In transition metal organic chemistry, metal carbene complexes have an important position. It not only has important theoretical significance for people to understand the bonding of transition metals and main group elements, but also has some excellent and unique reaction and catalytic properties. Many transition metal carbene complexes are synthesized and applied, but rare earth carbene complexes are an exception. The d orbital energy level of rare earth metal ions is obviously higher than that of other transition metals, resulting in poor orbital energy level matching between rare earths and carbene. The double bond of rare earth metal ions and carbene groups is extremely unstable, and it is very easy to occur. With weight distribution and other side effects. Although much research has been conducted, rare earth-terminated carbene complexes containing typical rare earth metal-carbon double bonds have not been successfully synthesized.

State Key Laboratory of Organometallic Chemistry, Institute of Organic Chemistry, Chinese Academy of Sciences Chen Yaofeng's research group is devoted to the study of rare earth metal-dominant element double bond chemistry. They successfully synthesized and crystallized the first rare-earth metal-nitrogen-binary bond-terminated nitrene complex containing lanthanum-terminated nitrene complexes (Chem. Commun. 2010, 46, 4469; Front Cover). Disclosed are unique reaction properties of rare earth metal-nitrogen single bond complexes (Chem. Commun., 2011, 47, 743; Angew. Chem. Int. Ed. 2011, 59, 7677; Chem. Commun. 2012, 48. , 3403; J. Am. Chem. Soc. 2013, 135, 8165; J. Am. Chem. Soc. 2014, 136, 10894). Based on the study of rare earth metal-nitrogen double bond chemistry, they recently carried out research on rare earth metal-carbon double bond chemistry. The use of macro-blocking ligands (2,6-diisopropylphenyl b-diimine ligands) to prevent the weight distribution and coordination of the ortho-phosphorus atom assisted stabilization, they successfully synthesized and crystal structure characterization The first rare-earth metal phosphine-based carbene complex - an osmium phosphine-based carbene complex (J. Am. Chem. Soc. 2017, 137, 1081). The complex has the shortest Sc-C bond length reported in the literature (2.089(3) Ã…). Laurent Maron, professor at the University of Toulouse, France, conducted an orbital analysis of the complex. The preliminary reaction properties of the complex have been found to be very active, allowing the rapid activation of HH bonds and CH bonds at room temperature and the ability to catalyze the hydrogenation of olefins. This work takes an important step in the synthesis of rare earth metal terminal carbene complexes and also predicts the possibility of synthesis of rare earth metal terminal carbene complexes.

The above research work was supported by the National Natural Science Foundation of China, the Ministry of Science and Technology, the China National Academy of Science and Technology (Class B) and the State Key Laboratory of Organometallic Chemistry.

MUAC tape measure

Clinic Pediatric MUAC Paper Tape Measure

Product Description:

Clinic pediatric MUAC paper tape measure is made of special PP material , MUAC tape measure is a early detection and referral of children with malnutrition. The tape is 20 mm wide. This increases the probability of the table covering the mid point of the upper arm and reduces the effect of over-pulling. The tape is numbered and colour-coded allowing use by community-based volunteers. There are three colors zone: RED, YELLOW, and GREEN.

RED COLOUR, indicates Severe Acute Malnutrition; YELLOW COLOUR, indicates that the child is at risk for acute malnutrition and should be counselled and followed-up for Growth Promotion and Monitoring; GREEN COLOUR, indicates that the child is well nourished.

Clinic Pediatric MUAC Paper Tape Measure is a simple but helpful medical device that can be used by service providers at different contact points without greatly increasing their workload and it can be effectively used by community-based people for active case finding.

MUAC is a better indicator of mortality risk associated with malnutrition than Weight-for-Height. It is therefore a better measure to identify children most in need of treatment.

Specification:

Features:

1. Scientific color zoned tape indicates severe acute malnutrition, risk of malnutrition and nourished, giving a simple and direct result to testers
2. A slot at the beginning of the tape. User can wrap a circle around the upper arm and fasten the tape to the closest number of the measurement
3. Number starts with 5.5cm. The fastener on the top occupies 5.5cm when measuring in a circle

Muac Measuring Tape 26.5,Head Circumference Measuring Tape,Baby Measuring Tape

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