Biotechnology has revolutionized agriculture through innovations such as genetically modified(GM)technology and CRISPR/Cas9 genome editing.In this review,a comparative analysis of these methods that addresses the conc...Biotechnology has revolutionized agriculture through innovations such as genetically modified(GM)technology and CRISPR/Cas9 genome editing.In this review,a comparative analysis of these methods that addresses the concerns regarding the oversimplification of the notion that the CRISPR-based editing approach is equivalent to traditional GM approaches is offered.Since the 1990s,despite the potential benefits for crop improvement and food security,controversies have arisen around recombinant technology and the introduction of GM products due to perceived environmental and health concerns.In contrast,the recent emergence of the CRISPR/Cas systemas a precise genome editing tool has garnered relatively less public resistance.In this review,the reasons for these contrasting findings are explored to shed light on the distinct characteristics inherent to each approach.Additionally,we conduct a bibliographic analysis to examine the shift in research priorities between the two technological eras,followed by a comprehensive comparison of the two approaches,to enable a better understanding of the potential synergies that can be achieved between agricultural biotechnology and conventional techniques for enhancing modern agriculture.A nuanced understanding of these technologies is crucial for informed decision-making,responsible implementation,and addressing the concerns surrounding agricultural biotechnology.展开更多
The difference in the microstructure,texture in the stir zone(SZ)of the AZ31(Mg-3 Al-1 Zn,wt.%)alloy after friction stir welding(FSW)and subsequent annealing at 400℃for 1 h was characterized by scanning electron micr...The difference in the microstructure,texture in the stir zone(SZ)of the AZ31(Mg-3 Al-1 Zn,wt.%)alloy after friction stir welding(FSW)and subsequent annealing at 400℃for 1 h was characterized by scanning electron microscopy(SEM)with electron backscatter diffraction(EBSD)measurements at the surface and core regions.The findings indicate that FSW produced grain refinement where the mean grain size decreases from 19μm(base metal)to 5.1 and 3.5μm at the surface and core regions,respectively.The c-axis of the grains at the surface region was aligned with the normal direction(<0001>//ND)due to the additional strain of the tool shoulder.In contrast,the core region shows a typical shear texture,where the c-axis tends to be oriented parallel to the welding direction(<0001>//WD).The Vickers microhardness mapping across the SZ revealed that the core region was soften than the surface region due to the dynamic recrystallization and texture weakening.The microstructure of the SZ remains principally deformed after annealing treatment except for the development of massive Mg_(17)Al_(12)precipitates and the abnormal grain growth of a few grains with<11-20>//WD orientation at the upper side of the surface region.The c-axis of the grains at the surface region was tilted about 10°toward WD,while an inclined<0001>//WD orientation about 30°from WD was developed at the core region.Consequently,the distribution of microhardness values across the SZ was more heterogeneous than the FSW sample.The results were discussed in the light of grain boundary misorientation,dislocation density and the pinning effect of Mg_(17)Al_(12)precipitates.Additionally,Schmid factor analysis was used to examine the activation of the basal slip mode to characterize the associated mechanical response.展开更多
Nowadays,magnesium alloys are emerging in biomedical implants for their similar properties to natural bones.However,the rapid degradation of magnesium alloys in biological media hinders successful implantation.Refinem...Nowadays,magnesium alloys are emerging in biomedical implants for their similar properties to natural bones.However,the rapid degradation of magnesium alloys in biological media hinders successful implantation.Refinement of microstructure,as well as reinforcement particles can significantly improve the degradation rate.In this work,multi-pass friction stir processing(FSP)was proposed to synthesize WE43/nano-hydroxyapatite(n HA)surface composite,the microstructure,reinforced particle distribution,micro-hardness,corrosion behavior and in-vitro bioactivity were studied.The subsequent FSP passes of WE43 alloy and WE43/n HA composite refined the grain size which was reduced by 94.29%and 95.92%(2.63 and 1.88μm,respectively)compared to base metal after three passes.This resulted in increasing the microhardness by 120%(90.86 HV0.1)and 135%(105.59 HV0.1)for the WE43 and WE43-n HA,respectively.It is found that increasing FSP passes improved the uniform distribution of n HA particles within the composite matrix which led to improved corrosion resistance and less degradation rate.The corrosion rate of the FSPed WE43/n HA composite after three passes was reduced by 38.2%(4.13 mm/year)and the degradation rate was reduced by 69.7%(2.87 mm/y).This is attributed to secondary phase(Mg24Y5and Mg41Nd5)particle fragmentation and redistribution,as well as a homogeneous distribution of n HA.Additionally,the growing Ca-P and Mg(OH)2layer formed on the surface represented a protective layer that reduced the degradation rate.The wettability test revealed a relatively hydrophilic surface with water contact angle of 49.1±2.2°compared to 71.2±2.1°for base metal.Also,biomineralization test showed that apatite layer grew after immersion 7d in simulated body fluid with atomic ratio of Ca/P 1.60 approaching the stoichiometric ratio(1.67)indicating superior bioactivity of FSPed WE43/n HA composite after three passes.These results raise that the grain refinement by FSP and introduction of n HA particles significantly improved the degradation rate and in-vitro bioactivity of WE43 alloy for biomedical applications.展开更多
Objective:To isolate,identify,and evaluate a new angiotensin-converting enzyme inhibitor from Peperomia pellucida(L.)Kunth herbs.Methods:A dried sample of Peperomia pellucida herb was successively macerated with n-hex...Objective:To isolate,identify,and evaluate a new angiotensin-converting enzyme inhibitor from Peperomia pellucida(L.)Kunth herbs.Methods:A dried sample of Peperomia pellucida herb was successively macerated with n-hexane and ethyl acetate.The ethyl acetate extract solution was evaporated to obtain the crude extract.Vacuum liquid column chromatography and thin layer chromatography were performed to obtain two pure compounds.Then,both compounds were elucidated and identified using the spectroscopic method.Angiotensin-converting enzyme inhibitory activity studies of both compounds were determined using angiotensin-converting enzyme kit WST-1 with spectrophotometer microplate reader 96-well at 450 nm wavelength.Results:Two bioactive compounds were successfully isolated from Peperomia pellucida herb,including a new compound of 2,3,5-trimethoxy-9-(12,14,15-trimethoxybenzyl)-1 H-indene and pellucidin A.Both compounds demonstrated angiotensin-converting enzyme inhibitory activity,with IC50 values of 72μM(27.95μg/mL)and 11μM(4.4μg/mL),respectively.Conclusions:In the present study,two active angiotensin-converting enzyme inhibitors were successfully isolated and purified from Peperomia pellucida which is used as an antihypertensive in traditional medicine,and support its use as an angiotensin-converting enzyme-inhibiting drug.展开更多
Nasicon type,Mg_(0.5+x/2)Si_(2-x)Al_(x)(PO_(4))_(3) was synthesized using citric acid assisted sol-gel method.The X-ray diffraction was applied to investigate the effect of extra Mg^(2+)interstitial ion on the phase,u...Nasicon type,Mg_(0.5+x/2)Si_(2-x)Al_(x)(PO_(4))_(3) was synthesized using citric acid assisted sol-gel method.The X-ray diffraction was applied to investigate the effect of extra Mg^(2+)interstitial ion on the phase,unit cell parameters and structure of the samples.The Mg_(0.625)Si_(1.75)Al_(0.25)(PO_(4))_(3) sample exhibited highest bulk conductivity value of 1.54×10^(−4)S cm^(−1)at ambient temperature.The frequency dependence of theσac of these ceramic electrolytes follows the universal power law variation,σac(ω)=σo+Aωα.The conductivity parameters such as hopping frequencies,charge carrier concentration and mobile ion concentration proved that the increase in conductivity with x was due to the existence of Mg^(2+) interstitial ions.The experiment results also revealed that the dielectric constant and dielectric loss decreased with frequency.The Mg_(0.625)Si_(1.75)Al_(0.25)(PO_(4))_(3) was found to be electrochemically stable up to 2.51 V at ambient temperature.展开更多
Sarcandra glabra(Thunb.)Nakai is a perennial evergreen herb categorised within the Sarcandra Gardner genus under the Chloranthaceae family.Indigenous to tropical and subtropical regions of East Asia and India,this spe...Sarcandra glabra(Thunb.)Nakai is a perennial evergreen herb categorised within the Sarcandra Gardner genus under the Chloranthaceae family.Indigenous to tropical and subtropical regions of East Asia and India,this species is extensively distributed across China,particularly in the southern regions(Sichuan,Yunnan,and Jiangxi).In addition to its high ornamental value,S.glabra has a rich history of use in traditional Chinese medicine,evident through its empirical prescriptions for various ailments like pneumonia,dysentery,fractures,bruises,numbness,amenorrhea,rheumatism,and other diseases.Besides,modern pharmacological studies have revealed various biological activities,such as antitumour,anti-bacterial,anti-viral anti-inflammatory and immunomodulatory effects.The diverse chemical constituents of S.glabra have fascinated natural product researchers since the 1900s.To date,over 400 compounds including terpenoids,coumarins,lignans,flavonoids,sterols,anthraquinones,organic acids,and organic esters have been isolated and characterised,some featuring unprecedented structures.This review comprehensively examines the current understanding of S.glabra’s phytochemistry and pharmacology,with emphasis on the chemistry and biosynthesis of its unique chemotaxonomic marker,the lindenane-type sesquiterpenoids.展开更多
The biomedical applications of iron oxide nanoparticles(IONPs)synthesized using environmentally friendly processes are extremely promising.Using eco-friendly and nontoxic methods is a safer alternative to conventional...The biomedical applications of iron oxide nanoparticles(IONPs)synthesized using environmentally friendly processes are extremely promising.Using eco-friendly and nontoxic methods is a safer alternative to conventional chemical synthesis,which generates toxic byproducts.It allows for greater control over particle size and morphology.The resulting unique magnetic and optical properties of IONPs enable their use in biomedical applications such as magnetic hyperthermia(MH)and magnetic resonance imaging(MRI).This review aimed to summarize recent advances in the synthesis,characterization,and biosafety of IONPs for use in MH and MRI.It also aimed to highlight the significance of eco-friendly synthesis techniques for producing IONPs with the desired magnetic and physicochemical properties.Overall,this review elucidated the most efficient methods for utilizing iron oxide while considering biocompatibility.展开更多
Pure, layered compounds of overlithiated Li1＋xNi0.8Co0.2O2（x = 0.05 and 0.1） were successfully prepared by a modified combustion method. XRD studies showed that cell parameters of the material decreased with increa...Pure, layered compounds of overlithiated Li1＋xNi0.8Co0.2O2（x = 0.05 and 0.1） were successfully prepared by a modified combustion method. XRD studies showed that cell parameters of the material decreased with increasing the lithium content. SEM revealed that the morphology of particles changed from rounded polyhedral-like crystallites to sharp-edged polyhedral crystals with more doped lithium. EDX showed that the stoichiometries of Ni and Co agrees with calculated synthesized values. Electrochemical studies revealed the overlithiated samples have improved capacities as well as cycling behavior. The sample with x = 0.05 shows the best performance with a specific capacity of 113.29 mA.h.g-1 and the best capacity retention of 92.2% over 10 cycles. XPS results showed that the binding energy of Li ls is decreased for the Li doped samples with the smallest value for the x = 0.05 sample, implying that Li＋ ions can be extracted more easily from Li1.05Ni0.8Co0.2O2 than the other stoichiometries accounting for the improved performance of the material. Considerations of core level XPS peaks for transition metals reveal the existence in several oxidation states. However, the percentage of the＋3 oxidation state of transition metals for the when x = 0.1 is the highest and the availability for charge transition from the ＋3 to＋4 state of the transition metal during deintercalation is more readily available.展开更多
基金supported by the by the Fundamental Research Grant Scheme(Grant No.FRGS/1/2023/STG03/UM/02/2)Universiti Malaya RU Fund(Grant No.ST087-2022).
文摘Biotechnology has revolutionized agriculture through innovations such as genetically modified(GM)technology and CRISPR/Cas9 genome editing.In this review,a comparative analysis of these methods that addresses the concerns regarding the oversimplification of the notion that the CRISPR-based editing approach is equivalent to traditional GM approaches is offered.Since the 1990s,despite the potential benefits for crop improvement and food security,controversies have arisen around recombinant technology and the introduction of GM products due to perceived environmental and health concerns.In contrast,the recent emergence of the CRISPR/Cas systemas a precise genome editing tool has garnered relatively less public resistance.In this review,the reasons for these contrasting findings are explored to shed light on the distinct characteristics inherent to each approach.Additionally,we conduct a bibliographic analysis to examine the shift in research priorities between the two technological eras,followed by a comprehensive comparison of the two approaches,to enable a better understanding of the potential synergies that can be achieved between agricultural biotechnology and conventional techniques for enhancing modern agriculture.A nuanced understanding of these technologies is crucial for informed decision-making,responsible implementation,and addressing the concerns surrounding agricultural biotechnology.
基金supported by the PHC-Tassili program No.24MDU114。
文摘The difference in the microstructure,texture in the stir zone(SZ)of the AZ31(Mg-3 Al-1 Zn,wt.%)alloy after friction stir welding(FSW)and subsequent annealing at 400℃for 1 h was characterized by scanning electron microscopy(SEM)with electron backscatter diffraction(EBSD)measurements at the surface and core regions.The findings indicate that FSW produced grain refinement where the mean grain size decreases from 19μm(base metal)to 5.1 and 3.5μm at the surface and core regions,respectively.The c-axis of the grains at the surface region was aligned with the normal direction(<0001>//ND)due to the additional strain of the tool shoulder.In contrast,the core region shows a typical shear texture,where the c-axis tends to be oriented parallel to the welding direction(<0001>//WD).The Vickers microhardness mapping across the SZ revealed that the core region was soften than the surface region due to the dynamic recrystallization and texture weakening.The microstructure of the SZ remains principally deformed after annealing treatment except for the development of massive Mg_(17)Al_(12)precipitates and the abnormal grain growth of a few grains with<11-20>//WD orientation at the upper side of the surface region.The c-axis of the grains at the surface region was tilted about 10°toward WD,while an inclined<0001>//WD orientation about 30°from WD was developed at the core region.Consequently,the distribution of microhardness values across the SZ was more heterogeneous than the FSW sample.The results were discussed in the light of grain boundary misorientation,dislocation density and the pinning effect of Mg_(17)Al_(12)precipitates.Additionally,Schmid factor analysis was used to examine the activation of the basal slip mode to characterize the associated mechanical response.
基金supported by the University Malaya(Grant code:FRGS/1/2022/TK10/UM/02/6)the National Natural Science Foundation of China(Grant No.51275414,No.51605387)Deanship of Scientific Research at King Khalid University for funding this work through the Large Groups Project under grant number RGP.2/303/44。
文摘Nowadays,magnesium alloys are emerging in biomedical implants for their similar properties to natural bones.However,the rapid degradation of magnesium alloys in biological media hinders successful implantation.Refinement of microstructure,as well as reinforcement particles can significantly improve the degradation rate.In this work,multi-pass friction stir processing(FSP)was proposed to synthesize WE43/nano-hydroxyapatite(n HA)surface composite,the microstructure,reinforced particle distribution,micro-hardness,corrosion behavior and in-vitro bioactivity were studied.The subsequent FSP passes of WE43 alloy and WE43/n HA composite refined the grain size which was reduced by 94.29%and 95.92%(2.63 and 1.88μm,respectively)compared to base metal after three passes.This resulted in increasing the microhardness by 120%(90.86 HV0.1)and 135%(105.59 HV0.1)for the WE43 and WE43-n HA,respectively.It is found that increasing FSP passes improved the uniform distribution of n HA particles within the composite matrix which led to improved corrosion resistance and less degradation rate.The corrosion rate of the FSPed WE43/n HA composite after three passes was reduced by 38.2%(4.13 mm/year)and the degradation rate was reduced by 69.7%(2.87 mm/y).This is attributed to secondary phase(Mg24Y5and Mg41Nd5)particle fragmentation and redistribution,as well as a homogeneous distribution of n HA.Additionally,the growing Ca-P and Mg(OH)2layer formed on the surface represented a protective layer that reduced the degradation rate.The wettability test revealed a relatively hydrophilic surface with water contact angle of 49.1±2.2°compared to 71.2±2.1°for base metal.Also,biomineralization test showed that apatite layer grew after immersion 7d in simulated body fluid with atomic ratio of Ca/P 1.60 approaching the stoichiometric ratio(1.67)indicating superior bioactivity of FSPed WE43/n HA composite after three passes.These results raise that the grain refinement by FSP and introduction of n HA particles significantly improved the degradation rate and in-vitro bioactivity of WE43 alloy for biomedical applications.
基金supported by grant “Hibah Tugas Akhir Mahasiswa Doktor(TADOK)Tahun 2018” Directorate of Research and Humanity Engagement Universitas Indonesia(grant number:1234/UN2.R3.1/HKP.05.00/2018)
文摘Objective:To isolate,identify,and evaluate a new angiotensin-converting enzyme inhibitor from Peperomia pellucida(L.)Kunth herbs.Methods:A dried sample of Peperomia pellucida herb was successively macerated with n-hexane and ethyl acetate.The ethyl acetate extract solution was evaporated to obtain the crude extract.Vacuum liquid column chromatography and thin layer chromatography were performed to obtain two pure compounds.Then,both compounds were elucidated and identified using the spectroscopic method.Angiotensin-converting enzyme inhibitory activity studies of both compounds were determined using angiotensin-converting enzyme kit WST-1 with spectrophotometer microplate reader 96-well at 450 nm wavelength.Results:Two bioactive compounds were successfully isolated from Peperomia pellucida herb,including a new compound of 2,3,5-trimethoxy-9-(12,14,15-trimethoxybenzyl)-1 H-indene and pellucidin A.Both compounds demonstrated angiotensin-converting enzyme inhibitory activity,with IC50 values of 72μM(27.95μg/mL)and 11μM(4.4μg/mL),respectively.Conclusions:In the present study,two active angiotensin-converting enzyme inhibitors were successfully isolated and purified from Peperomia pellucida which is used as an antihypertensive in traditional medicine,and support its use as an angiotensin-converting enzyme-inhibiting drug.
基金The authors would like to extend their gratitude toward the University of Malaya and Ministry of Education for funding this work through the Fundamental Research Grant Scheme(project no:FP006-2013B)University of Malaya Research Grant(project no:RP013A-13AFR)Postgraduate Research Grant(project no:PG032-2015A).
文摘Nasicon type,Mg_(0.5+x/2)Si_(2-x)Al_(x)(PO_(4))_(3) was synthesized using citric acid assisted sol-gel method.The X-ray diffraction was applied to investigate the effect of extra Mg^(2+)interstitial ion on the phase,unit cell parameters and structure of the samples.The Mg_(0.625)Si_(1.75)Al_(0.25)(PO_(4))_(3) sample exhibited highest bulk conductivity value of 1.54×10^(−4)S cm^(−1)at ambient temperature.The frequency dependence of theσac of these ceramic electrolytes follows the universal power law variation,σac(ω)=σo+Aωα.The conductivity parameters such as hopping frequencies,charge carrier concentration and mobile ion concentration proved that the increase in conductivity with x was due to the existence of Mg^(2+) interstitial ions.The experiment results also revealed that the dielectric constant and dielectric loss decreased with frequency.The Mg_(0.625)Si_(1.75)Al_(0.25)(PO_(4))_(3) was found to be electrochemically stable up to 2.51 V at ambient temperature.
文摘Sarcandra glabra(Thunb.)Nakai is a perennial evergreen herb categorised within the Sarcandra Gardner genus under the Chloranthaceae family.Indigenous to tropical and subtropical regions of East Asia and India,this species is extensively distributed across China,particularly in the southern regions(Sichuan,Yunnan,and Jiangxi).In addition to its high ornamental value,S.glabra has a rich history of use in traditional Chinese medicine,evident through its empirical prescriptions for various ailments like pneumonia,dysentery,fractures,bruises,numbness,amenorrhea,rheumatism,and other diseases.Besides,modern pharmacological studies have revealed various biological activities,such as antitumour,anti-bacterial,anti-viral anti-inflammatory and immunomodulatory effects.The diverse chemical constituents of S.glabra have fascinated natural product researchers since the 1900s.To date,over 400 compounds including terpenoids,coumarins,lignans,flavonoids,sterols,anthraquinones,organic acids,and organic esters have been isolated and characterised,some featuring unprecedented structures.This review comprehensively examines the current understanding of S.glabra’s phytochemistry and pharmacology,with emphasis on the chemistry and biosynthesis of its unique chemotaxonomic marker,the lindenane-type sesquiterpenoids.
文摘The biomedical applications of iron oxide nanoparticles(IONPs)synthesized using environmentally friendly processes are extremely promising.Using eco-friendly and nontoxic methods is a safer alternative to conventional chemical synthesis,which generates toxic byproducts.It allows for greater control over particle size and morphology.The resulting unique magnetic and optical properties of IONPs enable their use in biomedical applications such as magnetic hyperthermia(MH)and magnetic resonance imaging(MRI).This review aimed to summarize recent advances in the synthesis,characterization,and biosafety of IONPs for use in MH and MRI.It also aimed to highlight the significance of eco-friendly synthesis techniques for producing IONPs with the desired magnetic and physicochemical properties.Overall,this review elucidated the most efficient methods for utilizing iron oxide while considering biocompatibility.
文摘Pure, layered compounds of overlithiated Li1＋xNi0.8Co0.2O2（x = 0.05 and 0.1） were successfully prepared by a modified combustion method. XRD studies showed that cell parameters of the material decreased with increasing the lithium content. SEM revealed that the morphology of particles changed from rounded polyhedral-like crystallites to sharp-edged polyhedral crystals with more doped lithium. EDX showed that the stoichiometries of Ni and Co agrees with calculated synthesized values. Electrochemical studies revealed the overlithiated samples have improved capacities as well as cycling behavior. The sample with x = 0.05 shows the best performance with a specific capacity of 113.29 mA.h.g-1 and the best capacity retention of 92.2% over 10 cycles. XPS results showed that the binding energy of Li ls is decreased for the Li doped samples with the smallest value for the x = 0.05 sample, implying that Li＋ ions can be extracted more easily from Li1.05Ni0.8Co0.2O2 than the other stoichiometries accounting for the improved performance of the material. Considerations of core level XPS peaks for transition metals reveal the existence in several oxidation states. However, the percentage of the＋3 oxidation state of transition metals for the when x = 0.1 is the highest and the availability for charge transition from the ＋3 to＋4 state of the transition metal during deintercalation is more readily available.
