<div style="text-align:justify;"> <span style="font-family:Verdana;">Medicinal plants have been used to treat many diseases with fewer side effects compared to clinical medicines. The n...<div style="text-align:justify;"> <span style="font-family:Verdana;">Medicinal plants have been used to treat many diseases with fewer side effects compared to clinical medicines. The need for treatment by medicinal plants has been increasing in response to the accumulation of environmental pollutants. The herbicide 2, 4-Dichlorophenoxyacetic acid has been considered as fast spreadable environmental pollutant, which may cause many disorders in animals and possibly in humans. The aim of this study is to assess the protective and/or curative effect of </span><i><span style="font-family:Verdana;">Lepidium sativum</span></i><span style="font-family:Verdana;"> against hepatotoxicity induced by 2, 4-D herbicide in rats. 25 Albino Wistar rats were grouped into 4 groups: a control group, the curative group treated for 4 weeks with LS water extract after a single dose 2, 4-D LD</span><sub><span style="font-family:Verdana;">50</span></sub><span style="font-family:Verdana;"> administration, protective group which was treated for 4 weeks with LS water extract prior to the 2, 4-D LD</span><sub><span style="font-family:Verdana;">50</span></sub><span style="font-family:Verdana;"> administration, and LS only group that was given the LS water extract as a positive control. Using transmission electron microscope, the histological features showed that curative group hepatocytes still suffered from focal necrosis and vacuolation of hepatocytes as a result of 2, 4-D toxic effect whereas in the protective group hepatocytes were less accentuated expressed as less frequent necrotic area, and still large mitochondria were present with numerous undissolved lipid droplets and a small amount of rough endoplasmic reticulum. For the LS only group, nearly normal cells with centric nucleus, normal small mitochondria were at a normal nucleus-cytoplasmic ratio, but a few lipid droplets were noticed. This study proved that curative group has an advantage over the protective group that could be presented in the nucleus with narrow nuclear pores and intact nuclear envelope with dense small mitochondria and normal rough endoplasmic reticulum that were recorded as in the control group. Thus, </span><i><span style="font-family:Verdana;">Lepidium sativum </span></i><span><span style="font-family:Verdana;">administration to the rats prior or post to intoxication was effective in minimizing the 2, 4-D-induced damages likely through a free radical scavenging activity in liver tissue.</span></span> </div>展开更多
Hydroxylation of inert benzene through the activation of the C_(sp2)-H bond is a representative reaction about the transformation of CeH bonds to C-O bonds,which has far-reaching guiding significance but remains a cha...Hydroxylation of inert benzene through the activation of the C_(sp2)-H bond is a representative reaction about the transformation of CeH bonds to C-O bonds,which has far-reaching guiding significance but remains a challenging scientific problem.To overcome this problem,a series of VOx-Ga_(2)O_(3)/SiO_(2)-Al_(2)O_(3)were prepared to achieve an efficient and economical hydroxylation path of benzene to phenol.The results showed that the phenol yield was 72.89%(selectivity>98.1%)under the optimum conditions.The reason is that the CeH bond in the benzene ring is activated by heterolysis over a VOx-Ga_(2)O_(3)/SiO_(2)-Al_(2)O_(3)catalyst.Meanwhile,the introduction of aluminum(Al)and gallium(Ga)made a qualitative change in the catalyst,enhancing the electron motion and spin motion of vanadium species,resulting in the increase of V4^(+)/V5^(+)ratio.In addition,the catalyst can provide an optimal acidic environment and a threedimensional cross-linked surface structure that facilitates product diffusion.展开更多
A widely used herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) was imprinted on poly (4-vinylpyridine) (4-VP) using (40%) ethyleneglycol dimethacrylate (EGDMA) as crosslinking agent. The classical imprinting technolog...A widely used herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) was imprinted on poly (4-vinylpyridine) (4-VP) using (40%) ethyleneglycol dimethacrylate (EGDMA) as crosslinking agent. The classical imprinting technology makes use of a high degree of crosslinking which does not allow the template molecules to move freely. So the binding sites, located in the central area of the three dimensional polymer matrix are hard to be accessed and the template molecules cannot be extracted totally. But here we propose a low crosslinked system with high specificity and selectivity. The imprinted and non-imprinted polymers were characterized by various spectroscopic techniques. The extent of binding was followed by batch equilibration method and compared with the respective non-imprinted polymer. Conditions for maximum specific rebinding were set by altering certain factors like template/monomer ratio, concentration of template solution, rebinding medium, mass of polymer and time of incubation. The selectivity of the imprinted polymer was investigated by comparing the binding with structural analogues of 2,4-D like, phenoxyacetic acid (POA), 4-chlorophenoxyacetic acid (4-CPOA) and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T). The imprinted polymer exhibited high affinity towards the template molecule and was selectively rebound to the specific sites. The binding towards the structural analogues depends on the number of chlorine in the benzene ring.展开更多
文摘<div style="text-align:justify;"> <span style="font-family:Verdana;">Medicinal plants have been used to treat many diseases with fewer side effects compared to clinical medicines. The need for treatment by medicinal plants has been increasing in response to the accumulation of environmental pollutants. The herbicide 2, 4-Dichlorophenoxyacetic acid has been considered as fast spreadable environmental pollutant, which may cause many disorders in animals and possibly in humans. The aim of this study is to assess the protective and/or curative effect of </span><i><span style="font-family:Verdana;">Lepidium sativum</span></i><span style="font-family:Verdana;"> against hepatotoxicity induced by 2, 4-D herbicide in rats. 25 Albino Wistar rats were grouped into 4 groups: a control group, the curative group treated for 4 weeks with LS water extract after a single dose 2, 4-D LD</span><sub><span style="font-family:Verdana;">50</span></sub><span style="font-family:Verdana;"> administration, protective group which was treated for 4 weeks with LS water extract prior to the 2, 4-D LD</span><sub><span style="font-family:Verdana;">50</span></sub><span style="font-family:Verdana;"> administration, and LS only group that was given the LS water extract as a positive control. Using transmission electron microscope, the histological features showed that curative group hepatocytes still suffered from focal necrosis and vacuolation of hepatocytes as a result of 2, 4-D toxic effect whereas in the protective group hepatocytes were less accentuated expressed as less frequent necrotic area, and still large mitochondria were present with numerous undissolved lipid droplets and a small amount of rough endoplasmic reticulum. For the LS only group, nearly normal cells with centric nucleus, normal small mitochondria were at a normal nucleus-cytoplasmic ratio, but a few lipid droplets were noticed. This study proved that curative group has an advantage over the protective group that could be presented in the nucleus with narrow nuclear pores and intact nuclear envelope with dense small mitochondria and normal rough endoplasmic reticulum that were recorded as in the control group. Thus, </span><i><span style="font-family:Verdana;">Lepidium sativum </span></i><span><span style="font-family:Verdana;">administration to the rats prior or post to intoxication was effective in minimizing the 2, 4-D-induced damages likely through a free radical scavenging activity in liver tissue.</span></span> </div>
基金the Support Program for Hongliu Young Teachers of Lanzhou University of Technology(02/062214)Young Talent Innovation Project of Lanzhou(2023-QN-103)Major science and technology projects of Gansu Province(22ZD6GA013).
文摘Hydroxylation of inert benzene through the activation of the C_(sp2)-H bond is a representative reaction about the transformation of CeH bonds to C-O bonds,which has far-reaching guiding significance but remains a challenging scientific problem.To overcome this problem,a series of VOx-Ga_(2)O_(3)/SiO_(2)-Al_(2)O_(3)were prepared to achieve an efficient and economical hydroxylation path of benzene to phenol.The results showed that the phenol yield was 72.89%(selectivity>98.1%)under the optimum conditions.The reason is that the CeH bond in the benzene ring is activated by heterolysis over a VOx-Ga_(2)O_(3)/SiO_(2)-Al_(2)O_(3)catalyst.Meanwhile,the introduction of aluminum(Al)and gallium(Ga)made a qualitative change in the catalyst,enhancing the electron motion and spin motion of vanadium species,resulting in the increase of V4^(+)/V5^(+)ratio.In addition,the catalyst can provide an optimal acidic environment and a threedimensional cross-linked surface structure that facilitates product diffusion.
文摘A widely used herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) was imprinted on poly (4-vinylpyridine) (4-VP) using (40%) ethyleneglycol dimethacrylate (EGDMA) as crosslinking agent. The classical imprinting technology makes use of a high degree of crosslinking which does not allow the template molecules to move freely. So the binding sites, located in the central area of the three dimensional polymer matrix are hard to be accessed and the template molecules cannot be extracted totally. But here we propose a low crosslinked system with high specificity and selectivity. The imprinted and non-imprinted polymers were characterized by various spectroscopic techniques. The extent of binding was followed by batch equilibration method and compared with the respective non-imprinted polymer. Conditions for maximum specific rebinding were set by altering certain factors like template/monomer ratio, concentration of template solution, rebinding medium, mass of polymer and time of incubation. The selectivity of the imprinted polymer was investigated by comparing the binding with structural analogues of 2,4-D like, phenoxyacetic acid (POA), 4-chlorophenoxyacetic acid (4-CPOA) and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T). The imprinted polymer exhibited high affinity towards the template molecule and was selectively rebound to the specific sites. The binding towards the structural analogues depends on the number of chlorine in the benzene ring.
