On the characteristic vibrations of the NH2 group

1969 ◽  
Vol 47 (16) ◽  
pp. 2947-2952 ◽  
Author(s):  
B. R. Cain ◽  
J. M. Freeman ◽  
T. Henshall
Keyword(s):  
Group Frequency ◽  
Constituent Group ◽  
Secular Determinant

The group frequency factorization procedure developed by King and Crawford (1) for the reduction in size of a vibrational secular determinant, by factorizing from it those frequencies that are characteristic of a constituent group, and subsequently extended by us (2), has now been successfully applied to NH2 group vibrations.The method is exemplified by the skeletal vibrations of methylamine, for which satisfactory results are obtained on factorization from the secular determinant of frequencies that are characteristic of both NH2 and CH3 groups.

scholarly journals Retrospective study of frequency of ABO and Rhesus blood group among population of Safdarabad and Faisalabad cities of Pakistan

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Ali Sabir ◽  
Arslan Iftikhar ◽  
Muhammad Umar Ijaz ◽  
Ghulam Hussain ◽  
Azhar Rasul ◽  
...  
Keyword(s):  
Retrospective Study ◽  
Blood Group ◽  
The People ◽  
Group Frequency ◽  
Slide Test ◽  
Rhesus Blood Group ◽  
Group B ◽  
Antigen Antibody ◽  
Group Distribution ◽  
Blood Grouping

Abstract Objective The current study aimed to investigate the ABO and rhesus (Rh) blood group frequency in the people of District Faisalabad and Sheikhupura, Punjab Province, Pakistan. The retrospective study was conducted on more than thirty thousand people including both male and female patients admitted to the Tehsil Headquarter Hospital, Safdarabad and The Best Hospital, Faisalabad. Blood samples were taken from each subject and subsequently ABO and Rh blood groups were evaluated separately. The antigen antibody agglutination slide test for blood grouping (ABO) and Rh were used to assess the blood group frequencies. Results The frequencies of ABO blood group distribution indicated that blood group B was predominant in the people of Safdarabad followed by O, A and AB respectively. While, among people of Faisalabad, blood group O was predominant followed B, A and AB respectively. Rh negative phenotype was found lesser distributed as compared to the positive Rh phenotype.

Frequency distribution of space groups in soluble and membrane proteins and their complexes

2021 ◽  
Vol 77 (6) ◽  
pp. 187-191
Author(s):  
Rajneesh K. Gaur
Keyword(s):  
Membrane Proteins ◽  
Frequency Distribution ◽  
Data Bank ◽  
Frequency Distributions ◽  
Space Group ◽  
Space Groups ◽  
Group Frequency ◽  
Different Types ◽  
Analytical Assessment ◽  
Three Space

The space-group frequency distributions for two types of proteins and their complexes are explored. Based on the incremental availability of data in the Protein Data Bank, an analytical assessment shows a preferential distribution of three space groups, i.e. P212121 > P1211 > C121, in soluble and membrane proteins as well as in their complexes. In membrane proteins, the order of the three space groups is P212121 > C121 > P1211. The distribution of these space groups also shows the same pattern whether a protein crystallizes with a monomer or an oligomer in the asymmetric unit. The results also indicate that the sizes of the two entities in the structures of soluble proteins crystallized as complexes do not influence the frequency distribution of space groups. In general, it can be concluded that the space-group frequency distribution is homogenous across different types of proteins and their complexes.

scholarly journals No Increased Risk for Scoliosis After Early Selective Dorsal Rhizotomy - A Longitudinal Population-Based Controlled Registry Study from four to 25 years of Age

2020 ◽  
Author(s):  
Annika Lundkvist Josenby ◽  
Lena Westbom
Keyword(s):  
Spinal Pain ◽  
Control Group ◽  
Spastic Diplegia ◽  
Selective Dorsal Rhizotomy ◽  
Gross Motor ◽  
Dorsal Rhizotomy ◽  
Severe Spasticity ◽  
Increased Risk ◽  
Group Frequency ◽  
Gmfcs Level

Abstract Spasticity interfering with gross motor development in cerebral palsy (CP) can be reduced with selective dorsal rhizotomy (SDR). Although reported, it is unknown if SDR surgery increases the risk for later spine problems. Using CP-registry data from a geographically defined population with the same health care and habilitation services, the objectives were to compare reported scoliosis and spinal pain up to adult age in all SDR-operated with all non-SDR-operated individuals with same medical history, functional abilities, and level of spasticity at four years of age. Method In the total population with CP spastic diplegia in Skåne and Blekinge, born 1990-2006, 149 individuals had moderate to severe spasticity and no medical contraindications against SDR at four years of age and were included; 36 persons had undergone SDR at a median age of 4.0 years (range 2.5 – 6.6 years), and 113 individuals constituting the control group, had not. Data on scoliosis and spinal pain at 10, 15, 20 and 25 years of age were analyzed using Kaplan-Meier survival curves and Fisher’s exact test. Gross motor function classification (GMFCS) levels at four years of age (or pre-operatively) were used for stratification.Result Presence of scoliosis at 15, 20, and 25 years of age was the same in the SDR group as in the control group (p=0.734, 0.735 and 1.0). In severe functional disability (GMFCS IV), the SDR group had later onset and lower occurrence of scoliosis (p=0.004) than the control group. Frequency of reported spinal pain did not differ between the groups. Conclusion Neither scoliosis, nor spinal pain was more frequent after SDR than expected by natural history. On the contrary, in severe CP (GMFCS level IV), scoliosis was less frequently reported and had a later onset in the SDR group than in the same GMFCS-level control group.

scholarly journals Assessing ABO/Rh Blood Group Frequency and Association with Asymptomatic Malaria among Blood Donors Attending Arba Minch Blood Bank, South Ethiopia

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Getaneh Alemu ◽  
Mohammedaman Mama
Keyword(s):  
Blood Group ◽  
Malaria Infection ◽  
Blood Donors ◽  
Blood Groups ◽  
High Rate ◽  
Abo Blood Group ◽  
Asymptomatic Malaria ◽  
Abo Blood Groups ◽  
Group Frequency ◽  
Rh Blood Group

Background. Determination of the various ABO/Rh blood group distributions and their association with malaria infection has paramount importance in the context of transfusion medicine and malaria control. Methods. Facility based cross-sectional study was conducted from February to June, 2015, to assess ABO/Rh blood groups distribution and their association with asymptomatic malaria. A structured questionnaire was used to collect data. Blood grouping was done using monoclonal antibodies. Thin and thick blood films were examined for Plasmodium parasites. Data were analyzed using SPSS version 20.0. Results. A total of 416 blood donors participated with median age of 22±0.29 (median ± standard error of the mean). Distribution of ABO phenotypes, in decreasing order, was O (175, 42.1%), A (136, 32.7%), B (87, 20.9%), and AB (18, 4.3%). Most of them were Rh+ (386, 92.8%). The overall malaria prevalence was 4.1% (17/416). ABO blood group is significantly associated with malaria infection (P=0.022). High rate of parasitemia was seen in blood group O donors (6.899, P=0.003) compared to those with other ABO blood groups. Conclusion. Blood groups O and AB phenotypes are the most and the least ABO blood groups, respectively. There is significant association between ABO blood group and asymptomatic malaria parasitemia.

The non-planar vibrations of some substituted ethylenes and related compounds

1951 ◽  
Vol 206 (1084) ◽  
pp. 17-39 ◽  
Keyword(s):  
Resonance Effect ◽  
Aromatic Substitution ◽  
Fluorine Substitution ◽  
Vinyl Halides ◽  
Group Frequency ◽  
Related Series ◽  
Planar Group ◽  
Vinyl Group ◽  
Related Compounds ◽  
Resonance Hybrid

By applying a general normal co-ordinate treatment to the non-planar group of vibrations of related series of substituted ethylenes, it has been found possible to obtain consistent sets of force constants for the non-planar bending motions, and to correlate their variation with the observed shifts in the group frequencies and with the electro-negativities and electrondonating powers of the substituents. From calculations on twelve compounds, a linear relation between the CH 2 = bending constant, (ƒ CH 2 ), and fbe corresponding group frequency (δ CH 2 ) is obtained and used to fit a further nine compounds into the series. Substitution by CH 3 —, CH 3 .CO.O—, and the halogens leads to a decrease in ƒ CH 2 compared with its ‘neutral’ value in ethylene; the increment in CH 2 = C X 2 is greater than in CH 2 =CH. X for all the examples studied, and increases with the electronegativity of the substituent X , being particularly large for fluorine. Substitution by —CN and —CO.O.CH 3 leads to positive increments. These results suggest that the main effect operative is the electromeric, (resonance) effect directing aromatic substitution, the powers of conjugation of vinyl and phenyl being known to be approximately equal. CH 3 —, CH 3 . CO . O— and the halogens lead to ortho-para- substitution, and —CN and —CO. O . CH 3 to meta- substitution. Thus, withdrawal of electrons from the terminal carbon atom of the vinyl group results in an increase in the forces opposing non-planar bending of the = CH 2 group. The results can be extended to include related u n satu rated compounds. The relatively high value of ƒ CH 2 in form aldehyde can be related to the fact that this molecule is a resonance hybrid in which the ionic structure CH 2 + — O - is of considerable im portance. The low value of ƒ CH 2 in allene suggests that this is also a resonance hybrid, with contributions from ionic structures CH - 2 — C + = CH 2 . In the allyl halides, the resonance effect is inhibited by the CH 2 group, and the order of the frequencies is the reverse of that in the vinyl halides. The chloride lies midway between propylene and ethylene, agreeing with the fact that in C 6 H 5 . CHCl 2 there is no appreciable difference in the reactivity at the ortho-, para- and meta- carbon atoms. The resonance effect cannot operate directly on the odd = C —H bond in CH 2 —CH X ; the bending constant / CH decreases as th e electronegativity of th e sub stitu en t X increases, — CN now lying between CH 3 and Cl and the effect again being particularly large for fluorine. The values of ƒ CH in acetylene and benzene (non-planar) suggest that there may be an inverse relation between the constants for C— C stretching and for bending of the adjacent C— H bonds.

Infrared Group Frequency Correlations for Styrenes, α-Methylstyrenes, and Related Compounds

1986 ◽  
Vol 40 (2) ◽  
pp. 196-203 ◽  
Author(s):  
R. A. Nyquist
Keyword(s):  
Structure Identification ◽  
Ortho Position ◽  
Or Groups ◽  
Group Frequency ◽  
Steric Factors ◽  
Related Compounds

Infrared group frequency correlations are presented which aid in spectra-structure identification of styrenes, α-methylstyrenes, and related compounds. The vinyl and phenyl groups in styrene are coplanar in only those cases where atoms or groups such as Cl and CH3 are not substituted in the 2,6-positions, and the isopropenyl and phenyl groups in α-methylstyrenes are coplanar in only those cases where atoms or groups such as Cl and CH3 are not substituted in one ortho-position. Steric factors prevent the vinyl and phenyl groups from being coplanar in styrene substituted with atoms or groups in at least the 2,6-positions, and steric factors also prevent the isopropenyl and phenyl groups from being coplanar in 2-substituted α-methylstyrenes.

Sign in / Sign up

Export Citation Format

Share Document