Thymus serpyllum L.,often known as wild thyme,has been used since ancient times due to its multifaceted culinary and medicinal attributes.It is usually utilized in folk medicine to manage different health issues.This ...Thymus serpyllum L.,often known as wild thyme,has been used since ancient times due to its multifaceted culinary and medicinal attributes.It is usually utilized in folk medicine to manage different health issues.This work aimed to investigate the chemical composition and biological characteristics of T.serpyllum essential oil(EO),including its antimicrobial,antioxidant,and anti-inflammatory capabilities.Moreover,we have prompted an in-silico simulation to reveal the underlying mode of action of these properties.The chemical characterization of T.serpyllum(EO)by Gas Chromatography-Mass Spectrometry(GC-MS)indicated sabinene(17.33%),terpinen-4-ol(11.73%),phellandral(13.18%),and thymol(10.54%)as main components.The antimicrobial screening utilized the disc-diffusion technique,MIC,and MBC assays.The disc-diffusion test’s results revealed significant anti-Candida activity and notable antibacterial efficacy.The MIC and MBC tests showed that T.serpyllum EO effectively stops bacterial growth,including Gram-positive and Gram-negative strains and Candida strains.The tolerance level ratio demonstrated that this EO exhibits bactericidal and fungicidal effects on all tested bacteria and Candida strains.Also,T.serpyllum EO presented effective inhibitory activity against the 5-lipoxygenase(5-LOX)enzyme(IC50=744.19±0.1µg/mL)(p<0.05).It also effectively affected FRAP,β-carotene,DPPH,and ABTS radicals.In light of these findings,T.serpyllum holds promise for diverse applications across pharmaceuticals,nutraceuticals,and the food industry.However,further research and collaboration between traditional knowledge and modern medicine are crucial to fully realizing its potential benefits in these fields.展开更多
The growing global energy demand and worsening climate change highlight the urgent need for clean,efficient and sustainable energy solutions.Among emerging technologies,atomically thin two-dimensional(2D)materials off...The growing global energy demand and worsening climate change highlight the urgent need for clean,efficient and sustainable energy solutions.Among emerging technologies,atomically thin two-dimensional(2D)materials offer unique advantages in photovoltaics due to their tunable optoelectronic properties,high surface area and efficient charge transport capabilities.This review explores recent progress in photovoltaics incorporating 2D materials,focusing on their application as hole and electron transport layers to optimize bandgap alignment,enhance carrier mobility and improve chemical stability.A comprehensive analysis is presented on perovskite solar cells utilizing 2D materials,with a particular focus on strategies to enhance crystallization,passivate defects and improve overall cell efficiency.Additionally,the application of 2D materials in organic solar cells is examined,particularly for reducing recombination losses and enhancing charge extraction through work function modification.Their impact on dye-sensitized solar cells,including catalytic activity and counter electrode performance,is also explored.Finally,the review outlines key challenges,material limitations and performance metrics,offering insight into the future development of nextgeneration photovoltaic devices encouraged by 2D materials.展开更多
The advent of civilization has made humans dependent on plants for food and medicine,leading to the intensification of agricultural production.The intense cultivation of crops has resulted in the depletion of availabl...The advent of civilization has made humans dependent on plants for food and medicine,leading to the intensification of agricultural production.The intense cultivation of crops has resulted in the depletion of available nutrients from soil,thereby demanding the application of excess nutrients to soil to improve yield.Thus,mineral fertilizer discovery and application have,in many ways,contributed greatly to meeting global food demands.However,aside from the positive effects of mineral fertilizers,their excessive application to soil produces large amounts of pollutants that affect environmental sustainability.This necessitates the study of the major mineral fertilizer elements(nitrogen(N),phosphorus(P),and potassium(K)),the forms in which they are applied to soil,and their chemistry/reactions in soil.Here,we reviewed the forms of different N,P,and K mineral fertilizers to provide current knowledge on their constituents,the chemistry of N,P,and K in soil to understand the reactions they undertake in soil,the efficient methods of fertilizer application for environmental sustainability,the effects of mineral fertilizer loss to the environment,and improved fertilization technologies for environmental sustainability.Nanofertilizers are a promising technology for sustainable agricultural production and are discussed in detail in this review.展开更多
The toxicity and kinetic uptake potential of zinc oxide（Zn O） and titanium dioxide（TiO2）nanomaterials into the red bean（Vigna angularis） plant were investigated. The results obtained revealed that Zn O, due to i...The toxicity and kinetic uptake potential of zinc oxide（Zn O） and titanium dioxide（TiO2）nanomaterials into the red bean（Vigna angularis） plant were investigated. The results obtained revealed that Zn O, due to its high dissolution and strong binding capacity, readily accumulated in the root tissues and significantly inhibited the physiological activity of the plant. However, TiO2 had a positive effect on plant physiology, resulting in promoted growth. The results of biochemical experiments implied that Zn O, through the generation of oxidative stress, significantly reduced the chlorophyll content, carotenoids and activity of stress-controlling enzymes. On the contrary, no negative biochemical impact was observed in plants treated with TiO2. For the kinetic uptake and transport study, we designed two exposure systems in which Zn O and TiO2 were exposed to red bean seedlings individually or in a mixture approach. The results showed that in single metal oxide treatments, the uptake and transport increased with increasing exposure period from one week to three weeks.However, in the metal oxide co-exposure treatment, due to complexation and competition among the particles, the uptake and transport were remarkably decreased. This suggested that the kinetic transport pattern of the metal oxide mixtures varied compared to those of its individual constituents.展开更多
Zinc–bromine rechargeable batteries(ZBRBs)are one of the most powerful candidates for next-generation energy storage due to their potentially lower material cost,deep discharge capability,non-flammable electrolytes,r...Zinc–bromine rechargeable batteries(ZBRBs)are one of the most powerful candidates for next-generation energy storage due to their potentially lower material cost,deep discharge capability,non-flammable electrolytes,relatively long lifetime and good reversibility.However,many opportunities remain to improve the efficiency and stability of these batteries for long-life operation.Here,we discuss the device configurations,working mechanisms and performance evaluation of ZBRBs.Both non-flow(static)and flow-type cells are highlighted in detail in this review.The fundamental electrochemical aspects,including the key challenges and promising solutions,are discussed,with particular attention paid to zinc and bromine half-cells,as their performance plays a critical role in determining the electrochemical performance of the battery system.The following sections examine the key performance metrics of ZBRBs and assessment methods using various ex situ and in situ/operando techniques.The review concludes with insights into future developments and prospects for high-performance ZBRBs.展开更多
The Systemic Approach in Teaching and Learning Chemistry(SATLC)was established in 1997[1-3].Our interest in develo—ping the SATL strategy arose from the recognition of the increasing globalization of a wide spectrum ...The Systemic Approach in Teaching and Learning Chemistry(SATLC)was established in 1997[1-3].Our interest in develo—ping the SATL strategy arose from the recognition of the increasing globalization of a wide spectrum of human activities such as economics,media,politics,and entertainment.Systemics is our attempt to provide the student with a global view of his/her studies of chemistry.展开更多
In order to study the Fe-Cu interactions and their effects on 31p NMR, the structures of mononuclear complex Fe（CO）3fPhzPpy）a 1 and binuclear complexes Fe（CO）3（PhEPpy）z（CuXn） （2： Xn = Cl2^2-, 3： Xn = Cl-, ...In order to study the Fe-Cu interactions and their effects on 31p NMR, the structures of mononuclear complex Fe（CO）3fPhzPpy）a 1 and binuclear complexes Fe（CO）3（PhEPpy）z（CuXn） （2： Xn = Cl2^2-, 3： Xn = Cl-, 4： Xn = Br-） are calculated by density functional theory （DFT） PBE0 method. For complexes 1, 3 and 4, the 31p NMR chemical shifts calculated by PBE0-GIAO method are in good agreement with experimental results. The 31p chemical shift is 82.10 ppm in the designed complex 2. The Fe-Cu interactions （including Fe→Cu and Fe←Cu charge transfer） mainly exhibit the indirect interactions. Moreover, the Fe-Cu（I） interactions （mostly acting as σFe-p→4Scu and aFe-C→4Scu charge transfer） in complexes 3 and 4 are stronger than Fe-Cu（Ⅱ） interactions （mostly acting as σFe-p→4Scu and σFe-p←4Sc,） in complex 2. In complex 2, the stronger Fe←Cu interac- tions, acting as σFe-p←44SCu charge transfer, increase the electron density on P nucleus, which causes the upfield 31p chemical shift compared with mononuclear complex 1. For 3 and 4, although a little deshielding for P nucleus is derived from the delocalization of σFe-p→4Scu due to the Fe→Cu interactions, the stronger σFe-c→np charge-transfer finally increases the electron density on P nucleus. As a result, an upfield 31p chemical shift is observed compared with 1. The stability follows the order of 2〉3=4, indicating that Fe（CO）3（PhzPpy）2（CuCl2） is stable and could be synthesized experimentally. The N-Cu（Ⅱ） interaction plays an important role in the stability of 2. Because the delocalization of σFe-p→4SCu and σFe-c→πc-o weakens the a bonds of Fe-C and ~r bonds of CO, it is favorable for increasing the catalytic activity of binuclear complexes. Complexes 3 and 4 are expected to show higher catalytic activity compared to 2.展开更多
The convenient and efficient procedure for one-pot preparation of quinaldine derivatives from multi component reaction of anilines, acetone and benzaldehyde without any solvent under microwave irradiation on the surfa...The convenient and efficient procedure for one-pot preparation of quinaldine derivatives from multi component reaction of anilines, acetone and benzaldehyde without any solvent under microwave irradiation on the surface of alumina impregnated with hydrochloric acid is developed.展开更多
The synthesis, preparation, chemical reactivities and biological activity of simple heterocyclic and heteropolycyclic nitrogen systems as small units as functional pyrazoles, pyridine and pyrimidine, and the related f...The synthesis, preparation, chemical reactivities and biological activity of simple heterocyclic and heteropolycyclic nitrogen systems as small units as functional pyrazoles, pyridine and pyrimidine, and the related fused systems are reviewed. Among the various possible routes to the formation, isomeric structures have been cited because of patented reaching advanced phases of clinical trials, from 2000 to 2020.展开更多
Traditional medicinal practices have a profound influence on the daily lives of people living in developing countries,particularly in Africa,since the populations cannot generally afford the cost of Western medicines....Traditional medicinal practices have a profound influence on the daily lives of people living in developing countries,particularly in Africa,since the populations cannot generally afford the cost of Western medicines.We have undertaken to investigate the correlation between the uses of plants in Traditional African medicine and the biological activities of the derived natural products,with the aim to validate the use of traditional medicine in Northern African communities.The literature is covered for the period 1959-2015 and part III of this review series focuses on plant families with names beginning with letters T to Z.The authors have focused on curating data from journals in natural products and phytomedicine.Within each journal home page,a query search based on country name was conducted.All articles‘‘hits’’were then verified,one at a time,that the species was harvested within the Northern African geographical regions.The current data partly constitutes the bases for the development of the Northern African natural compounds database.The review discusses 284 plant-based natural compounds from 34 species and 11 families.It was observed that the ethnobotanical uses of less than 40%of the plant species surveyed correlated with the bioactivities of compounds identified.展开更多
Sulfonium salts and sulfur ylides are important S(Ⅳ) motifs,and have displayed many unique reactivities to provide simple,effective,and often stereoselective synthesis toward sulfur containing compounds.Impressive de...Sulfonium salts and sulfur ylides are important S(Ⅳ) motifs,and have displayed many unique reactivities to provide simple,effective,and often stereoselective synthesis toward sulfur containing compounds.Impressive developments have been witnessed within this field during the past several years.In light of the increasing demand of organosulfur compounds across the range of chemical sciences,our aim of this review is to provide a concise overview of recent advances of sulfonium salt and sulfur ylide chemistry.Selected examples are organized in three parts on the basis of their role in organic reactions(reactants,intermediates and catalysts).展开更多
In the present paper the isolation and characterization of seven major glycolipid classes (stigmasterol, acylated stigmasteryl glucoside, stigmasteryl glucoside, monogalactosyldiacylglycerol, digalactosyldiacylglycero...In the present paper the isolation and characterization of seven major glycolipid classes (stigmasterol, acylated stigmasteryl glucoside, stigmasteryl glucoside, monogalactosyldiacylglycerol, digalactosyldiacylglycerol, cerebroside and glucocerebroside) from Drymaria cordata (Linn.) Willd (Caryophyllaceae Family) are reported after an attempt has been made to congregate the traditional and pharmacological studies done on this important medicinal plant. Drymaria cordata is a weak spreading herb found widely dispersed in damp places all over the tropics of Africa, Asia and the Americas. There are many reports on its folk and traditional uses that include snake bite, skin diseases, peptic ulcer, headaches or nephritis, female infertility, sleeping disorders, convulsions, and febrile conditions in children. The plant has been examined on the basis of scientific in vitro and in vivo evaluations possessing the major pharmacological activities that include analgesic activity, antitussive activity, anxiolytic activity, antipyretic activity, antinociceptive activity, anti-inflammatory and antibacterial activities. The information summarized here is intended to serve as a reference tool for practitioners in the fields of ethnopharmacology, natural product chemistry and drug discovery related research.展开更多
A green and simplified room-temperature procedure was reported for the synthesis of carbon-carbon double bonds by Knoevenagel condensation of various aldehydes with malononitrile and ethyl cyanoacetate in the presence...A green and simplified room-temperature procedure was reported for the synthesis of carbon-carbon double bonds by Knoevenagel condensation of various aldehydes with malononitrile and ethyl cyanoacetate in the presence of catalytic amount of ZrOCl2·8H2O in aqueous media.展开更多
During the ongoing 2020 CoVid-19 crisis,the use of remote meeting technologies such as Zoom™,Microsoft Teams™and Google Meetings™has been paramount to theoretical teaching in a safe socially distanced environment.Howe...During the ongoing 2020 CoVid-19 crisis,the use of remote meeting technologies such as Zoom™,Microsoft Teams™and Google Meetings™has been paramount to theoretical teaching in a safe socially distanced environment.However,several problems arise when there is a need for an experimental approach.This paper looks at one of the possible solutions,including how to best separate the students,how to minimize close interactions and how a mixed environment of remote/presential teaching is required,minimizing the amount of extra materials,resources and protection equipment required,such that developing countries can quickly adopt this method,without the purchase of any external equipment.展开更多
Clausena anisata(Willd.)Hook.f.ex Benth.is a plant extensively used in traditional medicine.Here,a synopsis of the research on various aspects of Clausena anisata(Willd.)Hook.f.ex Benth.is presented.An electronic lite...Clausena anisata(Willd.)Hook.f.ex Benth.is a plant extensively used in traditional medicine.Here,a synopsis of the research on various aspects of Clausena anisata(Willd.)Hook.f.ex Benth.is presented.An electronic literature review revealed that formulations containing Clausena anisata(Willd.)Hook.f.ex Benth.are used to manage and treat diabetes,eye problems,malaria,snake envenomation,malignancies,as well as venereal,gastrointestinal,reproductive,respiratory,dermatological,and odonatological ailments.To date,90 compounds have been isolated and characterized from extracts of Clausena anisata(Willd.)Hook.f.ex Benth.Crude extracts and isolated compounds from Clausena anisata(Willd.)Hook.f.ex Benth.possess anti-inflammatory,antimicrobial,antioxidant,antiplasmodial,antiproliferative,anti-human immunodeficiency virus-1,antimycobacterial,antihypertensive,and antidiabetic activities.These bioactivities can be attributed to alkaloids,coumarins,limonoids,and phenylpropanoids present in different parts of the plant.Although some studies have indicated moderate toxicity of the extracts,some of the dominant compounds in this species,such as estragole and carbazole alkaloids,are mutagenic or cytotoxic.A clinical trial utilizing a Ghanaian herbal formulation containing Clausena anisata(Willd.)Hook.f.ex Benth.was found to be effective in reducing pain associated with osteoarthritis.Research progress to date supports the traditional use of this species in herbal medicine.However,these studies do not explain the relationships between traditional uses,pharmacological activities,and mechanisms of action.Thus,further studies should be designed to understand the biochemical properties and physiological effects of Clausena anisata(Willd.)Hook.f.ex Benth.extracts,facilitating the development and utilization of this medicinal resource.展开更多
Activated carbons were produced from palm nut hull,which is a waste material of palm oil extraction industries.Activated carbons having various pore size distributions and surface composition were obtained by conventi...Activated carbons were produced from palm nut hull,which is a waste material of palm oil extraction industries.Activated carbons having various pore size distributions and surface composition were obtained by conventional carbonization method via the sulphuric acid solution pre-treatment method.The surface areas,mesopore volume and-OH groups of activated carbons increase with the increases of sulphuric acid solution concentration.The activated carbons obtained were tested for the adsorption of pigments and free fatty acids from palm oil and shea butter.It comes out from this study that the amount of adsorbate(i.e.pigments and free fatty acids)fixed increases with the increase of the adsorption temperature and with the increases of mesopore volume.Intraparticle diffusion,pseudo-first-order and pseudo-second-order kinetics models were used to analyze the kinetics data obtained at different temperatures(temperature range 60℃ to 90℃).Among the kinetics models used,the pseudo-second order was the best applicable model to describe the adsorption of oil pigments and free fatty acid onto activated carbons.The activation energies obtained by applying the Arrhenius equation for the adsorption of pigments were low(i.e.less than 40 kJ·mol^-1 for the both vegetables oils),indicating that the adsorption could be assigned to physisorption.展开更多
The purpose of this research was conducted to determine the physical factors,namely water temperature,total dissolved solids,total suspended solids,electrical conductivity and chemical water including pH,phosphate,BOD...The purpose of this research was conducted to determine the physical factors,namely water temperature,total dissolved solids,total suspended solids,electrical conductivity and chemical water including pH,phosphate,BOD(biochemical oxygen demand),COD(chemical oxygen demand),DO(dissolved oxygen).The factors of physics and chemistry can affect the rate of eutrophication.The data obtained through laboratory analysis of physical and chemical parameters of water samples.Water samples were taken from 8 observation stations.Highly variable results were obtained in each observation station.Data physical parameters were tested with statistical multiple linear regression to determine the effect on water quality,the results show that the physical properties do not affect the rate of eutrophication in Lake Tondano.That is,the amount of total dissolved solids content and total suspended solids,will not affect the rate of eutrophication in Lake Tondano.The results of multiple linear regression satistik test against chemical parameter data that is phosphate,BOD,COD and DO showed as a significant effect on the rate of eutrophication in lakes.The higher phosphate levels will be higher as the increase of the rate of eutrophication in Lake Tondano.展开更多
When Periodic Chart of elements is consulted to find natural radioisotopes, one firstly finds tritium, followed by 10Be, 14C, 50V and many others. Before Bi, 12 cosmogenic radioisotopes are listed. They are those cont...When Periodic Chart of elements is consulted to find natural radioisotopes, one firstly finds tritium, followed by 10Be, 14C, 50V and many others. Before Bi, 12 cosmogenic radioisotopes are listed. They are those continuously produced by nuclear reactions among light elements present in earthly atmosphere and radiations coming from the outside space. Eighteen additional primordial radioisotopes are listed. They were created at the same time that the non-radioactive isotopes composing the 92 natural elements in the periodic table. From Bi on, every isotope is radioactive, up to U. Then follow the artificial elements produced by laboratory nuclear reactions from Np to element with atomic number 118. In this way, from 118 known elements, 64 are radioactive, which amount 55% of all those units forming the chemical compounds. Therefore, the complete understanding of radioactivity should be a suitable tool to advance our knowledge of Universe, and consequent applications to get better living conditions. So, this paper deals with radioisotopes as suitable instruments for chemical analysis.展开更多
Groundwater and surface water contamination by PTE(Potentially Toxic Elements)was assessed in Ruashi and Annexe municipalities of Lubumbashi city.Analyses of seventy water samples collected from six drilled wells,eigh...Groundwater and surface water contamination by PTE(Potentially Toxic Elements)was assessed in Ruashi and Annexe municipalities of Lubumbashi city.Analyses of seventy water samples collected from six drilled wells,eight spade-sunk wells,one river and one spring in both municipalities in 2017 and 2018 were carried out by ICP-SF-MS(Inductively Coupled Plasma-Sector Field Mass Spectrometry).Twenty PTEs including aluminum,arsenic,barium,bismuth,cadmium,cesium,chromium,cobalt,copper,iron,lead,manganese,molybdenum,nickel,strontium,thallium,tungsten,uranium,vanadium and zinc were detected at various concentrations in each one of the samples.Many samples had concentrations and mean concentrations of PTEs,such as aluminum,cadmium,copper,iron,lead,manganese,nickel and zinc,higher than the respective acceptable limits set for drinking water by the EU(European Union),the USEPA(United States Environmental Protection Agency),and the WHO(World Health Organization)standards.Most PTEs being deleterious to human health even at very low concentrations,people who use the groundwater and surface water to meet their water needs in both Ruashi and Annexe municipalities are at risk.展开更多
文摘Thymus serpyllum L.,often known as wild thyme,has been used since ancient times due to its multifaceted culinary and medicinal attributes.It is usually utilized in folk medicine to manage different health issues.This work aimed to investigate the chemical composition and biological characteristics of T.serpyllum essential oil(EO),including its antimicrobial,antioxidant,and anti-inflammatory capabilities.Moreover,we have prompted an in-silico simulation to reveal the underlying mode of action of these properties.The chemical characterization of T.serpyllum(EO)by Gas Chromatography-Mass Spectrometry(GC-MS)indicated sabinene(17.33%),terpinen-4-ol(11.73%),phellandral(13.18%),and thymol(10.54%)as main components.The antimicrobial screening utilized the disc-diffusion technique,MIC,and MBC assays.The disc-diffusion test’s results revealed significant anti-Candida activity and notable antibacterial efficacy.The MIC and MBC tests showed that T.serpyllum EO effectively stops bacterial growth,including Gram-positive and Gram-negative strains and Candida strains.The tolerance level ratio demonstrated that this EO exhibits bactericidal and fungicidal effects on all tested bacteria and Candida strains.Also,T.serpyllum EO presented effective inhibitory activity against the 5-lipoxygenase(5-LOX)enzyme(IC50=744.19±0.1µg/mL)(p<0.05).It also effectively affected FRAP,β-carotene,DPPH,and ABTS radicals.In light of these findings,T.serpyllum holds promise for diverse applications across pharmaceuticals,nutraceuticals,and the food industry.However,further research and collaboration between traditional knowledge and modern medicine are crucial to fully realizing its potential benefits in these fields.
基金supported by the IITP(Institute of Information & Communications Technology Planning & Evaluation)-ITRC(Information Technology Research Center) grant funded by the Korea government(Ministry of Science and ICT) (IITP-2025-RS-2024-00437191, and RS-2025-02303505)partly supported by the Korea Basic Science Institute (National Research Facilities and Equipment Center) grant funded by the Ministry of Education. (No. 2022R1A6C101A774)the Deanship of Research and Graduate Studies at King Khalid University, Saudi Arabia, through Large Research Project under grant number RGP-2/527/46
文摘The growing global energy demand and worsening climate change highlight the urgent need for clean,efficient and sustainable energy solutions.Among emerging technologies,atomically thin two-dimensional(2D)materials offer unique advantages in photovoltaics due to their tunable optoelectronic properties,high surface area and efficient charge transport capabilities.This review explores recent progress in photovoltaics incorporating 2D materials,focusing on their application as hole and electron transport layers to optimize bandgap alignment,enhance carrier mobility and improve chemical stability.A comprehensive analysis is presented on perovskite solar cells utilizing 2D materials,with a particular focus on strategies to enhance crystallization,passivate defects and improve overall cell efficiency.Additionally,the application of 2D materials in organic solar cells is examined,particularly for reducing recombination losses and enhancing charge extraction through work function modification.Their impact on dye-sensitized solar cells,including catalytic activity and counter electrode performance,is also explored.Finally,the review outlines key challenges,material limitations and performance metrics,offering insight into the future development of nextgeneration photovoltaic devices encouraged by 2D materials.
文摘The advent of civilization has made humans dependent on plants for food and medicine,leading to the intensification of agricultural production.The intense cultivation of crops has resulted in the depletion of available nutrients from soil,thereby demanding the application of excess nutrients to soil to improve yield.Thus,mineral fertilizer discovery and application have,in many ways,contributed greatly to meeting global food demands.However,aside from the positive effects of mineral fertilizers,their excessive application to soil produces large amounts of pollutants that affect environmental sustainability.This necessitates the study of the major mineral fertilizer elements(nitrogen(N),phosphorus(P),and potassium(K)),the forms in which they are applied to soil,and their chemistry/reactions in soil.Here,we reviewed the forms of different N,P,and K mineral fertilizers to provide current knowledge on their constituents,the chemistry of N,P,and K in soil to understand the reactions they undertake in soil,the efficient methods of fertilizer application for environmental sustainability,the effects of mineral fertilizer loss to the environment,and improved fertilization technologies for environmental sustainability.Nanofertilizers are a promising technology for sustainable agricultural production and are discussed in detail in this review.
基金supported by the research grant from the University of Malaya,HIR grant-UM C/625/1/HIR/MOHE/SC/04
文摘The toxicity and kinetic uptake potential of zinc oxide（Zn O） and titanium dioxide（TiO2）nanomaterials into the red bean（Vigna angularis） plant were investigated. The results obtained revealed that Zn O, due to its high dissolution and strong binding capacity, readily accumulated in the root tissues and significantly inhibited the physiological activity of the plant. However, TiO2 had a positive effect on plant physiology, resulting in promoted growth. The results of biochemical experiments implied that Zn O, through the generation of oxidative stress, significantly reduced the chlorophyll content, carotenoids and activity of stress-controlling enzymes. On the contrary, no negative biochemical impact was observed in plants treated with TiO2. For the kinetic uptake and transport study, we designed two exposure systems in which Zn O and TiO2 were exposed to red bean seedlings individually or in a mixture approach. The results showed that in single metal oxide treatments, the uptake and transport increased with increasing exposure period from one week to three weeks.However, in the metal oxide co-exposure treatment, due to complexation and competition among the particles, the uptake and transport were remarkably decreased. This suggested that the kinetic transport pattern of the metal oxide mixtures varied compared to those of its individual constituents.
基金flnancial support from Australian Research Council through its Discovery,Future Fellowship ProgramsImam Mohammad Ibn Saud Islamic University (IMSIU) in Riyadh,Saudi Arabia,for flnancial support of this work.
文摘Zinc–bromine rechargeable batteries(ZBRBs)are one of the most powerful candidates for next-generation energy storage due to their potentially lower material cost,deep discharge capability,non-flammable electrolytes,relatively long lifetime and good reversibility.However,many opportunities remain to improve the efficiency and stability of these batteries for long-life operation.Here,we discuss the device configurations,working mechanisms and performance evaluation of ZBRBs.Both non-flow(static)and flow-type cells are highlighted in detail in this review.The fundamental electrochemical aspects,including the key challenges and promising solutions,are discussed,with particular attention paid to zinc and bromine half-cells,as their performance plays a critical role in determining the electrochemical performance of the battery system.The following sections examine the key performance metrics of ZBRBs and assessment methods using various ex situ and in situ/operando techniques.The review concludes with insights into future developments and prospects for high-performance ZBRBs.
文摘The Systemic Approach in Teaching and Learning Chemistry(SATLC)was established in 1997[1-3].Our interest in develo—ping the SATL strategy arose from the recognition of the increasing globalization of a wide spectrum of human activities such as economics,media,politics,and entertainment.Systemics is our attempt to provide the student with a global view of his/her studies of chemistry.
基金Supported by the Natural Science Foundation of Guangdong Province (No. 5005938)
文摘In order to study the Fe-Cu interactions and their effects on 31p NMR, the structures of mononuclear complex Fe（CO）3fPhzPpy）a 1 and binuclear complexes Fe（CO）3（PhEPpy）z（CuXn） （2： Xn = Cl2^2-, 3： Xn = Cl-, 4： Xn = Br-） are calculated by density functional theory （DFT） PBE0 method. For complexes 1, 3 and 4, the 31p NMR chemical shifts calculated by PBE0-GIAO method are in good agreement with experimental results. The 31p chemical shift is 82.10 ppm in the designed complex 2. The Fe-Cu interactions （including Fe→Cu and Fe←Cu charge transfer） mainly exhibit the indirect interactions. Moreover, the Fe-Cu（I） interactions （mostly acting as σFe-p→4Scu and aFe-C→4Scu charge transfer） in complexes 3 and 4 are stronger than Fe-Cu（Ⅱ） interactions （mostly acting as σFe-p→4Scu and σFe-p←4Sc,） in complex 2. In complex 2, the stronger Fe←Cu interac- tions, acting as σFe-p←44SCu charge transfer, increase the electron density on P nucleus, which causes the upfield 31p chemical shift compared with mononuclear complex 1. For 3 and 4, although a little deshielding for P nucleus is derived from the delocalization of σFe-p→4Scu due to the Fe→Cu interactions, the stronger σFe-c→np charge-transfer finally increases the electron density on P nucleus. As a result, an upfield 31p chemical shift is observed compared with 1. The stability follows the order of 2〉3=4, indicating that Fe（CO）3（PhzPpy）2（CuCl2） is stable and could be synthesized experimentally. The N-Cu（Ⅱ） interaction plays an important role in the stability of 2. Because the delocalization of σFe-p→4SCu and σFe-c→πc-o weakens the a bonds of Fe-C and ~r bonds of CO, it is favorable for increasing the catalytic activity of binuclear complexes. Complexes 3 and 4 are expected to show higher catalytic activity compared to 2.
文摘The convenient and efficient procedure for one-pot preparation of quinaldine derivatives from multi component reaction of anilines, acetone and benzaldehyde without any solvent under microwave irradiation on the surface of alumina impregnated with hydrochloric acid is developed.
文摘The synthesis, preparation, chemical reactivities and biological activity of simple heterocyclic and heteropolycyclic nitrogen systems as small units as functional pyrazoles, pyridine and pyrimidine, and the related fused systems are reviewed. Among the various possible routes to the formation, isomeric structures have been cited because of patented reaching advanced phases of clinical trials, from 2000 to 2020.
基金Financial support is acknowledged from Lhasa Ltd,Leeds,UK through the Chemical and Bioactivity Information Centre(CBIC),University of Buea,CameroonFNK acknowledges a Georg Forster fellowship for postdoctoral researchers from the Alexander von Humboldt Foundation,Germany.
文摘Traditional medicinal practices have a profound influence on the daily lives of people living in developing countries,particularly in Africa,since the populations cannot generally afford the cost of Western medicines.We have undertaken to investigate the correlation between the uses of plants in Traditional African medicine and the biological activities of the derived natural products,with the aim to validate the use of traditional medicine in Northern African communities.The literature is covered for the period 1959-2015 and part III of this review series focuses on plant families with names beginning with letters T to Z.The authors have focused on curating data from journals in natural products and phytomedicine.Within each journal home page,a query search based on country name was conducted.All articles‘‘hits’’were then verified,one at a time,that the species was harvested within the Northern African geographical regions.The current data partly constitutes the bases for the development of the Northern African natural compounds database.The review discusses 284 plant-based natural compounds from 34 species and 11 families.It was observed that the ethnobotanical uses of less than 40%of the plant species surveyed correlated with the bioactivities of compounds identified.
基金the support from the National Natural Science Foundation of China(No.21702013)the Fundamental Research Funds for the Central Universities(Nos.XK1802-6 and buctrc201721)at the BUCT.JTan and Y.Liu are thankful for the support from the Open Project Program(No.SPFW2019YB06)of Beijing Key Laboratory of Flavor Chemistry,Beijing Technology and Business University(BTBU)。
文摘Sulfonium salts and sulfur ylides are important S(Ⅳ) motifs,and have displayed many unique reactivities to provide simple,effective,and often stereoselective synthesis toward sulfur containing compounds.Impressive developments have been witnessed within this field during the past several years.In light of the increasing demand of organosulfur compounds across the range of chemical sciences,our aim of this review is to provide a concise overview of recent advances of sulfonium salt and sulfur ylide chemistry.Selected examples are organized in three parts on the basis of their role in organic reactions(reactants,intermediates and catalysts).
文摘In the present paper the isolation and characterization of seven major glycolipid classes (stigmasterol, acylated stigmasteryl glucoside, stigmasteryl glucoside, monogalactosyldiacylglycerol, digalactosyldiacylglycerol, cerebroside and glucocerebroside) from Drymaria cordata (Linn.) Willd (Caryophyllaceae Family) are reported after an attempt has been made to congregate the traditional and pharmacological studies done on this important medicinal plant. Drymaria cordata is a weak spreading herb found widely dispersed in damp places all over the tropics of Africa, Asia and the Americas. There are many reports on its folk and traditional uses that include snake bite, skin diseases, peptic ulcer, headaches or nephritis, female infertility, sleeping disorders, convulsions, and febrile conditions in children. The plant has been examined on the basis of scientific in vitro and in vivo evaluations possessing the major pharmacological activities that include analgesic activity, antitussive activity, anxiolytic activity, antipyretic activity, antinociceptive activity, anti-inflammatory and antibacterial activities. The information summarized here is intended to serve as a reference tool for practitioners in the fields of ethnopharmacology, natural product chemistry and drug discovery related research.
文摘A green and simplified room-temperature procedure was reported for the synthesis of carbon-carbon double bonds by Knoevenagel condensation of various aldehydes with malononitrile and ethyl cyanoacetate in the presence of catalytic amount of ZrOCl2·8H2O in aqueous media.
文摘During the ongoing 2020 CoVid-19 crisis,the use of remote meeting technologies such as Zoom™,Microsoft Teams™and Google Meetings™has been paramount to theoretical teaching in a safe socially distanced environment.However,several problems arise when there is a need for an experimental approach.This paper looks at one of the possible solutions,including how to best separate the students,how to minimize close interactions and how a mixed environment of remote/presential teaching is required,minimizing the amount of extra materials,resources and protection equipment required,such that developing countries can quickly adopt this method,without the purchase of any external equipment.
文摘Clausena anisata(Willd.)Hook.f.ex Benth.is a plant extensively used in traditional medicine.Here,a synopsis of the research on various aspects of Clausena anisata(Willd.)Hook.f.ex Benth.is presented.An electronic literature review revealed that formulations containing Clausena anisata(Willd.)Hook.f.ex Benth.are used to manage and treat diabetes,eye problems,malaria,snake envenomation,malignancies,as well as venereal,gastrointestinal,reproductive,respiratory,dermatological,and odonatological ailments.To date,90 compounds have been isolated and characterized from extracts of Clausena anisata(Willd.)Hook.f.ex Benth.Crude extracts and isolated compounds from Clausena anisata(Willd.)Hook.f.ex Benth.possess anti-inflammatory,antimicrobial,antioxidant,antiplasmodial,antiproliferative,anti-human immunodeficiency virus-1,antimycobacterial,antihypertensive,and antidiabetic activities.These bioactivities can be attributed to alkaloids,coumarins,limonoids,and phenylpropanoids present in different parts of the plant.Although some studies have indicated moderate toxicity of the extracts,some of the dominant compounds in this species,such as estragole and carbazole alkaloids,are mutagenic or cytotoxic.A clinical trial utilizing a Ghanaian herbal formulation containing Clausena anisata(Willd.)Hook.f.ex Benth.was found to be effective in reducing pain associated with osteoarthritis.Research progress to date supports the traditional use of this species in herbal medicine.However,these studies do not explain the relationships between traditional uses,pharmacological activities,and mechanisms of action.Thus,further studies should be designed to understand the biochemical properties and physiological effects of Clausena anisata(Willd.)Hook.f.ex Benth.extracts,facilitating the development and utilization of this medicinal resource.
文摘Activated carbons were produced from palm nut hull,which is a waste material of palm oil extraction industries.Activated carbons having various pore size distributions and surface composition were obtained by conventional carbonization method via the sulphuric acid solution pre-treatment method.The surface areas,mesopore volume and-OH groups of activated carbons increase with the increases of sulphuric acid solution concentration.The activated carbons obtained were tested for the adsorption of pigments and free fatty acids from palm oil and shea butter.It comes out from this study that the amount of adsorbate(i.e.pigments and free fatty acids)fixed increases with the increase of the adsorption temperature and with the increases of mesopore volume.Intraparticle diffusion,pseudo-first-order and pseudo-second-order kinetics models were used to analyze the kinetics data obtained at different temperatures(temperature range 60℃ to 90℃).Among the kinetics models used,the pseudo-second order was the best applicable model to describe the adsorption of oil pigments and free fatty acid onto activated carbons.The activation energies obtained by applying the Arrhenius equation for the adsorption of pigments were low(i.e.less than 40 kJ·mol^-1 for the both vegetables oils),indicating that the adsorption could be assigned to physisorption.
文摘The purpose of this research was conducted to determine the physical factors,namely water temperature,total dissolved solids,total suspended solids,electrical conductivity and chemical water including pH,phosphate,BOD(biochemical oxygen demand),COD(chemical oxygen demand),DO(dissolved oxygen).The factors of physics and chemistry can affect the rate of eutrophication.The data obtained through laboratory analysis of physical and chemical parameters of water samples.Water samples were taken from 8 observation stations.Highly variable results were obtained in each observation station.Data physical parameters were tested with statistical multiple linear regression to determine the effect on water quality,the results show that the physical properties do not affect the rate of eutrophication in Lake Tondano.That is,the amount of total dissolved solids content and total suspended solids,will not affect the rate of eutrophication in Lake Tondano.The results of multiple linear regression satistik test against chemical parameter data that is phosphate,BOD,COD and DO showed as a significant effect on the rate of eutrophication in lakes.The higher phosphate levels will be higher as the increase of the rate of eutrophication in Lake Tondano.
文摘When Periodic Chart of elements is consulted to find natural radioisotopes, one firstly finds tritium, followed by 10Be, 14C, 50V and many others. Before Bi, 12 cosmogenic radioisotopes are listed. They are those continuously produced by nuclear reactions among light elements present in earthly atmosphere and radiations coming from the outside space. Eighteen additional primordial radioisotopes are listed. They were created at the same time that the non-radioactive isotopes composing the 92 natural elements in the periodic table. From Bi on, every isotope is radioactive, up to U. Then follow the artificial elements produced by laboratory nuclear reactions from Np to element with atomic number 118. In this way, from 118 known elements, 64 are radioactive, which amount 55% of all those units forming the chemical compounds. Therefore, the complete understanding of radioactivity should be a suitable tool to advance our knowledge of Universe, and consequent applications to get better living conditions. So, this paper deals with radioisotopes as suitable instruments for chemical analysis.
基金funding received from UNESCO-SIDA Project as well as Professor Martine Leermakers and Professor Willy Baeyens for their financial help to analyze the water samples in their laboratory at VUB.Acknowledgements
文摘Groundwater and surface water contamination by PTE(Potentially Toxic Elements)was assessed in Ruashi and Annexe municipalities of Lubumbashi city.Analyses of seventy water samples collected from six drilled wells,eight spade-sunk wells,one river and one spring in both municipalities in 2017 and 2018 were carried out by ICP-SF-MS(Inductively Coupled Plasma-Sector Field Mass Spectrometry).Twenty PTEs including aluminum,arsenic,barium,bismuth,cadmium,cesium,chromium,cobalt,copper,iron,lead,manganese,molybdenum,nickel,strontium,thallium,tungsten,uranium,vanadium and zinc were detected at various concentrations in each one of the samples.Many samples had concentrations and mean concentrations of PTEs,such as aluminum,cadmium,copper,iron,lead,manganese,nickel and zinc,higher than the respective acceptable limits set for drinking water by the EU(European Union),the USEPA(United States Environmental Protection Agency),and the WHO(World Health Organization)standards.Most PTEs being deleterious to human health even at very low concentrations,people who use the groundwater and surface water to meet their water needs in both Ruashi and Annexe municipalities are at risk.
