Injuries of the tarsometatarsal joints: treatment and outcome [Lisfrancova ozljeda]

Between January 2005 and May 2009, a total of 26 patients, 21 males and 5 females, were admitted for treatment of Lisfranc lesion. All patients were radiologically evaluated and classified according to the criteria proposed by Myerson: 5 (19.2%) patients had a type A injury, 2 patients (7.7%) presented with a type B1 injury, 17 (65.4%) sustained the most common type B2 injury and 1 (3.8%) patient suffered from a type C1 and C2 injury. Taking radiological and clinical findings in account, fifteen patients were elected for operative treatment and eleven patients were treated conservatively. According to type of fracture we established three groups; in group I metatarsal fracture was found in fourteen (53.9%) patients, group II with phalangeal fracture in three (11.5%) cases, whereas in group III nine (34.6%) patients sustained combined metatarsal, navicular and, most commonly, a cuneiform fracture. Using the American Orthopedic Foot and Ankle Society (AOFAS) midfoot scoring scale and SF-36 questionnaire, the functional outcome was assessed. The mean value for age distribution was 42.7 +/- 13.2 years and the mean follow up was 27.9 +/- 12.4 months. A p value < 0.005 was regarded as statistically significant for the analysis of the results. We found by means of SF 36 questionnaire a statistically significant difference in the role limitation due to existence of pain (p = 0.04) and poor general health (p = 0.013) in the group of patients that sustained combined foot fracture. The purpose of this study is to assess the treatment of Lisfranc injuries in our patients, according to SF36 and AOFAS criteria, clinical outcome was evaluated. In the group I the mean AOFAS score was 74.0 +/- 9.1 and in the group II it reached 72.0 +/- 5.2 signifying fair outcome! Poor outcome was present in the group III with mean AOFAS score 67.1 +/- 9.0. All unstable injuries require surgery. Clinical outcome is highly dependent on the restoration of normal anatomic alignment

Metodologija za analizo kriterijev alternativ ob izbiri novega proizvoda

This paper presents the methodology used in the research of a complex problem in business decision-making: determining the relative importance of criteria when selecting a new product. It facilitates obtaining recommendations for defining the relative importance of criteria and sub-criteria for selecting a new product depending on the current situation in the company (which is selecting the new product) and its setting. By applying this methodology, dependence of the criteria-relative importance for selecting a new product on the company’s degree of success can be determined. For that reason, the whole procedure has a dynamic character, and can be applied in different situations and at different times of observation. The recommendations obtained represent the input data and support for subsequent multicriteria ranking of alternatives for new products. The methodology is confirmed in practice; however this paper does not give ample details related to this, because of the aim of stressing the research procedure of criteria for selecting a new product, as well as its importance. Also, the applied procedure has importance because of its universality, given that it can also be applied to the research of the criteria for other decision- making issues, with or without adequate adaptations. Key words: methodology, research, criteria for selecting a new product.Prispevek obravnava metodologijo uporabljeno pri raziskavi kompleksnih problemov pri poslovnem odločanju: določitev relativne pomembnosti kriterijev ob izboru novega proizvoda. Metodologija podpira generiranje predlogov za definicijo relativne pomembnosti kriterijev in podkriterijev za izbiro novega proizvoda glede na trenutno situacijo v podjetju (ki izbira nov proizvod) in stanje. Z uporabo predlagane metodologije lahko določimo vpliv relativne pomembnosti kriterijev za izbor novega proizvoda na stopnjo uspešnosti podjetja. Zaradi omenjenega ima celotna procedura dinamičen značaj in je lahko uporabljena v različnih situacijah ter ob različnih časih opazovanja. Oblikovani predlogi predstavljajo vhodne podatke ter podporo sledečemu večkriterijskemu rangiranju alternativ za nove proizvode. Metodologija je potrjena v praksi vendar pričujoči prispevek ne podaja podrobnosti v zvezi s tem, saj je cilj prispevka predstavitev raziskovalne procedure na področju določitve kriterijev pri izboru novega proizvoda kakor tudi opredelitev pomembnosti le-te. Poleg tega je uporabljena procedura pomembna zaradi svoje univerzalnosti saj jo lahko uporabimo pri opredelitvi kriterijev v drugih odločitvenih situacijah z ali brez dodatnih sprememb. Ključne besede: metodologija, raziskave, kriteriji za izbiro novega proizvod

OPTIMIZATION BASED DETERMINATION OF THE SET OF CONTINUOUS-STATE COMPONENTS CRITICAL TO THE MECHANICAL SYSTEM STATE

This paper proposes a new approach to determining the set of the most critical continuous-state components in continuous-state mechanical systems. Unlike traditional importance measures, which determine the criticality of individual components, our approach provides selection of the entire set of critical components. In addition, it enables determination of the minimal budget for achieving full or any required performance levelof the mechanical system. We start from the continuum structure function and the system state definition through minimal cut sets. The problem defined in this paper is formulated as a determination of a set of components whose states maximize the system performance level under the budget constraint. Further, we prove that the solution of the formulated problem can be obtained based on the solution to a weighted minimal hitting set problem. The proposed approach is applied to a group of benchmark instances and the obtained results are compared to components’ rankings obtained by using traditional importance measures

Computational analysis of non-covalent interactions in phycocyanin subunit interfaces

Phycocyanins (C-phycocyanin and allophycocyanin) are stable water-soluble trimers (αβ)3 or hexamers (αβ)6, containing dark-blue covalently attached phycocyanobilin chromophore with variety of pharmacological properties. Molecular forces (non-covalent interactions) responsible for the observed differences in thermal and chemical stability of different phycocyanin complexes are not completely understood 1. In this study, we used the manually curated non-redundant dataset of 118 interfaces from 20 X-ray phycocyanin structures (PDB ID codes: 1all, 1b33, 1kn1, 2vjt, 3dbj, 4f0u, 4po5,4rmp, 1cpc, 1gh0, 1f99, 1jbo, 1phn, 2bv8, 2vml, 3o18, 4l1e, 4lm6, 4lms, 4yjj) to gain additional insight to this phenomenon using a robust inter-atomic non-covalent interaction analyzing tool PPCheck (http://caps.ncbs.res.in/ppcheck). For our dataset, the mean interface area was 1088 Å2 and there were on average 59 residues per interface. Most of the individual interface parameters are clustered at the middle of the range which we call “standard-size” interfaces. Our observations indicate that there is relatively high composition (51%) of hydrophobic residues at the phycocyanin interfaces; most frequent amino acids in interfaces are Ala (11.4%), Leu (10.0%), Arg (9.5%) and Thr (8.3%). The analysis shows that about 42% of the total hydrogen bonds in the interfaces under consideration are involved in the formation of multiple hydrogen bonds; 52.8% of total number of hydrogen bonds is formed by water (as donor or acceptor; Figure 1); the hydrogen bonds across the interfaces are predominantly the O–N type; the largest numbers are side chain–side chain hydrogen bonds (55.9%) between the phycocyanin interfaces; most of hydrogen bonds possess distances in the region 2.8–4.2 Å, indicating their moderate and weak strength. The mean number of hydrophobic interactions per interface is 13.6 (max 30); the hydrophobic side chains make larger number of these interactions than side chains of charged and the hydrophilic amino acid. On average, there are about 3 salt bridges per interface in phycocyanin interfaces (max 7); less than one-tenth of the salt bridges in our database are networked, to form several triads, and the remaining are isolated ones. Most salt bridges (~80%) contain at least one hydrogen bond between the atoms in their side-chain charged groups; there is no preferred combination of donors and acceptors. The stability of a non-covalent complex is usually related to the complexation energy, which is proportional to the strength of the interactions involved. Analysis shows that hydrogen bond energies contribute to about 88% to the total energy. Van der Waals and electrostatic energy contributes to 9.3% and 1.9% on average in these complexes, respectively. Thus, hydrogen bonds contribute maximally towards the stability of protein–protein complexes. Results show the total binding energy is more for large phycocyanin interfaces. The normalized energy per residue was less than -16 kJ/mol, while most of them have energy in the range from 6 to 14 kJ/mol. The non-covalent interacting residues in phycocyanin protein interfaces were found to be highly conserved (ConSurfserver: http://consurf.tau.ac.il/2016/); salt bridge forming residues have average conservation scores 7.3; for those involved in hydrogen bonds is 7.0; the amino acid residues forming hydrophobic interactions and water-bridged hydrogen bonds both have average conservation scores of 5.9 (on scale 1–9). Obtained results might contribute to the understanding of structural stability of this class of evolutionary essential proteins with increased practical application and future designs of novel protein–bioactive compound interactions

Kovalentno vezivanje glikoinozitolfosfolipida (GPI) za hemoglobin pod dejstvom insulina praćeno je aktiviranjem proteaze iz membrane eritrocita

Recently, it was demonstrated that prolonged hyperinsulinism associated with hypoglycemia, both in vivo and in vitro, caused covalent glycoinositolphospholipid (GPI) binding to the C termini of both hemoglobin beta-chains, which resulted in the formation of a novel, hitherto unrecognized, minor hemoglobin fraction (GPI-Hb) (Niketic et al. Biochem. Biophys. Res. Commun. 239 (1997)435). In this study, it was demonstrated that exposure of erythrocyte membranes to insulin causes the activation of membrane protease as well as that the formation of GPI-Hb parallels its activity. It is suggested that the insulin-activated protease is able to catalyze. albeit slowly, the transpeptidation, i.e., the replacement of the carboxy-terminal amino acid(s) residues of the Hb beta-chains with GPI as an exogenous nucleophile. To our knowledge the present results show for the first time that insulin stimulates protease activity in erythrocyte membranes, as well as that insulin-activated protease may be involved in post-translational GPI binding to proteins.U našim ranijim radovima pokazano je da u uslovima hiperinsulinizma i hipoglikemije, in vivo i in vitro, dolazi do kovalentnog vezivanja glikoinozitolfosfolipida (GPI) za karboksilne krajeve oba β-niza molekula hemoglobina (Hb), što se manifestuje nastajanjem nove, do tada nepoznate, manje frakcije hemoglobina (GPI-Hb) (Niketić et al., Biochem. Biophys. Res. Commun. 239 (1997) 435). U ovom radu je pokazano da vezivanje insulina za membrane eritrocita izaziva aktiviranje membranske proteaze, te da je nastajanje GPI-Hb u korelaciji sa proteaznom aktivnošću. Pretpostavljeno je da proteaza aktivirana insulinom može, mada sporo, da katalizuje reakciju transpeptidacije, tj. zamenu aminokiselinskih ostataka sa karboksilnog kraja β-nizova molekula Hb sa GPI-lipidom kao egzogenim nukleofilom. Prema našem saznanju opisani rezultati prvi puta pokazuju da insulin stimuliše proteaznu aktivnost u eritrocitima, te da je ova aktivnost povezana sa post-translacionim vezivanjem GPI-lipida za proteine

On the Aromatic Stability of a Conjugated C60 Cluster

The aromatic stability of recenlIy reported conjugated sixty-carbon system of spherical shape (representing a truncated icosahedron and named buckminsterfullerene) is discussed. Buckminsterfullerene is predicted by a majority of theoretical methods to be aromatic compound with the degree of aromaticity smaller than that of benzene

Enumeration of Kekule Structures for Helicenic Systems

Enumeration of Kekule structures is reported for five classes of helical benzenoids using the Gordon-Davison counting algorithm or its variants and the two-step decomposition procedure based on the concept of partial essential single and double bonds

Computational analysis of non-covalent interactions in phycocyanin subunit interfaces

Phycocyanins (C-phycocyanin and allophycocyanin) are stable water-soluble trimers (αβ)3 or hexamers (αβ)6, containing dark-blue covalently attached phycocyanobilin chromophore with variety of pharmacological properties. Molecular forces (non-covalent interactions) responsible for the observed differences in thermal and chemical stability of different phycocyanin complexes are not completely understood 1. In this study, we used the manually curated non-redundant dataset of 118 interfaces from 20 X-ray phycocyanin structures (PDB ID codes: 1all, 1b33, 1kn1, 2vjt, 3dbj, 4f0u, 4po5,4rmp, 1cpc, 1gh0, 1f99, 1jbo, 1phn, 2bv8, 2vml, 3o18, 4l1e, 4lm6, 4lms, 4yjj) to gain additional insight to this phenomenon using a robust inter-atomic non-covalent interaction analyzing tool PPCheck (http://caps.ncbs.res.in/ppcheck). For our dataset, the mean interface area was 1088 Å2 and there were on average 59 residues per interface. Most of the individual interface parameters are clustered at the middle of the range which we call “standard-size” interfaces. Our observations indicate that there is relatively high composition (51%) of hydrophobic residues at the phycocyanin interfaces; most frequent amino acids in interfaces are Ala (11.4%), Leu (10.0%), Arg (9.5%) and Thr (8.3%). The analysis shows that about 42% of the total hydrogen bonds in the interfaces under consideration are involved in the formation of multiple hydrogen bonds; 52.8% of total number of hydrogen bonds is formed by water (as donor or acceptor; Figure 1); the hydrogen bonds across the interfaces are predominantly the O–N type; the largest numbers are side chain–side chain hydrogen bonds (55.9%) between the phycocyanin interfaces; most of hydrogen bonds possess distances in the region 2.8–4.2 Å, indicating their moderate and weak strength. The mean number of hydrophobic interactions per interface is 13.6 (max 30); the hydrophobic side chains make larger number of these interactions than side chains of charged and the hydrophilic amino acid. On average, there are about 3 salt bridges per interface in phycocyanin interfaces (max 7); less than one-tenth of the salt bridges in our database are networked, to form several triads, and the remaining are isolated ones. Most salt bridges (~80%) contain at least one hydrogen bond between the atoms in their side-chain charged groups; there is no preferred combination of donors and acceptors. The stability of a non-covalent complex is usually related to the complexation energy, which is proportional to the strength of the interactions involved. Analysis shows that hydrogen bond energies contribute to about 88% to the total energy. Van der Waals and electrostatic energy contributes to 9.3% and 1.9% on average in these complexes, respectively. Thus, hydrogen bonds contribute maximally towards the stability of protein–protein complexes. Results show the total binding energy is more for large phycocyanin interfaces. The normalized energy per residue was less than -16 kJ/mol, while most of them have energy in the range from 6 to 14 kJ/mol. The non-covalent interacting residues in phycocyanin protein interfaces were found to be highly conserved (ConSurfserver: http://consurf.tau.ac.il/2016/); salt bridge forming residues have average conservation scores 7.3; for those involved in hydrogen bonds is 7.0; the amino acid residues forming hydrophobic interactions and water-bridged hydrogen bonds both have average conservation scores of 5.9 (on scale 1–9). Obtained results might contribute to the understanding of structural stability of this class of evolutionary essential proteins with increased practical application and future designs of novel protein–bioactive compound interactions