Bis(diphenylphosphido) Derivatives of the Heavier Group 2 Elements

2007 ◽  
Vol 46 (24) ◽  
pp. 10410-10415 ◽  
Author(s):  
Mark R. Crimmin ◽  
Anthony G. M. Barrett ◽  
Michael S. Hill ◽  
Peter B. Hitchcock ◽  
Panayiotis A. Procopiou
Keyword(s):  
Group 2 ◽  
2012 ◽  
pp. 1-19
Author(s):  
Anželika Gaidienė

  The article deals with nominal verbs with the suffix -(i)auti that have common categorical meaning ‘to be something/someone or such as what is denoted by the base word.' The object of the research consists of 239 verbs found in the electronic Dictionary of the Contemporary Lithuanian Language and 236 corresponding verbs from the electronic version of the Dictionary of the Lithuanian Language. According to the derivational meaning (darybos reikšmė), the verbs under investigation are classified into two groups: 1) verbs that mean ‘to be what is denoted by the base word' (they constitute 83% of all verbs that are analysed here) and 2) verbs, meaning ‘to be such as denoted by the base word' (17%). The verbs of the first category are further subdivided into four subclasses: 1) ‘to be someone denoted by the base word (not in the sense of work)' (they make up 69% of all the verbs of the first group), 2) ‘to work as what is denoted by the base word' (25%), 3) ‘to behave as behaves a person or another living being denoted by the base word' (5%) and 4) verbs denoting ‘states, processes that arise from the thing denoted by the base word' (only 1%).The derivatives of these subclasses are further divided according to the part of speech of the base words (nouns, adjectives or numerals) and the type of derivation (simple forms or derivatives: suffix, prefix, inflection or compounds). The investigation carried out has demonstrated that the verbs derived from nominals by adding the suffix -(i)auti which belong to the category meanings ‘to be something/someone or such as what is denoted by the base word' in standard language have few suffix and stem variants, they are not very characteristic of root vowel and consonant change, their base words do not vary a lot. 


2020 ◽  
Vol 8 (A) ◽  
pp. 691-698
Author(s):  
Yelena Valerievna Yepifantseva ◽  
Mayra Galimzhanovna Abdrakhmanova ◽  
Yelena Vladimirovna Pozdnyakova ◽  
Polina Sergeyevna Semenikhina ◽  
Ruslan Andreevich Belyayev ◽  
...  

BACKGROUND: Understanding the mechanisms of the behavioral disorders’ emergence under the influence of chronic stress is the most important aspect of the subsequent development of a strategy for its therapy and prevention. Changes in the oxidative metabolism processes can be decisive in the development of the pathogenetic cascade in the brain. Information about these processes can be obtained by studying protein carbonylation, lipid peroxidation, and catalase activity (CA). The complexity of the therapeutic impact in various behavioral disorders implies the search for new pharmacological substances and the study of the previously known drugs’ effects based on the available scientific data. AIM: The aim of the study was to study the reactive carbonyl derivatives of proteins (RCDP), malondialdehyde (MDA), and CA in the brain of rats after therapy following chronic unpredictable moderate stress (CUMS). METHODS: Forty male outbred rats weighing 450–500 g were used in this study. For 21 days, all animals were exposed to the diverse stress factors for developing the CUMS. The animals were divided into four groups of 10 rats, each using randomized selection. The rats of one group were euthanized by decapitation with subsequent brain harvesting (Group 4). Remaining three groups of rats were treated with placebo (Group 1), harmine hydrochloride (Group 2), and amitriptyline (Group 3) for 21 days. Upon completion of therapy, all rats were also euthanized by decapitation with subsequent brain harvesting. The levels of RCDP, MDA, and CA were studied in their brain, and after that, we compared the multiple studied indicators in four groups. RESULTS: The results of the rat brain examinations in four groups showed that RCDP level in Group 2 was significantly lower than in Group 4 (p = 0.000). Similarly, in Group 1, it was lower than in Group 4 (p = 0.021), plus, it did not differ statistically from the harmine hydrochloride group (p = 1,000). Indicators of Groups 3 and 4 did not have any significant differences in RCDP level, too, (p = 0.799); however, the RCDP level in Group 2 was significantly lower than in Group 3 (p = 0.040). MDA indicators did not show significant differences; however, a tendency for lower values was revealed in Group 1 (p = 0.233) and Group 2 (p = 0.151). CA in Group 4 was lower than that in Group 1 (p = 0.000), Group 2 (p = 0.001), and Group 3 (p = 0.003) contemporaneously, while all treatment groups were comparable (p = 1.000). CONCLUSION: The result of exposure to chronic stress can be reproduced with the best quality in the CUMS model. The neurobiological foundations of the model make it possible to assess biochemical markers of oxidative metabolism and evaluate the possibilities of pharmacological correction of stress-induced behavioral disorders. To assess the mechanisms of autoregulation of oxidative metabolism, this study included a placebo group (Group 1), the level of RCDP in which was significantly higher in comparison with Group 3 and Group 4 and slightly lower than in Group 2. In this study, harmine hydrochloride demonstrated activity exceeding amitriptyline, particularly limiting the process of protein carbonylation, not noted for amitriptyline. According to the results of the RCDP assessment in the CUMS model, the process of protein carbonylation can be considered to be one of the significant factors in the deactivation of neurotransmitters. The CA levels determined in all groups allowed us to consider this marker as the most sensitive to the effects of stress, which possibly has an inhibitory effect on catalase, as its activity in all groups after therapy was more than two-fold higher than in animals right after CUMS. We can assume that CA plays an important role in starting the processes of autoregulation of oxidative metabolism. The study was carried out as a part of the implementation of the scientific and technical program No. BR05236584 “Development of new herbal preparations and their pharmacological and clinical studies” (O.0820). (2018–2020) in the priority area, “Life and Health Sciences.”


1975 ◽  
Vol 151 (2) ◽  
pp. 281-290 ◽  
Author(s):  
R J Yon ◽  
R J Simmonds

1. The charge state of two derivatives of Sepharose prepared by the CNBr activation method were studied by acid-base titration and by ion-exchange chromatography. Dodecyl-Sepharose exhibited cationic groups (21mumol/ml of settled gel; pKa=9.6) that were tentatively assigned to the coupling isourea group. 2. CPAD-Sepharose [N-(3-carboxypropionyl)aminodecyl-Sepharose] has anionic (carboxyl) groups (pKa=4.5) and cationic groups (pKa=9.6) in roughly equal concentrations (e coupling group. CPAD-Sepharose is slightly negatively charged at pH 7.0 and substantially negatively charged at pH 8.5. 3. The pKa values of dodecyl-Sepharose and CPAD-Sepharose are unaffected by a 100-fold increase in the concentration of KCl. 4. CPAD-Sepharose has considerable affinity for wheat-germ aspartate transcarbamoylase at pH 8.5 when the adsorbent and enzyme are both negatively charged. The interaction involves the C10 chain but is relatively moderate compared with C10 chains associated only with positive charge. 5. Desorption of the enzyme adsorbed to CPAD-Sepharose can be achieved by raising the pH to increase the electrostatic repulsion, or by introducing the detergent sodium deoxycholate. Acetone and butan-1-ol also weaken the adsorption at pH 8.5. 6. High concentrations of sodium acetate or sodium phosphate induced the enzyme to bind more tightly to CPAD-Sepharose. 7. These results are discussed in terms of a ‘repulsion-controlled’ model or hydrophobic chromatography.


2020 ◽  
Vol 295 (36) ◽  
pp. 12739-12754
Author(s):  
Takahiro Masuya ◽  
Yuki Sano ◽  
Hinako Tanaka ◽  
Nicole L. Butler ◽  
Takeshi Ito ◽  
...  

The Na+-pumping NADH-ubiquinone (UQ) oxidoreductase (Na+-NQR) is present in the respiratory chain of many pathogenic bacteria and is thought to be a promising antibiotic target. Whereas many details of Na+-NQR structure and function are known, the mechanisms of action of potent inhibitors is not well-understood; elucidating the mechanisms would not only advance drug design strategies but might also provide insights on a terminal electron transfer from riboflavin to UQ. To this end, we performed photoaffinity labeling experiments using photoreactive derivatives of two known inhibitors, aurachin and korormicin, on isolated Vibrio cholerae Na+-NQR. The inhibitors labeled the cytoplasmic surface domain of the NqrB subunit including a protruding N-terminal stretch, which may be critical to regulate the UQ reaction in the adjacent NqrA subunit. The labeling was blocked by short-chain UQs such as ubiquinone-2. The photolabile group (2-aryl-5-carboxytetrazole (ACT)) of these inhibitors reacts with nucleophilic amino acids, so we tested mutations of nucleophilic residues in the labeled region of NqrB, such as Asp49 and Asp52 (to Ala), and observed moderate decreases in labeling yields, suggesting that these residues are involved in the interaction with ACT. We conclude that the inhibitors interfere with the UQ reaction in two ways: the first is blocking structural rearrangements at the cytoplasmic interface between NqrA and NqrB, and the second is the direct obstruction of UQ binding at this interfacial area. Unusual competitive behavior between the photoreactive inhibitors and various competitors corroborates our previous proposition that there may be two inhibitor binding sites in Na+-NQR.


1975 ◽  
Vol 26 ◽  
pp. 21-26

An ideal definition of a reference coordinate system should meet the following general requirements:1. It should be as conceptually simple as possible, so its philosophy is well understood by the users.2. It should imply as few physical assumptions as possible. Wherever they are necessary, such assumptions should be of a very general character and, in particular, they should not be dependent upon astronomical and geophysical detailed theories.3. It should suggest a materialization that is dynamically stable and is accessible to observations with the required accuracy.


Author(s):  
P. Bagavandoss ◽  
JoAnne S. Richards ◽  
A. Rees Midgley

During follicular development in the mammalian ovary, several functional changes occur in the granulosa cells in response to steroid hormones and gonadotropins (1,2). In particular, marked changes in the content of membrane-associated receptors for the gonadotropins have been observed (1).We report here scanning electron microscope observations of morphological changes that occur on the granulosa cell surface in response to the administration of estradiol, human follicle stimulating hormone (hFSH), and human chorionic gonadotropin (hCG).Immature female rats that were hypophysectcmized on day 24 of age were treated in the following manner. Group 1: control groups were injected once a day with 0.1 ml phosphate buffered saline (PBS) for 3 days; group 2: estradiol (1.5 mg/0.2 ml propylene glycol) once a day for 3 days; group 3: estradiol for 3 days followed by 2 days of hFSH (1 μg/0.1 ml) twice daily, group 4: same as in group 3; group 5: same as in group 3 with a final injection of hCG (5 IU/0.1 ml) on the fifth day.


Author(s):  
E.J. Prendiville ◽  
S. Laliberté Verdon ◽  
K. E. Gould ◽  
K. Ramberg ◽  
R. J. Connolly ◽  
...  

Endothelial cell (EC) seeding is postulated as a mechanism of improving patency in small caliber vascular grafts. However the majority of seeded EC are lost within 24 hours of restoration of blood flow in previous canine studies . We postulate that the cells have insufficient time to fully develop their attachment to the graft surface prior to exposure to hemodynamic stress. We allowed EC to incubate on fibronectin-coated ePTFE grafts for four different time periods after seeding and measured EC retention after perfusion in a canine ex vivo shunt circuit.Autologous canine EC, were enzymatically harvested, grown to confluence, and labeled with 30 μCi 111 Indium-oxine/80 cm 2 flask. Four groups of 5 cm x 4 mm ID ePTFE vascular prostheses were coated with 1.5 μg/cm.2 human fibronectin, and seeded with 1.5 x 105 EC/ cm.2. After seeding grafts in Group 1 were incubated in complete growth medium for 90 minutes, Group 2 were incubated for 24 hours, Group 3 for 72 hours and Group 4 for 6 days. Grafts were then placed in the canine ex vivo circuit, constructed between femoral artery and vein, and subjected to blood flow of 75 ml per minute for 6 hours. Continuous counting of γ-activity was made possible by placing the seeded graft inside the γ-counter detection crystal for the duration of perfusion. EC retention data after 30 minutes, 2 hours and 6 hours of flow are shown in the table.


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