Lanthanide(III) complexes with tridentate Schiff base ligand, antioxidant activity and x-ray crystal structures of the Nd(III) and Sm(III) complexes

The tridentate N4-type Schiff base was synthesized from the condensation reaction of 2-hydrazinopyridine and pyridine-2-carbaldehyde. Neodymium and Samarium complexes were isolated when the corresponding nitrate salt was added to the solution of the ligand. The isolated compounds were characterized by elemental analyses, IR study, room temperature magnetic measurements and single X-ray crystal diffraction of the two crystals. Both complexes crystallize in the monoclinic system with space group P21/c. The cell parameters of the Nd complex are a=11.0927(8) Å, b=17.9926 (13) Å, c=11.9395(9)Å and β = 115.274(5) ° while the Sm complex shows parameters cell of a = 11.0477(8) Å, b = 17.9254(13) Å, c = 11.9149(8) Å and β =115.489(5) °. The X-ray study reveals isotopic Nd/Sm binuclear structures were each metal ion is nine-coordinated in the same fashion. Both metal centers have distorted tricapped trigonal prism geometry, with the Schiff base acting as tridentate ligand. The DPPH· radical scavenging effects of the Schiff base ligand and its Ln(III) complexes were screened. The Ln(III) complexes were significantly more efficient in quenching DPPH· than the free Schiff base ligand.Keywords: Lanthanide complexes, hydrazino, antioxidant activity, X-ray structur

Synthesis, physical studies and crystal structure determination of Y(III) and Er(III) complexes of 1-(pyridin-2-yl)-2-(pyridine-2-ylmethylene)hydrazine

Two isotype mononuclear yttrium(III) and erbium(III) complexes, {[Y(HL)(OAc)2(H2O)2]. (H2O)∙(NO3)} (1) and {[Er(HL) (OAc)2(H2O)2].(H2O)∙(NO3)} (2), where HL is the neutral Schiff base ligand 1-(pyridin-2-yl)-2-(pyridine-2-ylmethylene)hydrazine, and OAc is the acetate anion, have been synthesized and characterized by physicochemical methods and single crystal X-ray determination. Both complexes crystallizes in the triclinic space group Pī with unit cell dimensions for complex of Y(III) a = 7.909 (2) Å, b = 11.718 (4) Å, c = 12.497 (3) Å,    α = 78.907 (3)°, b = 73.840 (3)°, γ = 72.074 (3)°, V = 1051.26 (6) Å3, Z = 2, R1 = 0.051 and    wR2 = 0.112 and for complex of Er(III)a = 7.913 (1) Å, b = 11.719 (2) Å, c = 12.487 (2) Å,          α = 78.832 (1)°, α = 73.674 (1)°, γ = 72.012 (1)°, V = 1049.64 (3) Å3, Z = 2, R1 = 0.028, and   wR2 = 0.062. In both complexes, the coordination polyhedra around Ln(III) atoms are best described as a distorted tricapped trigonal prism. Antioxidant activities of the ligand and its Y(III) and Er(III) complexes are studied

L'agriculture de décrue au gré de la variabilité des politiques publiques sénégalaises

Introduction Sur les rives de la moyenne vallée du fleuve Sénégal, la culture du sorgho de décrue a assuré la base de la subsistance des populations pendant quelques millénaires (fig. 1). Or, dès l’indépendance, le gouvernement sénégalais a opté pour une politique de modernisation de l’agriculture qui prévoyait le remplacement de cette agriculture de décrue par une riziculture irriguée intensive. Après la construction de deux grands barrages régulateurs, à Manantali en amont et à Diama en ava..

Yàlla-Yàlla ou la Mouridiyya « minoritaire » en France

La Mouridiyya est marquée par l’apparition de plusieurs groupes qui attirent des milliers d’adeptes. L’un, d’entre eux, est le mouvement spirituel Yàlla-Yàlla dont la spécificité réside dans sa prise d’autonomie par rapport au corps doctrinal mouride. Un courant de la Mouridiyya, issu de la clientèle « khalifale » au nom d’une prétention monopolistique, met en cause sa légitimité au sein de la confrérie. Leur réplique prend la forme d’une résistance passive à la prééminence de l’establishment. Cette concurrence souterraine s’est transnationalisée par l’entremise d’internet en France notamment où le Daara Univers Ndiamé symbolise l’affirmation des disciples de Cheikh Moussa Cissé.The Muridiyya is marked by the appearance of several groups that attract thousands of followers. One of them is the Yalla-Yalla spiritual movement, whose specificity lies in its autonomy from the Murid doctrinal body. A movement of the Muridiyya, from the "khalifale"'s clientele in the name of a monopolistic claim, calls into question its legitimacy within the brotherhood. Their reply takes the form of a passive resistance to the mightiness of the establishment. This underground competition has been transnationalized in France via the internet, particularly, where Daara Univers Ndiame symbolizes the affirmation of Sheikh Moussa Cisse's disciples

Commencements (suite) et minorités religieuses

Le présent numéro des Cahiers d’Études du Religieux-Recherches Interdisciplinaires continue à interroger les commencements avec l’étude de Kabira Masotta concernant l’influence des traditions inspirées du judaïsme sur les premiers Musulmans. Les deux autres articles évoquent les difficultés d’une communauté religieuse minoritaire aujourd’hui, que ce soit les protestants en Kabylie ou les Yàlla-Yàlla en France

Sub-Saharans in China versus Chinese in Africa: vectors of cultural and economic relations of a new kind? A case-study of two metropolises: Guangzhou (China) and Dakar (Senegal)

International audienceThe migration of Africans towards Asia started in the late 1990s and China is one of their main destinations. It is estimated that there are 500,000 immigrants of sub-Saharan origin in China (this represents half of the Chinese in Africa), and Guangzhou (Canton) is the Chinese city which hosts the largest number of them. A very dynamic commercial city, with nearly 15 million inhabitants. It is the administrative capital of Guangdong province, China’s leading economic region. This region alone produces 10% of China’s GDP. Since the early 2000s, it has been attracting businessmen and women from various countries: 200,000 Africans pass through Canton every year (Le monde, 2016) and 1,500 companies from this province are present in Africa. China’s entry into the World Trade Organization (WTO) facilitated its integration into the world economy and its opening. It is in this context that the number of Chinese (retail traders, entrepreneurs in the sector of public works) started increasing in Africa, where they currently account for 1 million persons. This is likely the effect of the expansion of China-Africa economic and cultural cooperation. Already in 2006, during the 3rd forum on China-Africa cooperation in Beijing, 48 African heads of state or of government were invited to Beijing. Today, Africa is China’s second investment destination, notably in the sectors of transport, energy and sanitation facilities. The goal of this contribution is to examine the situation of sub-Saharan Africans in Guangzhou and that of the Chinese diaspora in Dakar (Senegal), since these two movements are concurrent and started in the early 2000s. On the one hand, we have examined what is happening in Guangzhou: the evolution of the commercial activities carried out by African businesswomen and men and their profiles, focusing on a recent development. On the other hand, this contribution aims to question the economic, social and even cultural consequences of the Chinese presence in Africa and, on the opposite end, the impacts of Sub-Saharan presence in China. The analyses we propose here are based on surveys and field observations carried out jointly in China and Senegal between the years 2016 and 2020

Sub-Saharans in China versus Chinese in Africa: vectors of cultural and economic relations of a new kind? A case-study of two metropolises: Guangzhou (China) and Dakar (Senegal)

International audienceThe migration of Africans towards Asia started in the late 1990s and China is one of their main destinations. It is estimated that there are 500,000 immigrants of sub-Saharan origin in China (this represents half of the Chinese in Africa), and Guangzhou (Canton) is the Chinese city which hosts the largest number of them. A very dynamic commercial city, with nearly 15 million inhabitants. It is the administrative capital of Guangdong province, China’s leading economic region. This region alone produces 10% of China’s GDP. Since the early 2000s, it has been attracting businessmen and women from various countries: 200,000 Africans pass through Canton every year (Le monde, 2016) and 1,500 companies from this province are present in Africa. China’s entry into the World Trade Organization (WTO) facilitated its integration into the world economy and its opening. It is in this context that the number of Chinese (retail traders, entrepreneurs in the sector of public works) started increasing in Africa, where they currently account for 1 million persons. This is likely the effect of the expansion of China-Africa economic and cultural cooperation. Already in 2006, during the 3rd forum on China-Africa cooperation in Beijing, 48 African heads of state or of government were invited to Beijing. Today, Africa is China’s second investment destination, notably in the sectors of transport, energy and sanitation facilities. The goal of this contribution is to examine the situation of sub-Saharan Africans in Guangzhou and that of the Chinese diaspora in Dakar (Senegal), since these two movements are concurrent and started in the early 2000s. On the one hand, we have examined what is happening in Guangzhou: the evolution of the commercial activities carried out by African businesswomen and men and their profiles, focusing on a recent development. On the other hand, this contribution aims to question the economic, social and even cultural consequences of the Chinese presence in Africa and, on the opposite end, the impacts of Sub-Saharan presence in China. The analyses we propose here are based on surveys and field observations carried out jointly in China and Senegal between the years 2016 and 2020

Synthesis, physical studies and crystal structure determination of Y(III) and Er(III) complexes of 1-(pyridin-2-yl)-2-(pyridine-2-ylmethylene)hydrazine

Two isotype mononuclear yttrium(III) and erbium(III) complexes, {[Y(HL)(OAc)2(H2O)2]. (H2O)∙(NO3)} (1) and {[Er(HL) (OAc)2(H2O)2].(H2O)∙(NO3)} (2), where HL is the neutral Schiff base ligand 1-(pyridin-2-yl)-2-(pyridine-2-ylmethylene)hydrazine, and OAc is the acetate anion, have been synthesized and characterized by physicochemical methods and single crystal X-ray determination. Both complexes crystallizes in the triclinic space group Pī with unit cell dimensions for complex of Y(III) a = 7.909 (2) Å, b = 11.718 (4) Å, c = 12.497 (3) Å,    α = 78.907 (3)°, b = 73.840 (3)°, γ = 72.074 (3)°, V = 1051.26 (6) Å3, Z = 2, R1 = 0.051 and    wR2 = 0.112 and for complex of Er(III)a = 7.913 (1) Å, b = 11.719 (2) Å, c = 12.487 (2) Å,          α = 78.832 (1)°, α = 73.674 (1)°, γ = 72.012 (1)°, V = 1049.64 (3) Å3, Z = 2, R1 = 0.028, and   wR2 = 0.062. In both complexes, the coordination polyhedra around Ln(III) atoms are best described as a distorted tricapped trigonal prism. Antioxidant activities of the ligand and its Y(III) and Er(III) complexes are studied

L’hyperthyroïdie de l’enfant au centre hospitalier universitaire de Dakar (Sénégal)

Introduction: L'hyperthyroïdie de l'enfant semble rare et constitue un problème de par son retentissement psychosomatique. L’objectif était defaire le point sur ses aspects épidémiologiques et diagnostiques chez l’enfant à Dakar.Méthodes: Il s'agissait d'une étude multicentrique, descriptive sur 15 ans. Etaient analysés les aspects épidémiologiques, cliniques et étiologiques. Résultats: 239 patients sélectionnés avec une prévalence de 2.4%, un sex ratio (H/F) de 0.36, un âge moyen de 10.8 ans. À l'inclusion, il s'agissait d'un ainé de famille (26.3%), d'une croissance avancée (36.9%), retardée (12.5%), d'une corpulence insuffisante (40.1%). L'étiologie était la maladie de Basedow dans 90.3% avec un facteur psychoaffectif dans 22.1%. Sur le plan clinique, prédominaient la tachycardie (92.4%), le goitre (91.1%), l'exophtalmie (81.8%), l'amaigrissement (69.8%) avec cependant une énurésie (30.2%) et des manifestations psychiques (3.1%). Les manifestations cardiovasculaires et cutanées étaient positivement associées avec l'âge (p < 0.05). Le goitre était associé au sexe féminin (p = 0.005), aux signes cardiovasculaires (p = 0.02), neuropsychiques (p = 0.03), cutanées (p = 0.03) et à la diarrhée (p = 0.03). La T4 libre était corrélée à l'âge (p = 0.007), la diarrhée (p = 0.021), l'anxiété (p = 0.024), la fréquence cardiaque (p = 0.00) et la maladie de Basedow (p = 0.04). Plus le goitre était volumineux, plus était augmentée la T4 libre (p = 0.007). Conclusion: L'hyperthyroïdie de l'enfant se différencie de celle de l'adulte par les facteurs d'induction, les perturbations sur la croissance et l'énurésie. L’âge et le sexe semble favoriser le tableau clinique de thyrotoxicose et les signes associés.Mots clés: Hyperthyroïdie, enfant, Sénéga

Clinicians’ knowledge and practices regarding family planning and intrauterine devices in China, Kazakhstan, Laos and Mexico

Background: It is widely agreed that the practices of clinicians should be based on the best available research evidence, but too often this evidence is not reliably disseminated to people who can make use of it. This “know-do” gap leads to ineffective resource use and suboptimal provision of services, which is especially problematic in low- and middle-income countries (LMICs) which face greater resource limitations. Family planning, including intrauterine device (IUD) use, represents an important area to evaluate clinicians’ knowledge and practices in order to make improvements. Methods: A questionnaire was developed, tested and administered to 438 individuals in China (n = 115), Kazakhstan (n = 110), Laos (n = 105), and Mexico (n = 108). The participants responded to ten questions assessing knowledge and practices relating to contraception and IUDs, and a series of questions used to determine their individual characteristics and working context. Ordinal logistic regressions were conducted with knowledge and practices as dependent variables. Results: Overall, a 96 % response rate was achieved (n = 438/458). Only 2.8 % of respondents were able to correctly answer all five knowledge-testing questions, and only 0.9 % self-reported “often” undertaking all four recommended clinical practices and “never” performing the one practice that was contrary to recommendation. Statistically significant factors associated with knowledge scores included: 1) having a masters or doctorate degree; and 2) often reading scientific journals from high-income countries. Significant factors associated with recommended practices included: 1) training in critically appraising systematic reviews; 2) training in the care of patients with IUDs; 3) believing that research performed in their own country is above average or excellent in quality; 4) being based in a facility operated by an NGO; and 5) having the view that higher quality available research is important to improving their work. Conclusions: This analysis supports previous work emphasizing the need for improved knowledge and practices among clinicians concerning the use of IUDs for family planning. It also identifies areas in which targeted interventions may prove effective. Assessing opportunities for increasing education and training programs for clinicians in research and IUD provision could prove to be particularly effective