approach has the advantage of completely avoiding the risks of hemothorax,pneumothorax,and neck and chest scarring.Medical specialties presently engaged in this study in China include internal medicine,surgery,anesthesiology,and interventional departments.However,command over implantation techniques,treatment of complications,and proper use and maintenance of TIVAD remain uneven among different medical units.Moreover,currently,there are no established quality control standards for implantation techniques or specifications for handling complications.Thus,this expert consensus is proposed to improve the success rate of TIVAD implantation via the upper-arm approach,reduce complication rates,and ensure patient safety.This consensus elaborates on the technical indications and contraindications,procedures and technical points,treatment of complications,and the use and maintenance of upper-arm TIVAD,thus providing a practical reference for medical staff.
基金Supported by:the National Basic Research Program of China(973 Program),No. 2007CB512705the Natural Science Foundation of Guangdong Province,No. 8451063201000193
文摘BACKGROUND： Rho GTPase family members have been shown to participate in neurite growth by regulating the neuronal cytoskeleton. However, there are very few reports of developmental roles of signaling molecules related to Rho GTPases. OBJECTIVE： To investigate messenger ribonucleic acid mRNA expression of signaling molecules associated with Rho GTPases, including Rho-A, Rac-1, collapsin response mediator protein 1 （CRMP-1）, and tubulin 133 （Tub/33） during rat hippocampus development. DESIGN, TIME AND SETTING- A non-randomized, controlled, animal experiment, based on different developmental stages of the rat hippocampus, was performed at the Guangdong Key Laboratory of Tissue Construction and Detection, Institute of Clinical Anatomy, Southern Medical University between December 2005 and July 2007. MATERIALS： Trizol reagent was purchased from Invitrogen, USA. RNA PCR kit （AMV） Ver 3.0 and 150 bp DNA Ladder Marker were purchased from TaKaRa, Japan. Unless otherwise specified, all other reagents were purchased from Sigma-Aldrich, USA. METHODS： Twenty-five Sprague Dawley rats were assigned to five groups （n = 5） according to developmental stages： embryonic （embryonic 15 days）, neonatal （postnatal 5 days）, juvenile （postnatal 1 month）, adult （postnatal 3 months）, and senile （postnatal 18 months）. MAIN OUTCOME MEASURES： Detection of mRNA expression of Rho-A, Rac-1, CRMP-1, and Tub β3 during various hippocampal developmental stages by reverse-transcription polymerase chain reaction. RESULTS： Hippocampal mRNA expression of Rho-A, as well as Rac-1, reached peak levels at embryonic, juvenile, and senile stages, and was relatively less during neonatal and adult stages. mRNA expression of Rac-1 was greater than Rho-A during each hippocampal developmental stage. CRMP-1 mRNA expression levels were as follows： embryonic 〉 neonatal 〉 juvenile 〉 adult 〈 senile, while Tubβ3 mRNA expression was embryonic 〉 neonatal 〉 juvenile 〉 adult = senile. CONCLUSION： Rho-A and Rac-1 shared similar expression profiles, which demonstrated similar variations during the entire rat hippocampus developmental process. However, Rac-1 mRNA expression remained greater than Rho-A. Both CRMP-1 and Tubβ3 mRNA expression profiles gradually declined during hippocampal development from embryonic to adult stages. Tubβ3 mRNA expression arrested during the adult stage, and CRMP-1 mRNA expression increased during the senile stage.
