检索结果-南通市图书馆

Deep eutectic solvent-driven self-assembly of metal mercaptide complexes with enzyme-mimicking activities for detection of uric acid through one-step cascade catalytic reaction

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Green Chemical Engineering 2024年第1期5卷 75-84页

作者： jean claude Munyemana Jia Chen Xin Li Yangxia Han Hao Tang Hongdeng Qiu CAS Key Laboratory of Chemistry of Northwestern Plant Resources and Key Laboratory for Natural Medicine of Gansu Province Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou730000China University of Chinese Academy of Sciences Chinese Academy of SciencesBeijing100039China Department of Pharmacy Gansu Provincial HospitalLanzhou730000China

This work presents a generic strategy to create a series of metal mercaptides complexes via coordination selfassembly between transition metals(Mn,Cu,Co,Fe,and Ni)and cysteine(Cys)by forming the sulfur-metal *** strategy involves dissolving metal chlorides and Cys into deep eutectic solvents(DES),followed by the precipitation of metal mercaptides complexes(such as Cys-Mn)by adding water as an antisolvent,where DES serves as the solvent,shape directing,and capping agent,thereby preventing the formation of other metal ***,the prepared complexes possess both laccase and peroxidase-like properties,allowing the design of a technique for the detection of L-3,4-dihydroxyphenylalanine(L-DOPA)and uric acid,*** prepared Cys-Mn can linearly oxidize L-DOPA with its concentrations from 0.1 to 130μM and the detection limit was calculated to be 75.5 n ***,the Cys-Mn can mimic the activity of peroxidase towards oxidization of o-phenylenediamine at neutral p H,allowing single-step and one-pot cascade reactions for visual and fluorometric measurements of uric acid(UA)that could work in the range of 0.2-500μM UA with a detection limit of 0.06μM and 0.054μМ,*** assay was successful in detecting UA in serum and urine samples with relative standard deviation(RSD)ranging from 7.3%to 10.2%and 3.0%-8.5%respectively,suggesting that it may prove useful in medical diagnostic testing.

关键词： Metal-mercaptides Deep eutectic solvents Self-assembly Peroxidase-mimic catalyst Uric acid detection

The Njiki’s Fundamental Theorem-Definition on Fractions in the Mathematical Set ℚ and by Extension in ℝ and ℂ, for the Purpose of Leading to the Construction of Some Algebraic Structures as Its Theoretical Applications and for the Practical Ones

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

American Journal of Computational Mathematics 2024年第3期14卷 358-379页

作者： jean claude Njiki Independent Researcher Yaound Cameroon

The purpose of the research in the NJIKI’s fundamental THEOREM-DEFINITION on fractions in the mathematical set ℚand by extension in ℝand ℂand in order to construct some algebraic structures is about the proved EXISTENCE and the DEFINITION by NJIKI of two INNOVATIVE, IMPORTANT and TEACHAbLE operations of addition or additive operations, in ℚ, marked ⊕and +α,β, and taken as VECTORIAL, TRIANGULAR, of THREE or PROPORTIONAL operations and in order to make THEM not be different from the RATIONAL ONE, +, but to bring much more and new information on fractions, and, by extension in ℝand ℂ. And the very NJIKI’s fundamental THEOREM-DEFINITION having many APPLICATIONS in the everyday life of the HUMAN bEINGS and without talking about computer sciences, henceforth being supplied with very interesting new ALGORITHMS. And as for the work done in the research, it will be waiting for its extension to be done after publication and along with the research results concerned.

关键词： Operations of Addition Additive Operations in ℚ Laws in ℚ THEOREM-DEFINITION External Multiplication

New Insights in the biodegradability and the Ecotoxicological Effects of Solar Products Containing Mineral and Chemical UV-Filters on Marine Zoo- and Phytoplanktons: An in silico and in vitro Study

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Cosmetics, Dermatological Sciences and Applications 2024年第1期14卷 98-111页

作者： jean-claude Hubaud Karim Mekideche jean-Eric branka Luc Lefeuvre HELIOSCIENCE Cité de la cosmétique 2 rue Odette Jasse Marseille France EPHYSCIENCE 498ter route de Saint Joseph de Porterie Nantes France Laboratoires Dermatologiques d’Uriage Neuilly-sur-Seine France

background: Cosmetic formulations, and particularly solar products which contain mineral and chemical UV-filters, are often suspected of causing harmful effects on marine fauna and flora. After the publication of our work in 2019 concerning the ecotoxicological effects of such formulations on corals (Seriatopora hystrix), we here provide some new information about the biodegradability and the ecotoxicological effects of these products on marine zoo- and phytoplankton. Therefore, we choose to realize in silico and in vitro studies of the biodegradability of several solar products but also to evaluate the ecotoxicological effects of these products on one phytoplankton, i.e. Phaeodactylum tricornutum, and one zooplankton, i.e. Acartia tonsa, of a great importance for sea species survival (notably as sources of food). Materials and methods: Two different approaches were used to study the biodegradability of the tested products: One in silico method and an in vitro one. 2 solar products were involved in the in silico study which consisted in the determination of the degradation factor (DF) of each ingredient of the tested formulas in order to finally obtain their estimated biodegradability percentage. Already available data concerning each ingredient coupled to a computer model developed with one of our partners were used to achieve this study. The in vitro study involved 8 formulas containing UV-filters and was led by following the OECD 301 F guidelines. Ecotoxicological studies of 7 of the formulas containing UV-filters were for their part realized by following the ISO 10253 guidelines for the experiments led with Phaeodactylum tricornutum, and the ISO 14669 guidelines for the experiments led with Acartia tonsa. In these studies, the effect of each tested product on crustaceans’ mortality and algal growth inhibition was assessed. Results: The in silico study predicted that formulas containing chemical UV-filters display a high biodegradability (superior to the threshol

关键词： UV-Filters Chemical UV-Filter biodegradability Ecotoxicology in silico in vitro Zooplankton Phytoplankton Phaeodactylum tricornutum Acartia tonsa

Water Quality on the basement Areas in Kouba-Adougoul and Its Surroundings, Guera Province, Chad

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Geoscience and Environment Protection 2024年第9期12卷 388-406页

作者： Tekoum Leontine benadjingar Nguelmbaye jean claude Doumnang Mbaigane Laboratoire de geologie geomorphologie et de teledetection Dpartement de Gologie Facult de Sciences Exactes et Appliques Universit de NDjamna NDjamena Chad Laboratoire hydro-gosciences et reservoirs Dpartement de Gologie Facult de Sciences Exactes et Appliques Universit de NDjamna NDjamena Chad

Water is an essential element for all forms of life. The quantity and quality of water are a problem in places. In Kouba Adougoul and its surroundings in south guera, water-related health problems are reported. That is why this study focuses on the quality of water in the basement areas, of Kouba Adougoul. Our objective is to contribute to a better understanding of water of human consumption in these areas for this, we carried out a physicochemical and bacteriological control on a number water point. Ten water points were collected during May 2022 for analysis. To achieve this objective, we made the in-situ analysis of physical parameters such as pH, electrical conductivity, and temperature. These measurements were made using the multi-parameter kit. The result shows that, the water temperatures vary from 24.4˚C to 27.4˚C proving that the waters are from deep depths. For the use of these waters, it is necessary to take certain precautions. The pH values varied between 6.15 and 7.78, an average of 6.77 giving some waters an aggressive character. It was low mineralized, with electrical conductivity averages ranging from 182.1 to 2100 μS/cm−1 an average of 586.36 μS/cm−1. For the chemical parameters, it is by hydrometric titration that the content of the ions was determined. The determination of the various coliforms in these waters was carried out by its various methods which led to detecting that the waters of Kouba Adougoul are turbid, and present high proportions of nitrates, iron and ammonium. The presence of pathogenic germs, such as total coliforms and thermo-tolerant coliforms in these waters, has been demonstrated. For their consumption, these waters deserve treatment beforehand. In the study area, the anthropogenic activities are considered the most serious sources of groundwater.

关键词： Environmental Pollution Hydrochemistry Aquifers Crystalline basement Kouba-Adougoul (Guera-Chad)

Evaluation of Procedural Pain in Neonates in Cameroon

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Open Journal of Pediatrics 2024年第3期14卷 568-578页

作者： claude-Audrey Meguieze Rose bidias Etouckey georges Eric Nseme Koki Ndombo Paul Olivier Pediatrics Department Faculty of Medicine and Biomedical Sciences University of Yaounde I Yaounde Cameroon Morphologic Sciences Department Faculty of Medicine and Biomedical Sciences University of Yaounde I Yaounde Cameroon

Introduction: Acute pain associated with caregiving is a major cause of pain among neonates. Left untreated, it can lead to long-term neurosensory and psychoaffective consequences. In Cameroon, this subject has been scarcely explored, thus constituting an impediment to the management of care-induced pain. Objective: Assess procedural pain in neonates in Yaoundé. Material and Methods: We conducted a cross sectional study with prospective data collection over a period of eight months (October 2022 to May 2023) in three hospitals. We included neonates who were being cared for and were not crying prior to the onset of healthcare, whose parents consented to the study. Assessments were done using the DAN scale, which is specific to care-induced pain. Data was entered and analyzed using SPSS 23.0 software. Results: A total of 161 newborns were included. The hospital prevalence of care-induced pain in neonates was 85%. Neonatal sepsis was the main cause for admission (96.6%). The most common procedures were venous blood sampling (94.4%) and insertion of peripheral venous lines (93.8%). The pain intensity for these procedures was severe (83.9%). The most painful procedure was lumbar tap, followed by venous access procedures. Conclusion: Neonates in hospitals are subjected to many painful procedures. The pain experienced during these procedures is severe. The most nociceptive procedure is a lumbar puncture.

关键词： Assessment Procedural Pain Neonate Yaoundé Cameroon

Lanthanide mechanoluminescence

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Rare Earths 2018年第1期36卷 1-41页

作者： jean-claude G.bünzli Ka-Leung Wong Institute of Chemical Sciences and Engineering Swiss Federal Institute of Technology Lausanne (EPFL) CH-1015 Lausanne Switzerland Department of Chemistry Hong Kong Baptist University Kowloon Tong Hong Kong China

Mechanoluminescence （ML） is the emission of light consecutive to a mechanical force or stress imposed to a crystalline material. Many inorganic and organic compounds present this phenomenon that is known for over 400 years. Lanthanide and uranyl salts were among the first substances investigated for this property. Mechanoluminescence, also referred to as triboluminescence, is often considered as being a badly understood phenomenon. In fact it is because of two main reasons. Firstly, a variety of different mechanical stresses, from simple rubbing, to applied pressure, crushing, impact of a weight, ultrasound, laser-generated shock wave, crystallization, dissolution of crystals, or even wind can trigger it. Secondly, ML is very sensitive to the purity and morphology of the sample： in inorganic compounds, generation of traps by doping ＂impurities＂（e.g. lanthanide ions） is responsible for light emission so that the exact composition of the sample has to be known to a very detailed level; for chelates, the crystallization conditions are crucial since they often generate extended networks of weak interactions that are instrumental in triggering ML when they are broken. In fact mechanisms of ML are relatively well known and theories and models often reproduce very well the experiments. Additionally, practical applications are at hand, for example stress, crack, and impact sensors based on SrAI204：Eu11 or Et3NH[Eu（dbm）4] are used to test structures and materials as diverse as road bridges, reinforced concrete elements, pressur- ized containers or airplane wings and to image the propagation of cracks or stress distribution. Military and security applications involve detecting the passage of vehicle or soldiers and producing counter- feiting inks while more joyful applications are luminous balls, wrapping papers and adhesive tapes. Not only bulk materials, but micro- and nanoparticles feature mechanoluminescent properties and single particle manipulation under an AFM allows

关键词： MechanoluminescenceRare earthsStress sensorsPressure sensorsImpact sensors

31 Plant Species against blood Feeding and Disease Vectors Insects: beyond Anti-Insect Properties, Unvalued Opportunities and Challenges for Health and Sustainability

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Pharmacology & Pharmacy 2024年第5期15卷 167-206页

作者： Prudence bararunyeretse jean claude Niyokwizera Esperance Gateretse Mathias Hitimana Research Center for Natural and Environmental Sciences (CRSNE) University of Burundi Bujumbura Burundi Institutes of Agronomic Sciences of burundi (ISAbU) Bujumbura Burundi East African Nutritional Sciences Institute (EANSI) University of Burundi Bujumbura Burundi

Plants with bioactive properties are greatly useful in preventing and controlling blood-sucking and disease-vector invertebrates, particularly in developing countries and low-income communities. Their application is a promising alternative to synthetic compounds whose use remains a health, environmental, and economic challenge. However, many are still unknown and unvalued, while others are becoming ignored and threatened. The main objective of this ethnobotanical study is to identify and characterize indigenous and locally grown plants against blood-sucking and disease-vector insects. Salient opportunities and challenges of using these plants are documented and discussed. Semi-structured interviews, using a prepared questionnaire, were conducted with 228 informants. The consensus index (CI) was calculated to analyze the reliability of the collected information. The identified 31 anti-insect plant species belong to 20 botanical families, four morphological categories, and six habitat types. They can be categorized as insecticidal plants (42% of the total), insect repellent (42% of the total), and both insecticidal and insect repellent (16% of the total). More than 54% of these are still abundant in the study area, while about 35.5% have become rare and difficultly accessible. based on the numerical importance of related anti-insect plant species, the seven targeted blood-sucking insects range in the following decreasing order: Jiggers (16 species) > Fire Ants (9 species) > Flies (8 plants) > Mosquitoes (4 species) > Fleas (2 species) > bedbugs (1 species) > lice (0 species). The three most commonly used plants, with the highest confirmation indices, are Tetradenia riparia (ICs = 0.712), Eucalyptus globulus subsp. maidenii (ICs = 0.302), and Solanum aculeastrum (ICs = 0.288). The antimicrobial role of many locally grown anti-insect plants and the multiple other associated valorization possibilities are ignored by most informants. Domesticating, propagating, protecting

关键词： blood-Feeding Insects Anti-Insect Plants biopesticides Sustainability burundi

Actors of Psychoactive Drug Initiation among Adolescents in Yaoundé-Cameroon

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Open Journal of Pediatrics 2024年第2期14卷 246-254页

作者： claude-Audrey Meguieze Atabe Ngwene Neri Ngole georges Eric Nseme Etouckey Paul Olivier Koki Ndombo Department of Pediatrics Faculty of Medicine and Biomedical Sciences University of Yaoundé I Yaoundé Cameroon Department of Morphologic Sciences Faculty of Medicine and Biomedical Sciences University of Yaoundé I Yaoundé Cameroon

Introduction: Actors of psychoactive drug initiation refer to those who introduce others to psychoactive drug use (initiators) and those who are introduced to psychoactive drugs (users). by identifying their features, better prevention and intervention programs can be developed to reduce psychoactive drug use among adolescents. This article describes the role of actors of psychoactive drug initiation among teenagers in secondary schools in Yaoundé (Cameroon). Methodology: A cross sectional study was carried out in twelve secondary schools in Yaoundé from October 2022 to May 2023. Adolescents from Form four to upper sixth, who assented to participate in the study and received parental consent were included. Data were collected in a structured self-reported questionnaire and analyzed using SPSS 23. Quantitative variables were expressed using means, standard deviations, median and interquartile ranges depending on the distribution of data. Qualitative variables were expressed in the form of frequency and percentages. Results: Drug use was more prevalent among male adolescents (55.3%) from nuclear families (91.4%) who received relatively high pocket money. The main sources of drug exposure were non-family members (49.7%), especially friends outside school. The most frequent place of initiation was snack bars (33.1%). Conclusion: The study revealed the importance of the family, friends and leisure places in the initiation process of drug use in teenagers. based on these results, parents and school authorities should work together to create a safe and supportive environment that fosters communication, education to prevent drug abuse among adolescents in Yaoundé.

关键词： Initiators Drug Users Adolescents Cameroon

Lanthanide NIR luminescence for telecommunications, bioanalyses and solar energy conversion

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Rare Earths 2010年第6期28卷 824-842页

作者： jean-claude G. bünzli Svetlana V. Eliseeva cole Polytechnique Fédérale de Lausanne Institute of Chemical Sciences and Engineering WCU Professor Korea University Center for Next Generation Photovoltaic Systems Katholieke Universiteit Leuven Department of Chemistry Laboratory of Coordination Chemistry

Present-day advanced technologies heavily rely on the exciting magnetic and spectroscopic properties of lanthanide ions. In particular, their ability to generate well-characterized and intense near-infrared (NIR) luminescence is exploited in any modern fiber-optic telecommunication network. In this feature article, we first summarize the whereabouts underlying the design of highly luminescent NIR molecular edifices and materials. We then focus on describing the main trends in three applications related to this spectral range: telecommunications, biosciences, and solar energy conversion. In telecommunications, efforts concentrate presently on getting easily processable polymer-based waveguide amplifiers. Upconversion nanophosphors emitting in the visible after NIR excitation are now ubiquitous in many bioanalyses while their application to bio-imaging is still in its early stages; however, highly sensitive NIR-NIR systems start to be at hand for both in vitro and in vivo imaging, as well as dual probes combining magnetic resonance and optical imaging. Finally, both silicon-based and dye-sensitized solar cells benefit from the downconversion and upconversion capabilities of lanthanide ions to harvest UV and NIR solar light and to boost the overall quantum efficiency of these next-generation devices.

关键词： lanthanide luminescence near-infrared luminescence telecommunications bioanalysis solar energy conversion solar cell upconversion downconversion